1. Imashini zikora imiyoboro y'amashanyarazi zo mu gisekuru cya gatatu
Ikoranabuhanga rya semiconductor ryo mu gihe cya mbere ryakozwe hashingiwe ku bikoresho bya semiconductor nka Si na Ge. Ni ryo shingiro ry'ibikoresho byo guteza imbere transistors n'ikoranabuhanga rya circuit integrated. Ibikoresho bya semiconductor byo mu gihe cya mbere byashinze urufatiro rw'inganda z'ikoranabuhanga mu kinyejana cya 20 kandi ni byo bikoresho by'ibanze by'ikoranabuhanga rya circuit integrated.
Ibikoresho bya semiconductor byo mu gisekuru cya kabiri birimo gallium arsenide, indium phosphide, gallium phosphide, indium arsenide, aluminiyumu arsenide n'ibindi bikoresho byayo bya ternary. Ibikoresho bya semiconductor byo mu gisekuru cya kabiri ni byo shingiro ry'inganda z'amakuru ajyanye na optoelectronic. Ni muri urwo rwego, inganda zifitanye isano nka amatara, ecran, laser, na photovoltaics zarakozwe. Bikoreshwa cyane mu ikoranabuhanga rya none ry'amakuru n'inganda zerekana optoelectronic.
Ibikoresho by’ingenzi by’ibikoresho bya semiconductor byo mu gisekuru cya gatatu birimo gallium nitride na silicon carbide. Bitewe n’aho biherereye cyane, umuvuduko mwinshi wa electron saturation, ubwiyongere bw’ubushyuhe, n’imbaraga nyinshi zo kugabanya ingufu, ni ibikoresho byiza cyane byo gutegura ibikoresho by’ikoranabuhanga bifite imbaraga nyinshi, frequency nyinshi, n’ibitakaza bike. Muri byo, ibikoresho by’amashanyarazi bya silicon carbide bifite inyungu zo kuba bifite ingufu nyinshi, ingufu nke, n’ingano nto, kandi bifite amahirwe menshi yo gukoreshwa mu modoka nshya zikoresha ingufu, photovoltaics, ubwikorezi bwa gari ya moshi, amakuru menshi, n’ibindi. Ibikoresho bya Gallium nitride RF bifite inyungu zo kuba bifite frequency nyinshi, imbaraga nyinshi, bandwidth nini, ingufu nke n’ingano nto, kandi bifite amahirwe menshi yo gukoreshwa mu itumanaho rya 5G, interineti y’ibintu, radar ya gisirikare n’ibindi. Byongeye kandi, ibikoresho by’amashanyarazi bishingiye kuri gallium nitride byakoreshejwe cyane mu ishami rifite voltage nke. Byongeye kandi, mu myaka ya vuba aha, ibikoresho bishya bya gallium oxide byitezweho gukora ubwuzuzanye bwa tekiniki n’ikoranabuhanga risanzwe rya SiC na GaN, kandi bifite amahirwe menshi yo gukoreshwa mu ishami rifite voltage nke n’iry’amashanyarazi menshi.
Ugereranyije n'ibikoresho bya semiconductor byo mu gisekuru cya kabiri, ibikoresho bya semiconductor byo mu gisekuru cya gatatu bifite ubugari bwa bandgap bunini (ubugari bwa bandgap bwa Si, ibikoresho bisanzwe by'ibikoresho bya semiconductor byo mu gisekuru cya mbere, ni hafi 1.1eV, ubugari bwa bandgap bwa GaAs, ibikoresho bisanzwe by'ibikoresho bya semiconductor byo mu gisekuru cya kabiri, ni hafi 1.42eV, naho ubugari bwa bandgap bwa GaN, ibikoresho bisanzwe by'ibikoresho bya semiconductor byo mu gisekuru cya gatatu, buri hejuru ya 2.3eV), ubudahangarwa bukomeye bw'imirasire, ubudahangarwa bukomeye ku ngufu z'amashanyarazi, kandi ubudahangarwa buri hejuru y'ubushyuhe. Ibikoresho bya semiconductor byo mu gisekuru cya gatatu bifite ubugari bwa bandgap bunini birakwiriye cyane mu gukora ibikoresho bya elegitoroniki birwanya imirasire, bikoresha frequency nyinshi, ingufu nyinshi kandi bifite ubucucike bwinshi. Imikoreshereze yabyo mu bikoresho bya radiyo ya microwave, LED, laser, ibikoresho by'amashanyarazi n'ibindi byakuruye abantu benshi, kandi byagaragaje amahirwe menshi yo gutera imbere mu itumanaho rigendanwa, imiyoboro y'ikoranabuhanga, inzira za gari ya moshi, imodoka nshya zikoresha ingufu, ibikoresho by'ikoranabuhanga bikoreshwa n'abaguzi, n'ibikoresho by'urumuri rwa ultraviolet n'ubururu-icyatsi [1].
