Isici esingunxantathu
Ukukhubazeka kukanxantathu yiziphambeko ze-morphological ezibulala kakhulu ezingqimbeni ze-SiC epitaxial. Inombolo enkulu yemibiko yezincwadi ibonise ukuthi ukwakheka kwamaphutha angama-triangular kuhlobene nefomu le-crystal ye-3C. Kodwa-ke, ngenxa yezinqubo ezihlukene zokukhula, i-morphology yamaphutha amaningi angama-triangular ebusweni be-epitaxial layer ihluke kakhulu. Ingase ihlukaniswe cishe ibe yizinhlobo ezilandelayo:
(1) Kunamaphutha anxantathu anezinhlayiya ezinkulu phezulu
Lolu hlobo lwesici esingunxantathu lunezinhlayiya ezinkulu eziyindilinga phezulu, okungenzeka kubangelwe izinto eziwayo phakathi nenqubo yokukhula. Indawo encane engunxantathu enendawo emagebhugebhu ingabhekwa phansi ukusuka kule vertex. Lokhu kubangelwa ukuthi ngesikhathi senqubo ye-epitaxial, izingqimba ezimbili ezihlukene ze-3C-SiC zakhiwe ngokulandelana endaweni engunxantathu, lapho ungqimba lokuqala luyi-nucleated ku-interface futhi lukhula ngokugeleza kwesinyathelo se-4H-SiC. Njengoba ukushuba kongqimba lwe-epitaxial kukhula, ungqimba lwesibili lwe-3C polytype nucleates futhi lukhule emigodini emincane engunxantathu, kodwa isinyathelo sokukhula esingu-4H asiyivali ngokuphelele indawo ye-polytype engu-3C, okwenza indawo eyi-V-shaped groove ye-3C-SiC isacacile. ebonakalayo
(2) Kunezinhlayiya ezincane phezulu kanye namaphutha angunxantathu anomahhadlahhadla
Izinhlayiya eziqonde phezulu zalolu hlobo lwesici esingunxantathu zincane kakhulu, njengoba kuboniswe kuMfanekiso 4.2. Futhi ingxenye enkulu yendawo engunxantathu ihlanganiswe ukuhamba kwesinyathelo kwe-4H-SiC, okungukuthi, lonke ungqimba lwe-3C-SiC lufakwe ngokuphelele ngaphansi kwesendlalelo se-4H-SiC. Izinyathelo zokukhula ze-4H-SiC kuphela ezingabonakala endaweni enesici esingunxantathu, kodwa lezi zinyathelo zikhulu kakhulu kunezinyathelo ezivamile zokukhula kwe-crystal ye-4H.
(3) Amaphutha anxantathu anendawo ebushelelezi
Lolu hlobo lwesici esingunxantathu lunokwakheka komhlaba okubushelelezi, njengoba kukhonjisiwe kuMfanekiso 4.3. Ngokukhubazeka okunjalo kukanxantathu, ungqimba lwe-3C-SiC lumbozwe ukuhamba kwesinyathelo kwe-4H-SiC, futhi ifomu lekristalu le-4H ebusweni likhula kahle futhi libushelelezi.
Izinkinga ze-Epitaxial pit
I-Epitaxial pits (Imigodi) ingenye yezinkinga ezivame kakhulu ze-surface morphology, futhi i-surface morphology yazo ejwayelekile kanye nohlaka lwesakhiwo kuboniswa kuMfanekiso 4.4. Indawo yemigodi yokugqwala ye-threading dislocation (TD) ebonwe ngemva kokucwiliswa kwe-KOH ngemuva kwedivayisi inokuxhumana okucacile nendawo yemigodi ye-epitaxial ngaphambi kokulungiswa kwedivayisi, okubonisa ukuthi ukwakheka kokukhubazeka kwe-epitaxial pit kuhlobene nokuhlukaniswa kwentambo.
izaqathi ukukhubazeka
Ukukhubazeka kwe-carrot kuyisici esivamile se-surface ku-4H-SiC epitaxial layers, futhi i-morphology yabo evamile iboniswa ku-Figure 4.5. Isici se-carrot kubikwa ukuthi senziwa ukuphambana kwamaphutha we-Franconia kanye nama-prismatic stacking atholakala endizeni ye-basal exhunywe ngokususwa okufana nesinyathelo. Kuphinde kwabikwa ukuthi ukwakheka kwe-carrot ukukhubazeka kuhlobene ne-TSD ku-substrate. Tsuchida H. et al. ithole ukuthi ukuminyana kokukhubazeka kwezaqathi kungqimba lwe-epitaxial kuhambisana nokuminyana kwe-TSD ku-substrate. Futhi ngokuqhathanisa izithombe ze-surface morphology ngaphambi nangemva kokukhula kwe-epitaxial, zonke iziphambeko zezaqathi eziqashiwe zingatholakala zihambisana ne-TSD ku-substrate. Wu H. et al. isebenzise i-Raman scattering test characterization ukuze ithole ukuthi ukukhubazeka kwesanqante kwakungenalo ifomu le-crystal ye-3C, kodwa i-polytype ye-4H-SiC kuphela.
