The present invention describes a newly discovered full-length polynucleotide encoding an SH2 domain-containing adapter protein, called human MIST, cloned, isolated and identified from a human spleen cDNA library. Also described are the MIST polypeptide sequence, expression vectors, host cells, agonists, antagonists, antisense molecules, and antibodies related to the polynucleotide and/or polypeptide of the present invention. Novel splice variant forms of human MIST are provided. Methods for screening for modulators, particularly inhibitors, of the MIST protein and use of the human MIST polynucleotide and polypeptide for therapeutics and diagnostics are described.

Receptor signaling pathways and intracellular signaling by receptor tyrosine kinases are intimately involved in cell growth and differentiation. The binding of a particular growth factor or cellular ligand to its receptor on a cell's plasma membrane can stimulate a wide variety of biochemical responses, including changes in ion fluxes, activation of various kinases, alteration of cell shape, transcription of various genes and modulation of enzymatic activities in cellular metabolism.
Many cell receptors are tyrosine kinases whose signaling is dependent upon tyrosine phosphorylation of both the receptor and other molecules. Specific phosphorylated tyrosine residues on these receptors recruit soluble intracellular signaling molecules to the receptor-ligand complex upon extracellular ligand stimulation, thus initiating the intracellular signaling cascade that involves secondary signal transducer molecules generated by the activated receptor. The signal can then proceed through a series of steps to the nucleus and other subcellular locations where the final effects of activation by the extracellular ligand are produced. Recruitment of other molecules in the signaling pathway is often accomplished by adapter molecules, which contain only protein-protein interaction domains (e.g., SH2 and SH3 domains) and have no associated enzymatic activity. By isolating and characterizing the adapter proteins and the molecules that interact with these adapters, important parts of the signaling mechanism can be discovered, monitored and controlled.
For example, one such adapter protein is Grb2, a 24–25 kDa cytosolic adapter protein containing two SH3 domains flanking an SH2 domain, which is known to be involved in linking many important molecules in receptor-ligand signal transduction (E. J. Lowenstein et all., 1992, Cell, 70:431–442 and J. Downward, 1994, FEBS Letters, 338:113–117). The central SH2 domain of Grb2 binds to an autophosphorylation site on the receptor and the two flanking SH3 domains link to intracellular effector target molecules. An example of one such target molecule is the mammalian homolog of the Drosophila 'son of sevenless' (SOS) protein, which is a guanine nucleotide exchange factor for ras; thus, Grb2 links receptors with the ras signal transduction pathway. It is now known that the SH3 domains also link to a number of other proteins involved in the signaling pathway, including Vav (R. Ren et al., 1994, Genes Dev., 8:783–795; J. Wu et al., 1996, Immunity, 4:593; and L. Tuosto et al., 1996, J. Exp. Med., 184:1161); c-abl (Z. S. Ye and D. Baltimore, 1994, Proc. Nat'l Acad. Sci. USA, 91:12629–12633); dynamin (I. Gout et al., 1993, Cell, 75:25–36); and SLP-76 (J. K. Jackman et al., 1995, J. Biol. Chem., 270:7029–7032). In addition, several other binding proteins have been noted during B- and T-cell signaling (See, e.g., K. Reif et al., 1994, J. Biol. Chem., 269:14081–14087 and D. G. Motto et al., 1994, J. Biol. Chem., 269:21608–21613).
The SLP-76 family of adapter protein molecules includes the SLP-76, BLNK and Clnk proteins (P. S. Myung et al., 2000, "Adapter proteins in lymphocyte antigen-receptor signaling", Curr. Opin. Immunol., 12:256–266 and M. Y. Cao et al., 1999, "Clnk, a novel SLP-76-related adapter molecule expressed in cytokine-stimulated hemopoietic cells", J. Exp. Med., 190:1527–1534). Expressed exclusively in cells of hematopoietic origin, these adapter proteins are involved in intracellular signal transduction. SLP-76 is an SH2 domain-containing 76 kDa leukocyte protein l:hat undergoes tyrosine phosphorylation following activation of the T-cell antigen receptor (TCR). SLP-76, upon tyrosine phosphorylation, interacts with Grb2 and phospholipase C-γ (PLC-γ), (J. K. Jackman et al., supra). The phosphorylation of SLP-76 on tyrosine is required for TCR-mediated cytokine secretion.
SH2 domain-containing proteins bind phosphorylated tyrosine residues and transmit important intracellular signals in many cell types. In the immune system, SH2 domain-containing proteins, such as SLP-76 and BLNK, play crucial roles in T-cell and B-cell activation. Therefore, SH2 domain-containing proteins are likely to be important targets for therapeutic intervention in immunological disorders, including autoimmune disorders and inflammatory indications. In addition, a partial sequence containing only a middle portion of a MIST/Clnk protein isolated by R. Goitsuka et al. (2000, Int. Immunol., 12:573–580) was implicated as being involved in receptor-mediated mast cell degranulation, thus providing another type of hematopoietic cell in which such SH2-domain-containing proteins function to transmit intracellular signals.
With particular regard to B-cells, cell function is dependent on the ability of the membrane B-cell receptor (BCR) to bind to antigen and induce an efficient cascade of intracellular biochemical signaling events from the membrane to the nucleus. These events culminate in the cytosol to rearrange the morphology of the cell through cytoskeletal reorganization and in the nucleus to activate the transcription of new genes to promote cellular proliferation and differentiation. Such biochemical and cellular mechanisms are required for B-cells to mature and function to produce an efficient immune response to foreign pathogens. Conversely, the abnormal activation of B-cells can lead to unregulated cellular proliferation and uncontrolled clonal expansion, resulting in B-cell tumors, lymphomas and leukemias. In addition, unregulated activation of B-cells may also contribute to a variety of autoimmune diseases mediated by self-reactive antibodies.
Similarly, in the case of T-cells, unregulated activation of the TCR can lead to aberrant T-cell growth, resulting in, for example, T-cell tumors, lymphomas, leukemias and thymomas. Thus, the ability to modulate TCR- and BCR-mediated signaling events may provide a rational approach to the treatment of T- and B-cell mediated tumors, and the like, as well as provide therapies for autoimmune diseases in which aberrant B-cell activation may be the culprit for cell destruction by auto-reactive antibodies.
Because aberrant or uncontrolled regulation of the cellular processes involved in cell growth can have disastrous effects, it is important to elucidate and gain control over these processes. This requires identifying molecules that participate in the signaling events that lead to mitogenesis and dissecting their functions and mechanisms of action. The identification of these participants is important for a wide range of diagnostic, therapeutic and screening applications. More specifically, by knowing the structure of a particular participant in a receptor ligand activation cascade, one can rationally design compounds that affect that cascade, to either activate an otherwise inactive pathway, or inactivate an overly active pathway.
Similarly, having identified a particular molecule in a ligand receptor cascade, situations in which that cascade is defective can also be identified and intervention can be achieved by means of therapeutic compounds or drugs, to prevent the development of a particular pathological state. The identification of participants in particular receptor ligand activation cascades and intracellular signaling events is thus of critical importance for screening compounds that affect these cascades and events, and treating a variety of disorders resulting from anomalies in these cascades and events as therapeutic agents. The present invention meets these and many other needs.
In addition, the discovery of human MIST, a new member of the SLP-76 family of adapter proteins, and the polynucleotide encoding this protein provides the art with new compositions and methods of use and treatment for the diagnosis, screening, monitoring, therapy, and prevention of immune system related conditions or diseases, particularly those involving T-cell and B-cell neoplasms, and inflammation disorders, diseases and conditions, particularly those involving hyperactivity of B-cells and T-cells, or other immune cells, such as mast cells or eosinophils.

Identification and cloning of a full-length human Clnk-related gene, MIST (mast cell immunoreceptor signal transducer)


A system and method for providing premium transport in a DOCSIS-compliant cable network. An edge server in a DOCSIS-compliant cable network maintains a list of preferred content providers (PCPs). For each PCP, the PCP list comprises matching criteria. The edge server monitors the header of incoming packets for the matching criteria. A packet that matches the matching criteria is modified by the edge server causing the packet to be associated with a “premium” downstream service flow. Packets sent in response to a “preferred” packet are parsed by a cable modem and routed upstream according to a “premium” upstream service flow.

