Iindlela eziphambili zokukhulisa iikristale ze-silicon carbide single ziquka i-Physical Vapor Transport (PVT), i-Top-Seeded Solution Growth (TSSG), kunye ne-High-Temperature Chemical Vapor Deposition (HT-CVD).

Phakathi kwezi, indlela ye-PVT iye yaba yindlela ephambili yokuvelisa imveliso yemizi-mveliso ngenxa yokuseta kwayo izixhobo ezilula, ukulula kokusebenza nokulawula, kunye neendleko eziphantsi zezixhobo kunye nokusebenza.

---

Amanqaku abalulekileyo obuchwephesha bokukhula kwekristale yeSiC usebenzisa indlela yePVT

Ukuze kukhuliswe iikristale ze-silicon carbide kusetyenziswa indlela ye-PVT, kufuneka kulawulwe iinkalo ezininzi zobugcisa ngononophelo:

1. Ukucoceka kwezinto zeGraphite kwi-Thermal Field
   Izixhobo zegrafiti ezisetyenziswa kwintsimi yobushushu bokukhula kwekristale kufuneka zihlangabezane neemfuno ezingqongqo zobumsulwa. Umxholo wokungcola kwizixhobo zegrafiti kufuneka ube ngaphantsi kwe-5×10⁻⁶, kwaye kwiifelts zokukhusela ubushushu kufuneka ube ngaphantsi kwe-10×10⁻⁶. Ngokukodwa, umxholo we-boron (B) kunye ne-aluminium (Al) nganye mayibe ngaphantsi kwe-0.1×10⁻⁶.

2. I-Polarity echanekileyo ye-Seed Crystal
   Idatha eqinisekisiweyo ibonisa ukuba i-C-face (0001) ifanelekile ekukhuliseni iikristale ze-4H-SiC, ngelixa i-Si-face (0001) ifanelekile ekukhuleni kwe-6H-SiC.

3. Ukusetyenziswa kweekristale zembewu ezingasebenzi kwi-axis
   Imbewu engahambelaniyo nomgca ingatshintsha ulungelelwaniso lokukhula, inciphise iziphene zekristale, kwaye ikhuthaze umgangatho ongcono wekristale.

4. Indlela Ethembekileyo Yokubopha Imbewu Yekristale
   Ukubophana okufanelekileyo phakathi kwekristale yembewu kunye nesiphathi kubalulekile ukuze kubekho uzinzo ngexesha lokukhula.

5. Ukugcina Uzinzo lwe-Growth Interface
   Ngexesha lonke lomjikelo wokukhula kwekristale, ujongano lokukhula kufuneka luhlale luzinzile ukuqinisekisa uphuhliso lwekristale olukumgangatho ophezulu.

 

---

Iiteknoloji eziphambili ekukhuleni kwekristale yeSiC

1. Itekhnoloji yokuDopa kwiSiC Powder

Ukusebenzisa i-doping ye-SiC powder nge-cerium (Ce) kunokuzinzisa ukukhula kwe-polytype enye efana ne-4H-SiC. Indlela yokusebenza ibonise ukuba i-Ce doping ingenza oku kulandelayo:

• Ukwandisa izinga lokukhula kweekristale zeSiC;

• Phucula indlela yokujonga ikristale ukuze ikhule ngendlela efanayo neyasekunene;

• Nciphisa ukungcola kunye neziphene;

• Nciphisa ukugqwala kwekristale ngasemva;

• Yandisa izinga le-single crystal yield.

2. Ulawulo lweeGradients ze-Axial kunye ne-Radial Thermal

Iigradients zobushushu be-Axial zichaphazela i-crystal polytype kunye nesantya sokukhula. I-gradient encinci kakhulu inokukhokelela ekufakweni kwe-polytype kunye nokunciphisa ukuthuthwa kwezinto kwisigaba somphunga. Ukuphucula zombini iigradients ze-axial kunye ne-radial kubalulekile ekukhuleni kwekristale okukhawulezayo nokuzinzileyo ngomgangatho ohambelanayo.

3. Iteknoloji yoLawulo lweBasal Plane Dislocation (BPD)

Ii-BPD zenzeka ikakhulu ngenxa yoxinzelelo oluncinci oludlula umda obalulekileyo kwiikristale zeSiC, zivuselela iinkqubo zokutyibilika. Njengoko ii-BPD zithe nkqo kwicala lokukhula, zihlala zivela ngexesha lokukhula kwekristale kunye nokupholisa. Ukunciphisa uxinzelelo lwangaphakathi kunokunciphisa kakhulu uxinano lwe-BPD.

