The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 1989
Filed:
Dec. 16, 1987
Siang P Kwok, Colorado Springs, CO (US);
Ford Microelectronics, Inc., Colorado Springs, CO (US);
Abstract
A self-aligned MESFET is formed by implanting a first (channel) region in a first surface portion of a gallium arsenide substrate. A dielectric layer is formed on the surface of the substrate and portions of this layer are selectively removed, to leave a relatively thick substitutional gate mesa overlying a first surface portion of the first region and a relatively thin protective portion, contiguous with the substitutional gate, overlying a second surface portion of the first region, so that the substitutional gate has sidewalls extending above the protective portion. Sidewall spacers are formed contiguous with the sidewalls of the substitutional gate, so as to overlie surface portions of the protective portion of the dielectric layer contiguous with the substitutional gate. Ions are implanted into the substrate using the substitutional gate and the sidewall spacers as a mask, thereby forming source and drain regions in the first region. The structure is annealed and the substitutional gate and sidewall spacers are removed. A conductive gate layer is formed on the first region in place of the removed substitutional gate and apertures are formed in the reduced thickness portion of the dielectric layer to expose surface portions of the source and drain regions. Ohmic contacts are connected to the source and drain regions through the apertures.