Si avalanche photodetectors fabricated in standard complementary metal-oxide-semiconductor process

The authors report silicon avalanche photodetectors (APDs) fabricated with 0.18 mu m standard complementary metal-oxide-semiconductor (CMOS) process without any process modification or a special substrate. When the bias is above the avalanche breakdown voltage, CMOS-compatible APD (CMOS-APD) exhibits negative photoconductance in photocurrent-voltage relationship and rf peaking in the photodetection frequency response. The reflection coefficient measurement of CMOS-APD indicates that rf peaking is due to resonance caused by appearance of inductive components in avalanche region. The rf-peaking frequency increases with the increasing reverse bias voltage. (c) 2007 American Institute of Physics.