Silicon carbide (SiC) tsis yog ib qho khoom siv semiconductor xwb. Nws cov khoom siv hluav taws xob thiab thermal zoo heev ua rau nws tseem ceeb rau cov khoom siv hluav taws xob tiam tom ntej, EV inverters, RF devices, thiab cov ntawv thov high-frequency. Ntawm SiC polytypes,4H-SiCthiab6H-SiCtswj hwm kev ua lag luam—tab sis kev xaiv qhov yog yuav tsum muaj ntau dua li tsuas yog "uas pheej yig dua."
Tsab xov xwm no muab kev sib piv ntau yam ntawm4H-SiCthiab 6H-SiC substrates, npog cov qauv siv lead ua, hluav taws xob, thermal, mechanical zog, thiab cov ntawv thov ib txwm muaj.
1. Cov Qauv Siv Crystal thiab Cov Txheej Txheem Stacking
SiC yog ib yam khoom siv polymorphic, uas txhais tau tias nws muaj nyob rau hauv ntau yam qauv siv lead ua hu ua polytypes. Cov txheej txheem stacking ntawm Si-C bilayers raws c-axis txhais cov polytypes no:
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4H-SiC: Plaub txheej stacking sequence → Siab dua symmetry raws c-axis.
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6H-SiC: Rau-txheej stacking sib lawv liag → Me ntsis qis dua symmetry, txawv band qauv.
Qhov sib txawv no cuam tshuam rau kev txav mus los ntawm cov neeg nqa khoom, bandgap, thiab tus cwj pwm thermal.
| Feature | 4H-SiC | 6H-SiC | Cov Lus Cim |
|---|---|---|---|
| Kev sib sau ua ke ntawm cov txheej | ABCB | ABCACB | Txheeb xyuas cov qauv ntawm cov kab thiab cov dynamics ntawm cov cab kuj |
| Crystal symmetry | Hexagonal (sib xws ntau dua) | Hexagonal (me ntsis ntev) | Cuam tshuam rau kev etching, epitaxial kev loj hlob |
| Qhov loj me ntawm wafer | 2–8 nti | 2–8 nti | Muaj peev xwm nce ntxiv rau 4H, laus rau 6H |
2. Cov Khoom Siv Hluav Taws Xob
Qhov sib txawv tseem ceeb tshaj plaws yog nyob rau hauv kev ua haujlwm hluav taws xob. Rau cov khoom siv fais fab thiab cov zaus siab,kev txav mus los ntawm electron, bandgap, thiab resistivityyog cov yam tseem ceeb.
| Vaj tse | 4H-SiC | 6H-SiC | Kev Cuam Tshuam Rau Lub Cuab Yeej |
|---|---|---|---|
| Bandgap | 3.26 eV | 3.02 eV | Qhov bandgap dav dua hauv 4H-SiC tso cai rau qhov hluav taws xob tawg siab dua, qhov hluav taws xob xau qis dua |
| Kev txav mus los ntawm cov hluav taws xob | ~1000 cm²/V·s | ~450 cm²/V·s | Kev hloov pauv sai dua rau cov khoom siv hluav taws xob siab hauv 4H-SiC |
| Kev txav mus los ntawm qhov | ~80 cm²/V·s | ~90 cm²/V·s | Tsis tseem ceeb rau feem ntau cov khoom siv fais fab |
| Kev tiv taus | 10³–10⁶ Ω·cm (ib nrab rwb thaiv tsev) | 10³–10⁶ Ω·cm (ib nrab rwb thaiv tsev) | Tseem ceeb rau RF thiab epitaxial kev loj hlob sib xws |
| Dielectric tas mus li | ~10 | ~9.7 | Me ntsis siab dua hauv 4H-SiC, cuam tshuam rau lub peev xwm ntawm lub cuab yeej |
Cov Ntsiab Lus Tseem Ceeb:Rau cov fais fab MOSFETs, Schottky diodes, thiab kev hloov pauv ceev ceev, 4H-SiC yog qhov zoo dua. 6H-SiC txaus rau cov khoom siv hluav taws xob tsawg lossis RF.
