Iphutha elingunxantathu
Amaphutha angunxantathu yiwona amaphutha abulalayo kakhulu ezingqimbeni ze-epitaxial ze-SiC. Inani elikhulu lemibiko yezincwadi likhombisile ukuthi ukwakheka kwamaphutha angunxantathu kuhlobene nefomu lekristalu le-3C. Kodwa-ke, ngenxa yezindlela ezahlukene zokukhula, i-morphology yamaphutha amaningi angunxantathu ebusweni bengqimba ye-epitaxial ihlukile kakhulu. Ingahlukaniswa cishe ngezinhlobo ezilandelayo:
(1) Kuneziphambeko ezingunxantathu ezinezinhlayiya ezinkulu phezulu
Lolu hlobo lwesici esingunxantathu lunenhlayiya enkulu eyindilinga phezulu, okungase kubangelwe izinto eziwayo ngesikhathi senqubo yokukhula. Indawo encane engunxantathu enobuso obuqinile ingabonakala phansi kusukela kule vertex. Lokhu kungenxa yokuthi ngesikhathi senqubo ye-epitaxial, izendlalelo ezimbili ezahlukene ze-3C-SiC zakhiwa ngokulandelana endaweni engunxantathu, lapho ungqimba lokuqala luhlanganiswa khona endaweni ehlanganisiwe futhi lukhula ngokugeleza kwesinyathelo se-4H-SiC. Njengoba ubukhulu bengqimba ye-epitaxial bukhula, ungqimba lwesibili lwe-3C polytype nucleates futhi lukhula emigodini emincane engunxantathu, kodwa isinyathelo sokukhula se-4H asimbozi ngokuphelele indawo ye-3C polytype, okwenza indawo yomsele enomumo ongu-V we-3C-SiC isabonakala kahle.
(2) Kukhona izinhlayiya ezincane phezulu kanye neziphambeko ezingonxantathu ezinobuso obumahhadlahhadla
Izinhlayiya ezisemaphethelweni alolu hlobo lwesiphambeko esingunxantathu zincane kakhulu, njengoba kuboniswe kuMfanekiso 4.2. Futhi iningi lendawo engunxantathu limbozwe ukugeleza kwesinyathelo se-4H-SiC, okungukuthi, lonke ungqimba lwe-3C-SiC lufakwe ngokuphelele ngaphansi kwengqimba ye-4H-SiC. Izinyathelo zokukhula ze-4H-SiC kuphela ezingabonakala ebusweni besiphambeko esingunxantathu, kodwa lezi zinyathelo zinkulu kakhulu kunezinyathelo zokukhula kwekristalu ye-4H ezivamile.
(3) Amaphutha angunxantathu anobuso obubushelelezi
Lolu hlobo lwesici esingunxantathu lunokwakheka okubushelelezi kobuso, njengoba kuboniswe kuMfanekiso 4.3. Kulezi zici ezingunxantathu, ungqimba lwe-3C-SiC lumbozwe ukugeleza kwesinyathelo kwe-4H-SiC, futhi isimo sekristalu esingu-4H ebusweni sikhula sibe sincane futhi sibushelelezi.
Ukukhubazeka komgodi we-Epitaxial
Imigodi ye-Epitaxial (Imigodi) ingenye yeziphambeko ezivame kakhulu zesimo sobuso, futhi isimo sayo esijwayelekile sobuso kanye nohlaka lwesakhiwo kuboniswe kuMfanekiso 4.4. Indawo yemigodi yokugqwala kwe-threading dislocation (TD) ebonwe ngemuva kokuqoshwa kwe-KOH ngemuva kwedivayisi inokuhambisana okucacile nendawo yemigodi ye-epitaxial ngaphambi kokulungiswa kwedivayisi, okubonisa ukuthi ukwakheka kweziphambeko zemigodi ye-epitaxial kuhlobene nokugqwala kwe-threading.
ukukhubazeka kwesanqante
Amaphutha kakaroti ayisici esivamile ebusweni ezingqimbeni ze-epitaxial ze-4H-SiC, futhi isimo sazo esijwayelekile siboniswe kuMfanekiso 4.5. Isici kakaroti kubikwa ukuthi sakhiwe ukuhlangana kwamaphutha okuhlanganisa i-Franconian kanye ne-prismatic atholakala endaweni engezansi exhunywe yi-step-like dislocations. Kubikwe nokuthi ukwakheka kwamaphutha kakaroti kuhlobene ne-TSD ku-substrate. UTsuchida H. nabanye bathole ukuthi ubuningi bamaphutha kakaroti ku-epitaxial layer buhambisana nobuningi be-TSD ku-substrate. Futhi ngokuqhathanisa izithombe zesimo sobuso ngaphambi nangemva kokukhula kwe-epitaxial, wonke amaphutha kakaroti abonwe angatholakala ehambisana ne-TSD ku-substrate. UWu H. nabanye basebenzise ukuchazwa kokuhlolwa kokusabalalisa kwe-Raman ukuthola ukuthi amaphutha kakaroti ayengenalo uhlobo lwekristalu lwe-3C, kodwa kuphela uhlobo lwe-4H-SiC.