Embodiments of the present invention are directed generally to packet transport in a cable network. More particularly, embodiments of the present invention are directed to systems and methods for transporting packets originating from preferred content providers over a cable network according to a selected "premium" service flow.
Hybrid Fiber Coax (HFC) cable networks were originally built to deliver broadcast-quality TV signals to homes. The wide availability of such systems and the extremely wide bandwidth of these systems led to the extension of their functionality to include delivery of high-speed broadband data signals to end-users. Data over Cable System Interface Specifications (DOCSIS), a protocol elaborated under the leadership of Cable Television Laboratories, Inc., has been established as the major industry standard for two-way communications over HFC cable plants.
The basic elements of a DOCSIS-compliant cable network are the cable modem (CM), located on the subscriber's site, and the cable modem termination system (CMTS) and headend located in facilities operated by the cable service provider. The medium between the CMTS and the different CMs is a two-way shared medium, in which the downstream channels carry signals from the head-end to users and upstream channels carry signals from users to head-end. A CM is normally tuned to one upstream channel and the associated downstream channel. The upstream channel is an inherently shared medium in which slots are reserved using a contention system while the downstream is a broadcast dedicated link from the CMTS to the CM.
A quality of service (QoS) level is defined for communications between a CM and a CMTS for each service to which a subscriber subscribes. For example, a basic data service subscriber may receive downstream traffic at a maximum burst rate of 3 Mbps, while a premium subscriber may receive downstream traffic at a maximum burst rate of 6 Mbps. Voice over IP (VoIP) services are typically provided with very stringent QoS requirements to assure that the quality of a cable-delivered telephone call will equal or exceed the call quality of a call placed over the public switched telephone network.
The principal mechanism for providing enhanced QoS is to classify packets traversing the path between a CM and CMTS into a service flow. A service flow is a unidirectional flow of packets that is provided a particular Quality of Service. The CM and CMTS provide this QoS by shaping, policing, and prioritizing traffic according to a QoS parameter set defined for the service flow.
Service flows exist in both the upstream and downstream direction, and may exist without actually being activated to carry traffic. Service flows have a 32-bit service flow identifier (SFID) assigned by the CMTS. All service flows have an SFID. An active and admitted upstream service flow also has a 14-bit Service Identifier (SID). At least two service flows are defined in a configuration file received by a CM: one for upstream and one for downstream service. The first upstream service flow describes the primary upstream service flow, and is the default service flow used for otherwise unclassified traffic. The first downstream service flow describes service to the primary downstream service flow. Additional service flows defined in the configuration file create service flows that are provided QoS services.
Conceptually, incoming packets are matched to a classifier that determines to which QoS service flow the packet is forwarded. The header of the packet is examined. If the packet matches one of the classifiers, it is forwarded to the service flow indicated by the SFID attribute of the classifier. If the packet is not matched to a classifier, it is forwarded on the primary service flow.
A classifier is a set of matching criteria applied to each packet entering the cable network. It comprises some packet matching criteria (destination IP address, for example), a classifier priority, and a reference to a service flow. If a packet matches the specified packet matching criteria, it is then delivered on the referenced service flow. Several classifiers may all refer to the same service flow. The classifier priority is used for ordering the application of classifiers to packets. Explicit ordering is necessary because the patterns used by classifiers may overlap. Downstream classifiers are applied by the CMTS to packets it is transmitting, and upstream classifiers are applied at the CM and may be applied at the CMTS to police the classification of upstream packets. The characteristics of a provisioned downstream service flow are defined in a DOCSIS configuration file downloaded by the CM when it boots and provided to the CMTS by the CM during registration.
Multiple service flows can be assigned per cable modem in either the upstream or downstream direction, and each of these service flows can correspond to a different QoS parameter set with different characteristics. This is conducive to allowing the CM to accommodate multiple kinds of data traffic at once, such as standard Internet traffic and Voice over IP (VoIP).
To guarantee bandwidth for a specific service, a network device must be able to identify packets associated with that service in all the IP traffic flowing through it. This identification and grouping process is called packet classification. Media gateways and MTAs use various match criteria to place traffic into a certain number of classes. Packet marking is the process of setting a Type of Service (ToS) bits or Differentiated Service Code Point (DSCP) bits in the IP header.
Modern IP enabled services such as voice over IP (VoIP) and MPEG Video over IP have a requirement for an assured rate of throughput, as well as strict requirements for latency and jitter, which could not be provided in a best effort environment. In addition, these kinds of services are not typically always active and, as such, resources to accommodate them need only be allocated when these services are required. For this reason, DOCSIS provides a range of modes for CM data transmission that can be initiated and terminated dynamically to accommodate these advanced IP services. Each of these modes can be applied to a QoS Parameter Set that defines characteristics of an upstream service flow:                Unsolicited Grant Service (UGS)—A service flow is created that allows a Cable Modem to transmit fixed-size bursts of data at a guaranteed rate and with a guaranteed level of jitter by providing periodic transmission opportunities to the Cable Modem for fixed-size frames. This kind of service flow is particularly suitable for Voice over IP applications.        Real-Time Polling Service (rtPS)—A service flow is created giving a periodic opportunity for a Cable Modem to request permission to transmit data by polling one Cable Modem for a bandwidth request, rather than all modems. This satisfies applications that have a requirement for real time data transmission as well as allowing the cable modem to transmit data bursts of varying length. This kind of service flow is particularly suitable for MPEG video over IP.        Unsolicited Grant Service with Activity Detection (UGS/AD)—This kind of service flow is a combination of UGS and rtPS and is useful for services that require a UGS style of fixed-size and fixed-rate transmission opportunities, but have significant periods where no data is being sent. One good example of this might be a Voice over IP phone call where up to 50% or more of the call may be silence and require no data transmission. While words are being spoken and packetized voice needs to be transmitted, the Cable Modem receives UGS style grants from the CMTS. When there is silence, the CMTS detects the absence of data and switches to a rtPS style mode, which temporarily frees up upstream bandwidth. When the conversation restarts and the Cable Modem needs to transmit more packetized voice, the Cable Modem transmits a further request to the CMTS via an rtPS granted opportunity and then the UGS style grants recommence.        Non-Real-Time Polling Service—This kind of service flow is like the rtPS, however polling will typically occur at a much lower rate and may not necessarily be periodic. This applies to applications that have no requirement for a real time service but may need an assured high level of bandwidth. An example of this may be a bulk data transfer or an Internet Gaming application.
A downstream service flow also uses QoS parameters to define particular downstream service flows. For example, QoS parameters used in the downstream direction comprise a "minimum reserved traffic rate," a "traffic priority," and a "maximum downstream latency." These downstream QoS parameters may be used by a scheduler in the CMTS to ensure that preferred traffic receives some guarantees for delivery within a certain amount of time and that that traffic is given priority over other traffic during times of downstream network congestion.
DOCSIS thus provides tools to define service flows both statically and dynamically in the upstream and downstream directions based on service type. However, there is no current mechanism for a cable system operator to redefine the parameter set of an upstream or downstream service flow based on the source of the packets being sent to, or from, a subscriber. What would be useful are systems and methods for transporting packets originating from designated content providers over a cable network according to a selected "premium" downstream service flow. These systems and methods would further provide the option of establishing a premium upstream service flow for packets sent by a subscriber in response to the downstream packets. Additionally, such systems and methods would provide the cable system operator means for billing the designated content provider for packets delivered using the premium service flow.

System and method for providing premium transport in a DOCSIS-compliant cable network


A reticle box characterized by a generally rectangular base member having a base portion and four contiguous wall portions, a generally rectangular cover member which can be engaged with the base member to fully enclose a reticle, and a closing mechanism which causes resilient stand-offs attached to the base member and the cover member to firmly grip the reticle within the box. Mating peripheral seals are provided around portions of the base member and the cover member to prevent the influx of contaminants. The cover member is of unitary design with an integral frame portion, central cover portion, and hinge. The reticle box is preferably made from a non-static plastic material.

This invention relates generally to the manufacture of integrated circuits, and more particularly to reticle boxes which hold the reticles used in optical stepper machines to project an image of an integrated circuit layer onto a semiconductor wafer.
Photolithography is a necessary process in the production of most integrated circuits. The photolithography process includes the steps of forming a resist layer over semiconductor wafer, exposing the resist layer to a patterned light source, developing the resist layer, processing the semiconductor wafer through the developed resist layer, and removing the resist layer.
An optical stepper apparatus is often used to expose the resist layer. An image of a layer of an integrated circuit die is formed on a small, square piece of glass called a reticle. The reticle is placed in the optical stepper apparatus and the image of the layer is reduced and projected onto a portion of a resist layer covering the semiconductor wafer. The reticle is then indexed and the reduced image is focused on another portion of the resist layer and so forth until a majority of the resist layer has been exposed. A typical reticle is about 5-7 inches square, and the image of the layer is typically reduced to about 300-500 millimeters square.
Reticles are often stored in reticle boxes. Some optical stepper apparatus include a stepper reticle loader mechanism which automatically opens a reticle box, inserts the reticle into the stepper apparatus, exposes the wafer, returns the reticle to the stepper box, and closes the box. This type of automated handling is preferable because it minimizes contamination of and damage to the reticle and the stepper apparatus.
FIGS. 1 and 2 illustrate a reticle box which is commercially available from Canon, Inc. of Tokyo, Japan. FIG. 1 is a top plan view of a closed reticle box 10, and FIG. 2 is a cross-sectional view of the box taken along line 2--2 of FIG. 1. With reference to both figures, the reticle box 10 includes a base member 12 and a cover member 14 which is slidingly engageable with the base member 12. A camming bar 16 locks the cover member 14 to the base member 12. When closed and locked, the reticle box 10 surrounds a reticle 18 disposed within the box. The reticle is supported on its bottom surface by four base stand-offs 20 which include a resilient portion 22. Four cover stand-offs 24 extend close to, but do not touch, a top surface of the reticle 18.
In FIG. 1, it can be seen that the cover member 14 is an assembly of several parts including a frame portion 26 and a central cover portion 28. It is the frame portion 26 of the cover member 14 which engages with walls 30 of the base member 12. A pair of metal hinge pins 32 connect the frame portion 26 to the central cover portion 28. The hinge pins permit the opposing end of the central cover portion 28 (i.e. the end near camming bar 16) to pivot slightly upwardly and downwardly. A pair of metal leaf-springs 34 are attached to frame portion 26 and bias the pivoting end of the central cover portion away from the base member 12.
When the base member 12 and cover member 14 are fully engaged, the camming bar 16 may be rotated to force down the pivoting end of the central cover portion 28. This causes a pair of tabs 36 to engage with slots (not seen) on the upper portion of base member 12 to lock the cover member 14 to the base member 12. Even in this locked position, the reticle 18 is free to move slightly from side-to-side (as indicated by arrow 38 in FIG. 2), or up-and-down (as indicated by arrows 40 in FIG. 2).
Reticle box 10 has several drawbacks. For one, it is made from a plastic material which can accumulate a considerable amount of static charge--sometimes in excess of 1000 volts d.c. This high static charge can disrupt or damage delicate circuitry, mechanisms and optics of an optical stepper apparatus.
Another serious problem is the possibility of damage to a reticle 18 due to the loose way it is held within the reticle box 10. As the reticle moves back-and-forth and up-and-down, it can become scratched or broken. Since the reticle 18 sits loosely on the base stand-offs 20, the reticle box 10 must be stored in a flat, upright position. This means that a number of reticle boxes 10 cannot be compactly stored on their sides, nor can the reticle box 10 be used for shipping reticles.
Another problem with reticle box 10 is the use of metal hinge pins 32 and leaf springs 34. These metal surfaces rub against plastic surfaces of the cover member 14, creating a shower of particles which can contaminate the reticle box 10 and/or the reticle 18. With today's microscopic feature widths in I.C. devices, even small amounts of contaminants can damage an IC during the production process.
The reticle box 10 also has problems with contamination from yet another source. The walls 30 of base member 12 have peripheral flanges 42 which press against peripheral flanges 44 of cover member 14. Even when camming bar 16 is in a locked position, openings around the perimeter of the reticle box 10 allows a free path for particle entry into the box past these flanges as indicated by arrows 46.
Another drawback of reticle box 10 is that it has many parts and is therefore relatively difficult and expensive to manufacture. For example, the cover member 14 is a multi-part unit including a number of pins, leaf-springs, screws, etc. It would, of course, be desirable to reduce the number of parts of the reticle box to reduce its cost and to increase its reliability.


