 frequency integrated circuits (RFIC) and microwave components. PARC StressedMetal coils self-assemble into three-dimensional scaffolds that, when electroplated with copper, form highly conductive coil windings, suitable for future cell phones, TV tuners, wireless local networks, and other devices. High-quality coils are the last remaining circuit components that cannot be integrated on-chip. As a result, most radio frequency circuits are built with modular assemblies containing many discreet components. PARC Stressed- Metal coils can be fabricated directly on silicon or gallium arsenide, thus enabling these modular assemblies to be replaced with a single integrated component. For example, voltage-controlled oscillators (VCO), used in cellu- lar phone circuit boards, are modular circuits made up of many discreet com- ponents. These coils could be used to integrate these into a single chip that would be less than one-fifth the size of existing circuits and cost less to produce. Higher levels of integration are also possible. StressedMetal coils can be manufactured on a range of substrates, includ- ing fully active circuit wafers. They offer performance up to twice that of com- parably priced alternatives. The process for creating StressedMetal MEMS structures is similar to the deposition techniques used throughout the semi- conductor industry to grow thin film layers-ranging from less than 1 um to tens of micrometers-on substrates. The process uses a tool called a magnetron sputter system to bombard a surface with individual metal atoms. Beneath the bottom layer of atoms is a "sacrificial layer," which anchors the thin film to the substrate. Stripes or cantilevers are etched into the layers of metal atoms to define the shapes of the desired structures. Sections of the sacrificial layer are then dissolved with a chemical etchant, freeing the metal film from the substrate in the places where the sacrificial layer has been dissolved. To create StressedMetal MEMS, scientists change the deposition parame- ters for each