Kutheni izixhobo zeSemiconductor zifuna "i-Epitaxial Layer"

Imvelaphi yegama elithi "Epitaxial Wafer"

Ukulungiswa kwe-wafer kunamanyathelo amabini aphambili: ukulungiswa kwe-substrate kunye nenkqubo ye-epitaxial. I-substrate yenziwe nge-semiconductor enye ye-crystal material kwaye isetyenziselwa ukuvelisa izixhobo ze-semiconductor. Isenokwenza i-epitaxial processing ukwenza i-epitaxial wafer. I-Epitaxy ibhekisa kwinkqubo yokukhulisa umaleko omtsha wekristale kwi-crystal substrate ecutshungulwe ngocoselelo. Ikristale entsha enye ingaba yinto efanayo ne-substrate (i-epitaxy e-homogeneous) okanye i-epitaxy eyahlukileyo (i-epitaxy engafaniyo). Kuba umaleko omtsha wekristale ukhula ngolungelelwaniso kunye ne-substrate's orientation crystal, ibizwa ngokuba yi-epitaxial layer. I-wafer ene-epitaxial layer ibizwa ngokuba yi-epitaxial wafer (i-epitaxial wafer = i-epitaxial layer + substrate). Izixhobo ezenziwe kwi-epitaxial layer zibizwa ngokuba yi "forward epitaxy," ngelixa izixhobo ezenziwe kwi-substrate zibizwa ngokuba yi "reverse epitaxy," apho i-epitaxial layer isebenza kuphela njengenkxaso.

I-Homogeneous kunye ne-Heterogeneous Epitaxy

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

▪I-Heterogeneous Epitaxy:I-epitaxial layer kunye ne-substrate zenziwe ngezinto ezahlukeneyo: umz, i-Si / Al₂O₃, i-GaS / Si, i-GaAlAs / i-GaAs, i-GaN / i-SiC, njl.

IiWafers ezikhazimlisiweyo

Zeziphi iingxaki eziSombulula i-Epitaxy?

Imathiriyeli yekristale eninzi iyodwa ayonelanga ukuhlangabezana neemfuno eziya zintsokotha kakhulu zokwenza isixhobo se-semiconductor. Ke ngoko, ngasekupheleni kuka-1959, kwaphuhliswa indlela yokukhulisa imathiriyeli yekristale enye eyaziwa ngokuba yi-epitaxy. Kodwa itekhnoloji ye-epitaxial incede njani ngokukodwa ukuqhubela phambili kwemathiriyeli? Kwi-silicon, ukuphuhliswa kwe-silicon epitaxy kwenzeka ngexesha elibalulekileyo xa ukuveliswa kwe-high-frequency, i-high-power silicon transistors ijongene nobunzima obunzima. Ngokwembono yemigaqo ye-transistor, ukufikelela kwi-frequency ephezulu kunye namandla kufuna ukuba amandla ombane wokuqhekeka kwendawo yokuqokelela abephezulu, kunye nokumelana nothotho kube sezantsi, okuthetha ukuba amandla ombane wokugcwala kufuneka abe mncinci. Eyangaphambili idinga ukuxhathisa okuphezulu kwizinto zomqokeleli, ngelixa lo mva ufuna ukuxhathisa okuphantsi, okudala ukuchasana. Ukunciphisa ubukhulu bommandla wokuqokelela ukunciphisa ukuxhathisa kunokwenza ukuba i-silicon wafer ibe mncinci kakhulu kwaye ibe buthathaka ukusetyenzwa, kwaye ukwehlisa ukumelana kuya kungqubana nemfuno yokuqala. Ukuphuhliswa kobuchwepheshe be-epitaxial kusombulula ngempumelelo lo mbandela. Isisombululo yayikukukhulisa i-resistivity epitaxial layer kwi-low-resistivity substrate. Isixhobo senziwe kwi-epitaxial layer, siqinisekisa ukuba i-voltage ephezulu yokuphuka kwe-transistor, ngelixa i-substrate ephantsi-resistivity inciphisa ukuchasana kwesiseko kunye nokunciphisa i-voltage saturation, ixazulula ukuphikisana phakathi kweemfuno ezimbini.

