A planar amorphous Si/sub 1-x/Gex Separated-Absorption-Multiplication avalanche photo diode

We report a simple innovative and CMOS compatible planar Separated-Absorption-Multiplication (SAM) amorphous Si/sub 1-x/Ge/sub x/ avalanche photo diode (SAMAPD) for short-distance optical-fiber communication systems. The spectral response of this SAMAPD extends up to 0.93 μm with a bandwidth of 1.9 GHz. Due to its low-temperature process budget it can be post-fabricated in a CMOS wafer, which makes it ideal for building monolithic submicron CMOS fiber optic detector systems.