Theory of SiGe waveguide avalanche detectors operating at /spl lambda/=1.3 /spl mu/m

The potential performance of SiGe waveguide avalanche photodiodes is analyzed for operation at a wavelength of 1.3 /spl mu/m. It is found that response speeds in excess of 5 Gbit/s with gains of /spl sim/40 should be readily achievable in the absence of carrier trapping effects. Analysis of the electron initiated avalanche current shows an initial low-noise fast pulse due to primary ionization. This is followed by a noisy tail involving hole initiated processes. Structures for future experimental study are proposed.