Isiphene esingunxantathu
Iziphene ezinxantathu zezona ziphene zibulalayo kwi-SiC epitaxial layers. Inani elikhulu leengxelo zoncwadi lubonise ukuba ukubunjwa kweziphene ze-triangular kuhambelana nefom ye-crystal ye-3C. Nangona kunjalo, ngenxa yeendlela ezahlukeneyo zokukhula, i-morphology yeziphene ezininzi ze-triangular kumphezulu we-epitaxial layer yahluke kakhulu. Inokwahlulwa ngokwezi ntlobo zilandelayo:
(1) Kukho iziphene ezinxantathu ezinamasuntswana amakhulu phezulu
Olu hlobo lwesiphene esingunxantathu lune-particle enkulu ye-spherical phezulu, enokuthi ibangelwa zizinto eziwayo ngexesha lokukhula. Indawo encinci engunxantathu enomhlaba orhabaxa unokujongwa ezantsi ukusuka kule vertex. Oku kubangelwa ukuba ngexesha lenkqubo ye-epitaxial, iindidi ezimbini ezihlukeneyo ze-3C-SiC zenziwa ngokulandelelana kwindawo ye-triangular, apho i-layer yokuqala i-nucleated kwi-interface kwaye ikhula nge-4H-SiC yesinyathelo sokuhamba. Njengoko ubukhulu be-epitaxial layer sanda, i-second layer ye-3C polytype nucleates kwaye ikhula kwimigodi emincinci ye-triangular, kodwa inyathelo lokukhula kwe-4H aligubungeli ngokupheleleyo indawo ye-polytype ye-3C, okwenza indawo ye-V-shaped groove ye-3C-SiC isacacile. ebonakalayo
(2) Kukho amasuntswana amancinci phezulu kunye neziphene ezinxantathu ezinomgangatho orhabaxa
Iinqununu kwii-vertices zolu hlobo lwesiphene se-triangular zincinci kakhulu, njengoko kuboniswe kwi-Figure 4.2. Kwaye ininzi yommandla we-triangular igutyungelwe yinyathelo lokuhamba kwe-4H-SiC, oko kukuthi, yonke i-3C-SiC layer ifakwe ngokupheleleyo phantsi kwe-4H-SiC layer. Kuphela ngamanyathelo okukhula kwe-4H-SiC angabonwa kwindawo yesiphene esingunxantathu, kodwa la manyathelo makhulu kakhulu kuneendlela eziqhelekileyo zokukhula kwe-crystal ye-4H.
(3) Iziphene ezinxantathu ezinomgangatho ogudileyo
Olu hlobo lwesiphene se-triangular lune-morphology ye-smooth surface, njengoko kuboniswe kwi-Figure 4.3. Kwiziphene ezinjalo ezinxantathu, i-3C-SiC layer igutyungelwe yinyathelo lokuhamba kwe-4H-SiC, kwaye ifom ye-crystal ye-4H ebusweni ikhula kakuhle kwaye ilula.
Iziphene ze-Epitaxial pit
Imigodi ye-Epitaxial (Imigodi) yenye yezona ziphene eziqhelekileyo ze-surface morphology, kwaye i-morphology yazo eqhelekileyo kunye ne-structural outline iboniswe kwi-Figure 4.4. Indawo ye-threading dislocation (TD) imigodi ye-corrosion ebonwe emva kokuba i-KOH ifakwe ngasemva kweso sixhobo inembalelwano ecacileyo kunye nendawo yemigodi ye-epitaxial ngaphambi kokulungiswa kwesixhobo, ebonisa ukuba ukubunjwa kwe-epitaxial pit defects kuhambelana nokuxutywa kwe-threading dislocations.
iminqathe iziphene
I-carrot defects yi-performance surface defect kwi-4H-SiC epitaxial layers, kwaye i-morphology yabo eqhelekileyo iboniswe kwi-Figure 4.5. I-carrot defect ixelwe ukuba yenziwe ngokudibana kwe-Franconia kunye neempazamo ze-prismatic stacking ezibekwe kwi-plane ye-basal exhunywe ngamanyathelo afana ne-dislocations. Kwakhona kuye kwaxelwa ukuba ukubunjwa kweziphene ze-karoti kuhambelana ne-TSD kwi-substrate. Tsuchida H. et al. ufumanise ukuba ubuninzi beempazamo ze-carrot kwi-epitaxial layer bulingana nobuninzi be-TSD kwi-substrate. Kwaye ngokuthelekisa imifanekiso ye-morphology yomhlaba ngaphambi nangemva kokukhula kwe-epitaxial, zonke iziphene ze-carrot eziqatshelweyo zinokufunyanwa zihambelana ne-TSD kwi-substrate. Wu H. et al. wasebenzisa Raman ukusasazwa uvavanyo characterization ukufumanisa ukuba iziphene umnqathe akazange iqulathe ifomu crystal 3C, kodwa kuphela 4H-SiC polytype.
