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. 30, 2001
Filed:
Mar. 02, 2000
Helmut Fischer, Regensburg, DE;
Gisela Lang, Regensburg, DE;
Reinhard Sedlmeier, Neutraubling, DE;
Ernst Nirschl, Wenzenbach, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A process for producing a semiconductor device includes the following sequential steps: producing a semiconductor body having an Al,Ga,As layer with an upper surface, where x≦0.40; applying a contact metallization made of a non-noble metallic material to the Al,Ga,As layer; precleaning a semiconductor surface to produce a hydrophilic semiconductor surface; roughening the upper surface of the Al,Ga,As layer by etching with an etching mixture of hydrogen peroxide ≧30% and hydrofluoric acid ≧40% (1000:6) for a period of from 1 to 2.5 minutes; and re-etching with a dilute mineral acid. According to another embodiment, 0≦x≦1 and the upper surface of the Al,Ga,As layer is roughened by etching with nitric acid 65% at temperatures of between 0° C. and 30° C.