A system and method for testing the sensitivity of optical components comprises providing an optical testing unit which measures the sensitivity of an optical device under test (DUT). The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Optical components, including fiber optic cables, connectors, transmitters, receivers, switches, routers and all other types of optical components have become the backbone of the modern telecommunication infrastructure. Due to their extremely low error rate and wide bandwidth, optical communication systems have supported an explosion in the growth of data communication systems, such as the Internet. With the Internet in its infancy, it is expected that the reliance on optical components and systems will only increase as the Internet becomes more closely intertwined with mainstream business and consumer applications.
Although the technology associated with optical communication systems and components has greatly advanced over the last decade and the use of such technology has accelerated, the technology associated with testing optical communication systems and components has greatly lagged.
Bit error rate (BER) measurements are a standard tool in verifying the performance of any digital optical communication system. Nevertheless, such tests remain an underutilized resource in understanding and diagnosing issues with such systems; particularly with respect to the receive-side optical front end. There are many contributing factors to this situation; chief among them are a lack of hardware and software resources, the time consuming nature of such measurements, and a lack of appreciation and understanding of the information content such measurements can provide.
The principle of BER measurements is simple: send digital data through a device and compare the digital result to the input data. The BER is given by the ratio of incorrectly identified bits to the total number of bits processed. In optical systems, BER tests are most commonly associated with determining the sensitivity of the optical receiver. Clearly, if the input optical power decreases enough, the receiver will begin generating errors. Receiver sensitivity is the input optical power required for a particular BER. Sensitivity is typically measured in dBm where:
                              P          dBm                ≡                  10                                log                                      (                                                P                                                                                mW                                                  1                                                                                mW                                            )                                                          Eqn        .                                                    (          1          )
Accordingly, 0 dBm corresponds to 1 mW. The result depends strongly on the measurement conditions including the quality of the transmitter, the amount of input optical noise, the BER required, the data rate and the data being transmitted. A typical measurement might involve a high quality transmitter, no added input noise, a well-defined pseudorandom bit sequence and a required BER of 1×10−10.
For a network designer, sensitivity is often regarded as the most important figure of merit for a receiver since it suggests a minimum input operating power for the device. A designer would ordinarily plan to operate the receiver with an input power high enough above the quoted sensitivity such that the expected error rate will not impact the reliability of the link. But how high above the sensitivity power level the receiver should be operated at is one of the fundamental questions that careful BER measurements can answer.
Due to the current state of technology for optical testing equipment, testing an optical component at many small increments of optical power over the full operating range is not realistic. To wit, via current practices, in order to perform these measurements, it is often necessary for a technician first to set the optical power of the test equipment to the desired optical power (which is an iterative process), and then must separately measure the number of errors at that optical power. Since the number of errors exhibited by optical equipment is extremely low, (i.e., 1×10−9 or less), it would necessitate a technician to continually attend to the testing equipment over a series of hours or days.
Known testing regimens avoid the problem of lengthy test procedures by requiring a technician to measure the BER over a few discrete levels of optical power. These results are then extrapolated throughout the entire operating range of the optical component to arrive at the behavior of the component over the entire operating range of the component. Extrapolating the results in such a manner increases the risk that the true behavior exhibited by the optical component at levels of power between the measured discrete levels will be missed. This can lead to later errors in the technical specifications for the particular component.
What is needed is a simple and effective system and method for efficiently testing the sensitivity of optical components.

Automated system and method for determining the sensitivity of optical components


A semiconductor substrate which effectively prevents a chipping phenomenon, wherein the outer peripheral extremity of the insulation layer is located between the outer peripheral extremity of the semiconductor layer and the outer peripheral extremity of the support member, and wherein the semiconductor layer and the insulation layer produce a stepped profile.

1. Field of the Invention
This invention relates to a semiconductor substrate comprising a semiconductor layer arranged on a supporting base member and also to a method of manufacturing such a semiconductor substrate.
2. Related Background Art
SOI (semiconductor on insulator) substrates having an SOI structure obtained by forming a single crystal semiconductor layer on an insulation layer are well known. Devices comprising an SOI substrate provide a number of advantages over ordinary Si substrates, including the following:    (1) easy dielectric separation and adaptability to an enhanced degree of integration;    (2) excellent radiation resistance;    (3) small stray capacitance and potential for high speed device operation;    (4) no need of well-forming process;    (5) reliable latch-up prevention; and    (6) capability of reducing the film thickness and forming fully depleted type field effect transistors.
Because of the advantages of the SOI structure including the above, massive efforts have been paid for developing various methods of manufacturing substrates having an SOI structure in the last decades.
The SOI technology can go back to the days of the SOS (silicon on sapphire) technology of forming an Si layer on a single crystal sapphire substrate by means of hetero-epitaxial growth, using a CVD (chemical vapor phase growth) method. While the SOS technology is appreciated by many as one of the most matured technologies, it has not been commercialized remarkably because it is accompanied by a number of drawbacks including the generation of a large number of crystal defects due to lattice misalignment along the interface of the Si layer and the underlying sapphire substrate, the existence of aluminum mixed into the Si layer from the sapphire substrate originally containing it, a high cost of the substrate and a poor adaptability to the trend toward larger substrates.
The SIMOX (separation by ion implanted oxygen) technology followed the SOS technology. There have been various research efforts paid in the field of the SIMOX technology to reduce the crystal defects and the manufacturing cost. The methods known to date other than the SIMOX technology include a method of bonding a pair of wafers with an oxide film interposed therebetween and polishing or etching one of the wafers to leave a thin single crystal Si layer on the oxide film, a method of implanting hydrogen ions from the surface of an Si substrate carrying thereon an oxide film to a predetermined depth, bonding the substrate to another substrate and then peeling off the latter substrate with a thin single crystal Si layer left on the oxide film typically by means of heat treatment.
With the above method of manufacturing an SOI semiconductor substrate by bonding a pair of silicon wafers to each other with an insulation film interposed therebetween and thinning one of the substrates to produce a thin film or an Si layer on the insulation film, the strength of bonding the silicon substrates can be reduced and even nullified in the peripheral area as it is adversely affected typically by the operation of beveling the substrates.
Then, SOI wafers under such conditions can become chipped in areas where the bonding strength is not sufficient and the surfaces of the wafers can become damaged, if partly, by Si debris in the course of manufacturing semiconductor devices to reduce the yield of manufacturing high quality semiconductor devices.
To cope with this problem, techniques have been developed for removing silicon layers in areas showing a weak bonding strength. For instance, Japanese Patent No. 2658135 discloses a technique for preventing a chipping phenomenon from occurring in a semiconductor substrate comprising a semiconductor layer arranged on a support member by mechanically grinding the outer peripheral edge of the support member by means of a wheel having a electrodeposition surface of diamond. However, highly integrated high-density semiconductor devices require further preventive measures for preventing the appearance of fine debris.
FIGS. 13A through 13E of the accompanying drawings schematically illustrate a silicon removing process proposed by the inventors of the present invention. FIG. 13A shows an SOI substrate 5 prepared by bonding and etching-back operations and comprising an insulation film 2 and a thinned silicon layer 3 that are formed on a support member 1. An outer peripheral portion of the silicon layer 3 of the SOI substrate 5 has to be removed because the bonding strength is weak in that portion. The use of photolithography is the most popular technique for removing a silicon layer in the semiconductor technology. With such a technique, photoresist is applied to the surface of the SOI substrate and the applied photoresist is exposed to light so that only the photoresist on the portion of the silicon layer 3 to be removed may be removed. Thus, a photoresist mask as shown in FIG. 13B is produced. Then, as shown in FIG. 13C, the exposed extreme end portion of the silicon layer 3 showing only a weak bonding strength is removed, using the remaining photoresist as mask. Thereafter, a corresponding extreme end portion of the insulation film 2 located under the silicon layer 3 is removed. A wet etching technique using hydrofluoric acid as etchant is popularly employed for removing part of the insulation film 2 because it does not damage the underlying support member 1. Since the wet etching process proceeds isotropically, the insulation film 2 is also etched in an upper portion of its outer periphery located under the silicon layer 3 to produce an undercut as shown in FIG. 13D. The silicon removing process is completed when the photoresist is removed (FIG. 13E).
Thus, a peripheral portion of the silicon layer 3 showing a weak bonding strength is removed.
Note that, in the above illustration of an SOI substrate 5 prepared by bonding and etching-back operations, the support member 1 and the insulation film 2 are bonded together along their interface so that a portion of the insulation film 2 located directly under the removed extreme end portion of the silicon layer also has to be removed.
However, once an extreme end portion of the silicon layer 3 showing a weak bonding strength is removed, the remaining silicon layer 3 can become etched laterally when a corresponding extreme end portion of the insulation film 2 located under the silicon layer 3 is removed to produce an undercut there so that the outer peripheral end portion of the silicon layer located on the undercut will become overhung and not bonded at all. Then, the overhanging outer peripheral end portion of the silicon layer 3 can eventually give rise to a chipping phenomenon and produce debris.

