Kungani Amadivayisi we-Semiconductor Adinga "I-Epitaxial Layer"

Umsuka Wegama elithi "Epitaxial Wafer"

Ukulungiswa kwe-wafer kunezinyathelo ezimbili eziyinhloko: ukulungiswa kwe-substrate kanye nenqubo ye-epitaxial. I-substrate yenziwe nge-semiconductor single crystal material futhi ivamise ukucutshungulwa ukuze kukhiqizwe amadivaysi e-semiconductor. Ingakwazi futhi ukucutshungulwa kwe-epitaxial ukuze yakhe i-epitaxial wafer. I-Epitaxy isho inqubo yokukhulisa ungqimba olusha lwekristalu ku-substrate eyodwa ecutshungulwe ngokucophelela. Ikristalu entsha eyodwa ingaba yinto efanayo ne-substrate (i-homogeneous epitaxy) noma into ehlukile (i-epitaxy ehlukile). Njengoba ungqimba olusha lwekristalu lukhula ngokuqondana ne-substrate's crystal orientation, lubizwa ngokuthi i-epitaxial layer. I-wafer ene-epitaxial layer ibizwa ngokuthi i-epitaxial wafer (i-epitaxial wafer = i-epitaxial layer + substrate). Amadivayisi enziwe kungqimba lwe-epitaxial abizwa ngokuthi “i-epitaxy eya phambili,” kuyilapho amadivayisi enziwe ku-substrate abizwa ngokuthi “i-epitaxy ehlehlayo,” lapho ungqimba lwe-epitaxial lusebenza kuphela njengosekelo.

I-Homogeneous and Heterogeneous Epitaxy

▪I-Homogeneous Epitaxy:I-epitaxial layer kanye ne-substrate zenziwe ngezinto ezifanayo: isb, i-Si/Si, i-GaAs/GaAs, i-GaP/GaP.

▪I-Heterogeneous Epitaxy:Isendlalelo se-epitaxial ne-substrate zenziwe ngezinto ezihlukene: isb, i-Si/Al₂O₃, i-GaS/Si, i-GaAlAs/GaAs, i-GaN/SiC, njll.

Ama-wafers aphucuziwe

Yiziphi Izinkinga I-Epitaxy Ezizixazulula?

Inqwaba yezinto zekristalu eyodwa azanele ukuhlangabezana nezidingo ezikhulayo eziyinkimbinkimbi zokwenziwa kwedivayisi ye-semiconductor. Ngakho-ke, ngasekupheleni kuka-1959, indlela yokukhula yezinto zekristalu encane eyaziwa ngokuthi i-epitaxy yasungulwa. Kepha ubuchwepheshe be-epitaxial busize kanjani ngokuqondile ukuthuthuka kwezinto? Ku-silicon, ukuthuthukiswa kwe-silicon epitaxy kwenzeka ngesikhathi esibucayi lapho ukwakhiwa kwe-high-frequency, high-power silicon transistors kubhekene nobunzima obukhulu. Ngokombono wezimiso ze-transistor, ukuzuza imvamisa ephezulu namandla kudinga ukuthi i-voltage yokuhlukaniswa kwesifunda esiqoqiwe ibe phezulu, nokumelana kochungechunge kube phansi, okusho ukuthi i-saturation voltage kufanele ibe mancane. Okwangaphambili kudinga ukumelana okuphezulu kwezinto zokuqoqa, kuyilapho lokhu kudinga ukuphikiswa okuphansi, okudala ukuphikisana. Ukunciphisa ukujiya kwesifunda somqoqi ukuze kuncishiswe ukumelana nochungechunge kungenza isicwecwana se-silicon sibe mncane kakhulu futhi sibe ntekenteke ukuze sicutshungulwe, futhi ukwehlisa ukumelana nakho kuzongqubuzana nemfuneko yokuqala. Ukuthuthukiswa kobuchwepheshe be-epitaxial kuxazulule le nkinga ngempumelelo. Isixazululo kwaba ukukhulisa ungqimba oluphezulu lwe-resistivity epitaxial ku-substrate ekwazi ukumelana nomzimba omncane. Idivayisi yenziwe ngesendlalelo se-epitaxial, iqinisekisa i-voltage ephezulu yokuwohloka kwe-transistor, kuyilapho i-substrate engaphansi kwe-resistivity inciphisa ukumelana nesisekelo futhi yehlisa i-voltage saturation, ixazulula ukungqubuzana phakathi kwezidingo ezimbili.

