Babban fasahar don ci gabanSiC epitaxialAbu na farko shine fasahar sarrafa lahani, musamman don fasahar sarrafa lahani wanda ke iya haifar da gazawar na'ura ko lalacewar aminci. Nazarin tsarin lahani na substrate da ke faɗaɗa cikin Layer ɗin epitaxial yayin tsarin girma na epitaxial, dokokin canja wuri da canzawa na lahani a mahaɗin tsakanin substrate da Layer ɗin epitaxial, da kuma tsarin nucleation na lahani sune tushen fayyace alaƙar da ke tsakanin lahani na substrate da lahani na tsarin epitaxial, wanda zai iya jagorantar tantance substrate da inganta tsarin epitaxial yadda ya kamata.
Kurakurai naLayer na epitaxial na silicon carbideAn raba su galibi zuwa rukuni biyu: lahani na lu'ulu'u da lahani na siffar saman. Lalacewar lu'ulu'u, gami da lahani na maki, ɓarnar sukurori, lahani na microtubule, ɓarkewar gefen, da sauransu, galibi suna fitowa ne daga lahani akan abubuwan da ke cikin SiC kuma suna yaɗuwa cikin layin epitaxial. Ana iya ganin lahani na siffar saman kai tsaye da ido tsirara ta amfani da na'urar hangen nesa kuma suna da halaye na yau da kullun na siffar saman. Lalacewar siffar saman galibi sun haɗa da: Scratch, Triangle, Carrot, Downfall, da Barbashi, kamar yadda aka nuna a Hoto na 4. A lokacin aikin epitaxial, ƙwayoyin waje, lahani na substrate, lalacewar saman, da karkacewar tsarin epitaxial duk na iya shafar yanayin girma na matakin gida, wanda ke haifar da lahani na siffar saman.
Tebur 1. Dalilan da ke haifar da lahani na matrix da lahani na yanayin saman a cikin layukan epitaxial na SiC
Lalacewar maki
Ana samun lahani a wuraren da babu gurbi ko gibi a wurin layi ɗaya ko kuma wuraren layi da yawa, kuma ba su da faɗaɗa sarari. Lalacewar wuraren na iya faruwa a kowace hanyar samarwa, musamman a cikin dasa ion. Duk da haka, suna da wahalar gano su, kuma dangantakar da ke tsakanin canjin lahani a wuraren da sauran lahani shi ma yana da rikitarwa.
Ƙananan bututu (MP)
Ƙananan bututun ruwa sune ramukan da ba a iya gani ba waɗanda ke yaɗuwa a kan hanyar girma, tare da vector na Burgers <0001>. Diamita na ƙananan bututun ruwa yana daga ƙaramin micron zuwa goma na microns. Ƙananan bututun ruwa suna nuna manyan siffofi na saman rami a saman wafers na SiC. Yawanci, yawan ƙananan bututun ruwa yana kusan 0.1~1cm-2 kuma yana ci gaba da raguwa a cikin sa ido kan ingancin samar da wafer na kasuwanci.
Rushewar sukurori (TSD) da Rushewar gefen (TED)
Rushewar SiC shine babban tushen lalacewar na'urar da gazawarta. Rushewar sukurori (TSD) da Rushewar gefen (TED) suna gudana tare da ma'aunin girma, tare da vectors na Burgers na <0001> da 1/3<11–20>, bi da bi.
Dukansu nakasar sukurori (TSD) da nakasar gefen (TED) na iya miƙewa daga substrate zuwa saman wafer kuma suna kawo ƙananan siffofi na saman kamar rami (Hoto na 4b). Yawanci, yawan nakasar gefen ya ninka na kaskon sukurori sau 10. Nakasar sukurori mai tsawo, wato, daga substrate zuwa epilayer, suma na iya canzawa zuwa wasu lahani kuma su yaɗu tare da ma'aunin girma. A lokacinSiC epitaxialgirma, rushewar sukurori ana canza su zuwa lahani na tara (SF) ko lahani na karas, yayin da aka nuna cewa rushewar gefen epilayers an canza su daga rushewar basal plane (BPDs) da aka gada daga substrate yayin girmawar epitaxial.
