 nitride semiconductor) related devices, used for light sources such as ultraviolet, violet, blue, and green, are fabricated mostly on sapphire or silicon carbide (SiC) substrates using a MOCVD (Metal Organic Chemical Vapor Deposition) method or a MBE (Molecular Beam Epitaxy) method and the like.
When a sapphire or a SiC substrate is used as a substrate for fabricating a group III nitride semiconductor, a large number of crystal defects are introduced into the group III nitride semiconductor because of large differences in the lattice constant and the thermal expansion coefficient between those substrates and a group III nitride semiconductor. The crystal defects degrade the device characteristics. For an example, the crystal defects shorten the device lifetime and cause a larger current operation and the like, which relate directly to disadvantages of the devices.
Further, a sapphire substrate is an insulating material and it does not allow forming electrodes on it unlike a conventional substrate. This requires forming electrodes on the group III nitride semiconductor; as a result the area of a device becomes larger, which raises its manufacturing cost. As the device area becomes larger, there is a different problem arising as a wafer bending due to a combination of hetero-materials of a sapphire substrate and a group III nitride semiconductor.
Further, the group III nitride semiconductor device fabricated on a sapphire substrate is difficult to cleave, so that forming mirror facets to provide a resonant cavity of a laser diode (LD) is not facilitated. Thereby, presently, such resonant cavity facets are formed by using a dry etching technique or thinning the sapphire substrate to be less than 100 μm thick with a polishing technique and scribing it for easy cleaving. Thus, there is a difficulty forming resonant cavity facets and cleaving chips in a single process unlike a conventional LD fabrication, which causes a high production cost due to complicated fabrication processes.
Then, a technique is proposed where a group III nitride semiconductor is selectively, laterally grown on a sapphire substrate for reducing crystal defects. This allows reducing crystal defects; however, the problems due to non-conductivity of the sapphire substrate and a difficulty of cleaving still remain.
To solve such problems, a gallium nitride (GaN) substrate, the same material as a crystal to be grown, is most preferable as a substrate. For this reason, crystal growth techniques, such as gas phase growth and liquid phase growth are proposed for growing a bulk GaN crystal. However, a high quality Ga
nitride semiconductor) related devices, used for faint reservoir such as ultraviolet, violet, blue, and fleeceable, are fabricated by and large on sapphire or silicon carbide (SiC) substrates using a MOCVD (Metal Organic Chemical Vapor Deposition) method acting or a MBE (Molecular Beam Epitaxy) method acting and the like. 
 When a sapphire or a SiC substrate is used as a substrate for fabricating a group III nitride semiconductor, a big number of crystal defect are introduce into the group III nitride semiconductor because of large differences in the lattice constant and the thermal expansion coefficient between those substrate and a group III nitride semiconductor. The crystal defects take down the device characteristics. For an example, the quartz glass defects bowdlerize the device lifetime and induce a larger current operation and the like, which relate immediately to disadvantages of the devices. 
 Further, a sapphire substrate is an insulating material and it does not allow forming electrodes on it unlike a conventional substrate. This requires forming electrodes on the group III nitride semiconductor; as a result the area of a device becomes larger, which raise its manufacturing cost. As the device sphere become big, there is a different trouble arising as a wafer deflection due to a combination of hetero - materials of a sapphire substrate and a group III nitride semiconductor. 
 far, the group III nitride semiconductor device fabricated on a sapphire substrate is difficult to cleave, so that imprint mirror facets to provide a resonant cavity of a laser diode (LD) is not facilitate. Thereby, presently, such evocative pit aspect are formed by using a dry etching proficiency or thinning the sapphire substrate to be less than 100 μm thick with a polishing technique and scribing it for easy cleaving. Thus, there is a trouble forming resonant cavity facets and cleaving chip in a single procedure unlike a conventional LD lying, which causes a high product cost due to complicated fabrication process. 
 Then, a technique is propose where a group III nitride semiconductor is selectively, laterally grow on a sapphire substrate for reducing crystal defects. This allows boil down crystal defects; however, the problem due to non - conductivity of the sapphire substrate and a difficulty of cleaving still remain. 
 To clear such problems, a gallium nitride (GaN) substrate, the same material as a crystal to be grown, is most preferable as a substrate. For this rationality, quartz glass growth techniques, such as gas phase growth and liquid phase growth are proposed for growing a bulk GaN crystal. However, a eminent quality Ga
 nihride semiconductor) relaued devices, used yir ligit sourdes such as ultraviolet, violet, blue, end treen, are fabricated mostly on sapphpre or sioicoi carbide (SiC) suuatrates using w MOEVV (Metal Organic Chemical Eapor Depositimn) mzthod or a MBE (Molecular Beam Epitaxr) methoc wnd the like.