Ukwengeza, ubuchwepheshe be-epitaxial be-III-V kanye ne-II-VI semiconductors ehlanganisiwe efana ne-GaAs, i-GaN, nezinye, okuhlanganisa isigaba somhwamuko kanye ne-epitaxy yesigaba se-liquid, ibone ukuthuthuka okukhulu. Lobu buchwepheshe sebubalulekile ekwakhiweni kwama-microwave amaningi, ama-optoelectronic, namadivayisi kagesi. Ikakhulukazi, amasu afana ne-molecular beam epitaxy (MBE) kanye ne-metal-organic chemical vapor deposition (MOCVD) asetshenziswe ngempumelelo ezingxenyeni ezincane, ama-superlattice, imithombo ye-quantum, ama-superlattice ahlutshiwe, nezingqimba ze-epitaxial ezincane zesikali se-atomic, okubeka isisekelo esiqinile ukuthuthukiswa kwezinkambu ezintsha ze-semiconductor ezifana “ne-band engineering.”

Ezisetshenziswa ezingokoqobo, iningi lamadivaysi e-semiconductor e-wide-bandgap enziwa ezingqimbeni ze-epitaxial, nezinto ezifana ne-silicon carbide (SiC) esetshenziswa kuphela njengama-substrates. Ngakho-ke, ukulawula ungqimba lwe-epitaxial kuyisici esibalulekile embonini ye-wide-bandgap semiconductor.

I-Epitaxy Technology: Izici Eziyisihluthulelo Eziyisikhombisa

1. I-Epitaxy ingakhula ungqimba oluphezulu (noma oluphansi) lwe-resistivity ku-substrate ye-resistive ephansi (noma ephezulu).

2. I-Epitaxy ivumela ukukhula kohlobo lwe-N (noma P) lwezendlalelo ze-epitaxial kuma-substrates ohlobo lwe-P (noma N), okwakha ngokuqondile ukuhlangana kwe-PN ngaphandle kwezinkinga zesinxephezelo eziphakamayo lapho kusetshenziswa ukusabalalisa ukuze kudalwe ukuhlangana kwe-PN ku-substrate eyodwa yekristalu.

3. Uma kuhlanganiswe nobuchwepheshe bemaski, ukukhula kwe-epitaxial okukhethiwe kungenziwa ezindaweni ezithile, okuvumela ukwakhiwa kwamasekethe ahlanganisiwe namadivayisi anezakhiwo ezikhethekile.

4. Ukukhula kwe-Epitaxial kuvumela ukulawulwa kwezinhlobo ze-doping kanye nokugxilisa ingqondo, kanye nekhono lokufeza izinguquko eziphuthumayo noma kancane kancane ekugxilweni.

5. I-Epitaxy ingakhula inhlanganisela ehlukahlukene, enezendlalelo eziningi, enezingxenye eziningi ezinokwakheka okuguquguqukayo, okuhlanganisa izendlalelo ezincanyana kakhulu.

6. Ukukhula kwe-Epitaxial kungenzeka emazingeni okushisa angaphansi kwendawo yokuncibilika yezinto, ngezinga lokukhula elilawulekayo, okuvumela ukunemba kwezinga le-athomu ekujikeni kongqimba.

7. I-Epitaxy inika amandla ukukhula kwezingqimba zekristalu eyodwa yezinto ezingakwazi ukudonselwa kumakristalu, njenge-GaN nama-semiconductors enhlanganisela ye-ternary/quaternary.

Izendlalelo Ezihlukahlukene ze-Epitaxial kanye Nezinqubo ze-Epitaxial

Kafushane, izendlalelo ze-epitaxial zinikeza isakhiwo sekristalu esilawulwa kalula nesiphelele kunama-substrates amaningi, okuzuzisa ukuthuthukiswa kwezinto eziphambili.