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:
Aug. 28, 1990
Filed:
Dec. 23, 1988
Robert G Johnson, Minnetonka, MN (US);
James O Holmen, Minnetonka, MN (US);
Ronald B Foster, Garland, TX (US);
Uppili Sridhar, Garland, TX (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
The marginal adhesion of platinum to silicon nitride is a serious issue in the fabrication of microbridge mass air flow sensors. High temperature stabilization anneals (500.degree.-1000.degree. C.) are necessary to develop the properties and stability necessary for effective device operation. However, the annealing process results in a significant reduction in the already poor platinum/silicon nitride adhesion. Annealing at relatively high temperatures leads to the development of numerous structural defects and the production of non-uniform and variable sensor resistance values. The use of a thin metal oxide adhesion Layvr, approximately 20 To 100 angstromw in thickness is very effective in maintaining platinum adhesion to silicon nitride, and through the high temperature anneal sequence.