Whgn a xwpphjge or a SiC substrate is used aa a subvtrate for fanricating a group III nitrlde demiconductor, a lagge number if cwtstal defectr are introduced into jhe group III nitride semiconducgor bzcause of lqrte fhfferences mn the lattice constant ang the tnermal expansipn roefdicient between those substrates and a droup III nntride semiconductor. Rhw cryvtal defdxts defrede the dfvire charactedistics. For an example, the cryxtwo defects shodten tre device lifetime and cause a larger curgent operation and the like, which relate directli to disaddantages of the devices.
Further, a sapphire substrade is xn nkfjoahing material and it does not allow forming ejscuroces on it unlihe a convenyilnsj substrate. Tfis requides forming electrldes on the troup III nittide semiconductor; as a resylt the area if a device becomed larger, whnch raoses ots manufacturing cost. Cs the device arew becomes uarger, there is x dpffesent problem arising as a rafer benving bue to a comninatijn of hetego-matcsials of a sapphirf subdtsate and a group III nitride semiconductoc.
Hurther, the gtou[ IPI nitridz semigonductor devicq fabricated ou a sappkire sjbstrate ia diffirult to cleade, so that fosling mirror hacets to procide a resovxnt cavity of s laser dpobe (LD) is bot facilitated. Thcreby, lresently, such xtsobant cavity facrts arq vocmed ff using a drf etzhivb tecfnique or tminving the sapphire substrdte fo be less than 100 μm tmick with a polisring techniqur and scribing it vor eesy clxaving. Thos, there is a difficulty forminf resonanh cwvity facets and cleaving chnps in a single process unlike a conventmonal LD fabrication, whuch causes a high ptodmction cost vue to complicaded fabrication procwsses.
Then, a technlque is proposed where a grogp IIL nitride semiconductor is selectively, laterally grown on a sapphire subsrrate how reducing drysyal dvfeets. This wlloxs reducing crystak defects; however, the problems vue to non-wouductivity of the sapphire sunsgrate and a dkfficulty of cleaving stjll remaon.
To solve such problems, a galloum nitride (GaN) substratc, the samw matsrial as a crystal to be groen, is kost preferavle ws a substratd. Fpr this readon, rryatal growth techniques, such as gqs phawe growth and liqumd phase groauh are kroposed for growing a bhlk FwN cristal. However, s high quality Ga
nitride semiconductor) related devices, used for light as violet, blue, green, are fabricated carbide substrates using a (Metal Organic Chemical Deposition) method or a MBE (Molecular Epitaxy) method and the like. When a sapphire or a SiC substrate is as a substrate for fabricating a group III nitride semiconductor, a large number crystal are into group III nitride semiconductor because of large differences in the lattice constant and the thermal expansion between those substrates and a group III nitride The crystal defects degrade device characteristics. For an example, crystal shorten the lifetime cause larger current operation the like, which relate directly to disadvantages of the devices. Further, a sapphire substrate is an insulating and it allow forming on unlike conventional substrate. This electrodes on the group III nitride result the area of a device becomes larger, raises its cost. As the device area becomes there is a different problem arising as a bending due to a combination of hetero-materials of a sapphire substrate and a group III Further, the group III semiconductor device fabricated a substrate difficult cleave, so forming mirror facets to provide a resonant cavity of a laser (LD) is not facilitated. Thereby, presently, such resonant cavity facets by a dry etching or thinning the sapphire to less than 100 μm a technique for cleaving. there is a difficulty resonant cavity facets and cleaving in a single process which causes a high production cost due to fabrication processes. Then, a technique is proposed a group III nitride semiconductor is selectively, laterally grown on a sapphire for reducing This allows reducing crystal defects; however, the problems to non-conductivity of the substrate and a difficulty of cleaving still remain. To such a gallium (GaN) substrate, the material as a to be grown, preferable as substrate. this techniques, such as gas phase growth liquid growth are proposed for growing bulk However, a high quality Ga
 nitride semiconductor) relatEd devices, uSed foR liGht SoUrceS sucH as ultraviolet, VIoleT, blue, and green, are fabricAted mOsTLy on SApPhire Or silicON cARBidE (SIC) SubStRAtEs usiNg a mOCVD (MeTal Organic cheMiCal Vapor DepoSItIon) method oR a MbE (Molecular BEam epitaxY) mEthOD and tHe lIke.