Semiconductor substrate having a stepped profile


A switched boxcar integrating circuit suitable for use with high speed data acquisition systems such as an Optical Domain Reflectometer. The boxcar integrator comprises a differential pre-amplifier stage, a sampling switch, and an integrator. The sampling switch couples the output of the pre-amplifier to the input of the integrator. The integrator includes non-inverting and inverting stages for producing a differential integrated signal. The switch samples the output of the pre-amplifier. The samples are integrated by the integrator once a sufficient number have been acquired. The sampling switch includes a switch controller to synchronize the operation of the switch with the received signals. The integrator also includes an offset compensator and a reset switch which are coupled to the integrator. The offset compensator and reset switch set the integrator to zero and also correct any offset error. A feature of the boxcar integrator according to the present invention is the variable integrator aperture which allows the response of the receiver stage in an OTDR to be matched to the characteristics of the transmit stage.

The optical time domain reflectometer (OTDR) is an instrument which is used for measuring the attenuation and other characteristics of fibre optic cable. The OTDR sends light pulses into an optical fibre and measures the reflected and backscattered light. The principle advantages of the OTDR method are that the fibre cable does not have to be cut nor do both ends of the fibre cable have to be accessed.
The fibre characteristics and features along the cable will cause portions of the light pulse to be backscattered and reflected back to the OTDR. The OTDR has a photo detector which detects the backscattered and reflected light. The OTDR processes the signals from the photodetector to create a waveform which shows the characteristics and features of the fibre as a function of time. The waveform is then displayed on a monitor as a function of distance along the length of the cable.
The OTDR system can use a range of optical pulse widths to probe and test the fibre cable. In an OTDR system, an optical pulse with a greater width provides superior distance and dynamic range, while an optical pulse with a narrow width provides superior distance resolution. It will be appreciated that a narrow pulse width provides increased resolution for the OTDR at the expense of distance or dynamic range because less energy is sent into and received from in the cable.
The dynamic range and resolution of an OTDR instrument are the two most important specifications. To achieve superior performance, an OTDR must be capable of providing high dynamic range and distance resolution.
The problem is existing OTDR systems is the matching of the receiver frequency response to the varying pulse widths of the transmitter stage. To maximize the efficiency and accuracy of the data acquisition, the receiver must be able to respond to the varying optical pulse widths which can be generated by the transmitter stage. Another problem in existing OTDR systems occurs when a reflected light pulse having a large amplitude (e.g. reflection at connector) saturates the input amplifier and thereby prevents the detection of backscattered light which immediately follows the period of time between saturation and recovery of the amplifier. This is commonly known as the "dead-zone".
Another problem in practical OTDR systems is noise associated with electromagnetic interference. The signals present in the receiver stage of an OTDR are very wide bandwidth and very low level, and therefore the circuit is susceptible to noise which can degrade the dynamic range of the OTDR.

Differential boxcar integrator with auto-zero function


In wireless networks, data objects are typically transferred from a data distributor to a data recipient by reliable point-to-point communication between the distributor and the recipient. However, the time to transfer data by point-to-point communication can become excessive if the number of recipients is large. Efficient and reliable data transfer is provided by a system incorporating broadcast and point-to-point communication topologies. The data is initially broadcast to all recipients. Data broadcasting is followed by polling the recipients. If the data missing after a broadcast can be transferred in less time by point-to-point communication then that topology is chosen to complete the transfer. If not, the missing data is broadcast again to all recipients. The efficiency of the broadcast phase can be improved by designating a representative to acknowledge successful data transfer on behalf of all recipients. A most suitable representative of all recipients can be selected by comparing missing data for each recipient to the missing data of all other recipients.

The present invention relates to data transmission and, more particularly, a method of data transmission combining broadcast and point-to-point transmission topologies for efficient and reliable data transfer.
Emerging wireless communication systems are intended to provide voice and data communication between a wide variety of devices. Two such systems are systems complying with the SPECIFICATION OF THE BLUETOOTH SYSTEM, CORE, The Bluetooth Special Interest Group, 1999 (Bluetooth systems) and systems complying with the SHARED WIRELESS ACCESS PROTOCOL (CORDLESS ACCESS) SPECIFICATION (SWAP-CA), The HomeRF Technical Committee, 1999 (HomeRF systems). Bluetooth and HomeRF systems are short range wireless radio systems operating in the unlicensed Instrument, Scientific, and Medical (ISM) band at 2.4 GHz. Frequency hopping, spread spectrum techniques are utilized to reduce interference and fading in the noisy environment in which these systems will operate. For example, with Bluetooth systems information is exchanged as packets in a slotted communication channel. Slots in the communication channel are 625 μsec. in length and data packets are typically one-slot in length but can cover up to five slots. The system shifts transmission frequency for each slot by hopping through a psuedo-random sequence of 79 frequencies displaced from each other by 1 MHZ. The Bluetooth and Home RF systems support both asynchronous (primarily, data) and synchronous (voice) communication.
Typically, data communication between end systems of wireless networks utilizes a point-to-point communication topology. Point-to-point communication with acknowledgment by the receiver affords the opportunity to utilize error detection and control techniques to provide reliable data delivery. Reliable delivery is important for data transfer because any corruption of the data can render an entire data object useless. In the Bluetooth system forward error control (FEC) is applied to the packet header and a Cyclic Redundancy Check (CRC) is applied to the payload of data packets. FEC can also be applied to the data payload if it is determined that the communication channel is sufficiently unreliable to justify the additional overhead. The receiver acknowledges successful receipt of each packet with a reverse transmission to the sender and if an error is detected in either the packet header or the payload an automatic request for retransmission (ARQ) is issued. In response, the sender retransmits the data until the recipient either signals that the data was correctly received or a predetermined number of transmissions are exceeded. While point-to-point communication provides reliable delivery, it also requires that at least one copy of the data be transmitted individually to each recipient. Therefore, the total time required to distribute a data file to all recipients is proportional to the number of recipients and, if the number of recipients is large, the transmission time can become excessive.
On the other hand, broadcasting a single copy of the data simultaneously to all recipients eliminates the redundant transmission of copies to individual recipients that is inherent in point-to-point communication. Since the time required for data distribution by broadcasting is independent of the number of recipients, broadcasting is potentially more efficient when communicating with a large group. However, delivery is unreliable when broadcasting because the sender is unaware of the recipient's success in receiving the data. To improve the likelihood of success, data may be rebroadcast, one or more times, but rebroadcasting is performed without knowledge of the current conditions of the communication channel and the total time required for transmission increases in proportion to the number of times the data is broadcast. Since the likelihood of error increases as the size of the transmitted data object increases, broadcasting is not used to transmit large data objects in noisy, dynamic communication channels. Short range wireless systems, such as Bluetooth and HomeRF systems, are characterized by communication channels that are noisy and subject to multi-path fading due to structures in the transmission area.
What is desired, therefore, is a communication method for efficiently and reliably transferring data to a large number of recipients in a noisy communication environment.

Efficient and reliable transmission via a hybrid broadcast-point-to-point system


A method for self bonding epitaxy includes forming a passivation layer on a substrate surface of a semiconductor lighting element; etching to form recesses and protrusive portions with the passivation layer located thereon; starting forming epitaxy on the bottom surface of the recesses; filling the recesses with an Epi layer; then covering the protrusive portions and starting self bonding upwards the epitaxy to finish the Epi layer structure. Such a self bonding epitaxy growing technique can prevent cavity generation caused by parameter errors of the epitaxy and reduce defect density, and improve the quality of the Epi layer and increase internal quantum efficiency.

