Kungani kufanele sisebenzise i-Ge njenge-photodetector

Kungani kufanele sisebenzise i-Ge njenge-umshini wokuthola izithombe
1, Ukubeka Okuyisisekelo: Kungani Kudingeka Ukusebenzisa i-Ge Njenge-Photodetector
Kuma-silicon optical links, i-photodetector “ingabahumushi” abaguqula amasignali optical abuyele kumasignali kagesi. Kodwa-ke, i-silicon ngokwayo ine-bandgap engu-1.12 eV futhi icishe ibonakale kuma-band okuxhumana angu-1310/1550 nm, ngakho-ke i-germanium (Ge) kuphela engangeniswa.
I-Ge ine-bandgap eqondile engu-0.8 eV, ehlanganisa i-O/C band yokuxhumana, kodwa inokungalingani kwe-lattice okungu-4.2% ne-silicon. Ubuningi be-dislocation bokukhula okuqondile buphakeme njengo-4 × 10 ⁸ cm ⁻ ², futhi ugesi omnyama awutholakali nhlobo; Ngesikhathi esifanayo, i-Ge ine-bandgap engaqondile, futhi i-absorption coefficient yayo ngokwemvelo iphansi kakhulu kune-InGaAs, okuwubuthakathaka bemvelo.
2, Ukuphumelela Okuyinhloko: ukuhlanganiswa kwe-waveguide kuphula imbobo yokusebenza
"Ubude bokumunca = indlela yokuqoqwa komthwali" wezinto zokubona izithombe eziqondile zendabuko zine-"bandwidth yokusabela" seesaw, enomkhawulo ophezulu we-7GHz kuphela;
Njengamanje, izindlela zokulawula ezisetshenziswa kakhulu zihlukaniswe ngezigaba ezintathu:
Iphinikhodi eqondile: Le nqubo ilula futhi ijwayelekile embonini, ifinyelela ku-40Gb/s @ zero bias kanye ne-bandwidth engu->60GHz;
I-MSM Metal Semiconductor Metal: Asikho isidingo sokusebenzisa i-doping yokushisa okuphezulu, ingafakwa ku-backend, inomsinga omnyama ophezulu, kanye ne-bandwidth engaphezu kuka-40GHz;
Izinhlobo eziphezulu:Ama-photodetector amagagasi ahambayo(TWPD) kanye nama-photodetector e-single line carrier (UTC) asetshenziselwa izixhumanisi ze-photon ze-microwave, ukulinganisa i-bandwidth ephezulu kanye ne-photocurrent ephezulu yokugcwala.
3, Izinto Zokusebenza Nobuciko: Ukuguqula 'Amaphutha' Abe Izinzuzo
Ngenxa yokungalingani kwe-lattice kanye nokushiyeka kokusebenza, imboni isungule izixazululo ezivuthiwe:
Indlela yezinyathelo ezimbili ye-epitaxy: okokuqala, kukhuliswa ungqimba lwe-buffer oluphansi oluyi-30-50nm, bese kwandiswa izinga lokushisa ukuze kufinyelelwe ukujiya okuqondiwe, kunciphisa ubuningi be-dislocation bube ~10 ⁷ cm ⁻²;
Ubunjiniyela bokucindezeleka: Umehluko kuma-coefficients okwandisa ukushisa phakathi kwe-Ge ne-Si uzobangela ukucindezeleka kwe-biaxial tensile okungu-0.2% kwifilimu ye-Ge, okuholela ekunciphiseni kwegebe lebhendi eliqondile kusuka ku-0.8 eV kuya ku-0.77 eV kanye nokwandiswa komphetho wokumunca kusuka ku-1.55 μ m kuya ku-1.61 μ m, okumboza lonke ibhendi ye-C+L, futhi ngisho ne-coefficient yokumunca kubhendi ye-L ingalingana neye-InGaAs;
Ukuhlanganiswa kwe-CMOS: Kusesesigabeni sokuhlola. Ukuhlanganiswa kwe-front end (FEOL) kudinga ukumelana namazinga okushisa aphezulu ngaphezu kuka-750 ℃, kuyilapho ukuhlanganiswa kwe-back-end (BEOL) kuhambisana nokushisa kodwa ngaphandle kwe-crystal substrates, futhi akukakhi ikhambi elivuthiwe elihlanganisiwe. Njengamanje, imboni ngokuvamile isebenzisa indlela exubile ethi “90% single-chip+externali-laser“.