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. 13, 1989
Filed:
May. 27, 1987
Thomas Abraham, Kanata, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A plasma etching technique for producing tapered side walls on the desired Aluminum conductor pattern is described. This involves forming a resist pattern on the Aluminum layer of a wafer and carrying out a first etching step using Cl.sub.2, BCl.sub.3 and CF.sub.4 at predetermined flow rates and low pressure until all the exposed Aluminum is removed. At the end of this step the Aluminum side walls are virtually vertical and facets are present on the resist. A second etching step is carried out under essentially the same conditions as before except that the Cl.sub.2 is reduced. During this etching step the facets on the resist are propagated laterally while the Aluminum side walls become tapered. According to modifications a rounded or jogged configuration can be obtained on the side walls but these too are considered generally tapered in nature as they progress from a wider base to a narrower peak.