Conventional semiconductor lighting elements are made in a standard rectangular profile. As the general semiconductor material has a refractive index greatly different from the package material, total reflective angle is smaller. Hence when the light generated by the semiconductor lighting elements reaches the critical surface with air the light greater than the critical angle generates total reflection and returns to the crystals on the lighting elements. In addition, the rectangle has four parallel cross sections. The probability of protons leaving the semiconductor at the interface is smaller. The protons can only be totally reflected until fully absorbed. The light is converted to heat. As a result, light generation effect is not desirable.
Changing light reflection is an effective way to improve light generation efficiency. The present approach is forming a recess 11 and a protrusive portion 12 at the surface of a substrate 10 to generate light scattering or diffraction on the lighting area (referring to FIG. 1) to increase external quantum efficiency and enhance light generating efficiency.
However, the structure of the recess 11 and protrusive portion 12 also makes manufacturing of the epitaxy in the follow-on process more difficult. It generally requires to control the epitaxy in a desired condition to get a cavity-free semiconductor layer to enhance light generating efficiency. But the epitaxy parameters such as temperature, pressure, gas flow, V/III flux ratio and dopant content affect transverse and lateral growing speed of the epitaxy. Referring to FIG. 2, while an Epi layer 20 starts to form epitaxy on a bottom surface 13 of the recess 11 and a flat surface 14 at an upper side of the protrusive portion 12 the lateral growing speed of the Epi layer 20 on the protrusive portion 12 is greater than the lateral growing speed of the recess 11, hence squeezing takes place between them and cavities 21 occur after the Epi layer 20 is formed (referring to FIG. 3). These cavities 21 cause light loss in the semiconductor lighting element and reduce internal quantum efficiency. As a result lighting efficiency and life span of the lighting element suffer.


A method for ion-implanting a dopant species in semiconductors includes the steps of implanting a dopant species in a semiconductor material at a predetermined rate, the predetermined rate being based on a rate corresponding to a maximum in a characteristic graph of percent activation as a function of dopant species implantation rate; and annealing the dopant implanted semiconductor.

1. Field of the Invention
This invention relates to the field of electrical activation of ion-implanted semiconductors. In particular, the invention relates to ion-implanted silicon in GaAs.
2. Description of the Related Art
The ion-implantation of semiconductors, and in particular the ion-implantation of silicon into GaAs, is an important doping technology for device fabrication. Particle accelerators accelerate silicon ions to impinge on and be implanted into GaAs. Implantation is followed by an annealing procedure which removes radiation induced damage and thermally transports dopants into lattice positions where they become electrically active. An activation of 100% is desirable, but in practice this is seldom achieved. For low fluences (from nil to .apprxeq. 5.times.10.sup.12 cm.sup.-2) various annealing techniques can result in activations of more than 80%, but at higher fluences percent activation generally decrease. At higher fluences on the order of 10.sup.14 cm.sup.-2, the reported activations vary widely and have been seen to depend strongly on the specifics of the post-implantation processing, including annealing.
The study of electrical activation of implanted dopants in GaAs as a function of implanted species, fluence and post-implant processing (annealing) has been an active research area in recent years. The ion-implantation process induces damage in the crystalline structure of the semiconductor. The annealing process reduces or ameliorates a portion of the induced damage. The study of implantation induced damage and its anneal characteristics has been ongoing for an even longer time than the study of electrical activation. Few of these studies report the dose rate with which the fluence was administered and there have been no studies reporting the impact of various dose rates on the electrical activation of the implanted species.
Japanese Patent No. 62-2533 to Ozawa discloses a method for obtaining sharp carrier concentration distributions by implanting silicon ions into an InGaAs layer at a specific accelerating voltage and at a specific dose after the ion-implantation is annealed. Ozawa discloses obtaining a peak carrier concentration of 7.5.times.10.sup.18 cm.sup.-3 when an accelerating voltage of 100 KeV is used with doses between 3.times.10.sup.13 cm.sup.-2 and 3.times.10.sup.14 cm.sup.-2 after the ion-implantation has been heat treated at 600.degree. to 700.degree. C. Ozawa does not disclose activation percentages or their dependency on implantation dose rates.
Japanese Patent No. 62-2532 to Ozawa disclosed a method for annealing an InGaAs ion-implanted dopant layer using a lamp furnace to enhance the activation of a conducting layer and to sharpen the carrier concentration distribution. Ozawa does not disclose the dependence of electrical activation on implantation dose rates.
U.S. Pat. No. 4,396,437 to Kwok et al. discloses a post-ion implantation annealing technique which involves applying an encapsulation over a device area capable of gettering a species that renders a substrate semi-insulating and then annealing the substrate to remove implantation damage resulting in high carrier mobility in an active region. The Kwok et al. patent does not disclose the dependence of electrical activation on implantation dose rates.
Japanese Patent No. 1-93115 to Tamura discloses a heat treating method to improve activation by applying an insulating film to one main surface of a semi-insulating GaAs substrate and then annealing the substrate before ion-implantation with SiF.sub.3.sup.+ improve the degree of activation. Tomura does not disclose the dependence of electrical activation on implantation dose rates.
U.S. Pat. No. 4,615,766 to Jackson et al. disclose a method of annealing ion-implanted doping impurities on at least one surface of a GaAs substrate by depositing a silicon capping layer after ion-implanting, and before annealing to remove damage to the substrate so as to prevent arsenic from evaporating from the substrate. Jackson et al. do not disclose the dependence of electrical activation on implantation dose rates.

Implanting impurities in semiconductors and semiconductor implanted with impurities

The United States of America as represented by the Secretary of the Navy


The invention relates to a liquid cleaning device that is intended for purifying liquid from pollutants, which liquid cleaning device includes a vessel, having a lower chamber and an upper chamber, which lower chamber is connected to a heating member arranged to heat the liquid in said lower chamber, as well as further including a riser and liquid-distributor member, which riser is arranged to transport heated liquid from said lower chamber up to the upper part of said upper chamber, where the liquid-distributor member is arranged to impart the heated liquid an increased area of exposure to surrounding air, the liquid then, by means of the gravity, running back downward outside the riser and being collected in the lower part of the upper chamber of the vessel, said upper chamber and lower chamber being in at least conditioned communication with each other in order to allow transfer of the liquid from the upper chamber to the lower chamber. According to the invention, the heating member is arranged to be capable of assuming at least two power levels and that a change-over member is arranged to automatically reduce the power level of the heating member.

A problem that the present invention is related to is the following. In most larger cities, tap water is produced in big plants and is transported in piping systems to the consumers. In order to protect the water against risks of infection during the transportation, a certain quantity of chlorine is usually added before the clean water leaves the plant.
A certain quantity of this chlorine is consumed during the way and a certain quantity of is left in the water when it reaches the consumers. The intention of the addition of chlorine is that the chlorine should decompose potentially dangerous organisms and organic impurities in the pipes. When this takes place, chlorinated hydrocarbons of the type chloroform and bromoform are formed. Hence, also these substances are present in a certain quantity in the water that reaches the consumers.
Even if the amount of chlorine and chlorinated hydrocarbons is low in the water, it is known that the two types of impurities are mutagenic also in small doses, and it is therefore an advantage if it is possible to avoid them to as great an extent as possible.
Since long there are different types of filters on the market, by means of which it is possible to clean water from municipal piping or an own well. However, traditional filters that are in the form of fine-meshed nets do not stop volatile substances such as chlorine and chlorinated hydrocarbons. Neither filters that contain ion exchange mass (for instance softeners) manage this.
For this reason, in many places filters containing activated carbon are now used. The disadvantage of activated carbon is that it is difficult to know when the filter is full, and in many examinations it has been found that the activated carbon quickly may lose effect upon an unexpected load increase and in that connection further turn into a refuge, nutrition place and breeding ground for bacteria and pyrogenes.
For this reason, the carbon filter is frequently combined with other methods to a more complicated apparatus where accordingly also pre-filters to stop coarser particles and organic material, ultraviolet-light lamps to kill bacteria, and ion exchangers for picking up ions are included. Such an equipment becomes relatively expensive and works satisfactory only if the exchange of roughing filter, ultraviolet lamps, ion exchange mass and activated carbon is handled accurately. As an alternative to these multi-stage filters, equipment has also been developed based on distillation and the reversed osmosis. None of these methods, advanced per se, is however entirely efficient in removing chlorine and chlorinated hydrocarbons but have to be supplemented with an activated-carbon final filter. Even if the load on this final filter is much smaller than on carbon filters in the previously mentioned multi-stage filters, also these have to be exchanged at regular intervals, and the problem with overload remains.
A simpler way to kill bacteria as well as remove chlorine and chlorinated hydrocarbons and also other volatile substances from water is to boil water in a boiler or open vessel. The disadvantages of this simple method in comparison with what has been mentioned previously are foremost three. A large quantity of water has to be boiled away in order to be sure of getting rid of the volatile impurities, which in the first place entails that water is wasted and in the second place that the possible non-volatile impurities that are present in water are concentrated. The third disadvantage is that the user does not know when a satisfactory result has been attained.
Within the industry, many methods are developed for the separation of liquid from gas, gas from liquid and gas from another gas. The most common principle is the cyclone principle, which is based on a steam/gas/water mixture being centrifuged and the liquid thereby being pressed out of the mixture. A rather similar principle is that the mixture is led through a conduit having many bends, the liquid being stopped by devices of different forms in the bends.
Furthermore, area-enlarging devices are used in such a way that water/gas/steam mixture is sprayed or sprinkled on large plates or is left to run down large sheets or another type of device having a large area, for instance steel wool or plastic balls.
It is also possible to force a gas, for instance air or nitrogen, through the mixture. This gas then drives off or drags along other gases in the mixture. Frequently, a combination of these techniques is used.
A previously known liquid cleaning device of the relevant type is seen in the Swedish patent 518 388, according to which liquid is heated in a vessel having a lower part, provided with heating members, and an upper part intended for the liquid, as well as an inner central tubular riser member for heated liquid rising upward through the riser member, the heated liquid from the upper open end of the riser member by the gravity running back downward through the upper part outside the riser member for renewed heating and vaporization at constant power and time.
Per se, this liquid cleaning device works well. A disadvantage of the liquid cleaning device in the Swedish patent 518 388 is that when the volume of liquid in the product reaches the boiling temperature, the liquid begins to flash at unchanged supply of energy to the cleaning process. This in turn means that the desirable transport of liquid decreases and that a final product that has not been fully cleaned is obtained.


