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:
Oct. 15, 1985
Filed:
Jan. 27, 1983
Keith H Nicholas, Reigate, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A first masking layer on a semiconductor body is defined by exposing a layer of negative acting radiation sensitive resist to a radiation pattern through a mask. Doped regions are then formed at unmasked surface areas of the body. A layer of positive acting resist is provided on an insulating layer at the surface of the body, and a second masking layer is defined in this layer by exposure to the pattern radiation beam through the same mask. An insulating layer pattern which is accurately aligned above the doping region is then formed by etching the exposed parts of the layer. Alternatively, the same type of resist is used at both exposure stages. By adjusting the resist processing, the second masking layer is made larger than the first masking layer. In this case, the second masking layer is used to define an oxygen mask before oxidizing the exposed surface of the body to form an accurately aligned oxide layer pattern.