1. Ngā tukanga matua o te whakapūtanga matū i roto i te plasma
Ko te PECVD (Plasma Enhanced Chemical Deposition) he hangarau hou mō te whakatipu i ngā kiriata angiangi mā te tauhohenga matū o ngā matū hau me te āwhina o te plasma tukunga kanapa. Nā te mea ka whakaritea te hangarau PECVD mā te tukunga hau, ka whakamahia pai ngā āhuatanga tauhohenga o te plasma kore-taurite, ā, ka tino rerekē te aratau tuku pūngao o te pūnaha tauhohenga. I te nuinga o te wā, ina whakamahia te hangarau PECVD hei whakarite i ngā kiriata angiangi, ko te whakatipu i ngā kiriata angiangi ko ngā tukanga matua e toru e whai ake nei.
Tuatahi, i roto i te plasma kore-taurite, ka tauhohe ngā irahiko ki te hau tauhohenga i te wāhanga tuatahi hei wawahi i te hau tauhohenga, hei hanga i te ranunga o ngā katote me ngā rōpū hohe;
Tuarua, ka horapa, ka haria hoki ngā momo rōpū hohe katoa ki te mata me te pakitara o te kiriata, ā, ka puta ngā tauhohenga tuarua i waenga i ngā matū tauhohe i te wā kotahi;
Hei whakamutunga, ka mimitihia ngā momo hua tauhohenga tuatahi me tuarua katoa e tae atu ana ki te mata tipu, ka tauhohe ki te mata, me te tukunga anō o ngā ngota hau.
Ina koa, mā te hangarau PECVD e hangai ana ki te tikanga tukunga kanapa ka taea te whaka-ioniti i te hau tauhohenga hei hanga i te plasma i raro i te whakaoho o te papa hikohiko o waho. I roto i te plasma tukunga kanapa, ko te kaha nekeneke o ngā irahiko e whakaterea ana e te papa hiko o waho he tata ki te 10ev, neke atu rānei, he nui hei whakangaro i ngā hononga matū o ngā ngota hau tauhohe. Nō reira, mā te tukinga kore-whakapūmau o ngā irahiko kaha-tiketike me ngā ngota hau tauhohe, ka whaka-ionitihia, ka pakaruhia rānei ngā ngota hau hei whakaputa i ngā ngota koretake me ngā hua ngota. Ka whakaterea ngā katote pai e te papa hiko whakaterea o te papa katote, ā, ka tukinga ki te irahiko o runga. He papa hiko papa katote iti anō hoki kei te taha o te irahiko o raro, nō reira ka pāngia hoki te papa e ngā katote ki tētahi taumata. Nō reira, ka horapa te matū koretake i hangaia e te pirau ki te pakitara ngongo me te papa. I roto i te tukanga o te neke me te horapa, ka pāngia ēnei matūriki me ngā rōpū (ko ngā ngota me ngā ngota koretake hohe matū e kiia ana he rōpū) e te tauhohenga ngota katote me te tauhohenga ngota rōpū nā te ara kore utu poto toharite. He tino hohe ngā āhuatanga matū o ngā matū hohe (ko te nuinga he rōpū) e tae atu ana ki te papa, ā, ka mimitia, ā, ka hangaia te kiriata mā te taunekeneke i waenganui i a rātou.
2. Ngā tauhohenga matū i roto i te toto
Nā te mea ko te whakaoho o te hau tauhohenga i roto i te tukanga tukunga kanapa he tukinga irahiko te nuinga, he rerekē ngā tauhohenga taketake i roto i te plasma, ā, he tino uaua hoki te taunekeneke i waenga i te plasma me te mata totoka, e uaua ake ai te ako i te tikanga o te tukanga PECVD. Tae noa ki tēnei wā, he maha ngā pūnaha tauhohenga nui kua arotauhia e ngā whakamātautau kia whiwhi kiriata me ngā āhuatanga tino pai. Mō te whakatakotoranga o ngā kiriata angiangi e ahu mai ana i te silicon i runga i te hangarau PECVD, mena ka taea te whakaatu hohonu i te tikanga whakatakotoranga, ka taea te whakanui ake i te tere whakatakotoranga o ngā kiriata angiangi e ahu mai ana i te silicon i runga i te kaupapa o te whakarite i ngā āhuatanga ā-tinana pai o ngā rauemi.
I tēnei wā, i roto i te rangahau o ngā kiriata angiangi e ahu mai ana i te silicon, he whānuitia te whakamahinga o te hauwai waimeha silane (SiH4) hei hau tauhohenga nā te mea he nui te hauwai i roto i ngā kiriata angiangi e ahu mai ana i te silicon. He tino nui te mahi a te H i roto i ngā kiriata angiangi e ahu mai ana i te silicon. Ka taea e ia te whakakī i ngā hononga iri i roto i te hanganga rauemi, te whakaiti nui i te taumata pūngao hapa, me te ngāwari ki te whakatutuki i te whakahaere irahiko valence o ngā rauemi. Mai i te kitenga tuatahi a Spear et al. i te pānga tāpiri o ngā kiriata angiangi silicon me te whakarite i te hononga PN tuatahi i te tau, kua whanake haere te rangahau mō te whakarite me te tono o ngā kiriata angiangi e ahu mai ana i te silicon i runga i te hangarau PECVD. Nō reira, ka whakaahuahia, ka matapakihia hoki te tauhohenga matū i roto i ngā kiriata angiangi e ahu mai ana i te silicon i whakatakotoria e te hangarau PECVD i roto i ngā tuhinga e whai ake nei.
