1. Semiconductors na ƙarni na uku
An haɓaka fasahar semiconductor na ƙarni na farko bisa ga kayan aikin semiconductor kamar Si da Ge. Ita ce tushen kayan aiki don haɓaka transistor da fasahar kewayawa. Kayayyakin semiconductor na ƙarni na farko sun aza harsashin masana'antar lantarki a cikin ƙarni na 20 kuma su ne ainihin kayan fasahar haɗaɗɗiyar da'ira.
Abubuwan semiconductor na ƙarni na biyu sun haɗa da gallium arsenide, indium phosphide, gallium phosphide, indium arsenide, aluminum arsenide da mahaɗansu na ternary. Abubuwan semiconductor na ƙarni na biyu sune tushen masana'antar bayanai ta optoelectronic. A kan wannan, an haɓaka masana'antu masu alaƙa irin su hasken wuta, nuni, Laser, da photovoltaics. Ana amfani da su ko'ina a cikin fasahar bayanai na zamani da masana'antar nunin optoelectronic.
Abubuwan wakilci na kayan semiconductor na ƙarni na uku sun haɗa da gallium nitride da silicon carbide. Saboda faffadan bandejin su, babban saurin saturation na lantarki, haɓakar zafin jiki mai ƙarfi, da ƙarfin fage mai ƙarfi, kayan aiki ne masu kyau don shirya ƙarfin ƙarfin ƙarfi, mitoci, da ƙananan na'urorin lantarki. Daga cikin su, na'urorin wutar lantarki na silicon carbide suna da fa'idodi na yawan ƙarfin kuzari, ƙarancin amfani da makamashi, da ƙaramin girman, kuma suna da fa'idodin aikace-aikacen sabbin motocin makamashi, hotuna, jigilar jirgin ƙasa, manyan bayanai, da sauran fannoni. Na'urorin RF na Gallium nitride suna da fa'idodin mitar mitoci, babban iko, faffadan bandwidth, ƙarancin wutar lantarki da ƙananan girman, kuma suna da fa'idodin aikace-aikacen a cikin sadarwar 5G, Intanet na Abubuwa, radar soja da sauran fannoni. Bugu da ƙari, an yi amfani da na'urori masu amfani da wutar lantarki na gallium nitride a cikin ƙananan ƙarfin lantarki. Bugu da ƙari, a cikin 'yan shekarun nan, ana sa ran kayan gallium oxide masu tasowa za su samar da haɗin gwiwar fasaha tare da fasahar SiC da GaN na yanzu, kuma suna da yuwuwar aikace-aikacen aikace-aikacen a cikin ƙananan mitoci da manyan ƙarfin lantarki.
Idan aka kwatanta da na biyu-ƙarni na semiconductor kayan, na uku-ƙarni semiconductor kayan suna da fadi da fadi da bandgap (bandgap nisa na Si, na hali abu na farko-ƙarni semiconductor abu, ne game da 1.1eV, da bandgap nisa na GaAs, da hankula abu na biyu-ƙarni semiconductor abu, ne game da 1.42eV, da kuma bandgap nisa na GaN, da hankula abu na uku-ƙarni semiconductor abu, shi ne sama da 2.3eV), da karfi radiation juriya, da karfi juriya ga wutar lantarki rushewar filin, da kuma mafi girma zafin jiki juriya. Na uku-ƙarni na semiconductor kayan tare da fadi bandgap nisa musamman dace da samar da radiation-resistant, high-mita, high-ikon da kuma high-yawa-yawan na'urorin lantarki. Aikace-aikacen su a cikin na'urorin mitar rediyo na microwave, LEDs, lasers, na'urorin wutar lantarki da sauran fagage sun jawo hankali sosai, kuma sun nuna fa'idodin ci gaba a cikin sadarwar wayar hannu, grid mai kaifin baki, jigilar dogo, sabbin motocin makamashi, na'urorin lantarki, da ultraviolet da shuɗi. -Na'urorin haske koren [1].
