1. Inzira nyamukuru ya plasma yongereye imyuka ya chimique
Plasma yazamuye imyuka ya chimique (PECVD) nubuhanga bushya bwo gukura kwa firime yoroheje hifashishijwe imiti y’ibintu bya gaze hifashishijwe plasma isohoka. Kuberako tekinoroji ya PECVD itegurwa no gusohora gaze, ibiranga reaction ya plasma idahwanye neza ikoreshwa neza, kandi uburyo bwo gutanga ingufu za reaction zahinduwe muburyo bukomeye. Muri rusange, iyo tekinoroji ya PECVD ikoreshwa mugutegura firime yoroheje, imikurire ya firime yoroheje cyane ikubiyemo inzira eshatu zingenzi zikurikira:
Ubwa mbere, muri plasma idafite uburinganire, electron zifata gaze ya reaction mubyiciro byambere kugirango ibore gaze ya reaction hanyuma ikore uruvange rwa ion nitsinda rikora;
Icya kabiri, ubwoko bwose bwamatsinda akora arakwirakwira no gutwara hejuru no kurukuta rwa firime, kandi reaction ya kabiri hagati ya reaction iba icyarimwe;
Ubwanyuma, ubwoko bwose bwibicuruzwa byambere nubwa kabiri bigera ku buso bwikura byamamajwe kandi bigakora hamwe nubuso, biherekejwe no kurekura molekile ya gaze.
By'umwihariko, tekinoroji ya PECVD ishingiye ku buryo bwo gusohora urumuri rushobora gutuma gaze ya ionisiyonike ikora plasma mu rwego rwo gushimishwa n'umuriro w'amashanyarazi wo hanze. Muri plasma isohoka, ingufu za kinetic ya electron yihutishwa numurima wamashanyarazi wo hanze ubusanzwe iba nka 10ev, cyangwa irenga, ibyo birahagije kugirango isenye imiti ya molekile ya gaze ikora. Kubwibyo, binyuze mu kugongana kudafite ingufu za electron zifite ingufu nyinshi na molekile ya gaze ikora, molekile ya gaze izahinduka ion cyangwa ibora kugirango ikore atome zidafite aho zibogamiye nibicuruzwa bya molekile. Iyoni nziza yihutishwa na ion layer yihutisha amashanyarazi kandi igongana na electrode yo hejuru. Hariho kandi agace gato k'umuriro w'amashanyarazi hafi ya electrode yo hepfo, bityo substrate nayo igaterwa na ion kurwego runaka. Nkigisubizo, ibintu bidafite aho bibogamiye biterwa no kubora bigenda bitandukana kurukuta rwa tube na substrate. Muburyo bwo gutembera no gukwirakwira, ibyo bice hamwe nitsinda (atome na chimique ikora bitagira aho bibogamiye byitwa amatsinda) bizakorwa na ion molekile reaction hamwe na molekile ya reaction bitewe ninzira ngufi yubusa. Imiterere yimiti yibintu bikora (cyane cyane amatsinda) bigera kuri substrate kandi byamamajwe birakora cyane, kandi firime ikorwa nubufatanye hagati yabo.
2. Imyitwarire yimiti muri plasma
Kuberako gushimishwa na gaze ya reaction mubikorwa byo gusohora glow ahanini bigongana na electron, reaction yibanze muri plasma iratandukanye, kandi imikoranire hagati ya plasma nubuso bukomeye nayo iragoye cyane, bigatuma bigora kwiga uburyo. ya PECVD. Kugeza ubu, sisitemu nyinshi zingenzi zashizwe mubikorwa nubushakashatsi kugirango tubone firime zifite ibintu byiza. Kugirango hashyizwemo firime yoroheje ishingiye kuri silicon ishingiye ku ikoranabuhanga rya PECVD, niba uburyo bwo kubitsa bushobora kugaragara cyane, igipimo cyo kohereza ama firime yoroheje ashingiye kuri silikoni gishobora kwiyongera cyane hashingiwe ku kwemeza ibintu byiza bifatika bifatika.
Kugeza ubu, mu bushakashatsi bwakozwe na firime yoroheje ishingiye kuri silicon, hydrogen diluted silane (SiH4) ikoreshwa cyane nka gaze ya reaction kuko hari umubare munini wa hydrogène muri firime yoroheje ishingiye kuri silicon. H ifite uruhare runini cyane muri silicon ishingiye kuri firime yoroheje. Irashobora kuzuza imigozi ihindagurika muburyo bwibintu, igabanya cyane urwego rwingufu zifite inenge, kandi byoroshye kumenya valence electron igenzura ibikoresho Kuva icumu nibindi. Bwa mbere bamenye ingaruka za doping ya firime yoroheje ya silicon hanyuma bategura ihuriro rya mbere rya PN muri, ubushakashatsi bujyanye no gutegura no gushyira mu bikorwa ama firime yoroheje ashingiye kuri silicon ashingiye ku ikoranabuhanga rya PECVD yateguwe no gusimbuka. Kubwibyo, imiti yimiti muri silicon ishingiye kuri firime yoroheje yashyizwe mu buhanga bwa PECVD izasobanurwa kandi iganirwaho muri ibi bikurikira.