3. Cov Khoom Siv Thermal
Kev tso cua sov tawm yog qhov tseem ceeb rau cov khoom siv hluav taws xob siab. 4H-SiC feem ntau ua haujlwm zoo dua vim nws cov thermal conductivity.
| Vaj tse | 4H-SiC | 6H-SiC | Kev cuam tshuam |
|---|---|---|---|
| Kev ua kom sov tau zoo | ~3.7 W/cm·K | ~3.0 W/cm·K | 4H-SiC yaj cov cua sov sai dua, txo cov kev ntxhov siab thermal |
| Coefficient ntawm thermal expansion (CTE) | 4.2 × 10⁻⁶ /K | 4.1 ×10⁻⁶ /K | Kev sib phim nrog cov txheej epitaxial yog qhov tseem ceeb kom tiv thaiv kev ua kom tsis txhob muaj wafer warping |
| Qhov kub ua haujlwm siab tshaj plaws | 600–650 °C | 600 °C | Ob qho tib si siab, 4H zoo dua me ntsis rau kev ua haujlwm siab ntev |
4. Cov Khoom Siv Kho Tshuab
Kev ruaj khov ntawm lub tshuab cuam tshuam rau kev tuav wafer, kev txiav, thiab kev ntseeg tau mus sij hawm ntev.
| Vaj tse | 4H-SiC | 6H-SiC | Cov Lus Cim |
|---|---|---|---|
| Kev Nyuaj Siab (Mohs) | 9 | 9 | Ob leeg nyuaj heev, thib ob tsuas yog pob zeb diamond |
| Kev tawg tawv | ~2.5–3 MPa·m½ | ~2.5 MPa·m½ | Zoo sib xws, tab sis 4H sib xws me ntsis ntxiv |
| Qhov tuab ntawm cov wafer | 300–800 µm | 300–800 µm | Cov wafers nyias dua txo qhov kev tiv taus cua sov tab sis ua rau muaj kev pheej hmoo ntawm kev tuav |
5. Cov Ntawv Thov Ib Txwm Muaj
Kev nkag siab txog qhov twg txhua polytype ua tau zoo pab xaiv cov substrate.
| Pawg Daim Ntawv Thov | 4H-SiC | 6H-SiC |
|---|---|---|
| MOSFETs muaj zog siab | ✔ | ✖ |
| Cov Schottky diodes | ✔ | ✖ |
| Cov inverters tsheb fais fab | ✔ | ✖ |
| Cov khoom siv RF / microwave | ✖ | ✔ |
| LEDs thiab optoelectronics | ✖ | ✔ |
| Cov khoom siv hluav taws xob tsawg-zog siab | ✖ | ✔ |
Txoj Cai ntawm Tus Ntiv Tes:
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4H-SiC= Lub zog, qhov ceev, kev ua haujlwm zoo
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6H-SiC= RF, lub zog qis, cov khoom siv laus
6. Muaj thiab Tus Nqi
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4H-SiC: Keeb kwm nyuaj rau kev loj hlob, tam sim no muaj ntau zuj zus. Tus nqi siab dua me ntsis tab sis tsim nyog rau cov ntawv thov ua haujlwm siab.
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6H-SiC: Khoom siv laus, feem ntau tus nqi qis dua, siv dav rau RF thiab cov khoom siv hluav taws xob tsawg.
Xaiv Cov Khoom Siv Zoo
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Cov khoom siv hluav taws xob high-voltage, high-speed fais fab:4H-SiC yog qhov tseem ceeb.
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Cov khoom siv RF lossis LEDs:6H-SiC feem ntau txaus.
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Cov ntawv thov thermal-sensitive:4H-SiC muab kev tso cua sov zoo dua.
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Kev xav txog kev siv nyiaj lossis kev muab khoom:6H-SiC tej zaum yuav txo tus nqi yam tsis muaj kev cuam tshuam rau cov khoom siv.
Cov Kev Xav Kawg
Txawm hais tias 4H-SiC thiab 6H-SiC yuav zoo li lub qhov muag tsis tau kawm, lawv qhov sib txawv suav nrog cov qauv siv lead ua, kev txav mus los ntawm hluav taws xob, kev ua kom sov, thiab kev siv tau zoo. Kev xaiv cov polytype kom raug thaum pib ntawm koj qhov project ua kom muaj kev ua tau zoo tshaj plaws, txo kev ua haujlwm dua, thiab cov khoom siv txhim khu kev qha.
Lub sijhawm tshaj tawm: Lub Ib Hlis-04-2026