Iterambere ryihuse rya SiC kristu imwe ukoresheje CVD-SiC isoko ryinshi hakoreshejwe uburyo bwa sublimation

Gukura Byihuse bya SiC Crystal GukoreshaCVD-SiCInkomoko ikoresheje uburyo bwa Sublimation
Ukoresheje ibisubirwamoCVD-SiCnkisoko ya SiC, kristu ya SiC yakuze neza ku kigero cya 1,46 mm / h hakoreshejwe uburyo bwa PVT. Micropipe ikuze ya kirisiti hamwe nubucucike bwa dislokasiyo byerekana ko nubwo umuvuduko mwinshi witerambere, ubwiza bwa kristu ni bwiza.

Carbide ya Silicon (SiC)ni mugari-mugari wa semiconductor hamwe nibintu byiza cyane byokoreshwa muri voltage nyinshi, imbaraga nyinshi, na frequency nyinshi. Icyifuzo cyacyo cyiyongereye vuba mumyaka yashize, cyane cyane mumashanyarazi ya semiconductor. Kubikoresho bikoresha ingufu za semiconductor, kristu imwe ya SiC ikura mugukwirakwiza isoko ya SiC ifite isuku nyinshi kuri 2100-2500 ° C, hanyuma ikongera igashyirwa kuri kristu yimbuto ikoresheje uburyo bwo gutwara imyuka yumubiri (PVT), hanyuma igakurikiranwa kugirango ibone insimburangingo imwe ya kristu kuri wafer. . Gakondo,Kirisiti ya SiCzikura hakoreshejwe uburyo bwa PVT kumuvuduko wubwiyongere bwa 0.3 kugeza 0.8 mm / h kugirango ugenzure kristu, ibyo bikaba bitinda ugereranije nibindi bikoresho bya kristu imwe ikoreshwa mubikoresho bya semiconductor. Iyo kristu ya SiC ikuze kumuvuduko mwinshi ukoresheje uburyo bwa PVT, kwangirika kwiza harimo gushyiramo karubone, kugabanuka kwera, gukura kwa polyikristaline, gushiraho imipaka yimbuto, no gutandukana hamwe nubusembwa bwa porosity ntabwo byigeze bivaho. Kubera iyo mpamvu, iterambere ryihuse rya SiC ntabwo ryateye imbere, kandi umuvuduko witerambere wa SiC wabaye imbogamizi ikomeye ku musaruro w’ubutaka bwa SiC.

Ku rundi ruhande, raporo ziherutse kwiyongera ku iterambere ryihuse rya SiC zagiye zikoresha uburyo bwo hejuru bw’ubushyuhe bwo mu kirere (HTCVD) aho gukoresha uburyo bwa PVT. Uburyo bwa HTCVD bukoresha imyuka irimo Si na C nkisoko ya SiC mumashanyarazi. HTCVD itarakoreshwa mu bicuruzwa binini bya SiC kandi bisaba ko hakorwa ubushakashatsi n’iterambere mu bucuruzi. Igishimishije, nubwo haba hari umuvuduko mwinshi wa mm3 mm / h, kristu imwe ya SiC irashobora guhingwa hamwe nubwiza bwa kristu ikoresheje uburyo bwa HTCVD. Hagati aho, ibice bya SiC byakoreshejwe mugikorwa cya semiconductor ahantu habi bisaba kugenzura neza cyane. Kubikorwa bya semiconductor progaramu, ∼99.9999% (∼6N) ubuziranenge bwa SiC mubusanzwe butegurwa na CVD kuva methyltrichlorosilane (CH3Cl3Si, MTS). Nubwo, nubwo isuku ryinshi ryibigize CVD-SiC, byajugunywe nyuma yo gukoreshwa. Vuba aha, ibice bya CVD-SiC byajugunywe byafashwe nkisoko ya SiC yo gukura kwa kristu, nubwo inzira zimwe na zimwe zo gukira zirimo guhonyora no kwezwa ziracyasabwa kugira ngo zuzuze ibyifuzo byinshi by’isoko rikura. Muri ubu bushakashatsi, twakoresheje bloks ya CVD-SiC yataye kugirango dusubiremo ibikoresho nkisoko yo gukura kristu ya SiC. Inzitizi za CVD-SiC zo gukura kwa kristu imwe zateguwe nkubunini bugenzurwa nubunini bwajanjaguwe, butandukanye cyane muburyo nubunini ugereranije nifu ya SiC yubucuruzi ikunze gukoreshwa mubikorwa bya PVT, bityo imyitwarire yiterambere rya SiC imwe rukumbi yari iteganijwe kuba igaragara bitandukanye. Mbere yo gukora igerageza rya SiC imwe rukumbi yo gukura, hakozwe amashusho ya mudasobwa kugirango igere ku kigero cyo hejuru cyo gukura, kandi zone yumuriro yashizweho kugirango ikure neza. Nyuma yo gukura kwa kirisiti, kristu yakuze yasuzumwe na tomografiya yambukiranya ibice, micro-Raman spectroscopy, itandukaniro ryinshi rya X-ray, hamwe na synchrotron yera ya X-ray topografiya.
Igishushanyo 1 kirerekana isoko ya CVD-SiC ikoreshwa mugukura kwa PVT ya kristu ya SiC muri ubu bushakashatsi. Nkuko byasobanuwe mu ntangiriro, ibice bya CVD-SiC byashizwe muri MTS na gahunda ya CVD kandi byashizweho kugirango bikoreshe igice cya kabiri binyuze mu gutunganya imashini. N yakuwe mubikorwa bya CVD kugirango igere kuri progaramu ya semiconductor progaramu. Nyuma yo gukoreshwa mubikorwa bya semiconductor, ibice bya CVD-SiC byajanjaguwe kugirango hategurwe isoko yo gukura kwa kirisiti, nkuko bigaragara ku gishushanyo cya 1. Inkomoko ya CVD-SiC yateguwe nkibisahani bifite uburebure buri hagati ya mm 0.5,5 nubunini buringaniye buringaniye bwa 49,75 mm.