Mugihe cyo gusohora kwinshi, kubera ko electron muri plasma ya silane zifite ingufu zirenze nyinshi za EV, H2 na SiH4 zizabora mugihe zihuye na electron, zikaba ari reaction yambere. Niba tudasuzumye leta zishimye hagati, turashobora kubona reaction zikurikira zo gutandukana kwa sihm (M = 0,1,2,3) hamwe na 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)
Ukurikije ubushyuhe busanzwe bwo gutanga umusaruro wa molekile ya leta yubutaka, ingufu zisabwa muburyo bwo gutandukana hejuru (2.1) ~ (2.5) ni 2.1, 4.1, 4.4, 5.9 EV na 4.5 EV. Imbaraga za electron nyinshi muri plasma nazo zirashobora gukurikira reaction ya ionisation ikurikira
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)
Ingufu zisabwa kuri (2.6) ~ (2.9) ni 11.9, 12.3, 13.6 na 15.3 EV. Bitewe no gutandukanya ingufu za reaction, amahirwe yo (2.1) ~ (2.9) reaction ntago aringaniye. Mubyongeyeho, sihm yashizweho hamwe nuburyo bwo kubyitwaramo (2.1) ~ (2.5) bizakurikiraho ibya kabiri bikurikira kuri ionize, nka
SiH + e → SiH ++ 2e (2.10)
SiH2 + e → SiH2 ++ 2e (2.11)
SiH3 + e → SiH3 ++ 2e (2.12)
Niba reaction yavuzwe haruguru ikorwa hakoreshejwe inzira imwe ya electron, ingufu zisabwa ni 12 eV cyangwa zirenga. Urebye ko umubare wa electron zifite ingufu nyinshi ziri hejuru ya 10ev muri plasma idafite ionisiyonike ifite ubucucike bwa electron ya 1010cm-3 ni ntoya ugereranije n’umuvuduko w’ikirere (10-100pa) kugirango hategurwe firime zishingiye kuri silikoni, The cumulative ionisation ishoboka muri rusange ni ntoya kuruta kwishima. Kubwibyo, igipimo cyibintu byavuzwe haruguru muri silane plasma ni gito cyane, kandi itsinda ridafite aho ribogamiye rya sihm ryiganje. Ibisubizo by'isesengura rusange byerekana kandi uyu mwanzuro [8]. Bourquard n'abandi. Ikindi cyagaragaje ko kwibanda kwa sihm byagabanutse ukurikije gahunda ya sih3, sih2, Si na SIH, ariko kwibanda kwa SiH3 byikubye inshuro eshatu ibya SIH. Robertson n'abandi. Yavuze ko mu bicuruzwa bitagira aho bibogamiye bya sihm, silane yera yakoreshejwe cyane cyane mu gusohora ingufu nyinshi, mu gihe sih3 yakoreshejwe cyane cyane mu gusohora ingufu nke. Urutonde rwo kwibanda kuva hejuru kugeza hasi ni SiH3, SiH, Si, SiH2. Kubwibyo, ibipimo bya plasma bigira ingaruka zikomeye kubigize sihm idafite aho ibogamiye.
Usibye gutandukana hejuru no gutandukana kwa ionisiyoneri, reaction ya kabiri hagati ya molekile ya ionic nayo ni ngombwa cyane
SiH2 ＋+ SiH4 → SiH3 ++ SiH3 (2.13)
Kubwibyo, kubijyanye na ion yibanze, sih3 + irenze sih2 +. Irashobora gusobanura impamvu hariho sih3 + ion nyinshi kuruta sih2 + ion muri plasma ya SiH4.
Byongeye kandi, hazabaho reaction ya atome ya molekile aho atome ya hydrogen muri plasma ifata hydrogene muri SiH4
H + SiH4 → SiH3 + H2 (2.14)
Nibisubizo bidasanzwe kandi bibanziriza gushiraho si2h6. Nibyo, ayo matsinda ntabwo ari mubutaka gusa, ahubwo anashimishijwe na reta yishimye muri plasma. Ibyuka bihumanya bya plasma ya silane byerekana ko hari leta zinzibacyuho zemewe zishimishije za Si, SIH, h, hamwe na leta zishimishije za SiH2, SiH3
Igihe cyo kohereza: Apr-07-2021