Ungayikhetha, uyisebenzise kwaye uyigcine njani inqanawa yePECVD?

1. Yintoni isikhephe sePECVD?

1.1 Inkcazo kunye nemisebenzi ephambili

I-PECVD boat (Plasma Enhanced Chemical Vapor Deposition) sisixhobo esiphambili esisetyenziselwa ukuthwala ii-wafers okanye ii-substrates kwinkqubo ye-PECVD. Kufuneka isebenze ngokuzinzileyo kwindawo enobushushu obuphezulu (300-600°C), igesi evuselelweyo kwi-plasma kunye negesi ebolileyo (njenge-SiH₄, NH₃). Imisebenzi yayo ephambili ibandakanya:

● Indawo echanekileyo: qinisekisa ukuba isithuba se-wafer siyafana kwaye uphephe ukuphazamiseka kokugquma.
● Ulawulo lwentsimi yobushushu: phucula ukusasazwa kobushushu kwaye uphucule ukufana kwefilimu.
● Umqobo ochasene nongcoliseko: Ukwahlula i-plasma kwingxobo yesixhobo ukunciphisa umngcipheko wongcoliseko lwesinyithi.

1.2 Izakhiwo kunye nezinto eziqhelekileyo

Ukukhetha izinto:

● Isikhephe seGraphite (ukhetho oluqhelekileyo): ukuhanjiswa kobushushu obuphezulu, ukumelana nobushushu obuphezulu, ixabiso eliphantsi, kodwa kufuna ukugqunywa ukuze kuthintelwe ukubola kwegesi.
●Isikhephe seQuartz: Sicocekile kakhulu, asikwazi ukumelana neekhemikhali, kodwa sibuthathaka kakhulu kwaye sibiza kakhulu.
●Iiseramikhi (ezifana ne-Al₂O₃): azigugi, zifanelekile kwimveliso ye-frequency ephezulu, kodwa azikho mandla okuqhuba ubushushu afanelekileyo.

Iimpawu eziphambili zoyilo:

● Isithuba sesithuba: Ubukhulu be-wafer obuhambelanayo (obufana nokunyamezelana kwe-0.3-1mm).
●Uyilo lomngxuma wokuhamba komoya: phucula ukusasazwa kwegesi yokusabela kwaye unciphise isiphumo somphetho.
●Ukwambathisa umphezulu: Ukwambathisa okuqhelekileyo kweSiC, iTaC okanye iDLC (ikhabhoni efana nedayimani) ukuze kwandiswe ubomi benkonzo.

2. Kutheni kufuneka sinikele ingqalelo kwindlela ezisebenza ngayo iinqanawa zePECVD?

2.1 Izinto ezine eziphambili ezichaphazela ngokuthe ngqo isivuno senkqubo

✔ Ulawulo Longcoliseko:
Ukungcola emzimbeni wesikhephe (okufana neFe kunye neNa) kuyaguquguquka xa kushushu kakhulu, nto leyo ebangela ukuba kubekho imingxunya okanye ukuvuza kwifilimu.
Ukuxobuka kwengubo kuya kungenisa amasuntswana kwaye kubangele iziphene zokugquma (umzekelo, amasuntswana angaphezu kwe-0.3μm anokubangela ukuba ukusebenza kakuhle kwebhetri kwehle nge-0.5%).

✔ Ukufana kwentsimi yobushushu:
Ukuhanjiswa kobushushu okungalinganiyo kwesikhephe segrafiti sePECVD kuya kukhokelela kumahluko kubukhulu befilimu (umzekelo, phantsi kwemfuneko yokufana ye-±5%, umahluko wobushushu kufuneka ube ngaphantsi kwe-10°C).

✔ Ukuhambelana kwePlasma:
Izinto ezingalunganga zinokubangela ukukhupha okungaqhelekanga kwaye zonakalise i-wafer okanye ii-electrode zesixhobo.

✔ Ubomi benkonzo kunye neendleko:
Iinqanawa zomkhombe ezikumgangatho ophantsi kufuneka zitshintshwe rhoqo (umz. kanye ngenyanga), kwaye iindleko zokugcinwa kwazo ngonyaka zibiza kakhulu.

3. Ungayikhetha, uyisebenzise kwaye uyigcine njani inqanawa yePECVD?

3.1 Indlela yokukhetha enamanyathelo amathathu

Inyathelo 1: Cacisa iiparameter zenkqubo

● Uluhlu lobushushu: Ingubo yeGraphite + SiC ingakhethwa ngaphantsi kwe-450°C, kwaye i-quartz okanye i-ceramic iyadingeka ngaphezu kwe-600°C.
●Uhlobo lwegesi: Xa kukho iigesi ezirhabaxa ezifana ne-Cl2 kunye ne-F-, kufuneka kusetyenziswe i-high-density coating.
●Ubungakanani be-wafer: Amandla esakhiwo senqanawa esiyi-8-intshi/12-intshi ahluke kakhulu kwaye afuna uyilo olujoliswe kulo.