Isiphumo seziphene ezinxantathu kwiimpawu zesixhobo se-MOSFET
Umzobo 4.7 yi-histogram yokusasazwa kwamanani eempawu ezintlanu zesixhobo esineziphene ezinxantathu. Umgca onamachaphaza abhlowu ngumgca wokwahlulahlulwa kweempawu zesixhobo, kwaye umgca wamachokoza obomvu ngumgca wokwahlulahlula kwesixhobo. Ukusilela kwesixhobo, iziphene ezinxantathu zinempembelelo enkulu, kwaye izinga lokungaphumeleli likhulu kune-93%. Oku kubalelwa ikakhulu kwimpembelelo yeziphene ezinxantathu kwiimpawu zokuvuza ezingasemva kwezixhobo. Ukuya kuthi ga kwi-93% yezixhobo ezineziphene ezinxantathu zinyuse kakhulu ukuvuza okubuyela umva. Ukongeza, iziphene ezinxantathu nazo zinempembelelo enkulu kwiimpawu zokuvuza kwesango, kunye nezinga lokuthotywa kwe-60%. Njengoko kubonisiwe kwiThebhile 4.2, ukuthotywa kombane we-threshold kunye nokuthotywa kweempawu ze-diode yomzimba, impembelelo yeziphene ze-triangular incinci, kwaye imilinganiselo yokunciphisa i-26% kunye ne-33% ngokulandelanayo. Ngokumalunga nokubangela ukwanda kokuchasana, impembelelo yeziphene ezinxantathu zibuthathaka, kwaye umlinganiselo wokuthotywa malunga ne-33%.
Impembelelo ye-epitaxial pit defects kwiimpawu zesixhobo se-MOSFET
Umzobo 4.8 yi-histogram yokusasazwa kwamanani eempawu ezintlanu zesixhobo esineziphene ze-epitaxial pit. Umgca onamachaphaza abhlowu ngumgca wokwahlulahlulwa kweempawu zesixhobo, kwaye umgca wamachokoza obomvu ngumgca wokwahlulahlula kwesixhobo. Inokubonwa koku ukuba inani lezixhobo eziqulethe iziphene ze-epitaxial pit kwisampulu ye-SiC MOSFET ilingana nenani lezixhobo ezineziphene ezinxantathu. Impembelelo ye-epitaxial pit defects kwiimpawu zesixhobo zihluke kwi-triangular defects. Ngokumalunga nokungaphumeleli kwesixhobo, izinga lokungaphumeleli kwezixhobo eziqulethe iziphene ze-epitaxial pit kuphela ngama-47%. Xa kuthelekiswa neziphene ze-triangular, impembelelo ye-epitaxial pit defects kwi-reverse ukuvuza iimpawu kunye neempawu zokuvuza kwesango zesixhobo ziyancipha kakhulu, kunye ne-degradation ratios ye-53% kunye ne-38% ngokulandelanayo, njengoko kuboniswe kwiThebhile 4.3. Ngakolunye uhlangothi, impembelelo ye-epitaxial pit defects kwiimpawu zombane we-threshold voltage, iimpawu ze-diode conduction yomzimba kunye nokumelana ne-on-resistance inkulu kunaleyo yeziphene ezinxantathu, kunye ne-degradation ratio ifikelela kuma-38%.
Ngokubanzi, iziphene ezibini ze-morphological, ezizezi oonxantathu kunye nemingxuma ye-epitaxial, zinempembelelo enkulu ekungaphumeleli nasekuthotyweni kweempawu zezixhobo ze-SiC MOSFET. Ubukho beziphene ezinxantathu yeyona nto ibulalayo, kunye nezinga lokungaphumeleli ukuya kuma-93%, libonakaliswa ikakhulu njengokunyuka okubonakalayo kokuvuza okubuyela umva kwesixhobo. Izixhobo eziqulethe i-epitaxial pit defects zinezinga eliphantsi lokungaphumeleli kwe-47%. Nangona kunjalo, iziphene ze-epitaxial pit zinempembelelo enkulu kwi-voltage ye-threshold yesixhobo, iimpawu ze-diode conduction yomzimba kunye nokumelana nokumelana kuneziphene ezinxantathu.
Ixesha lokuposa: Apr-16-2024