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:
Oct. 27, 1992
Filed:
Jul. 02, 1991
Duane A Fasen, Loveland, CO (US);
Jerome E Beckmann, Loveland, CO (US);
John H Stanback, Fort Collins, CO (US);
Ulrich E Hess, Corvallis, OR (US);
James R Hulings, Fort Collins, CO (US);
Larry S Metz, Fort Collins, CO (US);
Charles E Moore, Loveland, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An improved thermal inkjet printhead having MOSFET drive transistors incorporated therein. The gate of each MOSFET transistor is formed by applying a layer of silicon dioxide onto a silicon substrate, applying a layer of silicon nitride onto the silicon dioxide, and applying a layer of polycrystalline silicon onto the silicon nitride. Portions of the substrate surrounding the gate are oxidized, forming field oxide regions. Drain and source regions are then conventionally formed, followed by the application of a protective dielectric layer onto the field oxide, drain, source, and gate. A resistive layer is deposited on the dielectric layer and directly connected to the source, drain, and gate. A conductive layer is deposited on a portion of the resistive layer, ultimately forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as electrical contacts to the transistor and resistor.