I raro i te āhua tukunga kanapa, nā te mea he nui ake i te maha o ngā pūngao EV o ngā irahiko i roto i te plasma silane, ka memeha a H2 me SiH4 ina tukinga rāua e ngā irahiko, nō roto i te tauhohenga tuatahi. Ki te kore tātou e whakaaro ki ngā āhua whakahihiri waenga, ka taea e tātou te whiwhi i ngā tauhohenga wehenga e whai ake nei o te sihm (M = 0,1,2,3) me te H
e+SiH4→SiH2+H2+e (2.1)
e+SiH4→SiH3+ H+e (2.2)
e+SiH4→Si+2H2+e (2.3)
e+SiH4→SiH+H2+H+e (2.4)
e+H2→2H+e (2.5)
E ai ki te wera paerewa o te whakaputanga o ngā ngota whenua, ko ngā pūngao e hiahiatia ana mō ngā tukanga wetewete i runga ake nei (2.1) ~ (2.5) ko 2.1, 4.1, 4.4, 5.9 EV me te 4.5 EV. Ka taea hoki e ngā irahiko pūngao teitei i roto i te plasma te whai i ngā tauhohenga ionization e whai ake nei.
e+SiH4→SiH2++H2+2e (2.6)
e+SiH4→SiH3++ H+2e (2.7)
e+SiH4→Si++2H2+2e (2.8)
e+SiH4→SiH++H2+H+2e (2.9)
Ko te pūngao e hiahiatia ana mō (2.6) ~ (2.9) ko 11.9, 12.3, 13.6 me te 15.3 EV. Nā te rerekētanga o te pūngao tauhohenga, he tino koretake te tūponotanga o ngā tauhohenga (2.1) ~ (2.9). Hei tāpiri, ko te sihm i hangaia me te tukanga tauhohenga (2.1) ~ (2.5) ka pāngia e ngā tauhohenga tuarua e whai ake nei kia ionize, pērā i
SiH+e→SiH++2e (2.10)
SiH2+e→SiH2++2e (2.11)
SiH3+e→SiH3++2e (2.12)
Mena ka whakahaerehia te tauhohenga i runga ake nei mā te tukanga irahiko kotahi, ko te kaha e hiahiatia ana he tata ki te 12 eV, neke atu rānei. I te mea he iti noa te maha o ngā irahiko kaha-teitei i runga ake i te 10ev i roto i te plasma ngoikore-ionized me te kiato irahiko o te 1010cm-3 i raro i te pēhanga hau (10-100pa) mō te whakarite i ngā kiriata silicon-based, ko te tūponotanga o te ionization kohikohi he iti ake i te tūponotanga whakaoho. Nō reira, he tino iti te ōwehenga o ngā matū ionized i runga ake nei i roto i te plasma silane, ā, ko te rōpū kūpapa o te sihm te mea matua. E whakaatu ana hoki ngā hua tātaritanga papatipu i tēnei whakatau [8]. I tohu anō a Bourquard et al. I heke te kukū o te sihm i te raupapa o te sih3, sih2, Si me te SIH, engari ko te kukū o te SiH3 e toru ngā wā neke atu i te SIH. I kōrero a Robertson et al. I roto i ngā hua kūpapa o te sihm, ko te silane parakore te nuinga i whakamahia mō te tukunga mana-teitei, ko te sih3 te nuinga i whakamahia mō te tukunga mana-iti. Ko te raupapa o te kukū mai i te teitei ki te iti ko SiH3, SiH, Si, SiH2. Nō reira, he kaha te pānga o ngā tawhā tukanga plasma ki te hanganga o ngā hua sihm kūpapa.
Haunga ngā tauhohenga wehewehe me te ionization i runga ake nei, he mea tino nui anō hoki ngā tauhohenga tuarua i waenga i ngā ngota ionic.
SiH2＋+SiH4→SiH3++SiH3 (2.13)
Nō reira, e ai ki te kukū o ngā katote, he nui ake te sih3 + i te sih2 +. Ka taea e ia te whakamārama he aha i nui ake ai ngā katote sih3 + i ngā katote sih2 + i roto i te toto SiH4.
Hei tāpiritanga, ka puta he tauhohenga tukinga ngota ngota ka hopukina e ngā ngota hauwai i roto i te toto te hauwai i roto i te SiH4.
H+ SiH4→SiH3+H2 (2.14)
He tauhohenga werawera tēnei, ā, he matū mua mō te hanganga o te si2h6. Heoi anō, ehara i te mea kei te āhua whenua anake ēnei rōpū, engari kei te whakaohokia hoki ki te āhua whakaohokia i roto i te parāuma. E whakaatu ana ngā hihi tukunga o te parāuma silane kei reira ngā āhua whakaohokia whakawhiti e whakaaetia ana e te whatu o Si, SIH, h, me ngā āhua whakaohokia wiri o SiH2, SiH3.
Wā tuku: Paenga-whāwhā-07-2021