Chiyambi Chachikulu cha SiC Epitaxial Growth Process

Epitaxial wosanjikiza ndi filimu yeniyeni ya kristalo yomwe imakula pamtengowo ndi ndondomeko ya ep · itaxial, ndipo gawo laling'ono laling'ono ndi filimu ya epitaxial imatchedwa epitaxial wafer. Pokulitsa silicon carbide epitaxial layer pa conductive silicon carbide substrate, silicon carbide homogeneous epitaxial wafer imatha kukonzedwanso kukhala Schottky diode, MOSFETs, IGBTs ndi zida zina zamagetsi, zomwe gawo lapansi la 4H-SiC ndilogwiritsidwa ntchito kwambiri.

Chifukwa cha njira zosiyanasiyana zopangira zida zamphamvu za silicon carbide ndi chipangizo champhamvu cha silicon, sichingapangidwe mwachindunji pa silicon carbide single crystal material. Zowonjezera zapamwamba za epitaxial ziyenera kukulitsidwa pagawo laling'ono la crystal conductive, ndipo zida zosiyanasiyana ziyenera kupangidwa pagawo la epitaxial. Chifukwa chake, mtundu wa epitaxial wosanjikiza umakhudza kwambiri magwiridwe antchito a chipangizocho. Kuwongolera kwa magwiridwe antchito a zida zosiyanasiyana zamagetsi kumayikanso patsogolo zofunikira za makulidwe a epitaxial layer, ndende ya doping ndi zolakwika.

CHITH. 1. Ubale pakati pa ndende ya doping ndi makulidwe a epitaxial wosanjikiza wa chipangizo cha unipolar ndi kutsekereza voteji

Kukonzekera njira za SIC epitaxial wosanjikiza makamaka monga evaporation kukula njira, madzi gawo epitaxial kukula (LPE), molecular mtengo epitaxial kukula (MBE) ndi mankhwala nthunzi deposition (CVD). Pakadali pano, chemical vapor deposition (CVD) ndiyo njira yayikulu yomwe imagwiritsidwa ntchito popanga zazikulu m'mafakitale.

CHITH. 2. Kuyerekezera njira zazikulu zokonzekera za epitaxial layer

Pamalo otalikirapo {0001} ndi ngodya yopendekeka, monga momwe tawonera pa Chithunzi 2(b), kachulukidwe ka masitepe ndi okulirapo, ndipo kukula kwa masitepewo ndi ang'onoang'ono, ndipo kristalo nucleation sikophweka. zimachitika pamasitepe, koma nthawi zambiri zimachitika pophatikizana. Pamenepa, pali kiyi imodzi yokha ya nucleating. Choncho, epitaxial wosanjikiza akhoza kubwereza mwangwiro dongosolo stacking ya gawo lapansi, motero kuthetsa vuto la kukhalirana kwamitundu yambiri.

CHITH. 3. Thupi ndondomeko chithunzi cha 4H-SiC sitepe control epitaxy njira

CHITH. 4. Zinthu zovuta za kukula kwa CVD ndi 4H-SiC njira yoyendetsedwa ndi epitaxy

CHITH. 5. Kuyerekeza kwa mitengo ya kukula pansi pa magwero osiyanasiyana a silicon mu 4H-SiC epitaxy

Pakalipano, teknoloji ya silicon carbide epitaxy ndiyokhwima kwambiri pamagetsi otsika komanso apakati (monga zipangizo za 1200 volt). Kufanana kwa makulidwe, kufanana kwa ndende ya doping ndi kugawa kwachilema kwa gawo la epitaxial kumatha kufika pamlingo wabwino, womwe ungakwaniritse zosowa zapakati ndi otsika voteji SBD (Schottky diode), MOS (metal oxide semiconductor field effect transistor), JBS ( mphambano diode) ndi zipangizo zina.

Komabe, pankhani ya kuthamanga kwambiri, ma epitaxial wafers amafunikirabe kuthana ndi zovuta zambiri. Mwachitsanzo, pazida zomwe zimafunika kupirira 10,000 volts, makulidwe a epitaxial layer ayenera kukhala pafupifupi 100μm. Poyerekeza ndi zida zotsika kwambiri, makulidwe a epitaxial wosanjikiza ndi kufanana kwa ndende ya doping ndizosiyana kwambiri, makamaka kufanana kwa ndende ya doping. Nthawi yomweyo, cholakwika cha makona atatu mu gawo la epitaxial chidzawononganso magwiridwe antchito onse a chipangizocho. M'mapulogalamu othamanga kwambiri, mitundu ya zida zimakonda kugwiritsa ntchito zida za bipolar, zomwe zimafunikira moyo wa anthu ochepa kwambiri mu epitaxial layer, kotero kuti ntchitoyi iyenera kukonzedwa kuti ikhale ndi moyo wocheperako.

Pakalipano, epitaxy yapakhomo imakhala yaikulu mainchesi 4 ndi mainchesi 6, ndipo gawo lalikulu la silicon carbide epitaxy likuwonjezeka chaka ndi chaka. Kukula kwa pepala la silicon carbide epitaxial makamaka kumachepetsedwa ndi kukula kwa gawo lapansi la silicon carbide. Pakalipano, gawo lapansi la 6-inch silicon carbide lagulitsidwa, kotero silicon carbide epitaxial ikusintha pang'onopang'ono kuchoka pa mainchesi 4 kufika pa mainchesi 6. Ndi kuwongolera kosalekeza kwa ukadaulo wa silicon carbide pokonzekera gawo lapansi ndikukulitsa mphamvu, mtengo wa silicon carbide gawo lapansi ukutsika pang'onopang'ono. Pakuphatikizidwa kwa mtengo wa pepala la epitaxial, gawo lapansi limawerengera ndalama zoposa 50% za mtengo, motero pakutsika kwa mtengo wagawo, mtengo wa silicon carbide epitaxial sheet ukuyembekezekanso kuchepa.