Cov txheej txheem tseem ceeb rau kev loj hlob ntawm silicon carbide ib leeg muaj xws li Lub Cev Vapor Thauj (PVT), Sab saum toj-Seeded Solution Growth (TSSG), thiab High-Temperature Chemical Vapor Deposition (HT-CVD).

Ntawm cov no, PVT txoj kev 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 khiav lag luam thiab tswj, thiab cov cuab yeej siv qis thiab cov nqi khiav lag luam.

---

Cov ntsiab lus tseem ceeb ntawm SiC Crystal Kev Loj Hlob Siv PVT Txoj Kev

Yuav kom loj hlob silicon carbide crystals siv PVT txoj kev, ntau yam kev kawm yuav tsum tau ua tib zoo tswj:

1. Purity ntawm Graphite Materials nyob rau hauv Thermal Field
   Cov graphite cov ntaub ntawv siv nyob rau hauv lub crystal kev loj hlob thermal teb yuav tsum tau raws li nruj purity yuav tsum tau. Cov ntsiab lus impurity nyob rau hauv graphite Cheebtsam yuav tsum yog qis dua 5 × 10⁻⁶, thiab rau rwb thaiv tsev felts hauv qab 10 × 10⁻⁶. Tshwj xeeb, cov ntsiab lus ntawm boron (B) thiab txhuas (Al) yuav tsum tau qis dua 0.1 × 10⁻⁶.

2. Kho Polarity ntawm Noob Crystal
   Cov ntaub ntawv pov thawj pom tau tias C-face (0001) yog qhov tsim nyog rau kev loj hlob 4H-SiC crystals, thaum Si-face (0001) tsim nyog rau 6H-SiC kev loj hlob.

3. Kev siv Off-Axis Seed Crystals
   Off-axis noob tuaj yeem hloov qhov kev loj hlob symmetry, txo cov siv lead ua tsis xws luag, thiab txhawb kev siv lead ua zoo.

4. Txhim khu kev qha Seed Crystal Bonding Technique
   Kev sib raug zoo ntawm cov noob siv lead ua thiab tus tuav yog qhov tseem ceeb rau kev ruaj ntseg thaum lub sij hawm loj hlob.

5. Kev ruaj ntseg ntawm Kev Loj Hlob Interface
   Thaum lub sij hawm tag nrho cov siv lead ua kev loj hlob, qhov kev loj hlob interface yuav tsum nyob ruaj khov kom ntseeg tau tias cov khoom siv lead ua zoo.

 

---

Core Technologies hauv SiC Crystal Growth

1. Doping Technology rau SiC hmoov

Doping SiC hmoov nrog cerium (Ce) tuaj yeem txhim kho kev loj hlob ntawm ib qho polytype xws li 4H-SiC. Kev xyaum tau pom tias Ce doping tuaj yeem:

• Ua kom muaj kev loj hlob ntawm SiC crystals;

• Txhim kho crystal orientation kom zoo ib yam thiab kev loj hlob;

• Txo impurities thiab tsis xws luag;

• Tshem tawm qhov rov qab corrosion ntawm cov siv lead ua;

• Txhim kho tus nqi siv lead ua ib leeg.

2. Tswj ntawm Axial thiab Radial Thermal Gradients

Axial kub gradients cuam tshuam cov crystal polytype thiab kev loj hlob tus nqi. Ib qho gradient uas me dhau tuaj yeem ua rau polytypes suav nrog thiab txo cov khoom thauj hauv cov theem vapor. Optimizing ob axial thiab radial gradients yog qhov tseem ceeb rau kev loj hlob sai thiab ruaj khov siv lead ua nrog zoo ib yam.

3. Basal Plane Dislocation (BPD) Tswj Technology

BPDs tsim feem ntau yog vim muaj kev ntxhov siab ntau tshaj qhov tseem ceeb hauv SiC crystals, ua kom lub cev plam. Raws li BPDs yog perpendicular rau txoj kev loj hlob, lawv feem ntau tshwm sim thaum lub sij hawm siv lead ua loj hlob thiab txias. Kev txo qis hauv kev ntxhov siab tuaj yeem txo qis BPD ceev.