Madogararsa na hoto: CASA, Cibiyar Nazarin Tsaro ta Zheshang
Hoto 1 Ma'aunin lokacin na'urar wutar lantarki na GaN
II Tsarin kayan GaN da halaye
GaN semiconductor na bandgap kai tsaye. Faɗin bandgap na tsarin wurtzite a zafin jiki yana kusan 3.26eV. Kayan GaN suna da manyan sifofin crystal guda uku, wato tsarin wurtzite, tsarin sphalerite da tsarin gishirin dutse. Daga cikin su, tsarin wurtzite shine mafi tsayayyen tsarin crystal. Hoto na 2 zane ne na tsarin wurtzite hexagonal na GaN. Tsarin wurtzite na kayan GaN na cikin tsari mai cike da kusada hexagonal. Kowane tantanin halitta yana da atom guda 12, gami da atom N 6 da kuma 6 Ga atom. Kowane Ga (N) zarra yana samar da haɗin gwiwa tare da atom ɗin N (Ga) guda 4 mafi kusa kuma an jera su a cikin tsari na ABABAB… tare da [0001] shugabanci [2].
Hoto 2 Tsarin Wurtzite GaN zanen kwayar halitta
III Abubuwan da aka saba amfani da su don GaN epitaxy
Da alama cewa epitaxy mai kama da juna akan abubuwan GaN shine mafi kyawun zaɓi ga GaN epitaxy. Koyaya, saboda babban ƙarfin haɗin gwiwa na GaN, lokacin da zafin jiki ya kai madaidaicin narkewa na 2500 ℃, madaidaicin lalatawar matsi yana kusan 4.5GPa. Lokacin da matsin lamba ya kasance ƙasa da wannan matsa lamba, GaN ba ya narkewa amma yana rubewa kai tsaye. Wannan ya sa fasahar shirye-shiryen balagagge irin su hanyar Czochralski ba ta dace da shirye-shiryen GaN guda ɗaya na kristal ba, yana sa kayan aikin GaN ke da wahalar samarwa da tsada. Saboda haka, abubuwan da aka saba amfani da su a cikin ci gaban GaN na epitaxial sun fi Si, SiC, sapphire, da sauransu. [3].
Chart 3 GaN da sigogin kayan aikin da aka saba amfani da su
GaN epitaxy akan sapphire
Sapphire yana da ingantaccen kaddarorin sinadarai, yana da arha, kuma yana da babban balaga na manyan masana'antar samarwa. Don haka, ya zama ɗaya daga cikin farkon kuma mafi yawan kayan da ake amfani da su a cikin injiniyoyin na'ura. A matsayin ɗaya daga cikin abubuwan da aka saba amfani da su don GaN epitaxy, manyan matsalolin da ake buƙatar magance su don sapphire substrates sune:
✔ Saboda babban rashin daidaituwa tsakanin sapphire (Al2O3) da GaN (kimanin 15%), ƙarancin lahani a mahaɗin tsakanin layin epitaxial da substrate yana da girma sosai. Domin rage illar sa, dole ne a yi amfani da substrate zuwa hadadden pretreatment kafin tsarin epitaxy ya fara. Kafin girma GaN epitaxy akan sapphire substrates, dole ne a fara tsaftace saman ƙasa don cire gurɓatacce, ragowar goge goge, da dai sauransu, da kuma samar da matakai da tsarin saman saman. Sa'an nan, da substrate surface ne nitrided don canza jika Properties na epitaxial Layer. A ƙarshe, wani bakin ciki AlN buffer Layer (yawanci lokacin kauri 10-100nm) yana buƙatar a ajiye shi akan saman ƙasa kuma a sanya shi cikin ƙananan zafin jiki don shirya don ci gaban epitaxial na ƙarshe. Duk da haka, yawan raguwa a cikin fina-finai na GaN epitaxial da aka girma akan sapphire substrates har yanzu yana da girma fiye da na fina-finai na homoepitaxial (kimanin 1010cm-2, idan aka kwatanta da ainihin sifili dislocation yawa a cikin fina-finai na silicon homoepitaxial ko gallium arsenide homoepitaxial films, ko tsakanin 1010 cm). 2). Mafi girman lahani yana rage motsi mai ɗaukar kaya, ta haka yana rage ƴan tsirarun dillalan rayuwa da rage zafin zafi, duk waɗannan zasu rage aikin na'urar [4];
✔ Ƙididdigar haɓakar haɓakar thermal na sapphire ya fi na GaN girma, don haka za a haifar da damuwa na damuwa na biaxial a cikin epitaxial Layer yayin aiwatar da sanyaya daga zafin jiki na ajiya zuwa zafin jiki. Don fina-finan epitaxial masu kauri, wannan damuwa na iya haifar da tsagewar fim ɗin ko ma abin da ke ciki;
✔ Idan aka kwatanta da sauran substrates, thermal conductivity na sapphire substrates ne m (kimanin 0.25W * cm-1 * K-1 a 100 ℃), da zafi dissipation yi ba shi da kyau;
✔ Saboda rashin aikin sa, sapphire substrates ba su da amfani ga haɗin kai da aikace-aikacen su tare da sauran na'urorin semiconductor.
