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. 23, 1991
Filed:
Dec. 15, 1988
Robert Blondeau, Ablis, FR;
Daniel Rondi, Paris, FR;
Anne Taineau, St. Cloud, FR;
Gervaise Vilain, Antony, FR;
Baudouin de Cremoux, Orsay, FR;
Thomson-CSF, Paris, FR;
Abstract
The method consists of the following successive steps: the deposition on a substrate, by epitaxy, of an optical confinement layer, formed by a first semiconducting material; the deposition, by epitaxy of an active layer, formed by a second semiconducting material; the deposition, by epitaxy, of a stop layer, formed by a third semiconducting material, with a thickness of between 0.005 and 0.02 microns; the deposition, by epitaxy, of a guide layer, formed by a fourth semiconducting material, with a thickness of between 0.01 and 0.03 microns; the deposition of a layer of photosensitive resin, and the cutting out of this layer in a shape to be given to the diffraction lattice which is to be made; the attacking of the guide layer by means of a selective, chemical agent which attacks neither the material of the stop layer nor the resin, this chemical agent being allowed to act until the entire thickness of the guide layer has been gone through, said thickness being chosen to be equal to the depth required for the diffraction lattice.