Epitaxial layers inobatsira sei semiconductor zvishandiso?

Kwakabva zita rekuti epitaxial wafer

Chekutanga, ngatiparidzire pfungwa diki: kugadzirira kwewafer kunosanganisira maviri makuru link: substrate kugadzirira uye epitaxial process. Iyo substrate iwafer yakagadzirwa semiconductor single crystal material. Iyo substrate inogona kupinda zvakananga mukugadzira wafer kugadzira zvigadzirwa zve semiconductor, kana inogona kugadziriswa ne epitaxial maitiro kugadzira epitaxial wafers. Epitaxy inoreva nzira yekukura mutsva wekrisiti imwe chete pane imwe crystal substrate yakanyatsogadziriswa nekucheka, kugaya, kupukuta, nezvimwewo. Iyo itsva crystal inogona kunge yakafanana neyo substrate, kana inogona kuva zvinhu zvakasiyana (homogeneous) epitaxy kana heteroepitaxy). Nekuti iyo nyowani yekristaro layer inotambanuka uye inokura zvinoenderana nekristaro chikamu cheiyo substrate, inonzi epitaxial layer (iyo ukobvu kazhinji mamicrons mashoma, kutora silicon semuenzaniso: zvinoreva silicon epitaxial kukura iri pasilicon imwe chete. kristaro substrate ine imwe kristaro yakatarisana neyakagadzika yekristaro ine yakanaka lattice chimiro kutendeseka uye kwakasiyana resistivity uye ukobvu ine yakafanana kristaro kutaridzika sezvo substrate inokura), uye iyo substrate ine epitaxial layer inonzi epitaxial wafer (epitaxial wafer = epitaxial layer + substrate). Kana chigadzirwa chacho chakaitwa pane epitaxial layer, inonzi positive epitaxy. Kana chigadzirwa chacho chakaitwa pane substrate, inonzi reverse epitaxy. Panguva ino, iyo epitaxial layer inongoita basa rekutsigira.

Chimedu chakanatswa

Epitaxial kukura nzira

Molecular beam epitaxy (MBE): Iyo semiconductor epitaxial kukura tekinoroji inoitwa pasi pe-ultra-high vacuum mamiriro. Mune iyi tekinoroji, sosi zvinhu zvinonyungudutswa muchimiro chedanda reatomu kana mamorekuru uye zvozoiswa pane yekristaro substrate. MBE ndeye chaiyo uye inodzoreka semiconductor mutete firimu kukura tekinoroji inogona kunyatso kudzora ukobvu hwezvinhu zvakaiswa padanho reatomu.
Metal organic CVD (MOCVD): Muchiitiko cheMOCVD, organic simbi uye hydride gasi N gasi ine zvinhu zvinodiwa inopihwa kune substrate pane tembiricha yakakodzera, inoitwa kemikari kuita kuti igadzire inodiwa semiconductor zvinhu, uye inoiswa pane substrate. pa, apo asara macompounds uye reaction products zvinobviswa.
Vapor phase epitaxy (VPE): Vapor phase epitaxy ndiyo tekinoroji yakakosha inowanzoshandiswa mukugadzira michina yesemiconductor. Nheyo yakakosha ndeyekutakura mhute yezvinhu zvekutanga kana makomisheni mune inotakura gasi, uye kuisa makristasi pane substrate kuburikidza nekuita kwemakemikari.

Ndeapi matambudziko anogadziriswa epitaxy process?

Chete zvakawanda zvekristaro zvinhu hazvigone kusangana nezvinodiwa zvinokura zvekugadzira akasiyana semiconductor zvishandiso. Naizvozvo, epitaxial kukura, yakaonda-layer imwe crystal zvinhu kukura tekinoroji, yakagadziridzwa pakupera kwa1959. Saka ndeupi mupiro chaiwo une epitaxy tekinoroji mukufambisira mberi kwezvinhu?

