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:
Jan. 25, 1977
Filed:
Dec. 05, 1975
Pham Ngu Tung, Paris, FR;
Thomson-CSF, Paris, FR;
Abstract
A method of manufacturing, making it possible to effect the simultaneous batch production in particular of field-effect transistors operating at frequencies in excess of 30 Gc/s, whose source and drain constitute two very narrow and very closely spaced bands, is provided. To this end, using a single masking operation, the source and drain of contacts are produced, these being covered by a chromium band. This band acts as a mask during the ion machining of a trench between the bands. The aluminium subsequently deposited, in particular in the trench, in order to form the gate of the transistor, is removed from the other regions of the structure by electrolytic etching. Along with the chromium, the aluminium serves as a mask during a final step of ion etching, which makes it possible to produce a 'mesa' structure.