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:
Jun. 15, 1976
Filed:
Jul. 09, 1975
Juergen Graul, Gruenwald, DT;
Helmuth Murrmann, Ottobrunn, DT;
Siemens Aktiengesellschaft, Berlin & Munich, DT;
Abstract
The surface of a semiconductor substrate, such as a silicon crystal, is uniformly coated with a layer of Si.sub.3 N.sub.4 and at least two selectively spaced windows are provided therein. The uncovered silicon surface within such windows is then coated with a layer of SiO.sub.2. Next, a SiO.sub.2 area within a first window along with a portion of the adjacent Si.sub.3 N.sub.4 areas are coated with a photo-lacquer mask while the substrate surface area beneath the second window is doped with a select dopant. This procedure is then reversed and the Photo-lacquer mask is removed from the first window and applied onto the second window while the substrate surface area beneath the first window is contacted with select dopant to produce a doped zone. In this manner, considerable tolerance for positioning of a diffusion mask is provided.