Tekinoloje yoyambira kukula kwaSiC epitaxialZida ndiukadaulo wowongolera chilema, makamaka paukadaulo wowongolera chilema womwe umakonda kulephera kwa chipangizo kapena kuwonongeka kodalirika. Kuphunzira kwa makina a gawo lapansi zolakwika zomwe zimafalikira mu epitaxial wosanjikiza panthawi ya kukula kwa epitaxial, kusuntha ndi kusintha malamulo a zolakwika pa mawonekedwe pakati pa gawo lapansi ndi epitaxial wosanjikiza, ndi nucleation mechanism of defects ndi maziko ofotokozera mgwirizano pakati pawo. Kuwonongeka kwa gawo lapansi ndi zolakwika zamapangidwe a epitaxial, zomwe zimatha kutsogolera bwino kuwunika kwa gawo lapansi ndi kukhathamiritsa kwa epitaxial.
Zowonongeka zasilicon carbide epitaxial zigawoamagawidwa makamaka m'magulu awiri: zolakwika za kristalo ndi zolakwika za morphology. Zowonongeka za kristalo, kuphatikizapo zolakwika za mfundo, kusokonezeka kwa ma screw, kuwonongeka kwa microtubule, kusokonezeka kwa m'mphepete, ndi zina zotero, makamaka zimachokera ku zolakwika za SiC substrates ndikufalikira mu epitaxial layer. Zowonongeka za kapangidwe ka zinthu zimatha kuwonedwa ndi maso pogwiritsa ntchito maikulosikopu ndipo zimakhala ndi mawonekedwe achilengedwe. Zowonongeka zamtundu wa morphology makamaka zikuphatikizapo: Kukanika, Kuwonongeka kwa Triangular, Kuwonongeka kwa Karoti, Kugwa, ndi Particle, monga momwe tawonetsera pa Chithunzi 4. Panthawi ya epitaxial, tinthu tating'onoting'ono, zowonongeka za gawo lapansi, kuwonongeka kwa nthaka, ndi kusokonezeka kwa epitaxial kungakhudze kayendedwe kameneka. kukula, zomwe zimapangitsa kuti pakhale vuto la morphology.
Table 1.Zoyambitsa pakupanga zolakwika za matrix wamba ndi zofooka zapamtunda zamtundu wa SiC epitaxial layers
Mfundo zolakwika
Zolakwika za nsonga zimapangidwa ndi mipata kapena mipata pamalo amodzi kapena malo angapo a lattice, ndipo alibe malo otalikirapo. Zolakwika za mfundo zitha kuchitika pakupanga kulikonse, makamaka pakuyika kwa ion. Komabe, zimakhala zovuta kuzizindikira, ndipo mgwirizano pakati pa kusintha kwa zolakwika za mfundo ndi zolakwika zina zimakhalanso zovuta kwambiri.
Ma Micropipe (MP)
Ma Micropipes ndi zomangira zopanda pake zomwe zimafalikira motsatira kukula, ndi vector ya Burgers <0001>. Kutalika kwa ma microtubes kumachokera ku kagawo kakang'ono ka micron mpaka makumi a ma microns. Ma Microtubes amawonetsa zazikulu ngati dzenje pamwamba pa zowotcha za SiC. Nthawi zambiri, kachulukidwe ka ma microtubes ndi pafupifupi 0.1 ~ 1cm-2 ndipo akupitilizabe kuchepa pakuwunika kwabwino kwa malonda.
Screw dislocations (TSD) ndi ma edge dislocations (TED)
Kutayika mu SiC ndiye gwero lalikulu la kuwonongeka kwa chipangizo ndi kulephera. Ma screw dislocations (TSD) ndi ma dislocations m'mphepete (TED) amayenda motsatira kukula, ndi ma Burger ma vector a <0001> ndi 1/3<11-20>, motero.
Ma screw dislocations (TSD) ndi ma dislocations (TED) amatha kupitilira kuchokera pagawo laling'ono kupita kumtunda ndikubweretsa mawonekedwe ang'onoang'ono ngati dzenje (Chithunzi 4b). Nthawi zambiri, kachulukidwe ka ma dislocations a m'mphepete mwake ndi pafupifupi nthawi 10 kuposa kusuntha kwa screw. Kuthamangitsidwa kwa screw screw, ndiko kuti, kuchoka pagawo laling'ono kupita ku epilayer, kumathanso kusinthika kukhala zolakwika zina ndikufalikira motsatira kukula. NthawiSiC epitaxialkukula, zomangira zomangira zimasandulika kukhala stacking zolakwa (SF) kapena kaloti zolakwika, pamene dislocation m'mphepete mwa epilayers akusonyeza kutembenuzidwa kuchokera basal plane dislocations (BPDs) chotengera ku gawo lapansi pa kukula epitaxial.