Ifoto yavuye: CASA, Ikigo cy’Ubushakashatsi ku Mpapuro z’Ubwishingizi za Zheshang
Igishushanyo cya 1 Igipimo cy'igihe cy'igikoresho cy'amashanyarazi cya GaN n'iteganyagihe
Imiterere n'imiterere y'ibikoresho bya II GaN
GaN ni semiconductor ya bandgap itaziguye. Ubugari bwa bandgap bw'imiterere ya wurtzite ku bushyuhe bw'icyumba ni hafi 3.26eV. Ibikoresho bya GaN bifite imiterere itatu y'ingenzi ya kristu, ari yo imiterere ya wurtzite, imiterere ya sphalerite n'imiterere y'umunyu w'amabuye. Muri byo, imiterere ya wurtzite ni yo imiterere ihamye ya kristu. Ishusho ya 2 ni igishushanyo cy'imiterere ya wurtzite ya hexagonal ya GaN. Imiterere ya wurtzite y'ibikoresho bya GaN igizwe n'imiterere ya hexagonal ifatanye. Buri karemangingo gafite atome 12, harimo atome 6 za N na atome 6 za Ga. Buri atome ya Ga (N) ihuza atome 4 za N (Ga) zegereye kandi ishyirwa hamwe mu buryo bwa ABABAB… mu cyerekezo [0001] [2].
Ishusho ya 2 Imiterere ya Wurtzite Ishusho y'akaremangingo ka GaN gakirisitu
III Ikoreshwa cyane mu gutera GaN epitaxy
Bigaragara ko epitaxy ihuye ku bice bya GaN ari yo mahitamo meza kuri epitaxy ya GaN. Ariko, bitewe n'ingufu nyinshi za GaN, iyo ubushyuhe bugeze ku rugero rwo gushonga rwa 2500℃, igitutu cyayo cyo kubora kiba kingana na 4.5GPa. Iyo igitutu cyo kubora kiri hasi ugereranije n'uyu gitutu, GaN ntishonga ahubwo irabora mu buryo butaziguye. Ibi bituma ikoranabuhanga ryo gutegura ibice byakuze nka Czochralski ritabereye mu gutegura ibice bya GaN bya kristale imwe, bigatuma ibice bya GaN bigorana kubitunganya kandi bihenze. Kubwibyo, ibice bikunze gukoreshwa mu gukura kwa GaN epitaxial ahanini ni Si, SiC, safiro, nibindi [3].
