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. 04, 1991
Filed:
Sep. 07, 1989
Harry F Lockwood, Waban, MA (US);
Margaret B Stern, Sudbury, MA (US);
Marvin Tabasky, Peabody, MA (US);
Victor Cataldo, Wilmington, MA (US);
Laboratories Incorporated, Waltham, MA (US);
Abstract
Method of forming conductive members on a substrate of GaAs. Silicon is placed on the substrate surface in the desired pattern of the conductive members. The substrate is exposed to a gaseous atmosphere containing WF.sub.6. WF.sub.6 is reduced by the silicon causing tungsten to selectively deposit on the silicon but not on the exposed GaAs. The substrate is given a rapid thermal annealing treatment which causes the silicon-tungsten elements to form conductive members having a silicon rich layer at the bottom, an intermediate tungsten silicide layer, and a tungsten rich layer at the top. The conductive members form ohmic contacts with underlying heavily doped GaAs and rectifying Schottky barrier contacts with underlying lightly doped GaAs.