Performance assesment of indium antimonide photodetectors on silicon substrates

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2003

Öğrenci: ÜMİD TÜMKAYA

Danışman: İBRAHİM GÜNAL

Özet:

In this study, detailed characteristics and performance assessment of 3-5 æm p-i-n InSb photodetectors on Si substrates are reported. The detector epilayers were grown on GaAs coated Si substrates by molecular beam apitaxy (MBE). Both homojunction and single heterojunction (AlInSb/InSb) detector structures were investigated. Arrays of 33x33 æm2 detectors were fabricated and flip-chip bonded to a test substrate for detailed electrical and optical characterization. A peak detectivity as high as 1x1010 cmHz1/2/W was achieved with InSb homojunction detectors on Si substrate in spite of the large lattice mismatch between InSb and Si (%19). In both homojunction and single heterojunction structures the differential resistance is significantly degraded by trap assisted tunneling (TAT) under moderately large reverse bias and by ohmic leakage near zero-bias. While the heterojunction structures provide a higher 80 K zero bias differential resistance, the responsivity of this structure is significantly lower than that of homojunction InSb photodiodes. In both homojunction and heterojunction photodetectors, 80K 1/f noise is dominated by TAT processes, and the noise current at 1 Hz follows the empirical relation in= aTAT(ITAT) β with aTAT~1.1x10ا6 and β~0.53.