1. Vim li cas thiaj muaj asilicon carbide txheej
Cov txheej txheem epitaxial yog ib qho tshwj xeeb siv lead ua nyias zaj duab xis cog rau ntawm lub hauv paus ntawm wafer los ntawm cov txheej txheem epitaxial. Lub substrate wafer thiab epitaxial nyias zaj duab xis yog sib sau ua ke hu ua epitaxial wafers. Ntawm lawv, covsilicon carbide epitaxialtxheej yog zus nyob rau hauv conductive silicon carbide substrate kom tau ib tug silicon carbide homogeneous epitaxial wafer, uas yuav tsum tau ntxiv mus rau hauv lub hwj chim li xws li Schottky diodes, MOSFETs, thiab IGBTs. Ntawm lawv, feem ntau siv yog 4H-SiC substrate.
Txij li thaum tag nrho cov khoom siv tau pib paub txog ntawm epitaxy, qhov zoo ntawmepitaxymuaj kev cuam tshuam zoo rau kev ua haujlwm ntawm cov cuab yeej, tab sis qhov zoo ntawm epitaxy cuam tshuam los ntawm kev ua cov khoom siv lead ua thiab cov substrates. Nws yog nyob rau hauv nruab nrab txuas ntawm kev lag luam thiab ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev lag luam.
Cov txheej txheem tseem ceeb rau kev npaj silicon carbide epitaxial txheej yog: evaporation txoj kev loj hlob; kua theem epitaxy (LPE); molecular beam epitaxy (MBE); Tshuaj vapor deposition (CVD).
Ntawm lawv, tshuaj vapor deposition (CVD) yog qhov nrov tshaj plaws 4H-SiC homoepitaxial txoj kev. 4-H-SiC-CVD epitaxy feem ntau siv CVD cov cuab yeej, uas tuaj yeem ua kom muaj kev txuas ntxiv ntawm cov txheej txheem epitaxial 4H siv lead ua SiC nyob rau hauv kev loj hlob kub.
Hauv cov khoom siv CVD, lub substrate tsis tuaj yeem muab tso ncaj qha rau ntawm cov hlau lossis tsuas yog muab tso rau ntawm lub hauv paus rau epitaxial deposition, vim hais tias nws muaj ntau yam xws li roj ntws kev taw qhia (kab rov tav, ntsug), kub, siab, fixation, thiab poob kuab paug. Yog li ntawd, yuav tsum muaj lub hauv paus, thiab tom qab ntawd lub substrate yog muab tso rau ntawm lub disk, thiab tom qab ntawd epitaxial deposition yog ua nyob rau hauv lub substrate siv CVD technology. Lub hauv paus no yog SiC coated graphite puag.
Raws li cov ntsiab lus tseem ceeb, lub hauv paus graphite muaj cov yam ntxwv ntawm lub zog tshwj xeeb thiab cov qauv tshwj xeeb, zoo thermal poob siab tsis kam thiab corrosion kuj, tab sis thaum lub sij hawm tsim cov txheej txheem, cov graphite yuav corroded thiab hmoov vim cov residue ntawm corrosive gases thiab hlau organic. teeb meem, thiab kev pab cuam lub neej ntawm graphite puag yuav raug txo kom tsawg.
Nyob rau tib lub sijhawm, cov hmoov poob graphite yuav ua rau cov nti. Hauv kev tsim cov txheej txheem ntawm silicon carbide epitaxial wafers, nws yog ib qho nyuaj rau ua tau raws li tib neeg cov kev xav tau ntxiv rau kev siv cov khoom siv graphite, uas txwv tsis pub nws txoj kev loj hlob thiab siv tau. Yog li ntawd, txheej tshuab pib nce.
2. Qhov zoo ntawmSiC txheej
Lub cev thiab tshuaj lom neeg cov khoom ntawm txheej txheej muaj cov kev cai nruj heev rau kev kub siab thiab kev tiv thaiv corrosion, uas cuam tshuam ncaj qha rau cov khoom lag luam thiab lub neej ntawm cov khoom. Cov khoom siv SiC muaj lub zog siab, siab hardness, qis thermal expansion coefficient thiab zoo thermal conductivity. Nws yog ib qho tseem ceeb ntawm high-temperature structural khoom thiab high-temperature semiconductor khoom. Nws yog siv rau graphite puag. Nws qhov zoo yog:
-SiC yog corrosion-resistant thiab tuaj yeem qhwv tag nrho cov graphite puag, thiab muaj qhov ntom ntom kom tsis txhob muaj kev puas tsuaj los ntawm cov roj corrosive.
-SiC muaj cov thermal conductivity siab thiab muaj zog sib txuas nrog lub hauv paus graphite, kom ntseeg tau tias cov txheej txheem tsis yooj yim poob tawm tom qab ntau qhov kub thiab txias.
-SiC muaj cov tshuaj zoo ruaj khov los tiv thaiv cov txheej txheem tsis ua haujlwm hauv qhov kub thiab txias.
Tsis tas li ntawd, epitaxial furnaces ntawm cov ntaub ntawv sib txawv yuav tsum muaj graphite tais nrog cov ntsuas kev ua tau zoo sib txawv. Lub thermal expansion coefficient txuam ntawm graphite cov ntaub ntawv yuav tsum tau yoog mus rau qhov loj hlob kub ntawm lub cub tawg epitaxial. Piv txwv li, qhov kub ntawm silicon carbide epitaxial kev loj hlob yog siab, thiab ib lub tais nrog ib tug siab thermal expansion coefficient txuam yuav tsum tau. Lub thermal expansion coefficient ntawm SiC yog ze rau ntawm graphite, ua rau nws haum raws li cov khoom nyiam rau txheej txheej ntawm graphite puag.
SiC cov ntaub ntawv muaj ntau hom siv lead ua, thiab feem ntau yog 3C, 4H thiab 6H. Cov qauv siv lead ua sib txawv ntawm SiC muaj kev siv sib txawv. Piv txwv li, 4H-SiC tuaj yeem siv los tsim cov khoom siv hluav taws xob siab; 6H-SiC yog qhov ruaj khov tshaj plaws thiab tuaj yeem siv los tsim cov khoom siv optoelectronic; 3C-SiC tuaj yeem siv los tsim GaN epitaxial txheej thiab tsim SiC-GaN RF cov khoom siv vim nws cov qauv zoo ib yam rau GaN. 3C-SiC kuj feem ntau hu ua β-SiC. Ib qho tseem ceeb ntawm kev siv β-SiC yog ua ib zaj duab xis nyias thiab txheej txheej. Yog li ntawd, β-SiC yog tam sim no cov khoom tseem ceeb rau txheej.
SiC coatings feem ntau yog siv hauv kev tsim khoom semiconductor. Lawv tsuas yog siv rau hauv substrates, epitaxy, oxidation diffusion, etching thiab ion implantation. Lub cev thiab tshuaj lom neeg cov khoom ntawm txheej txheej muaj cov kev cai nruj heev ntawm kev kub siab thiab kev tiv thaiv corrosion, uas cuam tshuam ncaj qha rau cov txiaj ntsig thiab lub neej ntawm cov khoom. Yog li ntawd, kev npaj ntawm SiC txheej yog qhov tseem ceeb.
Post lub sij hawm: Jun-24-2024