1. Iinkqubo eziphambili zeplasma yokuphucula ukubekwa komphunga wekhemikhali
I-Plasma ephuculweyo yokubeka umphunga wekhemikhali (PECVD) bubuchwephesha obutsha bokukhula kweefilim ezibhityileyo ngokusabela kweekhemikhali zezinto ezinerhasi ngoncedo lweplasma yokukhupha ukukhanya. Ngenxa yokuba itekhnoloji ye-PECVD ilungiselelwe ngokukhutshwa kwegesi, iimpawu zokusabela zeplasma ezingalinganiyo zisetyenziswa ngokufanelekileyo, kwaye imowudi yonikezelo lwamandla yenkqubo yokusabela iguqulwa ngokusisiseko. Ngokubanzi, xa itekhnoloji yePECVD isetyenziselwa ukulungiselela iifilimu ezibhityileyo, ukukhula kweefilimu ezibhityileyo ikakhulu kubandakanya ezi nkqubo zintathu zilandelayo.
Okokuqala, kwi-plasma engekho-equilibrium, ii-electron zisabela nge-reaction gas kwinqanaba lokuqala ukubola igesi yokusabela kwaye zenze umxube we-ion kunye namaqela asebenzayo;
Okwesibini, zonke iintlobo zamaqela asebenzayo zisasazeka kwaye zithuthelwa phezulu kunye nodonga lwefilimu, kunye neempendulo zesibini phakathi kwee-reactants zenzeka ngexesha elifanayo;
Ekugqibeleni, zonke iintlobo zeemveliso eziphambili kunye nezesekondari ezifikelela kumphezulu wokukhula ziyabhengezwa kwaye zisabela ngomphezulu, zikhatshwa kukukhutshwa kwakhona kweeathom zegesi.
Ngokukodwa, itekhnoloji ye-PECVD esekwe kwindlela yokukhutshwa okukhanyayo inokwenza i-ionize yegesi yokusabela yenze iplasma phantsi kochulumanco lwentsimi ye-electromagnetic yangaphandle. Kwiplasma yokukhutshwa okukhanyayo, amandla e-kinetic ee-electron akhawuleziswa yintsimi yombane yangaphandle ngokuqhelekileyo malunga ne-10ev, okanye nangaphezulu, eyaneleyo ukutshabalalisa iibhondi zekhemikhali ze-molecule zegesi esebenzayo. Ke ngoko, ngokungqubana kwe-inelastic yee-electron zamandla aphezulu kunye neamolekyu zegesi ezisebenzayo, iimolekyuli zegesi ziya kuba ionized okanye ziboliswe ukuvelisa iiathomu ezingathathi hlangothi kunye neemveliso zemolekyuli. I-ion e-positive ikhawuleza i-ion layer ikhawuleza intsimi yombane kwaye ingqubane ne-electrode ephezulu. Kukwakho nendawo encinci yombane ye-ion kufutshane ne-electrode esezantsi, ngoko ke i-substrate iphinda ihlaselwe yi-ion ukuya kwinqanaba elithile. Ngenxa yoko, i-substance engathathi hlangothi eveliswa ngokuchithwa isasazeka kwindonga ye-tube kunye ne-substrate. Kwinkqubo yokukhukuliseka kunye nokusabalalisa, la masuntswana kunye namaqela (i-athomu engathathi hlangothi ngokwekhemikhali kunye neemolekyuli zibizwa ngokuba ngamaqela) ziya kusabela kwi-ion molekyuli kunye nokusabela kwemolekyuli yeqela ngenxa yendlela emfutshane ekhululekileyo. Iimpawu zeekhemikhali zezinto ezisebenzayo zeekhemikhali (ikakhulukazi amaqela) ezifikelela kwi-substrate kwaye i-adsorbed iyasebenza kakhulu, kwaye ifilimu yenziwe ngokusebenzisana phakathi kwabo.
2. Ukuphendulwa kweekhemikhali kwiplasma
Ngenxa yokuba uchulumanco lwerhasi esabelayo kwinkqubo yokukhutshwa kokukhanya ikakhulu kukungqubana kwe-electron, iimpendulo ezisisiseko kwiplasma ziyahlukahlukana, kwaye intsebenziswano phakathi kweplasma kunye nomgangatho oqinileyo nayo intsonkothile kakhulu, nto leyo eyenza kube nzima ngakumbi ukufunda umatshini. yenkqubo ye-PECVD. Ukuza kuthi ga ngoku, uninzi lweenkqubo zokusabela ezibalulekileyo ziye zalungiswa ngovavanyo lokufumana iifilimu ezineempawu ezifanelekileyo. Ukubekwa kweefilimu ezibhityileyo ezisekwe kwi-silicon esekwe kwitekhnoloji ye-PECVD, ukuba indlela yokubeka inokutyhilwa ngokunzulu, ireyithi yokubeka iifilimu ezibhityileyo ezisekwe kwisilicon inokunyuswa kakhulu kwindawo yokuqinisekisa ezona mpawu zibalaseleyo zemathiriyeli.
