Semiconductor photodetector

US5942771A · kind A · utility

Assignee

• Mitsubishi Electric Corporation · JP

Inventor

• Eitaro Ishimura · Tokyo, JP

Key dates

• Filing date: Sep 3, 1997
• Grant date: Aug 24, 1999
• Expiry date: Sep 3, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F77/413

Abstract

A semiconductor photodetector includes a semiconductor substrate of a first conductivity type; a light absorption recombination layer disposed on a front surface of the semiconductor substrate and having a band gap energy smaller than the semiconductor substrate; a first conductivity type barrier layer disposed on the light absorption recombination layer and having a band gap energy larger than the light absorption recombination layer; an undoped light absorption layer disposed on the barrier layer and having a band gap energy larger than the light absorption recombination layer and smaller than the barrier layer; an undoped window layer disposed on the light absorption layer and having a band gap energy larger than the light absorption layer; and an impurity doped region of a second conductivity type in a region extending from the window layer to the light absorption layer. A portion of incident light not absorbed in a depletion layer in the light absorption layer is absorbed by the light absorption recombination layer, and electrons and holes generated in the light absorption recombination layer recombine immediately, resulting in reduced response distortion.