Isakhiwo se-InGaAs photodetector

Isakhiwo seIsitholi sezithombe se-InGaAs

Kusukela ngawo-1980, abacwaningi basekhaya nakwamanye amazwe baye bafunda isakhiwo sama-photodetector e-InGaAs, ahlukaniswe kakhulu ngezinhlobo ezintathu. Lawa yi-InGaAs metal-Semiconductor-metal photodetector (MSM-PD), i-InGaAs PIN Photodetector (PIN-PD), kanye ne-InGaAs Avalanche Photodetector (APD-PD). Kukhona umehluko omkhulu enkambisweni yokwenziwa kanye nezindleko zama-photodetector e-InGaAs anezakhiwo ezahlukene, futhi kukhona umehluko omkhulu ekusebenzeni kwedivayisi.

Insimbi ye-InGaAs-semiconductor-metalumshini wokuthola izithombe, okuboniswe kuMfanekiso (a), kuyisakhiwo esikhethekile esisekelwe ku-Schottky junction. Ngo-1992, uShi nabanye basebenzisa ubuchwepheshe be-epitaxy yesigaba somoya esinomfutho ophansi (LP-MOVPE) ukukhulisa izendlalelo ze-epitaxy kanye ne-InGaAs MSM photodetector elungisiwe, ene-A responseability ephezulu engu-0.42 A/W ku-wavelength engu-1.3 μm kanye nomsinga omnyama ongaphansi kuka-5.6 pA/ μm² ku-1.5 V. Ngo-1996, uZhang nabanye basebenzisa i-gas phase molecular beam epitaxy (GSMBE) ukukhulisa isendlalelo se-InAlAs-InGaAs-InP epitaxy. Isendlalelo se-InAlAs sibonise izici zokumelana okuphezulu, futhi izimo zokukhula zalungiswa ngokulinganisa kwe-X-ray diffraction, ukuze ukungafani kwe-lattice phakathi kwezingqimba ze-InGaAs ne-InAlAs kube ngaphakathi kwebanga elingu-1×10⁻³. Lokhu kuphumela ekusebenzeni kahle kwedivayisi ngogesi omnyama ongaphansi kuka-0.75 pA/μm² ku-10 V kanye nokuphendula okusheshayo kwesikhashana okufika ku-16 ps ku-5 V. Sekukonke, i-photodetector yesakhiwo se-MSM ilula futhi kulula ukuyihlanganisa, ikhombisa ugesi omnyama ophansi (i-pA order), kodwa i-electrode yensimbi izonciphisa indawo ephumelelayo yokumunca ukukhanya kwedivayisi, ngakho-ke impendulo iphansi kunezinye izakhiwo.

I-InGaAs PIN photodetector ifaka ungqimba lwangaphakathi phakathi kongqimba lokuxhumana lohlobo lwe-P kanye nongqimba lokuxhumana lohlobo lwe-N, njengoba kuboniswe kuMfanekiso (b), okwandisa ububanzi bendawo yokuphelelwa amandla, ngaleyo ndlela kukhanye ama-electron-hole pair amaningi futhi kwakha i-photocurrent enkulu, ngakho-ke inokusebenza okuhle kakhulu kokuqhuba ama-electron. Ngo-2007, u-A.Poloczek nabanye basebenzisa i-MBE ukukhulisa ungqimba lwe-buffer oluphansi ukuze kuthuthukiswe ubulukhuni bomphezulu futhi kunqobe ukungafani kwe-lattice phakathi kwe-Si ne-InP. I-MOCVD yasetshenziswa ukuhlanganisa isakhiwo se-InGaAs PIN ku-substrate ye-InP, futhi ukuphendula kwedivayisi kwakungaba ngu-0.57A /W. Ngo-2011, i-Army Research Laboratory (ALR) yasebenzisa ama-PIN photodetectors ukutadisha i-liDAR imager ukuze kuqondiswe, kugwenywe izithiyo/ukushayisana, kanye nokutholwa/ukuhlonza okuqondiwe okufushane kwezimoto ezincane zomhlaba ezingenamuntu, kuhlanganiswe ne-chip ye-microwave amplifier eshibhile eyathuthukisa kakhulu isilinganiso sesignali-kuya-kumsindo se-InGaAs PIN photodetector. Ngenxa yalokhu, ngo-2012, i-ALR isebenzise lesi sithombe se-liDAR kumarobhothi, anobubanzi bokuthola obungaphezu kwamamitha angu-50 kanye nesinqumo esingu-256 × 128.