Kune silicon, apo silicon epitaxial kukura tekinoroji yakatanga, yaive nguva yakaoma yekugadzirwa kwesilicon yakakwira-frequency uye yakakwirira-simba transistors. Kubva pamaonero emisimboti ye transistor, kuti uwane yakakwira frequency uye yakakura simba, iyo yekuputsika voltage yenzvimbo yekuunganidzira inofanirwa kunge yakakwira uye nhevedzano yekurwisa inofanira kunge iri diki, ndiko kuti, kudonha kwemagetsi kunofanirwa kuve kudiki. Iyo yekare inoda kuti resistivity yezvinhu munzvimbo yekuunganidza inofanira kuva yakakwirira, nepo iyo yekupedzisira inoda kuti resistivity yezvinhu munzvimbo yekuunganidza inofanira kuva yakaderera. Matunhu maviri aya anopokana. Kana ukobvu hwezvinhu munzvimbo yekuunganidzira hukadzikiswa kudzikisa kutevedzana kwekupokana, iyo silicon wafer ichave yakatetepa uye isina kusimba kuti igadziriswe. Kana iyo resistivity yezvinhu yakaderedzwa, inopesana nezvinodiwa zvekutanga. Zvisinei, kubudirira kwe epitaxial teknolojia yakabudirira. yakagadzirisa dambudziko iri.

Solution: Kura yakakwira-resistivity epitaxial layer pane yakanyanya kuderera-resistance substrate, uye ita mudziyo pane epitaxial layer. Iyi yakakwirira-resistivity epitaxial layer inovimbisa kuti chubhu ine high breakdown voltage, nepo pasi-resistance substrate Inoderedzawo kushorwa kwe substrate, nokudaro kuderedza saturation voltage drop, nokudaro kugadzirisa kupesana pakati pezviviri.

Pamusoro pezvo, tekinoroji epitaxy senge vapor phase epitaxy uye liquid phase epitaxy yeGaAs uye imwe III-V, II-VI uye mamwe mamolecular compound semiconductor zvinhu zvakagadziridzwa zvakanyanya uye zvave hwaro hwemazhinji microwave zvishandiso, optoelectronic zvishandiso, simba. Iyo yakakosha maitiro tekinoroji pakugadzirwa kwemidziyo, kunyanya kushandiswa kwakabudirira kwemamorekuru danda uye simbi organic vapor chikamu epitaxy tekinoroji mumatehwe matete, superlattices, quantum matsime, strained superlattices, uye atomic-level yakatetepa-layer epitaxy, inova nhanho nyowani mukutsvaga semiconductor. Kuvandudzwa kwe "energy belt engineering" mumunda kwakaisa hwaro hwakasimba.

Mumashandisirwo anoshanda, yakafara bandgap semiconductor zvishandiso zvinowanzogadzirwa pane epitaxial layer, uye iyo silicon carbide wafer pachayo inongoshanda seiyo substrate. Naizvozvo, kutonga kweiyo epitaxial layer chikamu chakakosha cheyakafara bandgap semiconductor indasitiri.

7 hunyanzvi hunyanzvi mune epitaxy tekinoroji

1. Yakakwirira (yakaderera) inopikisa epitaxial layers inogona kukura epitaxially pane yakaderera (yakakwirira) yekudzivirira substrates.
2. The N (P) type epitaxial layer inogona kukura epitaxially paP (N) type substrate kuti iite PN junction zvakananga. Iko hakuna dambudziko remuripo kana uchishandisa nzira yekuparadzira kugadzira PN junction pane imwechete crystal substrate.
3. Yakasanganiswa ne teknolojia yemasiki, inosarudza epitaxial kukura inoitwa munzvimbo dzakatarwa, kugadzira mamiriro ekugadzirwa kwemasekete akabatanidzwa nemichina ine zvivako zvakakosha.
4. Mhando uye kusungirirwa kwedoping kunogona kuchinjwa maererano nezvinodiwa panguva ye epitaxial kukura. Shanduko yekuisa pfungwa inogona kuve shanduko yakangoerekana yachinja kana kunonoka kuchinja.
5. Inogona kukura zvakasiyana-siyana, zvakasiyana-siyana, zvakasiyana-siyana zvinosanganiswa uye ultra-thin layers ine zvikamu zvakasiyana.
6. Kukura kweEpitaxial kunogona kuitwa pane tembiricha yakaderera pane yekunyungudika kwezvinhu, chiyero chekukura chinodzoreka, uye epitaxial kukura kweatomic-level thickness inogona kuwanikwa.
7. Inogona kukura imwe crystal zvinhu zvisingagoni kudhonzwa, zvakadai seGaN, single crystal layers ye tertiary uye quaternary compounds, nezvimwewo.