Basic plane dislocation (BPD)
Ana samunsa a kan babban layin SiC, tare da vector na Burgers na 1/3 <11–20>. BPDs ba kasafai suke bayyana a saman wafers na SiC ba. Yawanci suna mai da hankali kan substrate mai yawan 1500 cm-2, yayin da yawansu a cikin epilayer shine kusan 10 cm-2 kawai. Gano BPDs ta amfani da photoluminescence (PL) yana nuna siffofin layi, kamar yadda aka nuna a Hoto na 4c. A lokacinSiC epitaxialgirma, ana iya canza BPDs masu tsawo zuwa lahani na tara (SF) ko kuma nakasa gefen (TED).
Kurakurai na Tarawa (SFs)
Lalacewa a cikin jerin tarawar basal plane na SiC. Lalacewar tarawar na iya bayyana a cikin layin epitaxial ta hanyar gadon SFs a cikin substrate, ko kuma suna da alaƙa da faɗaɗawa da canjin taruwar basal plane (BPDs) da taruwar taruwar sukurori (TSDs). Gabaɗaya, yawan SFs bai wuce 1 cm-2 ba, kuma suna nuna fasalin triangle lokacin da aka gano su ta amfani da PL, kamar yadda aka nuna a Hoto na 4e. Duk da haka, ana iya ƙirƙirar nau'ikan lalacewar tarawar iri-iri a cikin SiC, kamar nau'in Shockley da nau'in Frank, saboda ko da ƙaramin adadin matsalar kuzarin tarawar tsakanin jiragen sama na iya haifar da rashin daidaituwa sosai a cikin jerin tarawar.
Faduwar Kasa
Lalacewar faɗuwar ta samo asali ne daga faɗuwar barbashi a bangon sama da na gefe na ɗakin amsawa yayin tsarin girma, wanda za'a iya inganta shi ta hanyar inganta tsarin kulawa na lokaci-lokaci na kayan amfani na ɗakin amsawa na graphite.
Lalacewar kusurwa uku
Haɗakar nau'in polytype 3C-SiC ce wadda ta miƙe zuwa saman Layer ɗin SiC tare da alkiblar jirgin ƙasa, kamar yadda aka nuna a Hoto na 4g. Ana iya samar da shi ta hanyar faɗuwar ƙwayoyin cuta a saman Layer ɗin SiC yayin haɓakar epitaxial. Ƙwayoyin suna cikin Layer ɗin epilayer kuma suna tsoma baki ga tsarin girma, wanda ke haifar da haɗakar nau'in polytype 3C-SiC, wanda ke nuna siffofin saman triangle mai kaifi tare da ƙwayoyin da ke kan iyakoki na yankin triangle. Nazari da yawa sun kuma danganta asalin haɗakar nau'in polytype zuwa ga karyewar saman, ƙananan bututu, da kuma sigogi marasa dacewa na tsarin girma.
Lalacewar karas
Lalacewar karas wani hadadden lahani ne mai tarawa wanda ke da gefuna biyu a saman TSD da SF basal crystal planes, wanda ya ƙare da dislocation na nau'in Frank, kuma girman lalacewar karas yana da alaƙa da lalacewar tarawa ta prismatic. Haɗin waɗannan fasalulluka yana samar da yanayin saman lalacewar karas, wanda yayi kama da siffar karas mai yawa ƙasa da 1 cm-2, kamar yadda aka nuna a Hoto na 4f. Lalacewar karas ana samun sauƙin samuwa a lokacin gogewa, TSDs, ko lahani na substrate.
Ƙira
Karce-karce lalacewa ce ta injiniya a saman wafers ɗin SiC da aka samar yayin aikin samarwa, kamar yadda aka nuna a Hoto na 4h. Karce-karce a kan substrate ɗin SiC na iya tsoma baki ga haɓakar epilayer, haifar da jerin katsewar abubuwa masu yawa a cikin epilayer, ko kuma karce-karce na iya zama tushen samuwar lahani na karas. Saboda haka, yana da mahimmanci a goge wafers ɗin SiC yadda ya kamata saboda waɗannan karce-karce na iya yin tasiri mai mahimmanci akan aikin na'urar lokacin da suka bayyana a yankin aiki na na'urar.
Wasu lahani na siffar saman
Haɗa matakai lahani ne na saman da aka samu yayin tsarin girma na SiC epitaxial, wanda ke samar da alwatika masu duhu ko siffofi na trapezoidal a saman Layer na SiC. Akwai wasu lahani da yawa na saman, kamar ramukan saman, kumbura da tabo. Waɗannan lahani galibi suna faruwa ne sakamakon rashin ingantaccen tsarin girma da kuma cire lalacewar gogewa gaba ɗaya, wanda ke shafar aikin na'urar.
Lokacin Saƙo: Yuni-05-2024