Ukongezelela, itekhnoloji ye-epitaxial ye-III-V kunye ne-II-VI ye-semiconductors edibeneyo efana ne-GaAs, i-GaN, kunye nabanye, kubandakanywa nesigaba somphunga kunye ne-epitaxy yesigaba solwelo, ibone ukuqhubela phambili okuphawulekayo. Ezi teknoloji ziye zayimfuneko ekwenziweni kwezixhobo ezininzi ze-microwave, i-optoelectronic, kunye nombane. Ngokukodwa, ubuchule obufana ne-molecular beam epitaxy (MBE) kunye ne-metal-organic chemical vapor deposition (MOCVD) zisetyenziswe ngempumelelo kumaleko amancinci, amaqula aphezulu, amaqula e-quantum, i-strained superlattices, kunye ne-atomic-scale epitaxial layers, ebeka isiseko esiqinileyo uphuhliso lwemimandla emitsha ye-semiconductor efana "nenjineli yebhendi."

Kwizicelo ezisebenzayo, uninzi lwezixhobo ezibanzi ze-bandgap semiconductor zenziwe kwi-epitaxial layers, kunye nemathiriyeli efana nesilicon carbide (SiC) esetyenziswa kuphela njenge substrates. Ke ngoko, ukulawula umaleko we-epitaxial yinto ebaluleke kakhulu kwishishini le-semiconductor ebanzi-bandgap.

IThekhnoloji ye-Epitaxy: Iimpawu ezisixhenxe eziphambili

1. I-Epitaxy inokukhula umgangatho ophezulu (okanye ophantsi) wokuxhathisa kwi-substrate ephantsi (okanye ephezulu).

2. I-Epitaxy ivumela ukukhula kwe-N (okanye i-P) yohlobo lwe-epitaxial layers kwi-P (okanye i-N) yohlobo lwe-substrates, ukwenza ngokuthe ngqo i-PN junction ngaphandle kwemiba yembuyekezo evelayo xa usebenzisa i-diffusion ukudala i-PN junction kwi-crystal substrate enye.

3. Xa kudibaniswa neteknoloji yemaski, ukukhula kwe-epitaxial okukhethiweyo kunokwenziwa kwiindawo ezithile, okwenza kube lula ukuveliswa kweesekethe ezidibeneyo kunye nezixhobo ezinezakhiwo ezikhethekileyo.

4. Ukukhula kwe-Epitaxial kuvumela ukulawulwa kweentlobo ze-doping kunye nogxininiso, kunye nokukwazi ukufezekisa utshintsho olukhawulezayo okanye ngokuthe ngcembe ekugxininiseni.

5. I-Epitaxy inokukhula i-heterogeneous, i-multi-layered, i-multi-component compounds kunye neengqungquthela eziguquguqukayo, ezibandakanya i-ultra-thin layers.

6. Ukukhula kwe-Epitaxial kungenzeka kumaqondo okushisa angaphantsi kwendawo yokunyibilika kwezinto, kunye nezinga lokukhula elilawulekayo, okuvumela ukuchaneka kwe-atomic-level in layer.

7. I-Epitaxy ivumela ukukhula kwe-crystal layers enye yezinto ezingenakutsalwa kwiikristale, ezifana ne-GaN kunye ne-ternary / quaternary compound semiconductors.

Iintlobo ezahlukeneyo ze-Epitaxial Layers kunye ne-Epitaxial Processes

Isishwankathelo, iileya ze-epitaxial zibonelela ngesakhiwo sekristale esilawulwa ngokulula kunye nesigqibeleleyo kune-substrates eninzi, enenzuzo ekuphuhliseni izinto eziphambili.