Imbonerahamwe ya 3 GaN n'ibipimo by'ibikoresho bisanzwe bikoreshwa mu buryo bwa substrate
GaN epitaxy kuri safiro
Safiro ifite imiterere ihamye ya shimi, irahendutse, kandi ifite ubushobozi bwo gukora ibintu byinshi. Kubwibyo, yabaye imwe mu bikoresho bya substrate bya kera kandi bikoreshwa cyane mu buhanga bw'ibikoresho bya semiconductor. Nk'imwe mu substrate zikoreshwa cyane muri GaN epitaxy, ibibazo by'ingenzi bigomba gukemurwa kuri substrate za safiro ni:
✔ Bitewe n'uko urukuta runini rudahuye hagati ya safiro (Al2O3) na GaN (hafi 15%), ubucucike bw'inenge ku gice kiri hagati y'urwego rwa epitaxial n'urwego rw'ubutaka ni bwinshi cyane. Kugira ngo bigabanye ingaruka mbi zabyo, urwo rufatiro rugomba gukorerwa isuzuma rikomeye mbere yuko inzira ya epitaxial itangira. Mbere yo guhinga epitaxial ya GaN ku butaka bwa safiro, ubuso bwa substrate bugomba kubanza gusukurwa neza kugira ngo haveho umwanda, ibyangiritse bisigaye byo gusiga, nibindi, kandi hagakorwa imiterere y'intambwe n'intambwe. Hanyuma, ubuso bwa substrate bushyirwamo nitride kugira ngo hahindurwe imiterere yo kunywesha kw'urwego rwa epitaxial. Amaherezo, urwego rworoshye rwa AlN buffer (ubusanzwe rufite ubunini bwa 10-100nm) rugomba gushyirwa ku buso bwa substrate hanyuma rugashyirwa ku bushyuhe buke kugira ngo bitegure gukura kwa nyuma kwa epitaxial. Nubwo bimeze bityo ariko, ubucucike bw’impinduka mu mafilime ya GaN epitaxial yahinzwe ku duce twa safiro buracyari hejuru ugereranyije n’ubw’amafilime ya homoepitaxial (hafi 1010cm-2, ugereranije n’ubucucike bwa zero mu mafilime ya silicon homoepitaxial cyangwa gallium arsenide homoepitaxial, cyangwa hagati ya 102 na 104cm-2). Ubucucike bwinshi bw’impinduka bugabanya kugenda kw’impinduka, bityo bigabanya igihe cyo kubaho cy’impinduka kandi bikagabanya imikorere y’ubushyuhe, byose bizagabanya imikorere y’igikoresho [4];
✔ Ingano y'ubushyuhe ya safiro iruta iya GaN, bityo imbaraga zo gukandagira hagati y'ibice bibiri zizavuka mu gice cya epitaxial mu gihe cyo gukonja kuva ku bushyuhe bwo gushyiramo kugeza ku bushyuhe bw'icyumba. Ku bice bikomeye bya epitaxial, iyi ntege nke ishobora gutera gucika kwa filimi cyangwa substrate;
✔ Ugereranyije n'izindi substrates, ubushobozi bwo gutwara ubushyuhe bwa substrates za safiro buri hasi (hafi 0.25W*cm-1*K-1 kuri 100℃), kandi imikorere yo gukwirakwiza ubushyuhe ni mibi;
✔ Bitewe n'uko idakora neza, ibikoresho bya safiro ntibifasha mu guhuza no gukoresha ibindi bikoresho bya semiconductor.
Nubwo ubucucike bw'ibice bya GaN epitaxial byatewe ku byuma bya safiro buri hejuru, bisa nkaho bitagabanya cyane imikorere ya optoelectronic ya GaN-based blue-green LEDs, bityo rero vitesi za safiro ziracyakoreshwa cyane kuri vitesi za LEDs-based GaN.
Bitewe n’iterambere ry’ikoreshwa rishya ry’ibikoresho bya GaN nka lazeri cyangwa ibindi bikoresho by’ingufu nyinshi, inenge zikomoka ku bikoresho bya safiro zarushijeho kuba imbogamizi ku ikoreshwa ryabyo. Byongeye kandi, hamwe n’iterambere ry’ikoranabuhanga ryo gukura kwa SiC substrate, kugabanuka kw’ikiguzi no gukura kw’ikoranabuhanga rya GaN epitaxial ku bikoresho bya Si, ubushakashatsi bwinshi ku gutera urwego rwa GaN epitaxial ku bikoresho bya safiro bwagaragaje buhoro buhoro koroherwa.
GaN epitaxy kuri SiC
Ugereranije na safiro, uduce twa SiC (4H- na 6H-crystals) dufite ubudasa buto n’uduce twa GaN epitaxial (3.1%, bingana na [0001] oriented epitaxial films), ubwiyongere bw’ubushyuhe (hafi 3.8W*cm-1*K-1), nibindi. Byongeye kandi, ubwiyongere bw’uduce twa SiC butuma habaho amashanyarazi inyuma y’uduce twa substrate, bifasha koroshya imiterere y’igikoresho. Kuba hari izi nyungu byakuruye abashakashatsi benshi gukora kuri GaN epitaxy kuri silicon carbide substrates.
