Intangiriro Yibanze ya SiC Epitaxial Gukura

Epitaxial layer ni firime imwe yihariye ya kristu ikura kuri wafer na ep · itaxial, na substrate wafer na epitaxial film bita epitaxial wafer. Mugukuza silicon karbide epitaxial layer kumurongo wa karubide ya silicon, karbide ya silicon karbide homogeneous epitaxial wafer irashobora gutegurwa kurushaho muri diode ya Schottky, MOSFETs, IGBTs nibindi bikoresho byamashanyarazi, muribwo substrate ya 4H-SiC ikoreshwa cyane.

Kubera uburyo butandukanye bwo gukora ibikoresho bya silicon carbide yamashanyarazi nibikoresho gakondo bya silicon, ntibishobora guhimbwa muburyo bwa silicon carbide ibikoresho bimwe bya kirisiti. Ibikoresho byongeweho byujuje ubuziranenge bigomba guhingwa kuri substrate imwe ya kristaliste, kandi ibikoresho bitandukanye bigomba gukorerwa kumurongo wa epitaxial. Kubwibyo, ubwiza bwa epitaxial layer bugira ingaruka zikomeye kumikorere yigikoresho. Gutezimbere imikorere yibikoresho byingufu zinyuranye nabyo bishyira imbere ibisabwa hejuru kubyimbye bya epitaxial layer, doping concentration hamwe nenge.

FIG. 1. Isano iri hagati yubushakashatsi bwa doping nubunini bwa epitaxial layer igikoresho cya unipolar no guhagarika voltage

Uburyo bwo gutegura SIC epitaxial layer burimo cyane cyane uburyo bwo gukura buguruka, gukura kwicyiciro cya epitaxial (LPE), gukura kwa molekile beam epitaxial (MBE) hamwe nubumara bwa chimique (CVD). Kugeza ubu, imyuka ya chimique (CVD) nuburyo nyamukuru bukoreshwa mu gukora umusaruro munini mu nganda.

FIG. 2. Kugereranya uburyo bwibanze bwo gutegura epitaxial layer

Kuri off-axis {0001} substrate hamwe nu mpande runaka ihengamye, nkuko bigaragara ku gishushanyo cya 2 (b), ubucucike bwubuso bwintambwe nini, kandi ubunini bwubuso bwintambwe ni buto, kandi nucleation ya kirisiti ntabwo byoroshye kuri bibaho hejuru yintambwe, ariko akenshi bibaho mugihe cyo guhuza intambwe. Kuri iki kibazo, hari urufunguzo rumwe gusa. Kubwibyo, epitaxial layer irashobora kwigana neza gahunda yo gutondekanya substrate, bityo ikuraho ikibazo cyubwoko bwinshi bwo kubana.

FIG. 3. Igishushanyo mbonera cyibikorwa bya 4H-SiC intambwe yo kugenzura epitaxy uburyo

FIG. 4. Ibintu byingenzi kugirango CVD ikure hakoreshejwe 4H-SiC intambwe igenzurwa na epitaxy

FIG. 5. Kugereranya umuvuduko wubwiyongere munsi ya silicon itandukanye muri epitaxy ya 4H-SiC

Kugeza ubu, tekinoroji ya silicon carbide epitaxy irakuze muburyo bukoreshwa na voltage ntoya (nkibikoresho 1200 volt). Uburinganire bwuburinganire, uburinganire bwa doping hamwe no gukwirakwiza inenge ya epitaxial layer irashobora kugera kurwego rwiza, rushobora ahanini guhuza ibikenewe na voltage yo hagati na ntoya SBD (Schottky diode), MOS (icyuma cya oxyde semiconductor field effect transistor), JBS ( ihuriro rya diode) nibindi bikoresho.

Ariko, murwego rwumuvuduko mwinshi, wafers epitaxial iracyakeneye gutsinda ibibazo byinshi. Kurugero, kubikoresho bigomba kwihanganira volt 10,000, ubunini bwigice cya epitaxial bugomba kuba hafi 100 mm. Ugereranije nibikoresho bito bito bito, ubunini bwa epitaxial layer hamwe nuburinganire bwa doping yibanze biratandukanye cyane cyane uburinganire bwa doping. Mugihe kimwe, inenge ya mpandeshatu murwego rwa epitaxial nayo izasenya imikorere rusange yigikoresho. Mubisabwa na voltage nyinshi, ubwoko bwibikoresho bikunda gukoresha ibikoresho bya bipolar, bisaba ubuzima buke buke mubuzima bwa epitaxial, bityo rero inzira ikeneye kunozwa kugirango ubuzima bwa bake bubeho.

Kugeza ubu, epitaxy yo mu rugo ahanini ifite santimetero 4 na santimetero 6, kandi igipimo cy’ibinini binini bya silicon karbide yiyongera uko umwaka utashye. Ingano ya silicon karbide epitaxial urupapuro igarukira cyane cyane kubunini bwa silicon karbide substrate. Kugeza ubu, insimburangingo ya 6 ya silicon karbide substrate yaracururizwaga, bityo epitaxial ya silicon karbide igenda ihinduka buhoro buhoro kuva kuri santimetero 4 kugera kuri santimetero 6. Hamwe nogukomeza kunoza uburyo bwa silicon karbide substrate yo gutegura no kwagura ubushobozi, igiciro cya silicon karbide substrate kigenda kigabanuka buhoro buhoro. Mu bigize igiciro cyurupapuro rwibanze, substrate irenga 50% yikiguzi, bityo hamwe nigabanuka ryigiciro cya substrate, igiciro cyurupapuro rwa epicaxial silicon nacyo giteganijwe kugabanuka.