Igishushanyo 1: Inkomoko ya CVD-SiC yateguwe na MTS ishingiye kuri CVD.

Ukoresheje isoko ya CVD-SiC yerekanwe ku gishushanyo 1, kristu ya SiC yakuze nuburyo bwa PVT mu itanura rishyushya induction. Kugirango dusuzume ikwirakwizwa ryubushyuhe muri zone yubushyuhe, hakoreshejwe kode yubucuruzi VR-PVT 8.2 (STR, Repubulika ya Seribiya). Imashini hamwe na zone yubushyuhe yagereranijwe nkicyitegererezo cya 2D axisymmetric, nkuko bigaragara ku gishushanyo cya 2, hamwe nicyitegererezo cyayo. Ibikoresho byose byakoreshejwe mu kwigana byerekanwe ku gishushanyo cya 2, kandi imitungo yabyo iri mu mbonerahamwe ya 1. Ukurikije ibisubizo by’ibigereranyo, kristu ya SiC yakuze hakoreshejwe uburyo bwa PVT ku bushyuhe bwa dogere 2250-250 ° C mu kirere cya Ar kuri 35 Torr kumasaha 4. Wafer ya 4 ° off-axis 4H-SiC yakoreshejwe nkimbuto ya SiC. Kirisiti ikuze yasuzumwe na micro-Raman spectroscopy (Witec, UHTS 300, Ubudage) hamwe na XRD ikemurwa cyane (HRXRD, X'Pert-PROMED, ​​PANalytical, Ubuholandi). Imyanda ihumanye muri kristu ya SiC ikuze yasuzumwe hifashishijwe imbaraga za kabiri ion mass spectrometrie (SIMS, Cameca IMS-6f, Ubufaransa). Ubucucike bwa dislocation ya kristu yakuze bwasuzumwe hifashishijwe synchrotron yera ya X-ray topografiya kuri Pohang Light Source.

Igishushanyo 2: Igishushanyo cya zone yubushyuhe hamwe nicyitegererezo cyerekana imikurire ya PVT mumatara ashyushya induction.