An optoelectronic assembly for a computer system includes an electronic chip(s), a substrate, an electrical signaling medium, an optoelectronic transducer, and an optical coupling guide. The electronic chip(s) is in communication with the substrate, which is in communication with a first end of the electrical signaling medium. A second end of the electrical signaling medium is in communication with the optoelectronic transducer, and includes the optical coupling guide for aligning an optical signaling medium with the optoelectronic transducer. An electrical signal from the electronic chip is communicated to the optoelectronic transducer via the substrate and the electrical signaling medium. The optical transducer and electronic chip(s) share a common heat spreader, and communication to other groups of electronic chip(s) is done without the need for communication via a second level electrical package.

The present disclosure relates generally to optoelectronic communication with an electronic device, and particularly to the attachment arrangement for providing optoelectronic communication between an electronic chip on a first level package and a high density optical transceiver.
Typically, optoelectronic transceivers are mounted on a second level package, such as a printed circuit board, and are provided with their own heat sink and a means of being electrically interconnected with a printed circuit board, such as via a socket or a solder Ball Grid Array (BGA). The typical pitch of the electrical connections in a BGA is approximately 1.27 mm, although some products use finer pitches such as 1.0 or 0.8 mm. The size of an optoelectronic transceiver is largely determined by the area required by the heat sink and/or the area required for electrical connections between the optoelectronic transceiver and the second level package.
The trend in the computer industry regarding large servers is to utilize multiple processor groups, each group containing multiple processors on a first level package, such as a Multi-Chip Module (MCM), which must be interconnected with very high speed data buses to enable the totality of processors to act in unison, otherwise referred to as a symmetric multi-processing (SMP) configuration. The first level package provides dense electrical interconnection between the multiple processor chip(s), each of which my contain multiple processor cores, cache memory chip(s) and other support chips, which may also be mounted on the MCM or other first level package. To connect between multiple MCMs, copper interconnect technology has been used as the interconnect medium, but is limited in its ability to scale to the bandwidth/distance requirements of next generation servers. These limitations are primarily associated with the signal loss and distortion in the electrical transport media, such as printed circuit boards and connectors for example, and bandwidth reduction due to the skin effect at high data transmission rates. To overcome some of these limitations, optical interconnection, which does not have the copper limitations and can operate at speeds sufficient to satisfy future generation server interconnection requirements, is becoming the interconnection technology of choice. Many of these same technical problems occur in data communication systems (for example, datacom and telephone switching networks) that may also benefit from optical interconnection technology. Accordingly, there is a need in the art to provide an improved apparatus and method for providing optoelectronic communication with electronic chips, and particularly with electronic chips on a first level package such as MCMs in large high speed servers or data communication systems.

Method and apparatus for providing optoelectronic communication with an electronic device

International Business Machines Corporation


Two data storage systems are interconnected by a data link for remote mirroring of data. Each volume of data is configured as local, primary in a remotely mirrored volume pair, or secondary in a remotely mirrored volume pair. Normally, a host computer directly accesses either a local or a primary volume, and data written to a primary volume is automatically sent over the link to a corresponding secondary volume. Each remotely mirrored volume pair can operate in a selected synchronization mode including synchronous, semi-synchronous, adaptive copy-remote write pending, and adaptive copy-disk. Direct write access to a secondary volume is denied if a xe2x80x9csync requiredxe2x80x9d attribute is set for the volume and the volume is not synchronized. If a xe2x80x9cvolume dominoxe2x80x9d mode is enabled for a remotely mirrored volume pair, access to a volume of the pair is denied when the other volume is inaccessible. In a xe2x80x9clinks dominoxe2x80x9d mode, access to all remotely mirrored volumes is denied when remote mirroring-is disrupted by an all-links failure. The domino modes can be used to initiate application-based recovery, for example, recovering a secondary data file using a secondary log file. In an active migration mode, host processing of a primary volume is concurrent with migration to a secondary volume. In an overwrite cache mode, remote write-pending data in cache can be overwritten. Write data for an entire host channel command word chain is bundled in one link transmission.