Inyathelo lesi-2: Vavanya iindlela zokusebenza

Iimpawu eziphambili:

●Uburhabaxa bomphezulu (Ra): ≤0.8μm (umphezulu woqhagamshelwano kufuneka ube ≤0.4μm)
●Amandla ebhondi yokugquma: ≥15MPa (umgangatho we-ASTM C633)
●Ukuguquguquka kobushushu obuphezulu (600℃): ≤0.1mm/m (uvavanyo lweeyure ezingama-24)

Inyathelo lesi-3: Qinisekisa ukuba iyahambelana

● Ukuhambelana kwezixhobo: Qinisekisa ubungakanani bomdibaniso ngeemodeli eziqhelekileyo ezifana ne-AMAT Centura, i-centrotherm PECVD, njl.njl.
● Uvavanyo lokuvelisa uvavanyo: Kucetyiswa ukuba kwenziwe uvavanyo oluncinci lwebhetshi yeziqwenga ezingama-50-100 ukuqinisekisa ukufana kwengubo (ukuphambuka okuqhelekileyo kobukhulu befilimu <3%).

3.2 Iindlela ezilungileyo zokusetyenziswa nokugcinwa

Iinkcukacha zokusebenza:

✔Inkqubo yokucoca kwangaphambili:

● Ngaphambi kokusetyenziswa kokuqala, iXinzhou kufuneka ihlatywe nge-Ar plasma imizuzu engama-30 ukuze kususwe ukungcola okufakwe kumphezulu.

●Emva kweqela ngalinye lenkqubo, i-SC1 (NH₄OH:H₂O₂:H₂O=1:1:5) isetyenziselwa ukucoca ukususa iintsalela zezinto eziphilayo.

✔ Ukulayisha izinto ezingavumelekanga:

●Ukulayisha kakhulu akuvumelekanga (umz. umthamo ophezulu wenzelwe ukuba ube ziingceba ezingama-50, kodwa umthwalo wokwenyani kufuneka ube ziingceba ezingama-≤ ezingama-45 ukuze kugcinwe indawo yokwandiswa).

●Umphetho we-wafer kufuneka ube ≥2mm ukusuka esiphelweni setanki yesikhephe ukuthintela imiphumo yomphetho we-plasma.

✔ Amacebiso Okwandisa Ubomi

● Ukulungiswa kwengubo: Xa uburhabaxa bomphezulu buyiRa ＞1.2μm, i-SiC coating ingaphinda ibekwe yiCVD (ixabiso liphantsi ngama-40% kunokutshintshwa).

✔ Uvavanyo oluqhelekileyo:

● Nyanga nganye: Jonga ukuthembeka kokugquma usebenzisa i-interferometry yokukhanya okumhlophe.
●Ngekota: Hlalutya inqanaba lokwakheka kwekristale yesikhephe nge-XRD (isikhephe se-quartz wafer esine-crystal phase > 5% kufuneka sitshintshwe).

4. Ziziphi iingxaki eziqhelekileyo?

Umbuzo 1: NgabaInqanawa yePECVDzingasetyenziswa kwinkqubo ye-LPCVD?

A: Akukhuthazwa! I-LPCVD inobushushu obuphezulu (ngesiqhelo yi-800-1100°C) kwaye kufuneka imelane noxinzelelo oluphezulu lwegesi. Ifuna ukusetyenziswa kwezinto ezimelana notshintsho lobushushu (ezifana ne-isostatic graphite), kwaye uyilo lwe-slot kufuneka luqwalasele imbuyekezo yokwandiswa kobushushu.
Umbuzo 2: Ungafumanisa njani ukuba umzimba wesikhephe awuphumelelanga?

A: Yeka ukuyisebenzisa ngoko nangoko ukuba kuvela ezi mpawu zilandelayo:
Ukuqhekeka okanye ukuxobuka kwengubo kubonakala emehlweni.
Ukuphambuka okuqhelekileyo kokufana kwe-wafer coating kube ngaphezulu kwe-5% kwiibhetshi ezintathu ezilandelelanayo.
Iqondo lokungafumani legumbi lenkqubo lehle ngaphezulu kwe-10%.

Q3: Isikhephe seGraphite vs. isikhephe sequartz, ungakhetha njani?

Isiphelo: Iinqanawa zeGraphite zikhethwa kakhulu xa kusenziwa imveliso eninzi, ngelixa iinqanawa zequartz zithathwa njengezisetyenziselwa uphando lwesayensi/iinkqubo ezikhethekileyo.

Isiphelo:

NangonaInqanawa yePECVDAyisosixhobo siphambili, “ngumlindi othuleyo” wozinzo lwenkqubo. Ukusuka ekukhetheni ukuya ekugcinweni, yonke into inokuba yindawo ephambili yokuphucula isivuno. Ndiyathemba ukuba esi sikhokelo siya kukunceda ungene kwinkungu yobugcisa kwaye ufumane isisombululo esifanelekileyo sokunciphisa iindleko kunye nokuphucula ukusebenza kakuhle!