Umphumela weziphambeko ezingunxantathu ezicini zedivayisi ye-MOSFET
Isithombe 4.7 siyi-histogram yokusatshalaliswa kwezibalo zezici ezinhlanu zedivayisi equkethe amaphutha angunxantathu. Umugqa oluhlaza okwesibhakabhaka onamachashazi uwumugqa ohlukanisayo wokonakala kwesici sedivayisi, kanti umugqa obomvu onamachashazi uwumugqa ohlukanisayo wokwehluleka kwedivayisi. Uma idivayisi ihluleka, amaphutha angunxantathu anomthelela omkhulu, futhi izinga lokuhluleka lingaphezu kuka-93%. Lokhu kubangelwa kakhulu yithonya lamaphutha angunxantathu ezicini zokuvuza ezingemuva kwamadivayisi. Kufika ku-93% wamadivayisi aqukethe amaphutha angunxantathu akhuphule kakhulu ukuvuza okungemuva. Ngaphezu kwalokho, amaphutha angunxantathu nawo anomthelela omkhulu ezicini zokuvuza kwesango, ngesilinganiso sokuwohloka esingu-60%. Njengoba kuboniswe kuThebula 4.2, uma kuqhathaniswa nokuwohloka kwe-threshold voltage kanye nokuwohloka kwesici se-diode yomzimba, umthelela wamaphutha angunxantathu mncane, kanti izilinganiso zokuwohloka zingama-26% kanye nama-33% ngokulandelana. Ngokuphathelene nokubanga ukwanda kokumelana, umthelela wamaphutha angunxantathu ubuthakathaka, kanti isilinganiso sokuwohloka singama-33%.
Umphumela wokukhubazeka kwe-epitaxial pit ezicini zedivayisi ye-MOSFET
Isithombe 4.8 siyi-histogram yokusatshalaliswa kwezibalo zezici ezinhlanu zedivayisi equkethe amaphutha emigodi ye-epitaxial. Umugqa oluhlaza okwesibhakabhaka onamachashazi uwumugqa ohlukanisayo wokonakala kwesici sedivayisi, kanti umugqa onamachashazi abomvu uwumugqa ohlukanisayo wokwehluleka kwedivayisi. Kungabonakala kulokhu ukuthi inani lamadivayisi aqukethe amaphutha emigodi ye-epitaxial kusampula ye-SiC MOSFET lilingana nenani lamadivayisi aqukethe amaphutha angunxantathu. Umthelela wamaphutha emigodi ye-epitaxial ezicini zedivayisi uhlukile kowamaphutha angunxantathu. Ngokuphathelene nokwehluleka kwedivayisi, izinga lokuhluleka kwamadivayisi aqukethe amaphutha emigodi ye-epitaxial lingu-47% kuphela. Uma kuqhathaniswa namaphutha angunxantathu, umthelela wamaphutha emigodi ye-epitaxial ezicini zokuvuza okuphambene kanye nezici zokuvuza kwesango ledivayisi ubuthakathaka kakhulu, ngezilinganiso zokubola ezingu-53% no-38% ngokulandelana, njengoba kuboniswe kuThebula 4.3. Ngakolunye uhlangothi, umthelela wamaphutha emigodi ye-epitaxial ezicini ze-threshold voltage, izici zokuqhuba kwe-diode yomzimba kanye nokumelana nokumelana mkhulu kunowemaphutha angunxantathu, kanti isilinganiso sokubola sifinyelela ku-38%.
Ngokuvamile, amaphutha amabili okwakheka, okungukuthi onxantathu kanye nemigodi ye-epitaxial, anomthelela omkhulu ekuhlulekeni nasekuwohlokeni kwezimpawu zamadivayisi e-SiC MOSFET. Ukuba khona kwamaphutha angunxantathu yikona okubulalayo kakhulu, ngesilinganiso sokuhluleka esiphezulu esingama-93%, okubonakala kakhulu njengokwanda okukhulu kokuvuza okuphambene kwedivayisi. Amadivayisi aqukethe amaphutha emigodi ye-epitaxial abe nesilinganiso sokuhluleka esiphansi sama-47%. Kodwa-ke, amaphutha emigodi ye-epitaxial anomthelela omkhulu ku-threshold voltage yedivayisi, izici zokuqhuba i-diode yomzimba kanye nokumelana kwayo kunemaphutha angunxantathu.
Isikhathi sokuthunyelwe: Ephreli-16-2024