Abstract

Interdigitated Metal-Semiconductor-Metal (MSM) Schottky diodes fabricated on GaAs and other III-V compounds are sensitive high speed photodetectors for multigigabit optical data processing systems. The compatibility of the fabrication process with the process technology of planar high speed electronic devices like FET's makes them extremely attractive for ultrafast integrated optoelectronic circuits. Narrow Schottky contact spacing permitting rapid carrier extraction after photoexcitation and a small active area in order to minimize the parasistic capacitance are the key design features of these diodes. First attempts to model the intrinsic transport of photoexcited carriers in MSM-diodes by a one-dimensional Monte Carlo simulation predict temporal separation of the electron and hole current /1,2/ and durations of electron and hole pulse of a few picoseconds and several ten picoseconds, respectively. Although frequency bandwidths in excess of several ten GHz for such detectors have been reported by several groups /3,4/ a direct comparison of theoretical and experimental results and a definite identification of the performance-limiting factors is still missing, so far.

© 1991 Optical Society of America