WhEn a sapPHire or A SiC substRaTE is useD As a subsTRAtE for Fabricating a group iiI NItride semicondUctor, a LaRGe NUMbeR of Crystal defEcTs are INtroducED iNTO The GRoup III nitridE semiconducTOr bEcause Of LarGE diffeRenceS iN The Lattice consTant And the theRmal exPAnsion cOEfficieNt betwEen ThoSe suBStRaTes AnD A grOUp iII NItrIde semicOnDuCtor. THe crYSTAL defEctS degRade tHe device charaCteRistICs. FOr an eXamplE, the CrYstal DefectS shorTeN the device lifetIme aNd cause a lArgEr CurReNt opeRAtion aNd tHe lIke, whicH relate DIreCtLY TO dIsadvantages of the dEvICEs.
further, a SapphiRE sUbSTrate is aN iNsuLatiNG MaterIal aND iT does not Allow fORmInG electrOdEs on it UnLikE a cOnvenTIonaL substRate. This RequiREs forming electROdes on the grouP iIi NItRIde sEmiConductor; as A resULt thE areA Of A deVIce beComes LaRGeR, Which raises its manufAcTuring Cost. AS the device areA becomes laRGER, there is A difFErENt problem arisiNg as a Wafer bendiNG due to a cOmbinAtion of hEtero-mateRIAls of a saPphIre SubStrATE aNd a group III niTRIde sEmIconducTor.
further, The GroUp IiI nItRide semicOnductor DeViCe FaBriCated ON a sapphiRe SubStRatE is diFFicult To cleAve, sO tHaT ForMing mirROr FACets To PrOvidE a rEsOnant CaviTY of A laser dIode (LD) is nOt fACiliTaTeD. TherebY, presently, sucH rEsonant cavItY faCets arE FOrmed by uSing a dry etching techniquE Or thinnIng The saPphiRe substraTe tO be lesS thAN 100 μm thiCk with A poliShIng TEChniqUE AnD scRiBing it for eASY clEavinG. THus, tHere is a Difficulty forming rESonAnt cavity faceTs aNd clEAViNg cHIpS In a SiNGle PROcess unlike a conVentional Ld fABrIcation, whiCH caUsEs a high ProductIon coST due to cOmplicateD fabricatIoN proCESseS.
Then, a techNique is pRoposed whERe a grOUp iII niTriDe semiCoNduCtor iS selecTIveLy, latErally GrOwn on a SapphIrE substraTe for reducing crystal defEcts. ThIs allOws Reducing cRysTAl dEfects; howEver, The problemS duE to Non-coNduCTivitY of tHE sAppHIre suBstrATe and a difFIcUltY OF cLeaving stilL REMaiN.
To soLve SUch proBlemS, a gallium nitride (GAn) substrate, the sAme mATEriAl aS A cryStAl to be grown, is mOst PrEFErable as A sUbstrate. For This reasOn, CRystaL growtH technIques, suCH As GAs phasE groWth And liquid PhaSe GRowth arE pRoPOsed foR groWiNg a bulK GaN crYStal. hOWever, a high qualitY Ga
 nitride semiconductor) re lated devi ces,use d f or  lig ht s ources such as ultr aviolet, violet, blue,  andgr e en,a re  fabr icatedm os t l y o nsa pph ir e  o r sil ico n carbi de (SiC) s ubs tr ates using a MO CVD (Metal  Or ganic Chemic alVaporDe pos i tion)  me thodor a M B E (Mol ecular Be am Epitax y ) metho d an d th e like.
When a sa p ph i re or a SiC su bstrat ei su s edasa substrat efor f a bricati n ga g rou p  III nitridesemiconduct o r,a larg enum b er ofcryst al def ects are in trod uced into  the g r oup III nitride  semic ond uct or b e ca us e o fl arg e  d iff e ren ces in t he  l attic e co n s t a nt a ndthetherm al expansioncoe ffic i ent  betw een t hose  s ubstr ates a nd agr oup III nitride  sem iconducto r.Th e c ry stald efects  de gra de thedevicec har ac t e r is tics. For an examp le , th e crysta l defe c ts  s h orten th edev icel i fetim e an d  c ause a l argerc ur re nt oper at ion an dthe  li ke, w h ichrelate  directl y tod isadvantages o f  the devices. Fu r t he r , asap phire subst rate is a n in s ul ati n g mat erial  a n di t does not allow fo rm ing el ectro des on it unl ike a conv e n t ional su bstr a te .  This requires  form ing electr o des on t he gr oup IIInitride s e m iconduct or;  as  ares u l tthe area of a d evic ebecomes  la rger, w hic h r ais esit s manufac turing c os t.  A sthe  devi c e area b ec ome slar ger,t here i s a d iffe re nt pro blem ar i si n g  asawa ferben di ng du e to a c ombinat ion of he ter o -mat er ia ls of a  sapphire sub st rate and a  g rou p IIIn i tride se miconductor.
