Isi mmalite mmalite nke SiC Epitaxial Growth Process

Epitaxial oyi akwa bụ kpọmkwem otu ihe nkiri kristal toro na wafer site na usoro ep·itaxial, a na-akpọkwa wafer mkpụrụ na ihe nkiri epitaxial epitaxial wafer. Site na itolite oyi akwa silicon carbide epitaxial na mkpụrụ silicon carbide na-eduzi, enwere ike ịkwado silicon carbide homogeneous epitaxial wafer n'ime Schottky diodes, MOSFETs, IGBTs na ngwaọrụ ike ndị ọzọ, n'ime nke 4H-SiC bụ ihe a na-ejikarị eme ihe.

N'ihi usoro nrụpụta dị iche iche nke ngwaọrụ ike silicon carbide na ngwaọrụ ike silicon ọdịnala, enweghị ike imepụta ya ozugbo na silicon carbide otu ihe kristal. A ghaghị itolite ihe ndị ọzọ dị elu nke epitaxial n'otu mkpụrụ kristal na-eduzi, yana ngwaọrụ dị iche iche ga-arụrịrị n'elu epitaxial oyi akwa. Ya mere, àgwà nke oyi akwa epitaxial nwere mmetụta dị ukwuu na arụmọrụ nke ngwaọrụ ahụ. Ọganihu nke arụmọrụ nke ngwaọrụ ike dị iche iche na-ebutekwa ihe ndị dị elu chọrọ maka ọkpụrụkpụ nke oyi akwa epitaxial, itinye uche doping na ntụpọ.

FIG. 1. Mmekọrịta dị n'etiti ntinye doping na ọkpụrụkpụ nke epitaxial oyi akwa nke unipolar ngwaọrụ na igbochi voltaji.

Ụzọ nkwadebe nke SIC epitaxial oyi akwa na-agụnye tumadi usoro evaporation uto, mmiri mmiri na-adọ epitaxial uto (LPE), molekul beam epitaxial uto (MBE) na chemical vapor deposition (CVD). Ka ọ dị ugbu a, ntinye mmiri mmiri kemịkalụ (CVD) bụ ụzọ bụ isi a na-eji emepụta nnukwu ụlọ ọrụ.

FIG. 2. Ntụle nke isi ụzọ nkwadebe nke epitaxial oyi akwa

N'elu mpụta-axis {0001} nwere ụfọdụ tilt Angle, dị ka e gosiri na Figure 2(b), njupụta nke nzọụkwụ elu bụ ibu, na nha nke nzọụkwụ elu dị obere, na crystal nucleation adịghị mfe. na-eme n'elu nzọụkwụ, ma ọ na-emekarị na njedebe nke nzọụkwụ ahụ. N'okwu a, enwere naanị otu igodo nucleating. Ya mere, oyi akwa epitaxial nwere ike ịmegharị usoro nchịkọta nke mkpụrụ osisi ahụ nke ọma, si otú ahụ wepụ nsogbu nke ịdị n'otu ụdị dị iche iche.

FIG. 3. Eserese usoro anụ ahụ nke 4H-SiC nzọụkwụ akara epitaxy usoro

FIG. 4. Ọnọdụ dị oke egwu maka uto CVD site na 4H-SiC usoro epitaxy na-achịkwa nzọụkwụ

FIG. 5. Ntụle nke ọnụego uto n'okpuru isi mmalite silicon dị na 4H-SiC epitaxy

Ugbu a, teknụzụ silicon carbide epitaxy tozuru oke na ngwa voltaji dị ala na nke ọkara (dị ka ngwaọrụ 1200 volt). The ọkpụrụkpụ uniformity, doping ịta uniformity na ntụpọ nkesa nke epitaxial oyi akwa nwere ike iru a dịtụ mma larịị, nke nwere ike ihu ọma izute mkpa nke etiti na ala voltaji SBD (Schottky diode), MOS (metal oxide semiconductor ubi mmetụta transistor), JBS ( junction diode) na ngwaọrụ ndị ọzọ.

Otú ọ dị, n'ọhịa nke nrụgide dị elu, epitaxial wafers ka kwesịrị imeri ọtụtụ ihe ịma aka. Dịka ọmụmaatụ, maka ngwaọrụ ndị chọrọ iguzogide 10,000 volts, ọkpụrụkpụ nke oyi akwa epitaxial kwesịrị ịdị ihe dịka 100μm. E jiri ya tụnyere ngwaọrụ ndị dị ala voltaji, ọkpụrụkpụ nke oyi akwa epitaxial na ịdị n'otu nke ntinye doping dị nnọọ iche, karịsịa n'otu nke ntinye doping. N'otu oge ahụ, ntụpọ triangle dị na oyi akwa epitaxial ga-ebibikwa arụmọrụ nke ngwaọrụ ahụ. N'ime ngwa voltaji dị elu, ụdị ngwaọrụ na-ejikarị ngwaọrụ bipolar, nke chọrọ ndụ pere mpe dị elu na oyi akwa epitaxial, yabụ na ọ dị mkpa ka emeziwanye usoro ahụ iji melite obere oge ndụ.

Ka ọ dị ugbu a, epitaxy anụ ụlọ na-abụkarị inch 4 na 6 inch, na oke nke nnukwu silicon carbide epitaxy na-abawanye kwa afọ. Oke mpempe akwụkwọ silicon carbide epitaxial na-ejedebe nke ukwuu site na nha nke mkpụrụ osisi silicon carbide. Ka ọ dị ugbu a, a na-ere ngwaahịa silicon carbide nke anụ ọhịa 6, ya mere silicon carbide epitaxial na-eji nwayọọ nwayọọ na-agbanwe site na inch 4 ruo 6 sentimita. Site na mmụba na-aga n'ihu nke teknụzụ nkwadebe mkpụrụ osisi silicon carbide na mgbasawanye ikike, ọnụahịa nke mkpụrụ osisi silicon carbide na-eji nwayọọ nwayọọ na-ebelata. N'ime ihe mejupụtara ọnụ ahịa mpempe akwụkwọ epitaxial, mkpụrụ ihe na-akpata ihe karịrị 50% nke ọnụ ahịa ya, yabụ na mbelata nke ọnụahịa mkpụrụ, a na-atụkwa anya na ọnụ ahịa silicon carbide epitaxial sheet ga-ebelata.