Cov txheej txheem tseem ceeb rau kev loj hlob silicon carbide ib leeg siv lead ua ke suav nrog Physical Vapor Transport (PVT), Top-Seeded Solution Growth (TSSG), thiab High-Temperature Chemical Vapor Deposition (HT-CVD).

Ntawm cov no, txoj kev PVT tau dhau los ua cov txheej txheem tseem ceeb rau kev tsim khoom lag luam vim nws cov khoom siv yooj yim teeb tsa, yooj yim ntawm kev ua haujlwm thiab kev tswj hwm, thiab cov khoom siv qis dua thiab cov nqi ua haujlwm.

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Cov Ntsiab Lus Tseem Ceeb ntawm SiC Crystal Growth Siv Txoj Kev PVT

Yuav kom loj hlob silicon carbide crystals siv txoj kev PVT, ntau yam kev txawj ntse yuav tsum tau tswj hwm kom zoo:

1. Kev Huv Si ntawm Cov Khoom Siv Graphite hauv Thermal Field
   Cov ntaub ntawv graphite siv rau hauv qhov chaw thermal loj hlob ntawm cov siv lead ua yuav tsum ua tau raws li qhov yuav tsum tau ua kom huv si. Cov ntsiab lus tsis huv hauv cov khoom graphite yuav tsum qis dua 5 × 10⁻⁶, thiab rau cov ntaub rwb thaiv tsev qis dua 10 × 10⁻⁶. Tshwj xeeb, cov ntsiab lus ntawm boron (B) thiab txhuas (Al) yuav tsum qis dua 0.1 × 10⁻⁶.

2. Yog Polarity ntawm Seed Crystal
   Cov ntaub ntawv qhia tau tias C-lub ntsej muag (0001) yog qhov tsim nyog rau kev loj hlob ntawm 4H-SiC siv lead ua, thaum Si-lub ntsej muag (0001) yog qhov tsim nyog rau kev loj hlob ntawm 6H-SiC.

3. Kev Siv Cov Pob Zeb Uas Tsis Yog-Axis
   Cov noob tawm ntawm txoj kab tuaj yeem hloov pauv qhov sib npaug ntawm kev loj hlob, txo cov teeb meem siv lead ua, thiab txhawb kom muaj qhov zoo dua ntawm cov siv lead ua.

4. Kev Siv Cov Khoom Siv Crystal Bonding Txhim Khu Kev
   Kev sib txuas zoo ntawm cov noob siv lead ua thiab tus tuav yog qhov tseem ceeb rau kev ruaj khov thaum lub sijhawm loj hlob.

5. Kev Tswj Xyuas Kev Ruaj Ntseg ntawm Kev Loj Hlob Interface
   Thaum lub sijhawm tag nrho cov voj voog loj hlob ntawm crystal, qhov kev loj hlob ntawm qhov interface yuav tsum ruaj khov kom ntseeg tau tias muaj kev loj hlob zoo ntawm crystal.

 

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Cov Txuj Ci Tseem Ceeb hauv SiC Crystal Growth

1. Kev Siv Tshuab Doping rau SiC Hmoov

Kev siv tshuaj Doping SiC hmoov nrog cerium (Ce) tuaj yeem ua kom ruaj khov kev loj hlob ntawm ib hom polytype xws li 4H-SiC. Kev xyaum tau qhia tias Ce doping tuaj yeem:

• Ua kom cov SiC crystals loj hlob sai dua;

• Txhim kho cov kev taw qhia siv lead ua kom muaj kev loj hlob zoo dua thiab muaj kev coj ua;

• Txo cov khoom tsis huv thiab cov teeb meem;

• Tiv thaiv kev xeb rov qab ntawm cov siv lead ua;

• Txhim kho qhov ib leeg siv lead ua kom muaj zog.

2. Kev Tswj Xyuas Axial thiab Radial Thermal Gradients

Qhov kub thiab txias axial gradients cuam tshuam rau cov siv lead ua polytype thiab kev loj hlob. Ib qho gradient uas me dhau tuaj yeem ua rau muaj polytype inclusions thiab txo cov khoom siv thauj mus los hauv theem vapor. Kev ua kom zoo dua ob qho tib si axial thiab radial gradients yog qhov tseem ceeb rau kev loj hlob sai thiab ruaj khov siv lead ua nrog qhov zoo sib xws.

3. Kev Tswj Xyuas Basal Plane Dislocation (BPD)

BPDs feem ntau tshwm sim vim muaj kev ntxhov siab ntau dua qhov tseem ceeb hauv SiC crystals, ua rau cov slip systems ua haujlwm. Vim tias BPDs yog perpendicular rau qhov kev loj hlob, lawv feem ntau tshwm sim thaum lub sijhawm loj hlob thiab txias ntawm crystal. Kev txo qis kev ntxhov siab sab hauv tuaj yeem txo qhov ceev ntawm BPD.