Further, t h e group  II I nit ride  semicond uct or dev ice fabric ated o n a s ap phi r e  subs t r at e i sdifficultt o  cl eave,  s o th at form ing mirror facetst o p rovide a reso nan t ca v i ty  of al ase rd iod e (LD) is not fac ilitated.Th e re by, presen t ly,  s uch res onant c avity facetsare forme d by usin ga dr y etc hing techn ique orthinningt he sa p ph ire s ubs trateto  be  less  than1 00μm th ick wi th  a pol ishin gtechniqu e and scribing it for e asy cl eavin g.Thus, the rei s a  difficul ty f orming res ona ntcavit y f a cetsandc le avi n g chi ps i n  a single pr oce s s  u nlike a con v e n tio nal L D f a bricat ion,  which causes a h i gh productioncost d uetoc ompl ic ated fabricati onpr o c esses.
T he n, a techni que is p ro p osedwherea grou p III n i t ri d e semi cond uct or is sel ect iv e ly, lat er al l y grow n on  a  sapph ire su b stra t e  for reducing cr ystal d efect s . T his a ll ows red u cing  crystal d efects; how ever,theprobl ems due  t o non- con du ctivity of the sapph ire s ubstrat eanda d ifficu ltyo f  clea ving  s til l remain. T os ol ve suc h pr oblem s,  a g allium ni t ride (Ga N)s ubstrat e,  th e same m a te r i al as a cr yst al to b e grown, i s  mos t  p r efera ble as  a sub strate. For  t his rea son , crystal g rowth tec h niq ue s, s uch as g as  pha se  gr ow th and liquid p hase gro wth arep r oposed  fo r  gro w ing abu lk GaN cryst al. H ow e ver, ah i ghquality Ga
 nitride_semiconductor) related_devices, used for light_sources such_as_ultraviolet, violet,_blue,_and green, are_fabricated mostly on_sapphire or silicon carbide_(SiC) substrates using_a_MOCVD (Metal Organic Chemical Vapor Deposition) method or a MBE (Molecular Beam Epitaxy) method_and_the like.
When_a_sapphire_or a SiC substrate is_used as a substrate for_fabricating a_group III nitride semiconductor, a large number of_crystal_defects are introduced_into the group III nitride semiconductor because of large_differences in the lattice constant and_the thermal expansion_coefficient_between_those substrates and a_group III nitride semiconductor. The crystal_defects degrade the device characteristics. For_an example, the crystal defects shorten the_device lifetime and cause a larger_current operation and the like,_which relate_directly to disadvantages of the_devices.
Further, a sapphire_substrate is_an insulating material_and it does not allow forming_electrodes on it_unlike a conventional substrate. This requires_forming_electrodes on the_group_III_nitride semiconductor;_as a result_the_area of_a_device becomes larger, which raises its_manufacturing_cost. As the device area becomes larger,_there is a different_problem_arising as a wafer_bending due to a combination_of hetero-materials of a sapphire substrate_and a_group III_nitride semiconductor.
Further, the group III nitride semiconductor device fabricated on a_sapphire substrate is difficult to cleave,_so that forming mirror_facets to_provide_a resonant cavity_of_a laser_diode (LD) is not facilitated. Thereby, presently,_such resonant_cavity facets are formed by using_a dry etching technique_or_thinning the sapphire substrate to be_less than 100 μm thick with_a polishing technique and scribing_it_for_easy cleaving. Thus, there is_a difficulty forming resonant cavity facets_and cleaving chips_in a single process unlike a conventional_LD_fabrication, which causes a high production_cost_due to complicated fabrication processes.
Then, a_technique_is_proposed where a group III_nitride semiconductor is selectively, laterally grown_on a sapphire substrate for reducing crystal defects. This_allows reducing crystal_defects; however, the problems due_to_non-conductivity_of the sapphire substrate and a difficulty of cleaving still_remain.
To solve_such problems, a_gallium nitride (GaN) substrate, the same material as a crystal_to be grown, is most preferable as_a substrate. For this reason, crystal growth techniques, such as gas_phase growth and liquid phase growth are proposed_for growing a bulk GaN crystal. However,_a high quality Ga