Ama-InGaAsumshini wokuthola izithombe we-avalancheuhlobo lwe-photodetector olune-gain, isakhiwo salo esiboniswe kuMfanekiso (c). Umbhangqwana we-electron-hole uthola amandla anele ngaphansi kwesenzo sensimu kagesi ngaphakathi kwesifunda esiphindwe kabili, ukuze ushayisane ne-athomu, ukhiqize ama-electron-hole pair amasha, wakhe umphumela we-avalanche, futhi wandise abathwali abangebona ukulingana ezintweni. Ngo-2013, uGeorge M wasebenzisa i-MBE ukukhulisa ama-InGaAs nama-InAlAs alloys afana ne-lattice ku-substrate ye-InP, esebenzisa izinguquko ekubunjweni kwe-alloy, ubukhulu be-epitaxial layer, kanye ne-doping kumandla e-carrier aguquliwe ukuze kwandiswe i-electroshock ionization ngenkathi kunciphisa i-hole ionization. Ekuzuzeni kwesignali yokukhipha okulinganayo, i-APD ikhombisa umsindo ophansi kanye nogesi omnyama ophansi. Ngo-2016, uSun Jianfeng nabanye bakhe isethi yesikhulumi sokuhlola i-laser active imaging esingu-1570 nm esekelwe ku-InGaAs avalanche photodetector. Isekethe yangaphakathi yeIsitholi sezithombe se-APDAma-echo atholiwe futhi akhipha ngqo izimpawu zedijithali, okwenza yonke idivayisi ibe ncane. Imiphumela yokuhlola iboniswe ku-FIG. (d) kanye no-(e). Umfanekiso (d) isithombe esibonakalayo sethagethi yesithombe, kanti Umfanekiso (e) isithombe sebanga esinobukhulu obuthathu. Kungabonakala ngokucacile ukuthi indawo yefasitela yendawo c inebanga elithile lokujula nendawo A kanye no-b. Ipulatifomu ibona ububanzi be-pulse obungaphansi kwama-10 ns, amandla e-pulse eyodwa (1 ~ 3) alungisekayo mJ, insimu yelensi etholayo i-Angle engu-2°, imvamisa yokuphindaphinda engu-1 kHz, isilinganiso somsebenzi wokuthola esingaba ngu-60%. Ngenxa yokwanda kwe-photocurrent yangaphakathi ye-APD, impendulo esheshayo, usayizi oqinile, ukuqina kanye nezindleko eziphansi, ama-photodetector e-APD angaba yi-oda eliphakeme kakhulu ngesilinganiso sokuthola kune-PIN photodetectors, ngakho-ke i-liDAR yamanje eyinhloko ilawulwa kakhulu ama-photodetector e-avalanche.

Sekukonke, ngokuthuthukiswa okusheshayo kobuchwepheshe bokulungiselela i-InGaAs ekhaya nakwamanye amazwe, singasebenzisa ngobuhlakani i-MBE, i-MOCVD, i-LPE kanye nobunye ubuchwepheshe ukulungiselela ungqimba lwe-InGaAs epitaxial olusezingeni eliphezulu endaweni enkulu ku-substrate ye-InP. Ama-photodetector e-InGaAs abonisa ugesi omnyama ophansi kanye nokuphendula okuphezulu, ugesi omnyama ophansi kakhulu ungaphansi kuka-0.75 pA/μm², ukuphendula okuphezulu kufikela ku-0.57 A/W, futhi unempendulo yesikhashana esheshayo (i-ps order). Ukuthuthukiswa kwesikhathi esizayo kwama-photodetector e-InGaAs kuzogxila kulezi zici ezimbili ezilandelayo: (1) Ungqimba lwe-InGaAs epitaxial lukhuliswa ngqo ku-substrate ye-Si. Njengamanje, iningi lamadivayisi e-microelectronic emakethe asekelwe ku-Si, futhi ukuthuthukiswa okulandelayo okuhlanganisiwe kwe-InGaAs kanye ne-Si based kuyisitayela esijwayelekile. Ukuxazulula izinkinga ezifana nokungafani kwe-lattice kanye nomehluko we-thermal expansion coefficient kubalulekile ekufundweni kwe-InGaAs/Si; (2) Ubuchwepheshe be-wavelength engu-1550 nm sebuvuthiwe, futhi ubude be-wavelength obude (2.0 ~ 2.5) μm buyindlela yocwaningo yesikhathi esizayo. Ngokwanda kwezingxenye ze-In, ukungafani kwe-lattice phakathi kwe-substrate ye-InP kanye ne-InGaAs epitaxial layer kuzoholela ekuhlukaniseni okukhulu kanye namaphutha, ngakho-ke kuyadingeka ukwenza ngcono amapharamitha enqubo yedivayisi, ukunciphisa amaphutha e-lattice, kanye nokunciphisa ugesi omnyama wedivayisi.