Authorization Pursuant to 37 C.F.R xc2xa71.17(e)
A portion of the disclosure of this patent document contains command formats and other computer language listings all of which are subject to copyright protection. The copyright owner, EMC Corporation, has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
This invention relates to data storage, and more particularly, to a system and method for automatically providing and maintaining a copy or mirror of data stored at a location geographically remote from the main or primary data storage device.
Nearly all data processing system users are concerned with maintaining back-up data in order to insure continued data processing operations should their data become lost, damaged, or otherwise unavailable.
Large institutional users of data processing systems which maintain large volumes of data such as banks, insurance companies, and stock market traders must and do take tremendous steps to insure back up data availability in case of a major disaster. These institutions recently have developed a heightened awareness of the importance of data recovery and back-up in view of the many natural disasters and other world events including the bombing of the World Trade Center in New York City.
Currently, data processing system users often maintain copies of their valuable data on site on either removable storage media, or in a secondary xe2x80x9cmirroredxe2x80x9d storage device located on or within the same physical confines of the main storage device. Should a disaster such as fire, flood, or inaccessibility to a building occur, however, both the primary as well as the secondary or backed up data will be unavailable to the user. Accordingly, more data processing system users are requiring the remote storage of back up data.
One prior art approach at data back-up involves taking the processor out of service while back-up tapes are made. These tapes are then carried off premises for storage purposes. Should access to the backed up data be required, the proper tape must be located, loaded onto a tape drive, and restored to the host system requiring access to the data. This process is very time consuming and cost intensive, both in maintaining an accurate catalog of the data stored on each individual tape, as well as storing the large number of tapes required to store the large amounts of data required by these institutions. Additionally and most importantly, it often takes twenty-four hours before a back-up tape reaches its storage destination during which time the back-up data is unavailable to the user.
Additionally, today""s systems require a significant amount of planning and testing in order to design a data recovery procedure and assign data recovery responsibilities. Typically, a disaster recovery team must travel to the test site carrying a large number of data tapes. The team then loads the data onto disks, makes the required network connections, and then restores the data to the xe2x80x9ctestxe2x80x9d point of failure so processing can begin. Such testing may take days or even weeks and always involves significant human resources in a disaster recovery center or back-up site.
Some providers of prior art data storage systems have proposed a method of data mirroring whereby one host Central Processing Unit (CPU) or processor writes data to both a primary, as well as a secondary, data storage device or system. Such a proposed method, however, overly burdens the host CPU with the task of writing the data to a secondary storage system and thus dramatically impacts and reduces system performance.
Accordingly, what is required is a data processing system which automatically and asynchronously, with respect to a first host system, generates and maintains a back-up or xe2x80x9cmirroredxe2x80x9d copy of a primary storage device at a location physically remote from the primary storage device, without intervention from the host which seriously degrades the performance of the data transfer link between the primary host computer and the primary storage device.
This invention features a system which controls storing of primary data received from a primary host computer on a primary data storage system, and additionally controls the copying of the primary data to a secondary data storage system controller which forms part of a secondary data storage system, for providing a back-up copy of the primary data on the secondary data storage system which is located in a geographically remote location from the primary data storage system. For remote copying of data from one storage system to the other without host involvement, the primary and secondary data storage system controllers are coupled via at least one high speed communication link such as a fiber optic link driven by LED""s or laser. The high speed communication link also permits one data storage system to read or write data to or from the other data storage system.
At least one of the primary and secondary data storage system controllers coordinates the copying of primary data to the secondary data storage system and at least one of the primary and secondary data storage system controllers maintains at least a list of primary data which is to be copied to the secondary data storage device.
Additionally, the secondary data storage system controller provides an indication or acknowledgement to the primary data storage system controller that the primary data to be copied to the secondary data storage system in identical form as secondary data has been received or, in another embodiment, has actually been written to a secondary data storage device.
Accordingly, data may be transferred between the primary and secondary data storage system controllers synchronously, when a primary host computer requests writing of data to a primary data storage device, or asynchronously with the primary host computer requesting the writing of data to the primary data storage system, in which case the remote data copying or mirroring is completely independent of and transparent to the host computer system.
At least one of the primary data storage system controller and the secondary data storage system controller maintains a list of primary data which is to be written to the secondary data storage system. Once the primary data has been at least received or optionally stored on the secondary data storage system, the secondary data storage system controller provides an indication or acknowledgement of receipt or completed write operation to the primary data storage system.
At such time, the primary and/or secondary data storage system controller maintaining the list of primary data to be copied updates this list to reflect that the given primary data has been received by and/or copied to the secondary data storage system. The primary or secondary data storage system controllers and/or the primary and secondary data storage devices may also maintain additional lists for use in concluding which individual storage locations, such as tracks on a disk drive, are invalid on any given data storage device, which data storage locations are pending a format operation, which data storage device is ready to receive data, and whether or not any of the primary or secondary data storage devices are disabled for write operations.
In accordance with one aspect of the invention, the remote mirroring facility can operate in a specified one of a number of different remote mirroring operating modes for each volume. The operating modes include a synchronous mode, a semi-synchronous mode, an adaptive copy-write pending mode, and an adaptive copy-disk mode. The operating mode for each logical volume can be specified to best suit the purposes of the desired remote mirroring, the particular application using the volume, and the particular use of the data stored on the volume.
In the synchronous mode, data on the primary (R1) and secondary (R2) volumes are always fully synchronized at the completion of an I/O sequence. The data storage system containing the primary (R1) volume informs the host that an I/O sequence has successfully completed only after the data storage system containing the secondary (R2) volume acknowledges that it has received and checked the data. All accesses (reads and writes) to the remotely mirrored volume to which a write has been performed are suspended until the write to the secondary (R2) volume has been acknowledged.
In the semi-synchronous mode, the remotely mirrored volumes (R1, R2) are always synchronized between the primary (R1) and the secondary (R2) prior to initiating the next write operation to these volumes. The data storage system containing the primary (R1) volume informs the host that an I/O sequence has successfully completed without waiting for the data storage system containing the secondary (R2) volume to acknowledge that it has received and checked the data. Thus, a single secondary (R2) volume may lag its respective primary volume (R1) by only one write. Read access to the volume to which a write has been performed is allowed while the write is in transit to the data storage system containing the secondary (R2) volume.
The adaptive copy modes transfer data from the primary (R1) volume to the secondary (R2) volume and do not wait for receipt acknowledgment or synchronization to occur. The adaptive copy modes are responsive to a user-configurable skew parameter specifying a maximum allowable write pending tracks. When the maximum allowable write pending tracks is reached, then write operations are suspended, and in a preferred arrangement, write operations are suspended by defaulting to a predetermined one of the synchronous or asynchronous modes. In the adaptive copy-write pending mode, the write pending tracks accumulate in cache. In the adaptive copy-disk mode, the write pending tracks accumulate in disk memory.
In accordance with another aspect of the invention, there are provided a number of automatic and non-automatic recovery mechanisms. The recovery mechanism can be also selected on a logical volume basis for a desired level of data integrity and degree of operator or application program involvement. The invention also provides various options that provide a tradeoff between the degree of data integrity, cache loading, processing speed, and link traffic.
In one embodiment, cache loading and processing speed is enhanced by queuing pointers to data in cache for transmission to the link, and permitting pending write data to be overwritten in cache. Link traffic can also be reduced in this case, since obsolete write pending data need not be transmitted over the link. However, unless the remote mirroring is operated in the synchronous mode, data integrity is subject to the possibility of a xe2x80x9crolling disaster.xe2x80x9d In the rolling disaster, a remote mirroring relationship exists between the two data storage systems. All links break between the sites, and application processing continues using the primary (R1) volumes. The links are restored, and resynchronization commences by copying data from the primary (R1) volumes to the secondary (R2) volumes. Before resynchronization is finished, however, the primary volumes are destroyed, and the attempt at resynchronization has further corrupted the secondary volumes, due to the cache overwrite option.
The invention provides options other than the synchronous and semi-synchronous operating modes to avoid the xe2x80x9crolling disasterxe2x80x9d possibility when performing automatic recovery. One option is to suspend processing whenever the host requests a write to write-pending data in cache. Another option is to log multiple versions of tracks containing remote pending data.
Another aspect of the present invention provides mechanisms for selectively inhibiting automatic or manual recovery when automatic or manual recovery would be inappropriate. In one embodiment, each write request transmitted over the link between the data storage systems includes not only the data for at least one track in the secondary (R2) volume to be updated but also the current xe2x80x9cinvalid trackxe2x80x9d count for the secondary (R2) volume as computed by the data storage system containing the corresponding primary (R1) volume. Therefore, once a disaster occurs that destroys the data storage system containing the primary (R1) volume, the data storage system containing the secondary (R2) volume has an indication of the degree of consistency of the secondary (R2) volume. The xe2x80x9cinvalid tracksxe2x80x9d count can be used to determine an appropriate recovery operation for the volume, and can be used to selectively restrict read/write access to the volume when the user decides that synchronization should be required for a write access.
In a preferred embodiment, direct write access to a secondary (R2) volume is denied if remote mirroring is not suspended. When remote mirroring is suspended, direct write access to the secondary volume is still denied if a xe2x80x9csync requiredxe2x80x9d attribute is set for the volume and the volume is not synchronized.
In accordance with another aspect of the invention, automatic recovery is selectively inhibited by domino modes. If a xe2x80x9cvolume domino modexe2x80x9d is enabled for a remotely mirrored volume pair, access to a volume of the remotely mirrored volume pair is denied when the other volume is inaccessible. In a xe2x80x9clinks domino mode,xe2x80x9d access to all remotely mirrored volumes is denied when remote mirroring is disrupted by an all-links failure.
The domino modes can be used to initiate application-based recovery in lieu of automatic recovery. In one application-based recovery scheme, an application program maintains a log file of all writes (xe2x80x9cbeforexe2x80x9d or xe2x80x9cafterxe2x80x9d images) to a data file. To ensure recovery, the application program always writes data to the primary (R1) copy of the log file before it is written to the primary (R1) copy of the data file. The degree of synchronization between the secondary (R2) and primary (R1) copies is selected so that the remote mirroring facility always writes data to the secondary (R2) copy of the log file before it is written to the secondary (R2) copy of the data file.
Therefore, in the case of an all-links failure where host processing continues so far beyond the failure that all versions of the following updates are not retained, the secondary (R2) copy of the data file can be recovered if the primary (R1) copies are destroyed. In this case, if the secondary (R2) copy of the data file is corrupted, it is recovered using the changes recorded in the secondary (R2) copy of the log file.
In accordance with another aspect of the invention, the remote mirroring facility is provided with a migration mode which is active during host processing of a primary (R1) volume and iteratively copies updates from the primary (R1) volume to a secondary (R2) volume. Initially all data elements (tracks or records) of the secondary (R2) volume are marked as invalid. During each iteration, the data elements of the volume, such as tracks or records, are scanned for data elements that are invalid on the secondary (R2) volume. The next iteration copies from the primary (R1) volume to the secondary (R2) volume data elements having been invalidated by writes from the host during the previous iteration. A count of the number of data elements transferred during each iteration, or a count of the invalid data elements in the secondary volume, is kept in order to monitor convergence toward synchronization of the primary (R1) and secondary (R2) volumes. Host processing of the primary volume is suspended for a last iteration to obtain complete synchronization.
In accordance with another aspect of the invention, the host processor sends chains of channel commands to the data storage system containing a primary (R1) volume of a remotely mirrored volume pair. The data storage system containing the primary (R1) volume bundles the write data for all write commands in the chain into a single write command for transmission over a link to the secondary data storage system containing the secondary (R2) volume. The data storage system containing the primary (R1) volume decodes the channel commands to determine when it has received the last channel command in the chain, and once the last channel command in the chain is received, it transmits the bundle of write data for the chain over the link to the data storage system containing the secondary (R2) volume.
In accordance with yet another aspect of the invention, there is provided host remote mirroring software for permitting a system operator or host application program to monitor and control remote mirroring, migration, and recovery operations. The host remote mirroring software provides the capability of changing the configuration of the remotely mirrored volumes in the data processing system, suspending and resuming remote mirroring for specified remotely mirrored volume pairs, synchronizing specified remotely mirrored volume pairs and notifying the system operator or host application program when synchronization is achieved, invalidating or validating specified remotely mirrored volume pairs, and controlling or limiting the direction of data transfer between the volumes in a specified remotely mirrored pair.
The present invention therefore provides a data storage system which achieves nearly 100 percent data integrity by assuring that all data is copied to a geographically remote site, and in those cases when a back-up copy is not made due to an error of any sort, an indication is stored that the data has not been copied, but instead must be updated at a future time. The system operator or application programmer is free to choose a variety of remote mirroring and recovery operations best suited for a desired processing speed and level of data integrity.
Such a system is provided which is generally lower in cost and requires substantially less manpower and facilities to achieve than the prior art devices.

Asynchronous remote data mirroring system


The separation tool allows separation of a horizontal pile of recipients into sub-piles of recipients, the first or last recipient of each sub-pile have been previously marked with ultra-violet detectable ink. The tool comprises a frame; a sensor mounted to the frame for detecting the last recipient of a current sub-pile or the first recipient of the next sub-pile upstream therefrom, which ever has been previously marked, and a manipulator arm provided with a fixed finger assembly for holding the recipients upstream from the last recipient of the current sub-pile and a separation finger for creating a gap between the held recipients and those from the current sub-pile.