Okwangoku, kuphando lweefilimu ezincinci ezisekelwe kwi-silicon, i-hydrogen diluted silane (SiH4) isetyenziswa ngokubanzi njengegesi yokusabela kuba kukho umlinganiselo othile we-hydrogen kwiifilimu ezincinci ezisekelwe kwi-silicon. I-H idlala indima ebaluleke kakhulu kwiifilimu ezincinci ezisekelwe kwi-silicon. Iyakwazi ukuzalisa iibhondi ezijingayo kwisakhiwo sezinto eziphathekayo, ukunciphisa kakhulu inqanaba lamandla anesiphene, kwaye kulula ukuqonda i-electron ye-valence yokulawula izinto Ekubeni umkhonto et al. Okokuqala yaqonda impembelelo ye-doping yeefilimu ezibhityileyo ze-silicon kwaye yalungiselela indawo yokuqala ye-PN, uphando malunga nokulungiswa kunye nokusetyenziswa kweefilimu ezibhityileyo ezisekelwe kwi-silicon esekelwe kwi-teknoloji ye-PECVD iye yaphuhliswa ngokuxhuma kunye nemida. Ngoko ke, ukuphendulwa kweekhemikhali kwiifilimu ezincinci ezisekelwe kwi-silicon ezifakwe kwi-teknoloji ye-PECVD ziya kuchazwa kwaye zixutyushwe ngokulandelayo.
Ngaphantsi kwemeko yokukhutshwa kokukhanya, ngenxa yokuba ii-electron kwi-plasma ye-silane inamandla angaphezu kwee-EV ezininzi, i-H2 kunye ne-SiH4 ziya kubola xa zidibene nee-electron, ezizezokuqala. Ukuba asiyi kuqwalasela amazwe aphakathi anemincili, sinokufumana ezi mpendulo zilandelayo ze-dissociation ye-sihm (M = 0,1,2,3) kunye no-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)
Ngokutsho kobushushu obuqhelekileyo bokuveliswa kweeamolekyu zombuso womhlaba, amandla afunekayo kwiinkqubo zokuqhawula ezingentla (2.1) ~ (2.5) yi-2.1, 4.1, 4.4, 5.9 EV kunye ne-4.5 EV ngokulandelanayo. Ii-elektroni zamandla aphezulu kwiplasma nazo zinokufumana ezi mpendulo ze-ionization zilandelayo
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)
Amandla afunekayo (2.6) ~ (2.9) yi-11.9, 12.3, 13.6 kunye ne-15.3 EV ngokulandelelanayo. Ngenxa yomahluko wokusabela kwamandla, amathuba okuba (2.1) ~ (2.9) iimpendulo azilingani kakhulu. Ukongeza, i-sihm eyenziwe kunye nenkqubo yokusabela (2.1) ~ (2.5) iya kuhlangabezana nezi mpendulo zesibini kwi-ionize, njenge
SiH+e→SiH++2e (2.10)
SiH2+e→SiH2++2e (2.11)
SiH3+e→SiH3++2e (2.12)
Ukuba impendulo engentla iqhutywe ngenkqubo ye-electron enye, amandla afunekayo malunga ne-12 eV okanye ngaphezulu. Ngenxa yokuba inani lee-electron zamandla aphezulu ngaphezu kwe-10ev kwi-plasma ene-ionized ebuthathaka kunye noxinano lwe-electron ye-1010cm-3 lincinci kakhulu phantsi koxinzelelo lwe-atmospheric (10-100pa) ukulungiselela iifilimu ezisekelwe kwi-silicon, I-cumulative amathuba e-ionization aqhelekile ukuba mancinci kunexesha lovuselelo. Ngoko ke, umlinganiselo wamacandelo e-ionized ngasentla kwi-plasma ye-silane incinci kakhulu, kwaye iqela elingathathi hlangothi le-sihm lilawula. Iziphumo zohlalutyo lwe-massspectrum zikwangqina esi sigqibo [8]. Bourquard et al. Ukuqhubela phambili kwabonisa ukuba ukuxinwa kwe-sihm kwehle ngomyalelo we-sih3, i-sih2, i-Si kunye ne-SIH, kodwa i-concentration ye-SiH3 yayininzi kathathu ye-SIH. Robertson et al. Kuxelwe ukuba kwiimveliso ezingathathi hlangothi ze-sihm, i-silane ecocekileyo yayisetyenziselwa ukukhutshwa kwamandla aphezulu, ngelixa i-sih3 yayisetyenziselwa ukukhutshwa kwamandla aphantsi. Umyalelo wokugxininiswa ukusuka phezulu ukuya phezulu wawuyi-SiH3, SiH, Si, SiH2. Ngoko ke, iiparamitha zenkqubo yeplasma zichaphazela kakhulu ukubunjwa kweemveliso ze-sihm ezingathathi hlangothi.
Ukongeza koku ngasentla kunye neempendulo ze-ionization, ukuphendula okwesibini phakathi kwee-athomu ze-ionic nazo zibaluleke kakhulu.
SiH2＋+SiH4→SiH3++SiH3 (2.13)
Ngoko ke, ngokumalunga ne-ion concentration, i-sih3 + ingaphezulu kwe-sih2 +. Iyakwazi ukucacisa ukuba kutheni kukho ii-sih3 + ion ezininzi kune-sih2 + ions kwi-plasma ye-SiH4.
Ukongeza, kuya kubakho ukungqubana kwe-athomu yemolekyuli apho iiathomu ze-hydrogen kwiplasma zibamba i-hydrogen kwi-SiH4.
H+ SiH4→SiH3+H2 (2.14)
Kukusabela kwe-exothermic kunye ne-precursor yokwenziwa kwe-si2h6. Ngokuqinisekileyo, la maqela awakho kuphela kwindawo ephantsi, kodwa avuyiswe kwimeko evuyayo kwi-plasma. Umboniso okhutshwayo weplasma ye-silane ubonisa ukuba kukho utshintsho oluvunyiweyo olubonakalayo lweemeko ze-Si, SIH, h, kunye neemeko ezichwayitisayo ze-SiH2, SiH3
Ixesha lokuposa: Apr-07-2021