Kodayake yawan lahani na GaN epitaxial yadudduka girma akan sapphire substrates yana da girma, da alama baya rage yawan aikin optoelectronic na LEDs blue-kore na tushen GaN, don haka sapphire substrates har yanzu ana amfani da substrates don tushen GaN LEDs.
Tare da haɓaka ƙarin sabbin aikace-aikacen na'urorin GaN kamar lasers ko wasu na'urori masu ƙarfi masu ƙarfi, lahani na asali na sapphire substrates sun ƙara zama iyakance akan aikace-aikacen su. Bugu da ƙari, tare da haɓaka fasahar ci gaban SiC substrate, rage farashi da kuma balagaggen fasahar GaN epitaxial a kan Si substrates, ƙarin bincike kan girma GaN epitaxial layers a kan sapphire substrates ya nuna sannu a hankali yanayin sanyi.
GaN epitaxy akan SiC
Idan aka kwatanta da sapphire, SiC substrates (4H- da 6H-crystals) suna da ƙananan ƙarancin lattice tare da GaN epitaxial layers (3.1%, daidai da [0001] fina-finai na epitaxial), mafi girman halayen thermal (kimanin 3.8W * cm-1 * K). -1), da dai sauransu Bugu da ƙari, ƙaddamar da ƙananan ƙwayoyin SiC kuma yana ba da damar yin lambobi na lantarki a baya na substrate, wanda ke taimakawa wajen sauƙaƙe tsarin na'urar. Kasancewar waɗannan fa'idodin ya jawo ƙarin masu bincike don yin aiki akan GaN epitaxy akan abubuwan siliki carbide.
Koyaya, yin aiki kai tsaye akan sinadarai na SiC don guje wa haɓakar GaN epilayers shima yana fuskantar jerin rashin lahani, gami da masu zuwa:
✔ Ƙaƙƙarfan yanayin SiC ya fi girma fiye da na sapphire substrates (sapphire roughness 0.1nm RMS, SiC roughness 1nm RMS), SiC substrates suna da tsayin daka da rashin aikin sarrafawa, kuma wannan rashin ƙarfi da ragowar lalacewar goge su ma ɗaya ne daga cikin. tushen lahani a cikin GaN epilayers.
✔ Ƙwararren ƙwanƙwasa ƙwanƙwasa na SiC yana da girma (yawan rarrabuwa 103-104cm-2), ɓangarorin dunƙule na iya yaduwa zuwa ga GaN epilayer kuma rage aikin na'urar;
✔ Tsarin atomic akan saman ƙasa yana haifar da samuwar kurakuran stacking (BSFs) a cikin GaN epilayer. Don Epitaxial GaN akan sinadarai na SiC, akwai yuwuwar oda na tsarin atomic akan ma'auni, wanda ya haifar da rashin daidaiton oda na stacking na farko na layin GaN na epitaxial akan sa, wanda ke da saurin tara kurakurai. Matsaloli (SFs) suna gabatar da ginanniyar filayen lantarki tare da axis c, wanda ke haifar da matsaloli irin su zubar da na'urorin raba jigilar jirgin sama;
✔ Ƙididdigar haɓakar haɓakar thermal na SiC substrate ya fi na AlN da GaN, wanda ke haifar da tarin damuwa na zafi tsakanin epitaxial Layer da substrate yayin aikin sanyaya. Waltereit da Brand sun yi annabta bisa sakamakon bincikensu cewa za a iya rage ko magance wannan matsalar ta hanyar girma GaN epitaxial layers a kan siraran sirara, masu daidaita al'adar nucleation;
✔ Matsalar rashin jika na Ga atom. Lokacin da girma GaN epitaxial yadudduka kai tsaye a kan SiC surface, saboda matalauta wettability tsakanin biyu zarra, GaN yana yiwuwa ga 3D tsibiri girma a kan substrate surface. Gabatar da abin rufe fuska shine mafi yawan maganin da ake amfani dashi don inganta ingancin kayan epitaxial a cikin GaN epitaxy. Gabatar da Layer buffer AlN ko AlxGa1-xN zai iya inganta yadda ya kamata a jika saman SiC kuma ya sa Layer epitaxial GaN ya girma cikin girma biyu. Bugu da ƙari, yana iya daidaita damuwa da kuma hana lahani na substrate daga ƙaddamarwa zuwa GaN epitaxy;
✔ Fasahar shirye-shiryen na SiC substrates ba ta da girma, farashin substrate yana da yawa, kuma akwai ƴan kaya da ƙarancin wadata.
Torres et al.'s bincike ya nuna cewa etching da SiC substrate tare da H2 a high zafin jiki (1600 ° C) kafin epitaxy iya samar da wani ƙarin umarni mataki tsarin a kan substrate surface, game da shi samun mafi girma ingancin AlN epitaxial fim fiye da lokacin da yake kai tsaye kai tsaye. girma a kan asali substrate surface. Har ila yau, binciken Xie da tawagarsa ya nuna cewa etching pretreatment na silicon carbide substrate iya muhimmanci inganta surface ilmin halittar jiki da kuma crystal ingancin GaN epitaxial Layer. Smith et al. gano cewa zaren dislocations samo asali daga substrate / buffer Layer da buffer Layer / epitaxial Layer musaya suna da alaka da flatness na substrate [5].
Hoto 4 TEM ilimin halittar jiki na GaN epitaxial Layer samfurori girma a kan 6H-SiC substrate (0001) a karkashin daban-daban jiyya yanayi (a) sinadaran tsaftacewa; (b) tsabtace sinadarai + maganin plasma na hydrogen; (c) tsaftacewar sinadarai + maganin plasma na hydrogen + 1300 ℃ maganin zafi na hydrogen na 30min
GaN epitaxy on Si
Idan aka kwatanta da silicon carbide, sapphire da sauran substrates, da silicon substrate shirye-shirye tsari ne balagagge, kuma zai iya tsayayye samar da balagagge manyan-size substrates tare da babban farashi yi. A lokaci guda, haɓakar thermal conductivity da wutar lantarki suna da kyau, kuma tsarin na'urar lantarki na Si ya girma. Yiwuwar haɗa na'urorin GaN na optoelectronic daidai tare da na'urorin lantarki na Si a nan gaba kuma yana sa haɓakar GaN epitaxy akan silicon da kyau sosai.
Koyaya, saboda babban bambance-bambance a cikin tsaka-tsakin lattice tsakanin Si substrate da kayan GaN, ƙayyadaddun epitaxy na GaN akan Si substrate babban babban rashin daidaituwa ne, kuma yana buƙatar fuskantar jerin matsaloli:
✔ Matsalolin makamashin sararin samaniya. Lokacin da GaN ya girma akan siginar Si, za a fara nitrided saman silin silin don samar da amorphous silicon nitride Layer wanda bai dace da haɓakawa da haɓakar GaN mai girma ba. Bugu da kari, Si surface zai fara tuntuɓar Ga, wanda zai lalata saman Si substrate. A yanayin zafi mai yawa, bazuwar siginar Si zai bazu zuwa cikin GaN epitaxial Layer don samar da baƙar fata siliki.
✔ Rashin daidaituwa akai-akai tsakanin GaN da Si yana da girma (~ 17%), wanda zai haifar da samuwar ɓangarorin zaren daɗaɗɗen ƙira kuma yana da mahimmanci rage ingancin Layer epitaxial;
✔ Idan aka kwatanta da Si, GaN yana da mafi girma na thermal fadada coefficient (GaN's thermal expansion coefficient is about 5.6×10-6K-1, Si's thermal expansion coefficient is about 2.6×10-6K-1), kuma ana iya haifar da fasa a cikin GaN. epitaxial Layer a lokacin sanyi na epitaxial zafin jiki zuwa dakin zafin jiki;
✔ Si yana amsawa tare da NH3 a babban yanayin zafi don samar da polycrystalline SiNx. AlN ba zai iya samar da madaidaiciyar madaidaiciyar tsakiya akan polycrystalline SiNx ba, wanda ke haifar da rashin daidaituwa na Layer GaN mai girma da yawa da lahani, wanda ke haifar da rashin kyawun kristal na GaN epitaxial Layer, har ma da wahala wajen samar da kristal guda ɗaya. GaN epitaxial Layer [6].