Kusamuka kwa ndege (BPD)
Ili pa SiC basal ndege, ndi Burgers vector ya 1/3 <11-20>. Ma BPD samawoneka kawirikawiri pamwamba pa zowotcha za SiC. Nthawi zambiri amakhazikika pa gawo lapansi ndi kachulukidwe ka 1500 cm-2, pomwe kachulukidwe kawo mu epilayer ndi pafupifupi 10 cm-2. Kuzindikira kwa ma BPD pogwiritsa ntchito photoluminescence (PL) kumawonetsa mizere yofananira, monga momwe tawonetsera pa Chithunzi 4c. NthawiSiC epitaxialkukula, ma BPD otalikirapo amatha kusinthidwa kukhala zolakwika za stacking (SF) kapena ma edge dislocation (TED).
Kuwonongeka kwa stacking (SFs)
Zowonongeka pamasanjidwe amtundu wa SiC basal plane. Zolakwika za stacking zitha kuwoneka mu epitaxial wosanjikiza potengera ma SF mu gawo lapansi, kapena kukhala okhudzana ndi kukulitsa ndi kusintha kwa ma basal plane dislocations (BPDs) ndi ma threading screw dislocations (TSDs). Kawirikawiri, kachulukidwe ka ma SFs ndi ochepera 1 cm-2, ndipo amasonyeza mawonekedwe a katatu akazindikiridwa pogwiritsa ntchito PL, monga momwe tawonetsera pa Chithunzi 4e. Komabe, mitundu yosiyanasiyana ya zolakwika za stacking zitha kupangidwa mu SiC, monga mtundu wa Shockley ndi mtundu wa Frank, chifukwa ngakhale kuchepa kwamphamvu kwapang'onopang'ono pakati pa ndege kumatha kupangitsa kuti pakhale kusakhazikika kwakanthawi.
Kugwa
The kugwa chilema makamaka zimachokera ku tinthu dontho kumtunda ndi mbali makoma a zimene chipinda pa kukula ndondomeko, amene akhoza wokometsedwa ndi optimizing ndi nthawi yokonza ndondomeko zimene chipinda graphite consumables.
Chilema cha katatu
Ndi 3C-SiC polytype kuphatikizidwa komwe kumafikira pamwamba pa epilayer ya SiC motsatira njira yoyambira ndege, monga momwe tawonetsera pa Chithunzi 4g. Ikhoza kupangidwa ndi tinthu tating'onoting'ono tomwe timakhala pamwamba pa SiC epilayer panthawi ya kukula kwa epitaxial. The particles ophatikizidwa mu epilayer ndi kusokoneza ndondomeko kukula, chifukwa 3C-SiC polytype inclusions, amene kusonyeza lakuthwa ngongodya triangular pamwamba mbali ndi particles ili pa vertices wa triangular dera. Kafukufuku wambiri wanenanso kuti chiyambi cha ma polytype inclusions ndi zingwe zapamtunda, ma micropipes, ndi magawo osayenera akukula.
Kuwonongeka kwa karoti
Kuwonongeka kwa kaloti ndi vuto la stacking lomwe lili ndi malekezero awiri omwe ali pa TSD ndi SF basal crystal ndege, zomwe zimathetsedwa ndi kusokonezeka kwamtundu wa Frank, ndipo kukula kwa chilema cha karoti kumakhudzana ndi vuto la prismatic stacking. Kuphatikizika kwa zinthuzi kumapanga mawonekedwe a pamwamba pa chilema cha karoti, chomwe chimawoneka ngati mawonekedwe a karoti ndi kachulukidwe osakwana 1 cm-2, monga momwe tawonetsera pa Chithunzi 4f. Zowonongeka za karoti zimapangika mosavuta pakupukuta, ma TSD, kapena kuwonongeka kwa gawo lapansi.
Zokanda
Zing'onozing'ono ndi zowonongeka pamakina pazitsulo za SiC zomwe zimapangidwa panthawi yopanga, monga momwe tawonetsera pa Chithunzi 4h. Zikwapu pa gawo lapansi la SiC zitha kusokoneza kukula kwa epilayer, kutulutsa mzere wothamangitsidwa kwambiri mkati mwa epilayer, kapena zokopa zitha kukhala maziko opangira zolakwika za karoti. Chifukwa chake, ndikofunikira kupukuta bwino zowotcha za SiC chifukwa zokwiyira izi zitha kukhala ndi vuto lalikulu pakuchita kwa chipangizochi zikawoneka pamalo ogwirira ntchito. chipangizo.
Zolakwika zina zamapangidwe apamwamba
Step bunching ndi chilema chapamwamba chomwe chimapangidwa panthawi ya kukula kwa SiC epitaxial, yomwe imapanga ma triangles a obtuse kapena mawonekedwe a trapezoidal pamtunda wa SiC epilayer. Palinso zolakwika zina zambiri zapamtunda, monga maenje apamtunda, totupa ndi madontho. Zowonongeka izi nthawi zambiri zimayamba chifukwa cha kukula kosakwanira komanso kuchotsedwa kosakwanira kwa kuwonongeka kwa kupukuta, zomwe zimasokoneza magwiridwe antchito a chipangizocho.
Nthawi yotumiza: Jun-05-2024