Daim ntawv thov ntawm TaC coated graphite qhov chaw

PART/1

Crucible, noob tuav thiab qhia nplhaib nyob rau hauv SiC thiab AIN ib leeg siv lead ua rauv tau zus los ntawm PVT txoj kev

Raws li pom nyob rau hauv daim duab 2 [1], thaum lub cev vapor thauj txoj kev (PVT) yog siv los npaj SiC, cov noob siv lead ua yog nyob rau hauv tsis tshua muaj kub cheeb tsam, SiC raw khoom yog nyob rau hauv lub kub kub cheeb tsam (ntau tshaj 2400).℃), thiab cov khoom siv raw decomposes los tsim SiXCy (tsuas yog suav nrog Si, SiC₂, Si₂C, thiab lwm yam). Cov khoom siv vapor theem yog thauj los ntawm cheeb tsam kub siab mus rau cov noob siv lead ua hauv thaj chaw uas tsis kub, forming noob nuclei, loj hlob, thiab tsim ib tug crystals. Cov ntaub ntawv thermal siv nyob rau hauv cov txheej txheem no, xws li crucible, flow guidering, noob siv lead ua yas dhos, yuav tsum tiv taus kub thiab yuav tsis pollute SiC raw cov ntaub ntawv thiab SiC ib tug crystals. Ib yam li ntawd, cov khoom cua kub hauv kev loj hlob ntawm AlN ib leeg muaju yuav tsum tiv taus Al vapor, N.₂corrosion, thiab yuav tsum muaj kub eutectic (nrog AlN) kom luv lub sij hawm npaj siv lead ua.

Nws tau pom tias SiC[2-5] thiab AlN[2-3] npaj los ntawmTAC coatedgraphite thermal teb cov ntaub ntawv tau huv si, yuav luag tsis muaj carbon (oxygen, nitrogen) thiab lwm yam impurities, tsawg dua ntug defects, me resistivity nyob rau hauv txhua cheeb tsam, thiab lub micropore ntom thiab etching qhov ntom ntom tau txo qis (tom qab KOH etching), thiab siv lead ua zoo. tau zoo heev. Ntxiv rau,TAS crucibleQhov hnyav poob qis yuav luag xoom, zoo li tsis muaj kev puas tsuaj, tuaj yeem rov ua dua tshiab (lub neej mus txog 200h), tuaj yeem txhim kho kev ruaj khov thiab kev ua haujlwm ntawm kev npaj siv lead ua ib leeg.

FIG. 2. (a) Schematic daim duab ntawm SiC ib qho siv lead ua ingot loj hlob los ntawm PVT txoj kev
(b) TopTAC coatednoob bracket (xws li SiC noob)
(c)TAC-coated graphite qhia nplhaib

PART/2

MOCVD GaN epitaxial txheej loj hlob cua sov

Raws li pom nyob rau hauv daim duab 3 (a), MOCVD GaN kev loj hlob yog cov tshuaj vapor deposition tshuab siv organometrical decomposition cov tshuaj tiv thaiv kom loj hlob nyias zaj duab xis los ntawm vapor epitaxial kev loj hlob. Qhov tseeb ntawm qhov kub thiab txias tsis sib xws hauv cov kab noj hniav ua rau lub tshuab cua sov ua qhov tseem ceeb tshaj plaws ntawm cov khoom siv MOCVD. Txawm hais tias lub substrate tuaj yeem ua kom sov sai thiab sib npaug rau lub sijhawm ntev (nyob rau hauv qhov rov ua kom txias), qhov ruaj khov ntawm qhov kub siab (ua haujlwm rau cov roj corrosion) thiab purity ntawm zaj duab xis yuav cuam tshuam ncaj qha rau qhov zoo ntawm zaj duab xis deposition, thickness sib xws, thiab kev ua haujlwm ntawm lub chip.

Txhawm rau txhim kho kev ua haujlwm thiab rov ua haujlwm ntawm lub rhaub hauv MOCVD GaN txoj kev loj hlob,TAC-coatedgraphite rhaub tau ua tiav kev qhia. Piv nrog GaN epitaxial txheej zus los ntawm cov pa cua sov (siv pBN txheej), GaN epitaxial txheej zus los ntawm TaC rhaub muaj yuav luag tib lub qauv siv lead ua, thickness uniformity, intrinsic defects, impurity doping thiab paug. Ntxiv rau, covTAC txheejmuaj qhov tsis kam tiv taus thiab tsis tshua muaj qhov emissivity, uas tuaj yeem txhim kho kev ua tau zoo thiab kev sib txig ntawm lub rhaub, yog li txo qis kev siv hluav taws xob thiab hluav taws xob poob. Lub porosity ntawm txheej tuaj yeem hloov kho los ntawm kev tswj cov txheej txheem tsis ua haujlwm txhawm rau txhim kho cov yam ntxwv hluav taws xob ntawm lub rhaub thiab txuas ntxiv nws lub neej kev pab cuam [5]. Cov txiaj ntsig no ua rauTAC coatedgraphite cua sov yog qhov kev xaiv zoo tshaj plaws rau MOCVD GaN txoj kev loj hlob.

FIG. 3. (a) Schematic daim duab ntawm MOCVD ntaus ntawv rau GaN epitaxial kev loj hlob
(b) Moulded TAC-coated graphite rhaub tau nruab rau hauv MOCVD teeb, tsis suav nrog lub hauv paus thiab bracket (pib qhia qhia lub hauv paus thiab bracket hauv cua sov)
(c) TAC-coated graphite rhaub tom qab 17 GaN epitaxial loj hlob. [6]

PART/3

Coated susceptor rau epitaxy (wafer cab kuj)

Wafer carrier yog ib qho tseem ceeb ntawm cov txheej txheem rau kev npaj ntawm SiC, AlN, GaN thiab lwm yam peb chav kawm semiconductor wafers thiab epitaxial wafer loj hlob. Feem ntau ntawm cov neeg nqa khoom wafer yog ua los ntawm graphite thiab coated nrog SiC txheej los tiv thaiv corrosion los ntawm cov txheej txheem gases, nrog rau qhov kub ntawm epitaxial ntawm 1100 txog 1600.°C, thiab corrosion kuj ntawm cov txheej tiv thaiv plays lub luag hauj lwm tseem ceeb nyob rau hauv lub neej ntawm wafer cab kuj. Cov txiaj ntsig tau pom tias qhov corrosion ntawm TaC yog 6 npaug qeeb dua SiC hauv qhov kub siab ammonia. Nyob rau hauv qhov kub thiab txias hydrogen, tus nqi corrosion yog ntau tshaj 10 npaug qeeb dua SiC.

Nws tau raug pov thawj los ntawm kev sim uas cov tais ntim nrog TaC qhia tau zoo sib xws hauv lub teeb xiav GaN MOCVD txheej txheem thiab tsis qhia impurities. Tom qab kev hloov kho cov txheej txheem tsawg, cov coj loj hlob siv TaC cov neeg nqa khoom nthuav tawm tib yam kev ua tau zoo thiab sib xws li cov neeg nqa khoom SiC. Yog li ntawd, lub neej kev pab cuam ntawm TAC-coated pallets yog zoo dua li ntawm liab qab pob zeb number case thiabSiC coatedgraphite pallets.