Accession Number : ADD013663

Title :   Process of Fabricating TiW/Si Self-Aligned Gate for GaAs MESFETs (Metal Silicon Field Effect Transistors).

Descriptive Note : Patent, Filed 6 Jun 85, patented 15 Dec 87,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : McLevige, William V

Report Date : 15 Dec 1987

Pagination or Media Count : 7

Abstract : A major difficulty with fabricating GaAs digital logic circuits using enhancement-mode MESFETs has been the large gate-source and gate-drain parasitic resistances inherent in conventional designs. A self-aligned gate process is presented, which incorporates a mushroom gate structure for self-aligning both an n + implant and the source/drain contacts to the gate, thus minimizing the parasitic resistances. The mushroom gate consists of a two-layer TiW/Si metallization in which the bottom TiW layer is undercut with a closely controllable chemical etch. The process is compatible with the high temperature anneal necessary to activate ion-implanted GaAs.

Descriptors :   *DIGITAL SYSTEMS, *GALLIUM ARSENIDES, *LOGIC CIRCUITS, ALIGNMENT, ANNEALING, DRAINAGE, GATES(CIRCUITS), HIGH TEMPERATURE, IMPLANTATION, RESISTANCE, SELF OPERATION

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE