Daim duab peb sab defect
Triangular defects yog cov feem ntau tuag morphological defects nyob rau hauv SiC epitaxial txheej. Ntau cov ntaub ntawv tshaj tawm tau qhia tias qhov kev tsim ntawm daim duab peb sab muaj feem xyuam nrog 3C siv lead ua daim ntawv. Txawm li cas los xij, vim muaj qhov sib txawv ntawm kev loj hlob mechanisms, morphology ntawm ntau daim duab peb sab nyob rau saum npoo ntawm epitaxial txheej yog txawv heev. Nws tuaj yeem muab faib ua ob hom hauv qab no:
(1) Muaj qhov tsis xws li daim duab peb sab nrog cov khoom loj rau saum
Cov yam ntxwv ntawm daim duab peb sab no muaj ib qho loj kheej kheej nyob rau saum toj, uas tej zaum yuav tshwm sim los ntawm cov khoom poob thaum lub sij hawm kev loj hlob. Ib cheeb tsam me me uas muaj qhov ntxhib saum npoo tuaj yeem pom hauv qab ntawm qhov vertex. Qhov no yog vim lub fact tias thaum lub sij hawm epitaxial txheej txheem, ob sib txawv 3C-SiC khaubncaws sab nraud povtseg yog ua tiav nyob rau hauv lub triangular cheeb tsam, uas cov thawj txheej yog nucleated ntawm lub interface thiab loj hlob los ntawm 4H-SiC kauj ruam ntws. Raws li lub thickness ntawm cov epitaxial txheej nce, txheej thib ob ntawm 3C polytype nucleates thiab loj hlob nyob rau hauv me me daim duab peb sab pits, tab sis 4H txoj kev loj hlob kauj ruam tsis tag npog 3C polytype cheeb tsam, ua rau V-shaped zawj cheeb tsam ntawm 3C-SiC tseem kom meej meej. pom
(2) Muaj cov khoom me me nyob rau sab saum toj thiab daim duab peb sab uas muaj qhov ntxhib saum npoo
Cov khoom ntawm qhov chaw ntawm qhov kev tsis zoo no yog qhov me me, raws li pom hauv daim duab 4.2. Thiab feem ntau ntawm daim duab peb sab yog them los ntawm cov kauj ruam ntws ntawm 4H-SiC, uas yog, tag nrho 3C-SiC txheej yog tag nrho embedded nyob rau hauv 4H-SiC txheej. Tsuas yog cov kauj ruam loj hlob ntawm 4H-SiC tuaj yeem pom ntawm daim duab peb sab tsis xws luag, tab sis cov kauj ruam no loj dua li cov qauv 4H siv lead ua kev loj hlob.
(3) Triangular defects nrog du nto
Hom ntawm daim duab peb sab no muaj ib tug du nto morphology, raws li qhia nyob rau hauv daim duab 4.3. Rau xws li daim duab peb sab tsis xws luag, 3C-SiC txheej yog them los ntawm cov kauj ruam ntws ntawm 4H-SiC, thiab 4H siv lead ua daim ntawv nyob rau saum npoo loj hlob zoo dua thiab smoother.
Epitaxial qhov tsis xws luag
Epitaxial pits (Pits) yog ib qho ntawm feem ntau qhov chaw morphology defects, thiab lawv cov morphology ntawm qhov chaw thiab cov qauv txheej txheem tau qhia hauv daim duab 4.4. Qhov chaw ntawm threading dislocation (TD) corrosion pits pom tom qab KOH etching nyob rau sab nraum qab ntawm lub cuab yeej muaj ib tug meej kev sib raug zoo nrog rau qhov chaw ntawm lub epitaxial pits ua ntej ntaus ntawv npaj, qhia tau hais tias tsim ntawm epitaxial pit defects muaj feem xyuam rau threading dislocations.
carrot tsis xws luag
Carrot defects yog ib qho chaw defect nyob rau hauv 4H-SiC epitaxial txheej, thiab lawv cov morphology raug pom nyob rau hauv daim duab 4.5. Carrot defect yog qhia los ntawm kev sib tshuam ntawm Franconian thiab prismatic stacking faults nyob rau hauv lub basal dav hlau txuas los ntawm kauj ruam-zoo li dislocations. Nws kuj tau tshaj tawm tias qhov tsim ntawm cov zaub ntug hauv paus muaj feem xyuam nrog TSD hauv substrate. Tsuchida H. et al. pom tias qhov ceev ntawm cov zaub ntug hauv paus tsis xws luag nyob rau hauv lub epitaxial txheej yog proportional rau qhov ceev ntawm TSD nyob rau hauv lub substrate. Thiab los ntawm kev sib piv cov duab morphology saum npoo ua ntej thiab tom qab kev loj hlob ntawm epitaxial, tag nrho cov kev pom ntawm cov zaub ntug hauv paus tuaj yeem pom tias sib haum rau TSD hauv substrate. Wu H. et al. siv Raman scattering test characterization kom pom tias cov zaub ntug hauv paus tsis zoo tsis muaj 3C siv lead ua daim ntawv, tab sis tsuas yog 4H-SiC polytype.
