Avalanche photodiode with central zone in active and absorptive layers

US4914494A · kind A · utility

Assignee

• RCA Corporation · US

Inventor

• Paul P. Webb · Keyano, CA

Key dates

• Filing date: Jun 9, 1988
• Grant date: Apr 3, 1990
• Expiry date: Jun 9, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/50

Abstract

The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surface. This photodetector includes a light-absorptive region, an active region overlying the absorptive region forming a heterojunction therebetween. The photodetector includes a central zone which has a greater concentration of conductivity modifiers than the remainder of the active region and is located in the active region extending into the absorptive region. A cap region overlies the active region and has the opposite conductivity type. The cap region extends a greater distance in the lateral direction than the central zone. A photodetector having a central zone extending across the heterojunction between the active region and light absorptive region have exhibited response times comparable with those of photodetectors having a quaternary layer located between the active region and the absorptive region. However, the photodetector of the present invention does not require the hard-to-grow quaternary layer.