Tsarin Kera Na'urar SiC Silicon Carbide (1)

Kamar yadda muka sani, a cikin filin semiconductor, siliki guda kristal (Si) shine mafi yawan amfani da mafi girma-girma na asali abu a duniya. A halin yanzu, fiye da 90% na samfuran semiconductor ana kera su ta amfani da kayan tushen silicon. Tare da karuwar buƙatun na'urori masu ƙarfi da ƙarfin lantarki a cikin filin makamashi na zamani, an gabatar da ƙarin buƙatu masu ƙarfi don mahimman sigogi na kayan semiconductor kamar faɗin bandgap, rushewar filin lantarki, ƙimar jikewar lantarki, da haɓakar zafi. A ƙarƙashin wannan yanayin, babban bandgap semiconductor kayan wakiltasiliki carbide(SiC) sun fito a matsayin masoyin aikace-aikace masu yawa masu ƙarfi.

A matsayin mahaɗan semiconductor,siliki carbideyana da wuya a yanayi kuma yana bayyana a cikin nau'i na moissanite na ma'adinai. A halin yanzu, kusan duk silicon carbide da aka sayar a duniya an haɗa su ta hanyar wucin gadi. Silicon carbide yana da fa'idodi na babban taurin, babban ƙarfin zafin jiki, ingantaccen yanayin zafi, da babban fashewar filin lantarki. Abu ne mai mahimmanci don yin babban ƙarfin lantarki da na'urorin semiconductor masu ƙarfi.

Don haka, ta yaya ake kera na'urorin wutar lantarki na silicon carbide?

Menene bambanci tsakanin tsarin kera na'urar siliki carbide da tsarin masana'anta na gargajiya na silicon? Fara daga wannan fitowar, "Abubuwa game daNa'urar Silicon CarbideManufacturing” zai tona asirin daya bayan daya.

I

Tsari kwarara na silicon carbide na'urar kera

Tsarin kera na'urorin carbide na silicon gabaɗaya yana kama da na na'urorin tushen silicon, galibi sun haɗa da photolithography, tsaftacewa, doping, etching, samuwar fim, bakin ciki da sauran matakai. Yawancin masu kera na'urorin wutar lantarki na iya biyan bukatun masana'anta na na'urorin siliki carbide ta haɓaka layin samar da su dangane da tsarin masana'anta na silicon. Koyaya, kaddarorin na musamman na kayan silicon carbide sun ƙayyade cewa wasu matakai a cikin masana'antar na'urar suna buƙatar dogaro da takamaiman kayan aiki don haɓaka na musamman don ba da damar na'urorin silicon carbide don tsayayya da babban ƙarfin lantarki da babban halin yanzu.

II

Gabatarwa zuwa siliki carbide na musamman na tsari kayayyaki

Modulolin tsari na musamman na silicon carbide galibi suna rufe alluran doping, ƙirar ƙofa, etching ilimin halittar jiki, ƙarfe, da matakan bakin ciki.

(1) Doping allura: Saboda babban ƙarfin haɗin gwiwar carbon-silicon a cikin silicon carbide, ƙazantattun ƙwayoyin cuta suna da wahalar yaduwa a cikin silicon carbide. Lokacin shirya na'urorin silicon carbide, doping na PN junctions za a iya samu kawai ta ion implantation a high zafin jiki.
Ana yin amfani da kwayoyi da yawa tare da ions na ƙazanta kamar boron da phosphorus, kuma zurfin doping yawanci shine 0.1μm ~ 3μm. Ƙunƙarar ion mai ƙarfi mai ƙarfi zai lalata tsarin lattice na silicon carbide abu kanta. Ana buƙatar ƙara yawan zafin jiki don gyara lalacewar lattice da aka yi ta hanyar ion implantation da kuma sarrafa tasirin annealing akan tarkace. Mahimman matakai sune ion implantation high-zazzabi da kuma zafi zafi annealing.

Hoto 1 Tsarin tsari na dasa ion da tasirin zafi mai zafi

(2) Ƙofar Ƙofar Ƙofar Ƙofar Ƙofar: Ƙarfafawar SiC / SiO2 yana da tasiri mai girma akan ƙaura ta tashar da amincin ƙofar MOSFET. Wajibi ne don haɓaka ƙayyadaddun hanyoyin oxide na ƙofa da hanyoyin haɓakar iskar oxygen don rama abubuwan haɗin gwiwa a SiC / SiO2 dubawa tare da atom na musamman (kamar atom ɗin nitrogen) don saduwa da buƙatun aiki na ƙirar SiC / SiO2 mai inganci da haɓaka. ƙaura na na'urori. Mahimman hanyoyin su ne kofa oxide oxygenation mai zafin jiki, LPCVD, da PECVD.

Hoto 2 Tsarin tsari na jigilar fim ɗin oxide na yau da kullun da yanayin zafi mai zafi

(3) Etching ilimin halittar jiki: Silicon carbide kayan ba su da ƙarfi a cikin kaushi na sinadarai, kuma ana iya samun madaidaicin sarrafa ilimin halittar jiki ta hanyar busassun etching; Abubuwan rufe fuska, zaɓin etching abin rufe fuska, gauraye gas, sarrafa bangon bango, ƙimar etching, rashin ƙarfi na bango, da sauransu suna buƙatar haɓaka bisa ga halayen kayan aikin silicon carbide. Mahimmin matakai sune jigon fim na bakin ciki, photolithography, lalata fim ɗin dielectric, da bushewar etching matakai.

Hoto 3 Tsarin tsari na tsarin etching na silicon carbide

(4) Metallization: Tushen lantarki na na'urar yana buƙatar ƙarfe don samar da kyakkyawar hulɗar ohmic mai ƙarancin juriya tare da silicon carbide. Wannan ba wai kawai yana buƙatar daidaita tsarin jigon ƙarfe ba da kuma sarrafa yanayin mu'amala na tuntuɓar ƙarfe-semiconductor, amma kuma yana buƙatar ɗaukar zafi mai zafi don rage tsayin shingen Schottky da cimma lambar ƙarfe-silicon carbide ohmic lamba. Mahimman matakai sune sputtering ƙarfe magnetron, ƙawancen katako na lantarki, da saurin zafi mai zafi.

Hoto 4 Tsarin tsari na ƙa'idar sputtering magnetron da tasirin ƙarfe

(5) Tsari na bakin ciki: Silicon carbide abu yana da halaye na babban taurin, high brittleness da ƙananan karaya tauri. Tsarin niƙansa yana da wuyar haifar da karyewar abu, yana haifar da lalacewa a saman wafer da ƙasa. Ana buƙatar haɓaka sabbin hanyoyin niƙa don biyan bukatun masana'anta na na'urorin carbide silicon. Mahimman hanyoyin tafiyar matakai sune thinning na niƙa fayafai, fim mai danko da kwasfa, da dai sauransu.

Hoto 5 Tsarin tsari na ƙa'idar niƙa/ƙara bakin ciki