4. Kev Tswj Xyuas Qhov Sib Piv ntawm Cov Pa Hauv Paus

Kev nce qhov sib piv ntawm carbon-rau-silicon hauv theem pa yog ib txoj hauv kev uas tau ua pov thawj rau kev txhawb nqa kev loj hlob ntawm ib qho polytype. Qhov sib piv C/Si siab txo qhov macrostep bunching thiab khaws cia qhov chaw qub txeeg qub teg los ntawm cov noob siv lead ua, yog li ntawd suppressing kev tsim ntawm cov polytypes tsis xav tau.

5. Cov Txuj Ci Kev Loj Hlob Uas Tsis Muaj Kev Nyuaj Siab

Kev ntxhov siab thaum lub sijhawm siv lead ua loj hlob tuaj yeem ua rau cov duab lattice nkhaus, tawg, thiab BPD ntom dua. Cov qhov tsis zoo no tuaj yeem nqa mus rau hauv cov txheej epitaxial thiab cuam tshuam tsis zoo rau kev ua haujlwm ntawm lub cuab yeej.

Muaj ntau txoj hauv kev los txo qhov kev ntxhov siab ntawm cov siv lead ua sab hauv xws li:

• Kho cov kev faib tawm ntawm thaj chaw thermal thiab cov txheej txheem kom txhawb kev loj hlob ze-equilibrium;

• Kev tsim qauv crucible kom zoo dua qub kom cov siv lead ua kom loj hlob tau yooj yim yam tsis muaj kev txwv tsis pub siv tshuab;

• Txhim kho qhov teeb tsa ntawm lub thawv noob kom txo qhov sib txawv ntawm kev nthuav dav ntawm cov noob thiab graphite thaum lub sijhawm cua sov, feem ntau los ntawm kev tso qhov sib txawv 2 hli ntawm cov noob thiab lub thawv;

• Cov txheej txheem annealing refining, cia cov siv lead ua kom txias nrog lub cub tawg, thiab kho qhov kub thiab lub sijhawm kom txo tau kev ntxhov siab sab hauv.

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Cov Qauv Hauv SiC Crystal Growth Technology

1. Cov Khoom Siv Crystal Loj Dua
Cov kab uas hla ntawm SiC ib leeg siv lead ua ke tau nce ntxiv los ntawm ob peb millimeters mus rau 6-nti, 8-nti, thiab txawm tias 12-nti wafers. Cov wafers loj dua ua rau muaj kev ua haujlwm ntau ntxiv thiab txo cov nqi, thaum ua tau raws li qhov xav tau ntawm cov ntawv thov khoom siv hluav taws xob siab.

2. Kev Siv Crystal Zoo Dua
Cov siv lead ua SiC zoo yog qhov tseem ceeb rau cov khoom siv ua haujlwm siab. Txawm hais tias muaj kev txhim kho zoo heev, cov siv lead ua tam sim no tseem muaj qhov tsis zoo xws li cov kav dej me me, kev tawg, thiab cov khoom tsis huv, uas txhua yam tuaj yeem ua rau cov khoom siv ua haujlwm tsis zoo thiab kev ntseeg siab poob qis.

3. Txo Nqi
Kev tsim cov siv lead ua los ntawm SiC tseem kim heev, ua rau kev siv dav dua tsis txaus. Kev txo cov nqi los ntawm kev ua kom zoo dua qub, kev ua kom zoo dua qub, thiab cov nqi khoom siv raw qis dua yog qhov tseem ceeb rau kev nthuav dav kev siv lag luam.

4. Kev Tsim Khoom Txawj Ntse
Nrog kev nce qib hauv kev txawj ntse ntawm cov khoom siv dag zog thiab cov thev naus laus zis loj, kev loj hlob ntawm SiC siv lead ua tau txav mus rau cov txheej txheem ntse, tsis siv neeg. Cov sensors thiab cov txheej txheem tswj hwm tuaj yeem saib xyuas thiab kho cov xwm txheej kev loj hlob hauv lub sijhawm tiag tiag, txhim kho kev ruaj khov thiab kev kwv yees tau. Kev tshuaj xyuas cov ntaub ntawv tuaj yeem ua kom zoo dua cov txheej txheem thiab qhov zoo ntawm cov siv lead ua.

Kev tsim cov thev naus laus zis loj hlob zoo ntawm SiC ib leeg siv lead ua ke yog qhov tseem ceeb hauv kev tshawb fawb txog cov ntaub ntawv semiconductor. Thaum thev naus laus zis nce qib, cov txheej txheem loj hlob siv lead ua ke yuav txuas ntxiv hloov zuj zus thiab txhim kho, muab lub hauv paus ruaj khov rau kev siv SiC hauv cov khoom siv hluav taws xob kub, zaus siab, thiab muaj zog siab.