Kubera ko uburyo bwa HTCVD na PVT bukura kristu munsi ya gaz-ikomeye iringaniza imbere yo gukura, iterambere ryihuse rya SiC hakoreshejwe uburyo bwa HTCVD ryateje ikibazo cyo gukura byihuse kwa SiC hakoreshejwe uburyo bwa PVT muri ubu bushakashatsi. Uburyo bwa HTCVD bukoresha isoko ya gaze igenzurwa byoroshye, mugihe uburyo bwa PVT bukoresha isoko ikomeye itagenzura neza imigendekere. Igipimo cyo gutembera gitangwa imbere yiterambere muburyo bwa PVT kirashobora kugenzurwa nigipimo cyo kugabanuka kwisoko rikomeye binyuze mukugenzura ubushyuhe, ariko kugenzura neza igabanywa ryubushyuhe muri sisitemu yo gukura ifatika ntabwo byoroshye kubigeraho.
Mu kongera ubushyuhe bwinkomoko muri reaction ya PVT, umuvuduko wubwiyongere bwa SiC urashobora kwiyongera mukongera igipimo cya sublimation yinkomoko. Kugirango ugere kumikurire ihamye, kugenzura ubushyuhe imbere yo gukura ni ngombwa. Kugirango wongere umuvuduko witerambere udashizeho polycristal, ubushyuhe bwo hejuru bugomba kugerwaho imbere yiterambere, nkuko bigaragazwa niterambere rya SiC hakoreshejwe uburyo bwa HTCVD. Ubushyuhe budahagije bwo guhagarikwa inyuma yumutwe bigomba gukwirakwiza ubushyuhe bwakusanyirijwe imbere yo gukura binyuze mumirasire yumuriro kugeza hejuru yikura, bigatuma habaho ubuso burenze urugero, ni ukuvuga gukura kwa polyikristaline.
Byombi kwimura no gusubiramo ibintu muburyo bwa PVT birasa cyane nuburyo bwa HTCVD, nubwo butandukanye mubisoko bya SiC. Ibi bivuze ko iterambere ryihuse rya SiC naryo rishobora kugerwaho mugihe igipimo cya sublimation yinkomoko ya SiC kiri hejuru bihagije. Ariko, kugera kuri sisitemu yo mu rwego rwohejuru ya SiC imwe murwego rwo hejuru rwo gukura hakoreshejwe uburyo bwa PVT ifite ibibazo byinshi. Ifu yubucuruzi mubisanzwe irimo uruvange ruto kandi runini. Bitewe ningufu zinyuranye zitandukanijwe, uduce duto dufite ubunini bwikigereranyo cyinshi kandi bugabanuka mbere yingingo nini, biganisha kumyanda ihumanye mugihe cyambere cyo gukura kwa kristu. Byongeye kandi, nkuko SiC ikomeye ibora mubwoko bwumwuka nka C na Si, SiC2 na Si2C mubushyuhe bwinshi, C ikomeye byanze bikunze iyo isoko ya SiC igabanutse muburyo bwa PVT. Niba ifumbire ikomeye C ari ntoya kandi yoroheje bihagije, mugihe cyikura ryihuse, uduce duto twa C, tuzwi nka "umukungugu wa C," urashobora kujyanwa hejuru ya kirisiti hamwe no kwimura abantu benshi, bikavamo kwinjiza muri kristu ikuze. Kubwibyo, kugirango ugabanye umwanda wibyuma n ivumbi rya C, ingano yinkomoko ya SiC igomba kugenzurwa muri diameter ya munsi ya 200 mkm, kandi umuvuduko wubwiyongere ntugomba kurenga .4 0.4 mm / h kugirango ukomeze kwimuka buhoro kandi usibye kureremba hejuru Umukungugu. Umwanda wibyuma hamwe n ivumbi rya C biganisha ku kwangirika kwa kristu ya SiC ikuze, nizo mbogamizi nyamukuru zibangamira iterambere ryihuse rya SiC hakoreshejwe uburyo bwa PVT.
Muri ubu bushakashatsi, inkomoko ya CVD-SiC yajanjaguwe idafite uduce duto twakoreshejwe, ikuraho umukungugu C ureremba hejuru yimurwa ryinshi. Niyo mpamvu, imiterere yubushyuhe bwa zone yashizweho hifashishijwe uburyo bwa PVT bwo kwigana bushingiye ku buryo bwa PVT kugirango bugere ku iterambere ryihuse rya SiC, kandi ikwirakwizwa ry’ubushyuhe ryagereranijwe hamwe n’ubushyuhe bwerekanwe ku gishushanyo cya 3a.