Ariko, gukora ku buryo butaziguye ku duce twa SiC kugira ngo wirinde kororoka uduce twa GaN epilayers nabyo bihura n'ingaruka mbi zitandukanye, harimo izi zikurikira:
✔ Ubukana bw'ubuso bw'ibice bya SiC buri hejuru cyane ugereranyije n'ubw'ibice bya safiro (ubukana bwa safiro 0.1nm RMS, ubukana bwa SiC 1nm RMS), ibice bya SiC bifite ubukana bwinshi n'imikorere mibi yo kubitunganya, kandi ubukana n'ubukana bw'ibice byangiritse nabyo ni bimwe mu bitera inenge mu bice bya GaN epilayers.
✔ Ubucucike bw'imigozi ya SiC substrates buri hejuru (ubucucike bw'imigozi 103-104cm-2), imigozi ishobora gukwirakwira mu gice cya GaN epilayer no kugabanya imikorere y'igikoresho;
✔ Imiterere ya atome ku buso bwa substrate ituma habaho amakosa yo gukusanya (BSFs) muri epilayer ya GaN. Kuri epitaxial GaN kuri substrates za SiC, hari uburyo bwinshi bushoboka bwo gukusanya atome kuri substrate, bigatuma habaho uburyo buhindagurika bwo gukusanya atome bwa epitaxial GaN kuri yo, bushobora gutera amakosa yo gukusanya. Ibibazo byo gukusanya (SFs) byongera amashanyarazi yubatswe ku murongo wa c, bigatera ibibazo nko gusohoka kw'ibikoresho byo gutandukanya indege;
✔ Ingano y'ubushyuhe bwa SiC substrate ni ntoya ugereranyije n'iya AlN na GaN, ibyo bigatuma ubushyuhe bwiyongera hagati y'urwego rwa epitaxial na substrate mu gihe cyo gukonjesha. Waltereit na Brand bashingiye ku byavuye mu bushakashatsi bwabo, bahanuye ko iki kibazo gishobora kugabanuka cyangwa gukemurwa no gukura uturemangingo twa GaN epitaxial ku duce tworoheje kandi dufatanye twa AlN nucleation;
✔ Ikibazo cy’uko atome za Ga zidashobora kumena neza. Iyo urimo gukura imiterere y’uturemangingo twa GaN epitaxial ku buso bwa SiC, bitewe n’uko atome zombi zidashobora kumena neza, GaN ikunze kumera ku buso bwa 3D. Gushyiraho urwego rw’ubuhumekero ni cyo gisubizo gikoreshwa cyane mu kunoza ubwiza bw’ibikoresho bya epitaxial muri epitaxy ya GaN. Gushyiraho urwego rw’ubuhumekero rwa AlN cyangwa AlxGa1-xN bishobora kunoza neza uburyo ubuso bwa SiC bushobora kumena neza kandi bigatuma urwego rw’ubuhumekero rwa GaN epitaxial rukura mu buryo bubiri. Byongeye kandi, bishobora kandi kugenzura stress no gukumira ko inenge za substrate zigera kuri epitaxy ya GaN;
✔ Ikoranabuhanga ryo gutegura substrate za SiC ntirimaze igihe kinini, ikiguzi cya substrate kiri hejuru, kandi hari abatanga ibikoresho bake kandi hari ababitanga bake.
Ubushakashatsi bwa Torres n'abandi bwerekana ko gukata substrate ya SiC na H2 ku bushyuhe bwinshi (1600°C) mbere ya epitaxy bishobora gutanga imiterere ihamye ku buso bwa substrate, bityo bikabona filime ya epitaxial ya AlN nziza kurusha iyo ikuze neza ku buso bwa substrate bwa mbere. Ubushakashatsi bwa Xie n'ikipe ye bwerekana kandi ko gukata substrate ya silicon carbide mbere yo kuyikata bishobora kunoza cyane imiterere y'ubuso n'ubwiza bwa kristale y'urwego rwa GaN epitaxial. Smith n'abandi basanze gukata insinga bikomoka ku rwego rwa substrate/buffer hamwe n'urwego rwa buffer/epitaxial bifitanye isano n'ubugari bwa substrate [5].
