Method of making a broadband backside illuminated MESFET with collecting microlens

US5811322A · kind A · utility

Assignee

• W.L. Gore & Associates GmbH · DE

Inventor

• Gerald D. Robinson · Lompoc, US

Key dates

• Filing date: Jul 15, 1996
• Grant date: Sep 22, 1998
• Expiry date: Jul 15, 2016

Classification

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

Abstract

A composite-layer semiconductor device includes a gate above a host substrate, an n++ contact layer above the gate, and source and drain ohmic contacts applied to the n++ contact layer. The source and drain ohmic contacts define a central gate location which is recessed through the n++ contact layer toward the gate. The source and drain ohmic contacts create a barrier to chemical etching so that a current path below the central gate location can be incrementally recessed in repeated steps to precisely tailor the operating mode of the device for depletion or enhancement applications. The composite-layer semiconductor device is fabricated by depositing a gate on an n++ contact layer above a semi-insulating substrate. The semi-insulating substrate and gate are flipped onto an epoxy layer on the host substrate so that the gate is secured to the epoxy layer and the semi-insulating substrate presents an exposed backside. A portion of the exposed backside is removed. The source and drain ohmic contacts are applied to the exposed backside. The exposed backside is recessed at the central gate location to define the current path which connects the source and drain ohmic contacts.