Umthelela wokukhubazeka kukanxantathu kuzici zedivayisi ye-MOSFET
Umfanekiso 4.7 uyi-histogram yokusabalalisa kwezibalo izici ezinhlanu zedivayisi equkethe ukukhubazeka kukanxantathu. Ulayini onamachashazi aluhlaza umugqa ohlukanisayo wokucekelwa phansi kwesici sedivayisi, futhi ulayini onamachashazi abomvu umugqa ohlukanisayo wokwehluleka kwedivayisi. Ngokwehluleka kwedivayisi, ukonakala kukanxantathu kunomthelela omkhulu, futhi izinga lokuhluleka likhulu kuno-93%. Lokhu kubangelwa kakhulu umthelela wokukhubazeka kukanxantathu ezicini zokuvuza ezihlehlayo zamadivayisi. Kufikela ku-93% wamadivayisi aqukethe ukukhubazeka kukanxantathu akhulise kakhulu ukuvuza okubuyela emuva. Ukwengeza, amaphutha anxantathu nawo anomthelela omubi kakhulu ezicini zokuvuza kwesango, ngezinga lokuwohloka lika-60%. Njengoba kuboniswe kuThebula 4.2, ngokuwohloka kwamandla kagesi e-threshold kanye nokuwohloka kwesici se-diode yomzimba, umthelela wamaphutha kanxantathu mncane, futhi izilinganiso zokuwohloka zingama-26% nama-33% ngokulandelanayo. Mayelana nokubangela ukwanda kokumelana, umthelela wokukhubazeka kukanxantathu awunamandla, futhi isilinganiso sokuwohloka singaba ngu-33%.
Umthelela wokukhubazeka kwe-epitaxial pit ezicini zedivayisi ye-MOSFET
Umfanekiso 4.8 uyi-histogram yokusabalalisa kwezibalo izici ezinhlanu zedivayisi equkethe ukukhubazeka kwe-epitaxial pit. Ulayini onamachashazi aluhlaza umugqa ohlukanisayo wokucekelwa phansi kwesici sedivayisi, futhi ulayini onamachashazi abomvu umugqa ohlukanisayo wokwehluleka kwedivayisi. Kungabonwa kulokhu ukuthi inani lamadivayisi aqukethe ukukhubazeka kwe-epitaxial pit kusampula ye-SiC MOSFET lilingana nenani lamadivayisi aqukethe ukukhubazeka kukanxantathu. Umthelela wokukhubazeka kwe-epitaxial pit ezicini zedivayisi uhlukile kulowo wokukhubazeka kukanxantathu. Mayelana nokwehluleka kwedivayisi, izinga lokuhluleka kwamadivayisi aqukethe amaphutha e-epitaxial pit angama-47% kuphela. Uma kuqhathaniswa nokukhubazeka kukanxantathu, umthelela wokulimala komgodi we-epitaxial ezicini zokuvuza okuhlanekezelwe nezici zokuvuza zesango zedivayisi ziba buthaka kakhulu, ngezilinganiso zokuwohloka ezingama-53% no-38% ngokulandelana, njengoba kuboniswe kuThebula 4.3. Ngakolunye uhlangothi, umthelela wokukhubazeka kwe-epitaxial pit ezicini zamandla kagesi e-threshold, izici zokuqhuba i-diode yomzimba kanye nokumelana nokumelana mkhulu kunokonakala kukanxantathu, nesilinganiso sokuwohloka sifinyelela ku-38%.
Ngokuvamile, ukukhubazeka okubili kokuma kwemvelo, okungonxantathu kanye nemigodi ye-epitaxial, kunomthelela omkhulu ekuhlulekeni nasekucekeleni phansi kwesici kwamadivayisi we-SiC MOSFET. Ukuba khona kokukhubazeka kukanxantathu yikona okubulalayo kakhulu, ngezinga lokungaphumeleli elifinyelela ku-93%, ikakhulukazi elibonakala njengokwenyuka okuphawulekayo kokuvuza okuhlehlayo kwedivayisi. Amadivayisi aqukethe ukukhubazeka kwe-epitaxial pit abe nezinga lokuhluleka eliphansi lama-47%. Kodwa-ke, ukukhubazeka kwe-epitaxial pit kunomthelela omkhulu ku-threshold voltage yedivayisi, izici zokuqhuba i-diode yomzimba kanye nokumelana nokuqina kunonxantathu.
Isikhathi sokuthumela: Apr-16-2024