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:
Jul. 19, 1994
Filed:
Nov. 15, 1991
Michel Haond, Meylan, FR;
France Telecom, , FR;
Abstract
The invention relates to a method for etching an integrated-circuit layer to a fixed depth. The method consists in depositing onto the layer to be etched a protective layer forming a stop layer and then onto the latter a reference layer made of a material compatible with that of the layer to be etched the thickness of the reference layer being proportional to the depth of the etch to be produced. A mask is applied to the reference layer and the etching of this layer is carried out by chemical attack until encountering the stop layer. After removal of the mask and of the stop layer, in the etching zone, the reference layer and the layer of material to be etched 1 are simultaneously subjected to a chemical attack until encountering the stop layer. An etch having the plane dimensions of the etch of the reference layer and a depth proportional to the thickness of the reference layer is thus created. Application to the etching of integrated-circuit layers or to the creation of inverted-T-shaped elements.