Igishushanyo 3: (a) Ikwirakwizwa ryubushyuhe hamwe nubushyuhe buringaniye hafi yo gukura imbere ya reaction ya PVT yabonetse kubisesengura ryibintu bitagira ingano, na (b) gukwirakwiza ubushyuhe buhagaze kumurongo wa axisymmetric.
Ugereranije nubushyuhe busanzwe bwa zone yubushyuhe bwo gukura kristu ya SiC kumuvuduko wubwiyongere bwa 0.3 kugeza 0.8 mm / h munsi yubushyuhe buke buri munsi ya 1 ° C / mm, igenamiterere rya zone yubushyuhe muri ubu bushakashatsi rifite ubushyuhe buringaniye bwa ∼ 3.8 ° C / mm ku bushyuhe bwo gukura bwa 682268 ° C. Agaciro gahoro gahoro muri ubu bushakashatsi kagereranywa nubwiyongere bwihuse bwa SiC ku kigero cya 2,4 mm / h ukoresheje uburyo bwa HTCVD, aho ubushyuhe bwashyizwe kuri ∼14 ° C / mm. Duhereye ku gukwirakwiza ubushyuhe bwa vertical bwerekanwe ku gishushanyo cya 3b, twemeje ko nta gipimo cy’ubushyuhe gishobora gukora polyikristal cyari gihari hafi y’ikura, nkuko byasobanuwe mu bitabo.
Ukoresheje sisitemu ya PVT, kristu ya SiC yakuwe mu isoko ya CVD-SiC mu gihe cy'amasaha 4, nkuko bigaragara ku gishushanyo cya 2 n'icya 3.Iterambere rya SiC rihagarariye riva muri SiC ryakuze ryerekanwa ku gishushanyo cya 4a. Umubyimba nubwiyongere bwa kirisiti ya SiC igaragara ku gishushanyo cya 4a ni mm 5.84 na mm 1,46 mm / h. Hakozwe iperereza ku nkomoko ya SiC ku bwiza, polytype, morphologie, n’ubuziranenge bwa kirisiti ya SiC ikuze igaragara ku gishushanyo cya 4a, nkuko bigaragara ku gishushanyo cya 4b-e. Ishusho ya tomografiya yambukiranya ishusho ya 4b yerekana ko imikurire ya kristu yari imeze nka convex bitewe nuburyo bwo gukura budasanzwe. Nyamara, micro-Raman spectroscopi ku gishushanyo cya 4c yerekanaga kristu ikuze nkicyiciro kimwe cya 4H-SiC nta polytype irimo. Agaciro ka FWHM k'impinga (0004) yakuwe mu isesengura rya X-ray yo gutondeka umurongo yari 18.9 arcseconds, nayo yemeza ubuziranenge bwa kristu.

Igicapo ca 4: e) Imiterere ya X-ray.

Igicapo ca 4e cerekana urumuri rwera X-ray topografiya yerekana ibishushanyo hamwe nuduce twudodo muri wafer isennye ya kristu ikuze. Ubucucike bwa dislokisiyo ya kristu yakuze yapimwe ko ∼3000 ea / cm², hejuru gato ugereranije n'ubucucike bwa disiketi y'imbuto ya kirisiti, yari ∼2000 ea / cm². Ikirahure cyakuze cyemejwe ko gifite ubucucike buke bwa dislokisiyo, ugereranije nubwiza bwa kristu bwa wafer yubucuruzi. Igishimishije, gukura byihuse bya kristu ya SiC byagezweho hakoreshejwe uburyo bwa PVT hamwe na CVD-SiC yajanjaguwe munsi yubushyuhe bunini. Ubushuhe bwa B, Al, na N muri kristu yakuze yari 2.18 × 10¹⁶, 7.61 × 10¹⁵, na 1.98 × 10¹⁹ atom / cm³. Ubwinshi bwa P muri kristu yakuze yari munsi yurugero rwo kumenya (<1.0 × 10¹⁴ atom / cm³). Imyanda yanduye yari mike bihagije kubatwara ibicuruzwa, usibye N, yapimwe nkana mugihe cya CVD.
Nubwo iterambere rya kristu muri ubu bushakashatsi ryabaye rito urebye ibicuruzwa byubucuruzi, kwerekana neza iterambere ryihuse rya SiC hamwe nubwiza bwa kirisiti ukoresheje isoko ya CVD-SiC binyuze muburyo bwa PVT bifite ingaruka zikomeye. Kubera ko isoko ya CVD-SiC, nubwo ifite imitungo myiza, irushanwa-igiciro cyo gutunganya ibikoresho byajugunywe, turateganya ko bizakoreshwa cyane nkisoko ya SiC itanga icyizere cyo gusimbuza ifu ya SiC. Gukoresha CVD-SiC inkomoko yo gukura byihuse kwa SiC, harasabwa gukwirakwiza ubushyuhe muri sisitemu ya PVT, bitanga ibindi bibazo kubushakashatsi buzaza.

Umwanzuro
Muri ubu bushakashatsi, kwerekana neza iterambere rya SiC ryihuta ryihuse hifashishijwe amashanyarazi ya CVD-SiC yajanjaguwe mu gihe cy'ubushyuhe bwo hejuru bukabije binyuze mu buryo bwa PVT byagezweho. Igishimishije, ubwiyongere bwihuse bwa kristu ya SiC bwagaragaye mugusimbuza isoko ya SiC nuburyo bwa PVT. Ubu buryo buteganijwe kuzamura cyane umusaruro munini wa sisitemu ya SiC imwe ya kristu, amaherezo bikagabanya igiciro cyibice bya SiC substrate no guteza imbere ikoreshwa ryinshi ryibikoresho byamashanyarazi.