Avalanche photodiode and a method of making same

US4700209A · kind A · utility

Assignee

• RCA Corporation · US

Inventor

• Paul P. Webb · Keyano, CA

Key dates

• Filing date: Oct 30, 1985
• Grant date: Oct 13, 1987
• Expiry date: Oct 30, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S257/919

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 and having a central zone which has a greater concentration of conductivity modifiers than the remainder of the active region. A cap region overlies the first region, has the opposite conductivity type and extends a greater distance in the lateral direction than the central zone. The invention is also a method of forming this detector comprising the steps of forming a first region of the active region, embedding an excess concentration of conductivity modifiers into a portion thereof and then forming a second region of the active region on the first region. A cap region of opposite conductivity type is then formed over the active region. The cap region has a greater lateral extent than the portion containing the excess concentration of conductivity modifiers.