Domin magance matsalar babban rashin daidaituwar lattice, masu bincike sun yi ƙoƙarin gabatar da kayan kamar AlAs, GaAs, AlN, GaN, ZnO, da SiC a matsayin madaidaitan yadudduka akan Si substrates. Don kauce wa samuwar polycrystalline SiNx da kuma rage mummunan tasirinsa akan ingancin crystal na kayan GaN / AlN / Si (111), TMAl yawanci ana buƙatar gabatar da shi na wani lokaci kafin girma epitaxial na AlN buffer Layer. don hana NH3 amsawa tare da fallasa Si surface don samar da SiNx. Bugu da ƙari, ana iya amfani da fasahohin epitaxial kamar fasaha mai ƙira don inganta ingancin Layer epitaxial. Haɓaka waɗannan fasahohin na taimakawa wajen hana samuwar SiNx a cikin ƙirar epitaxial, inganta haɓakar haɓakar nau'i biyu na GaN epitaxial Layer, da haɓaka haɓakar haɓakar haɓakar epitaxial Layer. Bugu da kari, an gabatar da wani Layer buffer na AlN don rama damuwa da damuwa da ke haifar da bambance-bambancen haɓakar haɓakar thermal don guje wa fashewar GaN epitaxial Layer a kan siliki. Binciken Krost ya nuna cewa akwai ingantacciyar alaƙa tsakanin kauri na AlN buffer Layer da raguwar iri. Lokacin da kauri mai kauri ya kai 12nm, za a iya girma Layer epitaxial mai kauri fiye da 6μm akan ma'aunin siliki ta tsarin haɓaka mai dacewa ba tare da fashewar epitaxial ba.
Bayan dogon ƙoƙarin da masu bincike suka yi, ingancin GaN epitaxial yadudduka da aka girma a kan silinda ya inganta sosai, kuma na'urori irin su transistor tasirin filin, Schottky barrier ultraviolet detectors, blue-kore LEDs da ultraviolet lasers sun sami gagarumin ci gaba.
A taƙaice, tunda abubuwan da aka saba amfani da su na GaN epitaxial substrates duk epitaxy ne daban-daban, dukkansu suna fuskantar matsalolin gama gari kamar rashin daidaituwar lattice da manyan bambance-bambance a cikin haɓakar haɓakar thermal zuwa digiri daban-daban. Matsalolin GaN na epitaxial masu kama da juna an iyakance su ta hanyar balagaggen fasaha, kuma har yanzu ba a samar da kayan aikin da yawa ba. Farashin samarwa yana da girma, ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ba su da kyau. Ci gaba da sababbin abubuwan da ke haifar da GaN epitaxial substrates da kuma inganta ingancin epitaxial har yanzu suna daya daga cikin muhimman abubuwan da ke hana ci gaba da ci gaban masana'antar GaN epitaxial.
IV. Hanyoyin gama gari don GaN epitaxy
MOCVD (zubar da tururi na sinadarai)
Da alama cewa epitaxy mai kama da juna akan abubuwan GaN shine mafi kyawun zaɓi ga GaN epitaxy. Duk da haka, tun da precursors na sinadaran tururi jijiya ne trimethylgallium da ammonia, da kuma m gas ne hydrogen, da hankula MOCVD girma zafin jiki ne game da 1000-1100 ℃, da kuma girma kudi na MOCVD ne game da 'yan microns a sa'a. Yana iya samar da musaya mai zurfi a matakin atomic, wanda ya dace sosai don haɓaka heterojunctions, rijiyoyin ƙididdiga, superlatices da sauran sifofi. Girman haɓakarsa mai sauri, daidaitaccen daidaituwa, da dacewa don babban yanki da haɓakar yanki da yawa ana amfani da su a cikin samar da masana'antu.
MBE (kwayoyin bim epitaxy)
A cikin epitaxy na kwayoyin halitta, Ga yana amfani da tushen asali, kuma ana samun nitrogen mai aiki daga nitrogen ta hanyar plasma na RF. Idan aka kwatanta da hanyar MOCVD, zafin girma na MBE yana kusan 350-400 ℃ ƙasa. Ƙananan zafin jiki na girma zai iya guje wa wasu gurbataccen yanayi wanda yanayin zafi mai zafi ya haifar. Tsarin MBE yana aiki a ƙarƙashin matsananci-high, wanda ke ba shi damar haɗa ƙarin hanyoyin gano wuri. A lokaci guda, ba za a iya kwatanta girman girmansa da ƙarfin samarwa da MOCVD ba, kuma an fi amfani dashi a cikin binciken kimiyya [7].