Cov teebmeem ntawm daim duab peb sab ntawm MOSFET cov yam ntxwv
Daim duab 4.7 yog ib qho histogram ntawm kev faib tawm ntawm tsib tus yam ntxwv ntawm ib lub cuab yeej uas muaj qhov tsis xws luag. Cov kab xiav dotted yog kab sib faib rau cov yam ntxwv ntawm cov cuab yeej degradation, thiab cov kab liab dotted yog cov kab sib faib rau cov cuab yeej tsis ua haujlwm. Rau cov cuab yeej tsis ua haujlwm, cov kev tsis zoo ntawm daim duab peb sab muaj qhov cuam tshuam zoo, thiab qhov tsis ua haujlwm yog ntau dua 93%. Qhov no feem ntau yog ntaus nqi los ntawm kev cuam tshuam ntawm daim duab peb sab tsis xws luag ntawm cov yam ntxwv thim rov qab ntawm cov khoom siv. Txog li 93% ntawm cov khoom siv uas muaj qhov tsis xws li daim duab peb sab tau ua rau muaj qhov thim rov qab ntau ntxiv. Tsis tas li ntawd, cov teeb meem ntawm daim duab peb sab kuj muaj kev cuam tshuam loj heev rau cov yam ntxwv ntawm lub rooj vag to, nrog rau qhov degradation ntawm 60%. Raws li pom nyob rau hauv Table 4.2, rau qhov pib voltage degradation thiab lub cev diode yam ntxwv degradation, qhov cuam tshuam ntawm triangular defects yog me me, thiab degradation proportions yog 26% thiab 33% feem. Nyob rau hauv cov nqe lus ntawm kev ua kom nce nyob rau hauv-kuj, qhov cuam tshuam ntawm daim duab peb sab tsis muaj zog, thiab qhov degradation piv yog li ntawm 33%.
Qhov cuam tshuam ntawm epitaxial qhov tsis xws luag ntawm MOSFET cov yam ntxwv
Daim duab 4.8 yog ib qho histogram ntawm kev faib tawm ntawm tsib tus yam ntxwv ntawm ib lub cuab yeej uas muaj qhov tsis xws luag ntawm epitaxial pit. Cov kab xiav dotted yog kab sib faib rau cov yam ntxwv ntawm cov cuab yeej degradation, thiab cov kab liab dotted yog cov kab sib faib rau cov cuab yeej tsis ua haujlwm. Nws tuaj yeem pom los ntawm qhov no tias tus naj npawb ntawm cov khoom siv uas muaj qhov tsis xws luag hauv qhov chaw epitaxial hauv SiC MOSFET tus qauv yog sib npaug rau cov khoom siv uas muaj qhov tsis xws luag. Qhov cuam tshuam ntawm epitaxial pit defects ntawm cov yam ntxwv ntawm cov cuab yeej yog txawv ntawm qhov tsis xws ntawm daim duab peb sab. Nyob rau hauv cov nqe lus ntawm cov cuab yeej tsis ua hauj lwm, qhov tsis ua hauj lwm tus nqi ntawm cov cuab yeej muaj cov kab mob epitaxial qhov tsis xws luag tsuas yog 47%. Piv nrog rau daim duab peb sab tsis xws luag, qhov cuam tshuam ntawm epitaxial qhov tsis xws luag ntawm qhov rov qab xau cov yam ntxwv thiab cov yam ntxwv ntawm lub rooj vag to ntawm lub cuab yeej yog qhov tsis muaj zog, nrog rau kev puas tsuaj ntawm 53% thiab 38% raws li qhia hauv Table 4.3. Ntawm qhov tod tes, qhov cuam tshuam ntawm epitaxial qhov tsis xws luag ntawm qhov pib voltage tus yam ntxwv, lub cev diode conduction yam ntxwv thiab on-resistance yog ntau dua li ntawm daim duab peb sab tsis xws luag, nrog lub degradation piv mus txog 38%.
Feem ntau, ob qhov tsis xws luag morphological, uas yog daim duab peb sab thiab epitaxial pits, muaj kev cuam tshuam tseem ceeb rau kev ua tsis tiav thiab cov yam ntxwv degradation ntawm SiC MOSFET cov cuab yeej. Lub hav zoov ntawm daim duab peb sab tsis xws luag yog qhov ua rau tuag taus, nrog rau qhov tsis ua haujlwm siab txog li 93%, feem ntau tshwm sim raws li qhov tseem ceeb hauv kev thim rov qab ntawm lub cuab yeej. Cov khoom siv uas muaj qhov tsis xws luag hauv qhov epitaxial muaj qhov ua tsis tau qis dua ntawm 47%. Txawm li cas los xij, qhov tsis xws luag hauv qhov epitaxial muaj qhov cuam tshuam ntau dua ntawm qhov ntsuas hluav taws xob ntawm lub cuab yeej, lub cev diode conduction yam ntxwv thiab kev tiv thaiv ntau dua li qhov tsis xws li daim duab peb sab.
Post lub sij hawm: Apr-16-2024