The manufacturing process of Styrofoam or other types of recipients usually ends by the manufactured recipients exiting a trim press on a feed table. The recipients are then separated in groups of a predetermined number of recipients, which are then packaged for shipping. The conventional method of separating the recipients involves the steps of individuals manually counting the appropriate number of recipients on the feed table and feeding them to bags or boxes for shipping. A drawback of this conventional recipient separating method is that it is time consuming and bound to error as any other human-handled repetitive process.

Method and tool for the separation of a pile of recipients


A nanocomposite optical plastic article has a plastic host material with a temperature sensitive optical vector (x) and a core shell nanoparticulate material dispersed into the plastic host material. The core shell nanoparticulate material is characterized by a core defined by a nanoparticulate material which has a temperature sensitive optical vector (x1) and a shell defined by a coating material layer coated onto the core. It is important to the invention that temperature sensitive vector (x1) is directionally opposed to the temperature sensitive optical vector (x) and nshell<nplastic host<ncore.

Plastic lenses and glass lenses often perform the same function in optical systems, such as in cameras, microscopes, telescopes, and opthalmic wear. The two main attributes that separate plastic lenses from glass lenses are cost and optical stability. Plastic lenses typically cost 1/100th the price of a similar glass lens while the stability of the refractive index of a glass lens with respect to temperature and humidity is typically 100 times better than that of a plastic lens.
The difference in cost is due largely to the difference in manufacturing processes that are required for the two materials and the relative temperatures that the materials must be formed at. Plastic lenses are typically produced at 230° C. using injection molding at cycle times that are 10 times faster than glass lenses that are largely produced by grinding and polishing or compression molding at 625° C. Grinding and polishing are labor intensive while the high temperatures that glass must be formed at requires expensive mold materials and extensive maintenance costs.
In contrast, the difference in optical stability between plastic and glass is due to differences in their basic material properties. This difference in optical stability results in substantially more variation in focus and image quality in articles such as cameras when plastic lenses are used in place of glass. What is desired, and a remaining challenge in the art, is a material with the optical stability of glass that processes like a plastic.
While optical plastic materials such as cyclic olefins greatly improve the refractive index stability with respect to humidity, improving the refractive index stability with respect to temperature has remained an opportunity. A study on the competing fundamental material characteristics that determine the sign and the magnitude of the dn/dT of glasses is available, for instance, by Lucien Prod'homme, "A New Approach To The Thermal Change In The Refractive Index Of Glasses," Physics and Chemistry of Glasses, Vol. 1, No. 4, August 1960. There are two competing effects that determine the dn/dT in glasses. These are the density change, which produces a negative dn/dT and the electronic polarizability, which produces a positive dn/dT. The net dn/dT in a glass material depends on which effect dominates. In optical plastics however, the electronic polarizability is very small compared to the density change so that all unfilled plastic materials have negative dn/dT values. Nonetheless, the article by Prod'homme does identify the possibility of using glass-like fillers with positive dn/dT values to substantially alter the dn/dT of a glass-plastic composite material.
Nanoparticulate fillers have been used to modify the index of refraction of optical plastics. By using a nanoparticulate filler small enough that it is well below the wavelength of visible light (400–700 nm), light scattering from the nanoparticles is reduced and the filled plastic can remain transparent. WIPO Patent No. WO97/10527 by John S. Toeppen, published Mar. 20, 1997, titled "Structured Index Optics And Ophthalmic Lenses For Vision Correction" describes the use of nanoparticles to increase the refractive index of plastics for opthalmic applications. In addition, technical references that describe the addition of nanoparticles to increase the refractive index of plastics include: "Optical And Thermomechanical Investigations On Thermoplastic Nanocomposites With Surface Modified Silica Nanoparticles" by C. Becker et al., SPIE Conference, Vol. 3469, pp. 88–98, July 1998; and "Tantalum Oxide Nanomers For Optical Applications" by B. Braune et al., SPIE Conference, Vol. 3469, pp. 124–132, July 1998. While these references disclose the use of nanoparticles to modify refractive index of optical plastics they do not discuss the issue of refractive index stability with respect to temperature which requires a different set of characteristics in the nanoparticle.
U.S. Pat. No. 6,441,077 titled "Polysulfone Nanocomposite Optical Plastic Article And Method Of Making Same" issued Aug. 27, 2002 to Border et al., discloses the use of a nanoparticulate filler in an optical plastic, where the nanoparticulate filler has been chosen with a positive dn/dT to counteract the negative dn/dT of the plastic host material such that the overall dn/dT of the nanocomposite has a substantially reduced magnitude of dn/dT, where dn is the change in refractive index of the nanocomposite material produced by a change in temperature dT.
In experiments and computer modeling done at Eastman Kodak, it has been noted that the addition of even very small nanoparticles (10–40 nm) into plastic host materials can lead to low level light scattering or haze in the nanocomposite material which limits light transmission to less than 90%. The haze is especially noticeable at loadings greater than 10% of the nanoparticles in the plastic host material, such as is required to substantially improve the thermal stability of the refractive index (reduced dn/dT) of the nanocomposite material. Haze is also particularly noticeable if the refractive index of the nanoparticles is substantially different from the refractive index of the plastic host material.
While there have been several attempts to modify properties of plastics using nanoparticles, none of these attempts have proven successful in producing optical plastic articles with improved temperature stable optical properties while retaining important processing characteristics and low levels of haze.
U.S. Pat. No. 5,252,441 titled "Transparent Magnetic Recording Layers And Photographic Elements Containing The Same" issued Oct. 12, 1993 to James et al. and U.S. Pat. No. 5,217,804 titled "Magnetic Particles" issued Jun. 8, 1993 to James et al. disclose a coating technique for magnetic particles that reduces the extinction coefficient by applying coatings to high refractive index magnetic particles thereby reducing the haze of the material. Examples show how the coating of the particles with a low refractive index layer reduced the optical density (haze). However, James et al. do not contemplate the impact of the particles or the coating material on the overall thermal stability of the refractive index of the nanocomposite material.
U.S. Pat. No. 5,985,173 titled "Phosphors Having A Semiconductor Host Surrounded By A Shell" issued Nov. 16, 1999 to Gray et al. describes a technique for applying a shell coating to doped zinc sulfide particles. However, the goal of this invention is related to establishing a bandgap to modify the surface electronic state of the doped host particle. This invention does not address the transparency of the nanocomposite material.
Likewise, in WIPO Publication Number WO99/21934 by Mulvaney et al., published May 6, 1999 and titled "Stabilized Particles And Methods Of Preparation And Use Thereof," Mulvaney et al. disclose a method for stabilizing nanoparticles by coating them with an insulating, semiconducting and/or metallic coating. While Mulvaney et al., do disclose techniques for applying coatings to nanoparticles and some of the materials presented do have positive dn/dT values such cadmium sulfide, zinc sulfide, zinc selenide, silica, and alumina, Mulvaney et al. only disclose the use of coated nanoparticles to improve fluorescence, electrofluorescence, and detection of an analyte. Mulvaney et al. do not anticipate the use of coated nanoparticles to modify the optical performance of optical articles such as lenses to improve thermal stability (dn/dT) of the refractive index. In fact, in Example F. on page 19, line 6, Mulvaney et al. make the statement that "the optical properties of the CdS particles are not significantly altered by silica deposition."
Therefore, a need persists in the art for optical plastic articles, such as lenses, and a method of making same that have improved temperature stable optical properties with low levels of haze.

This patent is subject to a terminal disclaimer.

Core shell nanocomposite optical plastic article


A sash locator for locating a casement window sash relative to a sash arm, includes an abutment structure disposed at a selected disposition relative to the sash arm such that positioning the sash proximate the sash arm with a selected portion of the sash abutting the abutment structure disposes the sash relative to the sash arm in a desired disposition for affixing the sash to the sash arm. A method of sash location relative to a sash arm is also included.

A casement window generally includes a frame portion, which is mounted in a rough opening provided in a structure, and an operable sash portion mounted in the frame with one or more hinges. A typical casement window hinge includes a track portion, which attaches to the window frame, and a sash arm, which attaches to the window sash. One end of the sash arm is pivotally attached to a shoe that is slidable on the track. A link arm is pivotally attached to each of the track and the sash arm. In operation, as the sash swings from the closed position to the open position, the sliding shoe slides along the track so that the inward side of the sash moves away from the corresponding side of the frame. Various prior casement window hinges are described and depicted in U.S. Pat. Nos. 1,706,830; 1,711,927; 2,094,990; 2,383,395; 3,797,169; 4,726,092; 5,040,267; 5,152,102; 5,491,930; 6,112,371; 6,134,751; and 6,643,896, all of which are hereby fully incorporated herein by reference.
A small degree of misalignment of the sash in the window frame may cause leaks and interference between the sash and frame during operation of the window. Consequently, a relatively high degree of accuracy and precision is required during window manufacture to ensure proper positioning and attachment of the sash arm to the sash. Fastener holes are generally pre-drilled in the sash using a jig in order to achieve the desired accuracy, thereby adding steps and attendant manufacturing costs. What is needed in the industry is a casement window hinge that is repeatably accurately attachable to a sash without pre-drilling or attachment jigs.