Hoto na 5 (a) Eiko-MBE dabara (b) MBE babban tsari na tsarin amsawa
Hanyar HVPE (hydride vapor period epitaxy)
Madogaran hanyar hydride tururi lokaci epitaxy sune GaCl3 da NH3. Detchprohm et al. yayi amfani da wannan hanyar don girma gaN epitaxial Layer ɗaruruwan microns mai kauri akan saman sapphire substrate. A cikin gwajin nasu, an shuka wani Layer na ZnO tsakanin sapphire substrate da epitaxial Layer a matsayin maƙalar buffer, kuma an fitar da Layer na epitaxial daga saman ƙasa. Idan aka kwatanta da MOCVD da MBE, babban fasalin hanyar HVPE shine girman girman girmansa, wanda ya dace da samar da yadudduka masu kauri da kayan girma. Duk da haka, lokacin da kauri daga cikin epitaxial Layer ya wuce 20μm, epitaxial Layer da aka samar da wannan hanya yana da wuyar fashewa.
Akira USUI ya gabatar da fasaha mai ƙima bisa wannan hanyar. Da farko sun girma wani bakin ciki 1-1.5μm mai kauri na GaN epitaxial Layer akan sapphire substrate ta amfani da hanyar MOCVD. Layin epitaxial ya ƙunshi kauri mai kauri 20nm gaN buffer Layer girma a ƙarƙashin ƙananan yanayin zafi da kuma Layer GaN da aka girma a ƙarƙashin yanayin zafi mai girma. Sa'an nan, a 430 ℃, wani Layer na SiO2 aka plated a saman epitaxial Layer, da kuma taga da aka yi ratsan a kan SiO2 fim ta photolithography. Tazarar tsiri ya kasance 7μm kuma faɗin abin rufe fuska ya bambanta daga 1μm zuwa 4μm. Bayan wannan haɓakawa, sun sami GaN epitaxial Layer a kan ɗigon sapphire diamita 2-inch wanda ba shi da fashe kuma mai santsi kamar madubi koda lokacin da kauri ya ƙaru zuwa dubun ko ma ɗaruruwan microns. An rage ƙarancin lahani daga 109-1010cm-2 na hanyar HVPE na al'ada zuwa kusan 6 × 107cm-2. Sun kuma nuna a cikin gwajin cewa lokacin da girma ya wuce 75μm/h, samfurin saman zai zama m[8].
Hoto na 6 Tsarin Tsarin Zane na Zane
V. Summary da Outlook
Kayayyakin GaN sun fara fitowa ne a cikin 2014 lokacin da hasken shuɗi na LED ya sami lambar yabo ta Nobel a Physics a waccan shekarar, kuma ya shiga fagen aikace-aikacen cajin jama'a cikin sauri a cikin filin na'urorin lantarki. A haƙiƙa, aikace-aikace a cikin na'urorin ƙara ƙarfin wuta da na'urorin RF da aka yi amfani da su a tashoshin tushe na 5G waɗanda yawancin mutane ba za su iya gani ba suma sun fito cikin nutsuwa. A cikin 'yan shekarun nan, ci gaban na'urorin wutar lantarki na tushen GaN ana tsammanin zai buɗe sabbin abubuwan haɓaka don kasuwar aikace-aikacen kayan GaN.
Babban buƙatun kasuwa tabbas zai haɓaka haɓaka masana'antu da fasaha masu alaƙa da GaN. Tare da balaga da haɓakar sarkar masana'antu da ke da alaƙa da GaN, matsalolin da fasahar Epitaxial GaN ke fuskanta a ƙarshe za a inganta ko shawo kan su. A nan gaba, tabbas mutane za su haɓaka ƙarin sabbin fasahohin epitaxial da mafi kyawun zaɓin substrate. A lokacin, mutane za su iya zaɓar mafi dacewa fasahar bincike na waje da substrate don yanayi daban-daban na aikace-aikacen bisa ga halaye na yanayin aikace-aikacen, da kuma samar da samfuran musamman na gasa.
Lokacin aikawa: Juni-28-2024