2. Epitaxial nyias zaj duab xis loj hlob
Lub substrate muab cov txheej txheem kev txhawb nqa lub cev lossis txheej txheej rau Ga2O3 cov khoom siv hluav taws xob. Cov txheej txheem tseem ceeb tom ntej yog txheej txheej channel lossis txheej txheej epitaxial siv rau kev tiv thaiv hluav taws xob thiab kev thauj mus los. Txhawm rau txhawm rau ua kom tawg hluav taws xob thiab txo qis kev ua haujlwm tsis zoo, tswj cov thickness thiab doping concentration, nrog rau cov khoom siv zoo, yog qee qhov yuav tsum tau ua ua ntej. High quality Ga2O3 epitaxial khaubncaws sab nraud povtseg feem ntau tso siv molecular beam epitaxy (MBE), hlau organic chemical vapor deposition (MOCVD), halide vapor deposition (HVPE), pulsed laser deposition (PLD), thiab pos CVD raws li deposition cov tswv yim.
Table 2 Qee cov neeg sawv cev epitaxial technologies
2.1 MBE txoj kev
MBE thev naus laus zis muaj npe nrov rau nws lub peev xwm loj hlob zoo, tsis muaj qhov tsis xws luag β-Ga2O3 cov yeeb yaj kiab nrog kev tswj hwm n-hom doping vim nws qhov chaw nqus tsev ultra-siab thiab cov khoom siv purity siab. Yog li ntawd, nws tau dhau los ua ib qho ntawm cov kev kawm dav tshaj plaws thiab muaj peev xwm ua lag luam β-Ga2O3 nyias zaj duab xis tso tawm thev naus laus zis. Tsis tas li ntawd, txoj kev MBE kuj tau ua tiav cov txheej txheem zoo, qis-doped heterostructure β-(AlXGa1-X)2O3 / Ga2O3 nyias txheej txheej. MBE tuaj yeem saib xyuas cov qauv saum npoo thiab morphology hauv lub sijhawm tiag tiag nrog cov txheej txheem atomic precision los ntawm kev siv lub zog hluav taws xob siab diffraction (RHEED). Txawm li cas los xij, β-Ga2O3 cov yeeb yaj kiab loj hlob siv MBE thev naus laus zis tseem ntsib ntau yam kev cov nyom, xws li kev loj hlob tsawg thiab cov yeeb yaj kiab me me. Txoj kev tshawb nrhiav pom tias qhov kev loj hlob yog nyob rau hauv qhov kev txiav txim ntawm (010)>(001)>(−201)>(100). Nyob rau hauv me ntsis Ga-nplua nuj tej yam kev mob ntawm 650 mus rau 750 ° C, β-Ga2O3 (010) qhia pom kev loj hlob nrog ib tug du nto thiab loj hlob tus nqi. Siv txoj kev no, β-Ga2O3 epitaxy tau ua tiav nrog RMS roughness ntawm 0.1 nm. β-Ga2O3 Nyob rau hauv ib puag ncig Ga-nplua nuj, MBE cov yeeb yaj kiab loj hlob ntawm qhov kub sib txawv tau pom hauv daim duab. Novel Crystal Technology Inc. tau ua tiav epitaxially tsim 10 × 15mm2 β-Ga2O3MBE wafers. Lawv muab cov khoom zoo (010) taw qhia β-Ga2O3 ib leeg siv lead ua substrates nrog lub thickness ntawm 500 μm thiab XRD FWHM hauv qab 150 arc vib nas this. Lub substrate yog Sn doped lossis Fe doped. Sn-doped conductive substrate muaj doping concentration ntawm 1E18 rau 9E18cm-3, thaum hlau-doped semi-insulating substrate muaj ib tug resistivity siab tshaj 10E10 Ω cm.
2.2 MOCVD method
MOCVD siv cov hlau organic sib txuas ua cov ntaub ntawv ua ntej kom loj hlob cov yeeb yaj kiab nyias, yog li ua tiav kev lag luam loj. Thaum loj hlob Ga2O3 siv txoj kev MOCVD, trimethylgallium (TMGa), triethylgallium (TEGa) thiab Ga (dipentyl glycol formate) feem ntau yog siv los ua Ga qhov chaw, thaum H2O, O2 lossis N2O yog siv los ua cov pa oxygen. Kev loj hlob siv txoj kev no feem ntau yuav tsum tau kub siab (> 800 ° C). Cov thev naus laus zis no muaj peev xwm ua tiav cov neeg nqa khoom qis thiab siab thiab tsis tshua muaj hluav taws xob hloov hluav taws xob, yog li nws tseem ceeb heev rau kev ua tiav ntawm kev ua haujlwm siab β-Ga2O3 cov khoom siv hluav taws xob. Piv nrog rau MBE txoj kev loj hlob, MOCVD muaj qhov zoo ntawm kev ua tiav kev loj hlob ntawm β-Ga2O3 cov yeeb yaj kiab vim muaj cov yam ntxwv ntawm kev loj hlob kub thiab tshuaj lom neeg.