4. Ulawulo lweSilinganiselo soBume beSigaba soMphunga

Ukwandisa umlinganiselo wekhabhoni-kwi-silicon kwisigaba somphunga yindlela eqinisekisiweyo yokukhuthaza ukukhula kwe-polytype enye. Umlinganiselo ophezulu we-C/Si unciphisa i-macrostep bunching kwaye ugcina ilifa lomphezulu kwi-crystal yembewu, ngaloo ndlela ucinezela ukwakheka kwe-polytypes ezingafunekiyo.

5. Iindlela Zokukhula Ngoxinzelelo Oluphantsi

Uxinzelelo ngexesha lokukhula kwekristale lunokukhokelela kwiiplani ze-lattice ezigobileyo, imifantu, kunye noxinano oluphezulu lwe-BPD. Ezi ziphene zinokudlulela kwiileya ze-epitaxial kwaye zichaphazele kakubi ukusebenza kwesixhobo.

Amaqhinga amaninzi okunciphisa uxinzelelo lwangaphakathi lwekristale aquka:

• Ukulungisa ukusasazwa kwentsimi yobushushu kunye neeparamitha zenkqubo ukukhuthaza ukukhula okusondeleleneyo;

• Ukuphucula uyilo olunokubethelelwa ukuze kuvunyelwe ikristale ukuba ikhule ngokukhululekileyo ngaphandle kwemida yoomatshini;

• Ukuphucula ubume be-seed holder ukuze kuncitshiswe ukungalingani kokukhula kobushushu phakathi kwembewu kunye ne-graphite ngexesha lokufudumeza, ngokuhlala kushiyeka isithuba se-2 mm phakathi kwembewu kunye ne-seed holder;

• Ukucokisa iinkqubo zokuqhoboshela, ukuvumela ikristale ukuba iphole ngesithando somlilo, kunye nokulungisa ubushushu kunye nobude bexesha ukuze kuncitshiswe ngokupheleleyo uxinzelelo lwangaphakathi.

---

Iindlela zoBugcisa bokuKhula kweSiC Crystal

1. Ubungakanani obukhulu bekristale
Iidayimitha zekristale enye zeSiC zinyukile ukusuka kwiimilimitha ezimbalwa ukuya kwiiwafers eziyi-6-intshi, eziyi-8-intshi, kwaneziyi-12-intshi. Iiwafers ezinkulu zinyusa ukusebenza kakuhle kwemveliso kwaye zinciphisa iindleko, ngelixa zihlangabezana neemfuno zezicelo zezixhobo ezinamandla aphezulu.

2. Umgangatho ophezulu wekristale
Iikristale zeSiC ezikumgangatho ophezulu zibalulekile kwizixhobo ezisebenza kakuhle. Nangona kukho uphuculo olukhulu, iikristale zangoku zisabonisa iziphene ezifana nee-micropipes, ukudilika, kunye nokungcola, konke oku kunokonakalisa ukusebenza kwesixhobo kunye nokuthembeka kwaso.

3. Ukuncitshiswa kweendleko
Imveliso yekristale yeSiC isabiza kakhulu, nto leyo ethintela ukwamkelwa ngokubanzi. Ukunciphisa iindleko ngeenkqubo zokukhula eziphuculiweyo, ukonyuka kokusebenza kakuhle kwemveliso, kunye neendleko eziphantsi zezinto eziluhlaza kubalulekile ekwandiseni ukusetyenziswa kwemarike.

4. Ukwenziwa koBukrelekrele
Ngokuqhubela phambili kubukrelekrele bokwenziwa kunye nobuchwepheshe bedatha enkulu, ukukhula kwekristale yeSiC kuya phambili kwiinkqubo ezikrelekrele nezizenzekelayo. Iisensors kunye neenkqubo zolawulo zinokubeka esweni kwaye zilungise iimeko zokukhula ngexesha langempela, ziphucule uzinzo lwenkqubo kunye nokuqikelelwa kwangaphambili. Uhlalutyo lwedatha lunokuphucula ngakumbi iiparameter zenkqubo kunye nomgangatho wekristale.

Uphuhliso lwetekhnoloji yokukhula kwekristale enye yeSiC ekumgangatho ophezulu yeyona nto iphambili kuphando lwezixhobo ze-semiconductor. Njengoko itekhnoloji iqhubela phambili, iindlela zokukhula kwekristale ziya kuqhubeka zikhula kwaye ziphucuka, zibonelela ngesiseko esiqinileyo sezicelo zeSiC kwizixhobo ze-elektroniki ezisebenzisa ubushushu obuphezulu, ii-frequency eziphezulu, kunye namandla aphezulu.