4. Vapor Phase Composition Ratio Control

Kev nce cov pa roj carbon-rau-silicon piv rau theem vapor yog ib txoj hauv kev ua pov thawj rau kev txhawb kev loj hlob ib leeg. Qhov siab C / Si piv txo cov macrostep bunching thiab khaws cov khoom qub txeeg qub teg los ntawm cov noob siv lead ua, yog li suppressing qhov tsim ntawm undesired polytypes.

5. Tsawg-Stress Growth Techniques

Kev ntxhov siab thaum lub sij hawm siv lead ua tuaj yeem ua rau lub dav hlau nkhaus, tawg, thiab siab dua BPD. Cov teeb meem no tuaj yeem nqa mus rau hauv cov txheej txheem epitaxial thiab cuam tshuam tsis zoo rau kev ua haujlwm ntawm cov cuab yeej.

Ntau lub tswv yim los txo cov kev ntxhov siab sab hauv crystal muaj xws li:

• Kho cov thermal teb faib thiab cov txheej txheem tsis zoo los txhawb kev loj hlob ze-equilibrium;

• Optimizing crucible tsim kom cia cov siv lead ua kom loj hlob dawb yam tsis muaj kev txwv kev siv tshuab;

• Txhim kho cov noob qoob loo kom txo tau qhov thermal expansion mismatch ntawm cov noob thiab graphite thaum cua sov, feem ntau yog tawm ntawm 2 hli sib txawv ntawm cov noob thiab cov yas tuav;

• Refining annealing txheej txheem, tso cai rau cov siv lead ua kom txias nrog lub cub tawg, thiab kho qhov kub thiab txias thiab lub sij hawm kom tag nrho cov kev ntxhov siab sab hauv.

---

Trends nyob rau hauv SiC Crystal Growth Technology

1. Loj Crystal Loj
SiC ib leeg siv lead ua diameters tau nce los ntawm ob peb millimeters mus rau 6-nti, 8-nti, thiab txawm tias 12-nti wafers. Cov wafers loj dua txhawb kev tsim khoom thiab txo cov nqi, thaum ua tau raws li qhov xav tau ntawm cov khoom siv hluav taws xob siab.

2. Siab dua Crystal zoo
High-quality SiC crystals yog qhov tseem ceeb rau cov khoom siv ua haujlwm siab. Txawm hais tias muaj kev txhim kho tseem ceeb, cov khoom siv lead ua tam sim no tseem pom cov teeb meem xws li micropipes, dislocations, thiab impurities, tag nrho cov uas tuaj yeem degrade ntaus ntawv kev ua tau zoo thiab kev ntseeg tau.

3. Kev txo nqi
SiC siv lead ua ntau lawm tseem kim heev, txwv tsis pub siv dav dav. Txo cov nqi los ntawm cov txheej txheem kev loj hlob zoo, nce kev ua tau zoo, thiab txo cov nqi raw khoom yog qhov tseem ceeb rau kev nthuav dav kev lag luam.

4. Kev tsim khoom ntse
Nrog rau kev nce qib hauv kev txawj ntse txawj ntse thiab cov ntaub ntawv loj, SiC siv lead ua kev loj hlob yog txav mus rau cov txheej txheem ntse, automated. Sensors thiab tswj tshuab tuaj yeem saib xyuas thiab kho cov xwm txheej loj hlob hauv lub sijhawm tiag tiag, txhim kho cov txheej txheem kev ruaj ntseg thiab kev kwv yees. Cov ntaub ntawv analytics tuaj yeem ua kom zoo dua cov txheej txheem tsis zoo thiab siv lead ua zoo.

Txoj kev loj hlob zoo ntawm SiC ib leeg siv lead ua kev loj hlob technology yog qhov tseem ceeb hauv kev tshawb fawb cov ntaub ntawv semiconductor. Raws li kev siv thev naus laus zis, txoj kev loj hlob siv lead ua yuav txuas ntxiv txhim kho thiab txhim kho, muab lub hauv paus ruaj khov rau SiC cov ntawv thov hauv high-temperature, high-frequency, thiab high-power electronic devices.