Method for fabricating a self-focusing detector pixel and an array fabricated in accordance with the method

US6147349A · kind A · utility

Assignee

• Raytheon Company · US

Inventor

• Michael Ray · Goleta, US

Key dates

• Filing date: Jul 31, 1998
• Grant date: Nov 14, 2000
• Expiry date: Jul 31, 2018

Classification

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

Abstract

Disclosed is a method for fabricating an array of electromagnetic radiation responsive photodiodes, and an array fabricated in accordance with the method. The method includes steps of (a) providing a transparent substrate (12); (b) growing on the substrate an electrically conductive buffer layer (14), an n-type radiation absorbing layer (16), and a p-type cap layer (18) forming a p-n junction; and (c) etching first trenches through the cap layer, the radiation absorbing layer, and partially through the buffer layer for forming initial mesa structures each having a top surface, a base, and sloping sidewalls that terminate in the buffer layer. The method further (d) forms a passivating layer (22) on the sloping side walls; (e) forms an electrical contact (24) that surrounds the bases of the initial mesa structures and that makes an ohmic contact with a surrounding portion of the buffer layer; and (f) etches a plurality of second trenches through exposed portions of the buffer layer and into the substrate. The second trenches delineate a plurality of larger mesa structures each of which supports one of the initial mesa structures. A common layer of metalization (30) is applied to expo…