Method of making avalanche photodiodes with epitaxially-regrown guard rings

Abstract

A SAM avalanche photodiode formed with an epitaxially regrown guard ring and a planar P-N junction defined between a cap layer and a multiplication layer. The multiplication layer is part of a multi-layer semiconductor platform having a conductivity opposite to the conductivity type of the cap layer, including a light absorption layer, a substrate and an intermediate layer. A second embodiment of the present invention is disclosed including a SAM avalanche photodiode having a guard ring with a variable distribution of impurity dopant concentrations. In addition, a third embodiment of the present invention is disclosed in which a narrow band gap layer completely covers the cap layer and a non-alloy metal contact is formed to completely cover the narrow band gap layer, forming a mirror junction. In this embodiment, incident light is shined through the substrate and reflected from the mirror junction, enhancing the absorption efficiency.

Dependencies are inferred from the claim text.