Ishusho ya 4 Imiterere ya TEM y'ibipimo bya GaN epitaxial layer byatewe kuri substrate ya 6H-SiC (0001) mu buryo butandukanye bwo gutunganya ubuso (a) gusukura imiti; (b) gusukura imiti + kuvurwa hifashishijwe plasma ya hydrogen; (c) gusukurwa hifashishijwe chemical + kuvurwa hifashishijwe hydrogène + kuvurwa hifashishijwe ubushyuhe bwa hydrogène mu gihe cy'iminota 30
GaN epitaxy kuri Si
Ugereranyije na karubide ya silikoni, safiro n'izindi substrate, uburyo bwo gutegura substrate ya silikoni bumaze gukura, kandi bushobora gutanga substrate nini zikuze kandi zihenze cyane. Muri icyo gihe, uburyo bwo gutwara ubushyuhe n'amashanyarazi ni byiza, kandi uburyo bwo gukoresha ibikoresho bya elegitoroniki bya Si bumaze gukura. Uburyo bwo guhuza neza ibikoresho bya optoelectronic GaN n'ibikoresho bya elegitoroniki bya Si mu gihe kizaza nabyo bituma iterambere rya GaN epitaxy kuri silikoni rikurura cyane.
Ariko, bitewe n'itandukaniro rinini mu miterere ya lattice hagati ya substrate ya Si n'ibikoresho bya GaN, epitaxy itandukanye ya GaN kuri substrate ya Si ni epitaxy nini idahuye, kandi igomba no guhura n'ibibazo byinshi:
✔ Ikibazo cy'ingufu zo guhuza ubuso. Iyo GaN ikuriye kuri substrate ya Si, ubuso bwa substrate ya Si buzabanza guhindurwamo nitride kugira ngo habeho urwego rwa silicon nitride rudafite ireme rudatuma GaN ikura kandi idatera imbere mu miterere yayo. Byongeye kandi, ubuso bwa Si buzabanza gukora kuri Ga, bugahindura ubuso bwa substrate ya Si. Iyo ubushyuhe bwinshi bukabije, kubora k'ubuso bwa Si kuzakwirakwira mu urwego rwa GaN epitaxial kugira ngo habeho utudomo twa silicon twirabura.
✔ Ubudasa buhoraho hagati ya GaN na Si ni bunini (~17%), bizatuma habaho kwimuka kw'imigozi ifite ubucucike bwinshi kandi bigabanye cyane ubwiza bw'urwego rwa epitaxial;
✔ Ugereranyije na Si, GaN ifite igipimo cyo kwaguka k'ubushyuhe kinini (igipimo cyo kwaguka k'ubushyuhe bwa GaN ni hafi 5.6 × 10-6K-1, igipimo cyo kwaguka k'ubushyuhe bwa Si ni hafi 2.6 × 10-6K-1), kandi imiyoboro ishobora kuvuka mu gice cya GaN epitaxial mu gihe ubushyuhe bwa epitaxial bukonjeshwa n'ubushyuhe bw'icyumba;
✔ Si ikorana na NH3 ku bushyuhe bwinshi ikarema SiNx ya polycrystalline. AlN ntishobora gukora nucleus ishingiye ku buryo bwihariye kuri SiNx ya polycrystalline, bigatuma urwego rwa GaN rwakuze rudakora neza ndetse hakavuka ubusembwa bwinshi, bigatuma urwego rwa GaN epitaxial rwa GaN rugira ubuziranenge bubi, ndetse bikagorana no gukora urwego rumwe rwa GaN epitaxial [6].
Kugira ngo bakemure ikibazo cy’uko hari itandukaniro rinini hagati y’urutare, abashakashatsi bagerageje kwinjiza ibikoresho nka AlAs, GaAs, AlN, GaN, ZnO, na SiC nk’ibice by’ubutabazi ku bice bya Si. Kugira ngo hirindwe ikorwa rya SiNx ya polycrystalline no kugabanya ingaruka mbi zayo ku bwiza bwa kristale y’ibikoresho bya GaN/AlN/Si (111), TAl ikunze kuba ikenewe gushyirwaho igihe runaka mbere y’uko epitaxial ikura y’urwego rwa AlN buffer kugira ngo hirindwe ko NH3 yakwitwara n’ubuso bwa Si bwagaragaye kugira ngo hakorwe SiNx. Byongeye kandi, ikoranabuhanga rya epitaxial nk’ikoranabuhanga rya substrate rishobora gukoreshwa mu kunoza ubwiza bw’urwego rwa epitaxial. Iterambere ry’ubu buryo rifasha kubuza ikorwa rya SiNx ku gice cya epitaxial, guteza imbere ikura ry’urwego rwa GaN epitaxial, no kunoza ubwiza bw’urwego rwa epitaxial. Byongeye kandi, urwego rwa AlN buffer rushyirwaho kugira ngo rutunganye stress yo gukurura iterwa n’itandukaniro ry’ibipimo by’ubushyuhe kugira ngo hirindwe ko hacikamo ibice mu gice cya GaN epitaxial ku gice cya silikoni. Ubushakashatsi bwa Krost bwerekana ko hari isano nziza hagati y'ubugari bw'urwego rwa AlN buffer no kugabanuka k'uburemere. Iyo ubugari bw'urwego rwa buffer bugeze kuri 12nm, urwego rwa epitaxial rufite ubunini burenze 6μm rushobora guhingwa ku gice cya silikoni binyuze mu buryo bukwiye bwo gukura nta ruhushya rwa epitaxial rucitse.
