Integrated LPE-grown structure for simultaneous detection of infrared radiation in two bands

US5559336A · kind A · utility

Assignee

• Santa Barbara Research Center · US

Inventors

• Kenneth Kosai · Goleta, US
• Jerry A. Wilson · Beloit, US
• Bonnie A. Baumgratz · Goleta, US

Key dates

• Filing date: Jul 5, 1994
• Grant date: Sep 24, 1996
• Expiry date: Jul 5, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/8063

Abstract

A radiation detector (1) unit cell (10) includes an n-p+ LWIR photodiode that is vertically integrated with a p+-n MWIR photodiode in a n-p+-n structure. Electrical contact is made separately to each of these layers in order to simultaneously detect both the LWIR and MWIR bands. The electrical contact is made via indium bump interconnections (23, 25, 27) enabling the unit cell to be subsequently hybridized with a topside mounted electronic readout integrated circuit (30). The n-p+-n structure in a given pixel of an array of radiation detector pixels is electrically isolated from all neighboring pixels by a trench (28) that is etched into an underlying substrate (12). To compensate for a reduction in the optically sensitive area due to the placement of the electrical contacts and the presence of the pixel isolation trench, a microlens (34) may be provided within, upon, or adjacent to the backside, radiation receiving surface of the substrate in registration with the unit cell.