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:
May. 28, 1985
Filed:
Oct. 05, 1983
Donald G Chesebro, Colchester, VT (US);
Francis J Soychak, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method is provided for making a semiconductor device which includes the steps of forming a first insulating layer on the surface of a semiconductor layer having a given conductivity type, forming an opening in the insulating layer and forming a diffusion region of a conductivity type opposite to that of the given conductivity type at the surface of the semiconductor layer to provide a P-N junction below the surface of the semiconductor layer. A trench is then formed along a given axis in the semiconductor layer having a sidewall passing through the opening and through the P-N junction. A second layer of insulation is formed on the sidewall of the trench, on the first insulating layer and through the opening onto the diffusion region. The second layer of insulation is etched in the direction of the given axis until substantially all of the second layer of the insulation is removed from the opening, and an electrical contact is formed on the diffusion region within the opening. In a preferred embodiment of the invention, the second layer is a dual insulating layer which may include a layer of silicon dioxide grown on the semiconductor layer and a layer of silicon nitride deposited on the layer of silicon dioxide.