High-speed polysilicon resonant-cavity photodiode with SiO/sub 2/-Si Bragg reflectors

This is the authors' abstract. We don't add key points for this paper.

Previously, it has been shown that the bandwidth of Si photodiodes can be increased by more than an order of magnitude, without sacrificing responsivity, by a resonant-cavity structure that utilized GeSi-Si asymmetric Bragg reflectors. We report an interdigitated p-i-n polysilicon resonant-cavity photodiode, which employs a Si-SiO2Bragg reflector, that is more compatible with standard Si processing technology. For an absorbing region thickness of only 0.5 μm, a peak quantum efficiency of 40% was achieved and the dark current was <60 nA at 10 V. For 2 μm×2-μm finger width and spacing the bandwidth was 10 GHz.