Motorola Corporation

Gregory L Hansell

Jaeshin Cho

Bruce A Bernhardt

Bertrand Francis Cambou

Schyi-Yi Wu

Naresh C Saha

James G Gilbert

An ohmic contact to a III-V semiconductor material is fabricated by dry etching a silicon nitride layer overlying the III-V semiconductor material with a chemical comprised of a group VI element. An ohmic metal layer is formed on the III-V semiconductor material after the silicon nitride layer is etched and before any exposure of the III-V semiconductor material to a chemical which etches the III-V semiconductor material or removes the group VI element.

Method of forming an ohmic contact to a III-V semiconductor material

A III-V semiconductor FET (10, 30, 40) having etched ohmic contacts (19, 20, 36, 37, 43, 44). A gate (16) of the FET (10, 30, 40) is formed in contact with a surface of a III-V substrate (11). An ohmic contact (19, 20, 36, 37, 43, 44) is created to include an alloy in contact with the surface of the substrate (11). The ohmic contact (19, 20, 36, 37, 43, 44) is formed to abut the gate structure (16, 17, 18) by covering a portion of the gate structure (16, 17, 18) and the substrate (11) with the ohmic contact (19, 20, 36, 37, 43, 44), then, removing portions of the ohmic contact from the gate structure (16, 17, 18) by etching. The ohmic contact (19, 20, 36, 37, 43, 44) is formed to be substantially devoid of gold.

Self-aligned FET having etched ohmic contacts

A method of fabricating a MESFET is comprised of providing a semiconductor material having a channel region formed therein, forming a gate on the semiconductor material over the channel region, forming a spacer adjacent a first portion of the gate disposed on the semiconductor material, and forming a hard mask disposed on a second portion of the gate and on a portion of the semiconductor material.

Method of making symmetrical and asymmetrical MESFETS

The present invention provides a III-V semiconductor FET (10, 30, 40) having etched ohmic contacts (19, 20, 36, 37, 43, 44). A gate (16) of the FET (10, 30, 40) is formed in contact with a surface of a III-V substrate (11). An ohmic contact (19, 20, 36, 37, 43, 44) is created to include an alloy in contact with the surface of the substrate (11). The ohmic contact (19, 20, 36, 37, 43, 44) is formed to abut the gate structure (16, 17, 18) by covering a portion of the gate structure (16, 17, 18) and the substrate (11) with the ohmic contact (19, 20, 36, 37, 43, 44), then, removing portions of the ohmic contact from the gate structure (16, 17, 18) by etching. The ohmic contact (19, 20, 36, 37, 43, 44) is formed to be substantially devoid of gold.

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Tempe, AZ, United States of America

Gregory L Hansell