Nyuma y’ingamba z’igihe kirekire zakozwe n’abashakashatsi, ubwiza bw’ibice bya GaN epitaxial byatewe ku byuma bya silikoni bwarushijeho kunozwa cyane, kandi ibikoresho nka transistors za field effect, Schottky barrier ultraviolet detectors, LEDs z’ubururu n’icyatsi kibisi na ultraviolet lasers byateye imbere cyane.
Muri make, kubera ko uduce dusanzwe dukoreshwa na GaN epitaxial twese ari utundi duce dutandukanye twa epitaxial, twose duhura n'ibibazo bisanzwe nko kudahuza neza kw'utugega n'itandukaniro rinini mu mibare y'ubushyuhe ku rugero rutandukanye. Uduce duto twa epitaxial GaN duhuza imiterere y'ubushyuhe turagabanywa n'ikoranabuhanga rigezweho, kandi uduce duto ntabwo turakorwa ku bwinshi. Igiciro cyo gukora ni kinini, ingano ya substrate ni nto, kandi ubwiza bwa substrate ntabwo ari bwiza. Iterambere rya substrate nshya za GaN epitaxial no kunoza ubwiza bwa epitaxial biracyari kimwe mu bintu by'ingenzi bibangamira iterambere ry'inganda za GaN epitaxial.
IV. Uburyo busanzwe bwo kuvura GaN epitaxy
MOCVD (gushyira umwuka w'ibinyabutabire mu kirere)
Bigaragara ko epitaxy ihuye ku bice bya GaN ari yo mahitamo meza kuri epitaxy ya GaN. Ariko, kubera ko ibintu byabanjirije ubushyuhe bwa chemical ari trimethylgallium na ammonia, naho gaze itwara ikaba ari hydrogen, ubushyuhe busanzwe bwa MOCVD bungana na 1000-1100℃, kandi igipimo cyo gukura cya MOCVD ni hafi mikoroni nke ku isaha. Ishobora gukora ahantu hahanamye ku rwego rwa atome, ibi bikaba bikwiriye cyane mu gukura heterojunctions, quantum wells, superlattices n'izindi nyubako. Igipimo cyayo cyo gukura vuba, uburinganire bwiza, no kuba ikwiriye gukura ahantu hanini no mu bice byinshi akenshi bikoreshwa mu nganda.
MBE (molecular beam epitaxy)
Muri epitaxy y’imirasire y’urumuri, Ga ikoresha isoko y’ibintu, kandi azote ikora iboneka muri azote binyuze muri plasma ya RF. Ugereranyije n’uburyo bwa MOCVD, ubushyuhe bwo gukura bwa MBE buri hagati ya 350-400℃. Ubushyuhe bwo gukura buri hasi bushobora kwirinda umwanda ushobora guterwa n’ubushyuhe bwinshi. Sisitemu ya MBE ikora munsi y’ingufu nyinshi, ituma ihuza uburyo bwinshi bwo kumenya aho iri. Muri icyo gihe, igipimo cyo gukura kwayo n’ubushobozi bwayo bwo kuyikora ntibishobora kugereranywa na MOCVD, kandi ikoreshwa cyane mu bushakashatsi bwa siyansi [7].
Igishushanyo 5 (a) Igishushanyo cya Eiko-MBE (b) MBE nyamukuru reaction yicyumba
Uburyo bwa HVPE (hydride vapor phase epitaxy)
Inzira zabanjirije uburyo bwa epitaxy bwa hydride vapor phase ni GaCl3 na NH3. Detchprohm n'abandi bakoresheje ubu buryo kugira ngo bakure urwego rwa GaN epitaxial rufite ubugari bwa mikoroni amagana ku buso bwa substrate ya safiro. Mu igerageza ryabo, urwego rwa ZnO rwatewe hagati ya substrate ya safiro n'urwego rwa epitaxial nk'urwego rw'ubutabazi, maze urwego rwa epitaxial rugakurwa ku buso bwa substrate. Ugereranyije na MOCVD na MBE, ikintu nyamukuru kiranga uburyo bwa HVPE ni uko bufite umuvuduko wo gukura mwinshi, ukwiriye gukorwamo urwego runini n'ibikoresho byinshi. Ariko, iyo ubunini bw'urwego rwa epitaxial burenze 20μm, urwego rwa epitaxial rukorwa n'ubu buryo rushobora kwangirika.
Akira USUI yashyizeho ikoranabuhanga rya substrate rifite imiterere ishingiye kuri ubu buryo. Babanje gukura urwego rworoshye rwa GaN epitaxial rufite ubugari bwa 1-1.5μm ku gice cya safiro bakoresheje uburyo bwa MOCVD. Igice cya epitaxial cyari kigizwe n'urwego rwa GaN buffer rufite ubugari bwa 20nm rwakuriye mu bushyuhe buke n'urwego rwa GaN rwakuriye mu bushyuhe bwinshi. Hanyuma, kuri 430℃, urwego rwa SiO2 rwashyizwe ku buso bw'urwego rwa epitaxial, maze imirongo y'amadirishya ikorwa kuri filime ya SiO2 hakoreshejwe photolithography. Intera y'imirongo yari 7μm kandi ubugari bwa mask bwari kuva kuri 1μm kugeza kuri 4μm. Nyuma y'iri terambere, babonye urwego rwa GaN epitaxial ku gice cya safiro gifite umurambararo wa santimetero 2 cyari kidafite icyuho kandi cyoroshye nk'indorerwamo nubwo ubunini bwazamutse bukagera kuri mikoroni icumi cyangwa amagana. Ubucucike bw'inenge bwagabanutse kuva kuri 109-1010cm-2 by'uburyo bwa HVPE busanzwe bugera kuri 6×107cm-2. Nanone bagaragaje mu igerageza ko iyo igipimo cyo gukura kirenze 75μm/h, ubuso bw'icyitegererezo bwahinduka imiterere mibi [8].
Ishusho ya 6 Igishushanyo mbonera cy'ibishushanyo
V. Incamake n'Icyerekezo
Ibikoresho bya GaN byatangiye kugaragara mu 2014 ubwo urumuri rw'ubururu rwa LED rwegukanaga igihembo cya Nobel muri Fiziki muri uwo mwaka, ndetse rukinjira mu rwego rwo gusharija vuba mu rwego rw'ibikoresho by'ikoranabuhanga. Mu by'ukuri, porogaramu mu byuma bitanga ingufu n'ibikoresho bya RF bikoreshwa muri sitasiyo za 5G abantu benshi batabona nabyo byagaragaye bucece. Mu myaka ya vuba aha, iterambere ry'ibikoresho by'amashanyarazi byo mu rwego rw'imodoka bishingiye kuri GaN ryitezwe ko rizatuma isoko ry'ibikoresho bya GaN rizamuka.
Ubukene bunini bw’isoko buzateza imbere iterambere ry’inganda n’ikoranabuhanga bifitanye isano na GaN. Hamwe n’iterambere ry’uruhererekane rw’inganda bifitanye isano na GaN, ibibazo bihura nabyo mu ikoranabuhanga rya GaN epitaxial bizarushaho kunozwa cyangwa bigakemuka. Mu gihe kizaza, abantu bazateza imbere ikoranabuhanga rishya rya epitaxial n’amahitamo meza cyane ya substrate. Icyo gihe, abantu bazaba bashobora guhitamo ikoranabuhanga ry’ubushakashatsi n’substrate bikwiriye gukoreshwa mu buryo butandukanye hakurikijwe imiterere y’uburyo bwo gukoreshwa, kandi bagakora ibicuruzwa bigezweho kandi birusha ibindi guhatana.
Igihe cyo kohereza: Kamena-28-2024