Daim duab 7 β-Ga2O3 (010) AFM duab
Daim duab 8 β-Ga2O3 Kev sib raug zoo ntawmμ thiab daim ntawv tsis kam ntsuas los ntawm Hall thiab kub
2.3 HVPE method
HVPE yog ib tug paub tab epitaxial technology thiab tau dav siv nyob rau hauv lub epitaxial loj hlob ntawm III-V compound semiconductors. HVPE paub txog nws cov nqi qis, kev loj hlob sai, thiab cov yeeb yaj kiab siab. Nws yuav tsum raug sau tseg tias HVPEβ-Ga2O3 feem ntau nthuav tawm qhov ntxhib saum npoo morphology thiab qhov ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom. Yog li ntawd, cov txheej txheem tshuaj thiab cov tshuab polishing yuav tsum tau ua ua ntej tsim cov cuab yeej. HVPE thev naus laus zis rau β-Ga2O3 epitaxy feem ntau siv gaseous GaCl thiab O2 ua ntej los txhawb qhov kub-kub cov tshuaj tiv thaiv ntawm (001) β-Ga2O3 matrix. Daim duab 9 qhia txog qhov xwm txheej saum npoo av thiab kev loj hlob ntawm cov yeeb yaj kiab epitaxial raws li kev ua haujlwm ntawm qhov kub thiab txias. Nyob rau hauv xyoo tas los no, Nyiv lub Novel Crystal Technology Inc. tau ua tiav kev lag luam tseem ceeb hauv HVPE homoepitaxial β-Ga2O3, nrog epitaxial txheej thicknesses ntawm 5 mus rau 10 μm thiab wafer qhov ntau thiab tsawg ntawm 2 thiab 4 ntiv tes. Tsis tas li ntawd, 20 μm tuab HVPE β-Ga2O3 homoepitaxial wafers tsim los ntawm Tuam Tshoj Electronics Technology Group Corporation kuj tau nkag mus rau theem kev lag luam.
Daim duab 9 HVPE txoj kev β-Ga2O3
2.4 PLD txoj kev
PLD thev naus laus zis feem ntau yog siv los tso cov yeeb yaj kiab oxide complex thiab heterostructures. Thaum lub sij hawm PLD txoj kev loj hlob, photon zog yog ua ke rau cov khoom siv los ntawm cov txheej txheem electron emission. Nyob rau hauv sib piv rau MBE, PLD qhov chaw hais yog tsim los ntawm laser hluav taws xob uas muaj zog heev (> 100 eV) thiab tom qab tso rau ntawm ib tug rhuab substrate. Txawm li cas los xij, thaum lub sij hawm ablation txheej txheem, qee cov khoom siv hluav taws xob siab yuav cuam tshuam ncaj qha rau cov khoom nto, tsim cov ntsiab lus tsis xws luag thiab yog li txo qhov zoo ntawm cov yeeb yaj kiab. Zoo ib yam li MBE txoj kev, RHEED tuaj yeem siv los saib xyuas cov qauv saum npoo thiab morphology ntawm cov khoom siv hauv lub sijhawm tiag tiag thaum lub sijhawm PLD β-Ga2O3 deposition txheej txheem, tso cai rau cov kws tshawb fawb kom tau txais cov ntaub ntawv loj hlob. PLD txoj kev xav kom loj hlob β-Ga2O3 cov yeeb yaj kiab zoo heev, ua rau nws ua kom zoo dua ohmic kev daws teeb meem hauv Ga2O3 cov khoom siv hluav taws xob.
Daim duab 10 AFM duab ntawm Si doped Ga2O3
2.5 MIST-CVD txoj kev
MIST-CVD yog ib qho yooj yim thiab nqi-zoo nyias zaj duab xis loj hlob technology. Txoj kev CVD no suav nrog cov tshuaj tiv thaiv ntawm kev txau cov atomized precursor mus rau lub substrate kom ua tiav cov yeeb yaj kiab nyias. Txawm li cas los xij, txog tam sim no, Ga2O3 loj hlob siv cov huab cua CVD tseem tsis muaj cov khoom siv hluav taws xob zoo, uas tawm ntau chav rau kev txhim kho thiab ua kom zoo rau yav tom ntej.
Post lub sij hawm: May-30-2024