Propagating avalanche position-sensitive photon detector with resolution in the micrometer and picosecond range

A position-sensitive silicon photodetector based on a new principle is introduced. The device is a special avalanche photodiode operated above the breakdown voltage. The exploited physical effect is the propagation of the avalanche perpendicularly to the electric field. The time and position (one dimension) information are extracted from the avalanche current leading edge. Experimental measurements on test structures with a position-sensitive area of 14*70 mu m are presented. Spatial resolution better than 10- mu m FWHM combined with ultrahigh sensitivity (single photon detection) and time resolution better than 100 ps are demonstrated.<>