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:
Jan. 03, 1989
Filed:
Mar. 16, 1987
Masanori Murakami, Goldens Bridge, NY (US);
William H Price, E. Rockaway, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A thermally stable low resistance ohmic contact to gallium arsenide is fabricated using a layer of refractory material, and a layer of indium and a metal which forms thermally stable intermetallic compounds or single solid phase with indium. In forming the contact, a layer of indium is sandwiched between two layers of nickel, the sandwiched array of layers sitting on the substrate with the refractory tungsten layer on top to form a stratified structure. The stratified structure is heated to form nickel and indium intermetallic compounds and InGaAs layer at the metal/semiconductor interface. A thin layer of nickel between the indium and the gallium arsenide tends to form intermetallic compounds and limit a rate of diffusion of the indium into the gallium arsenide during heating so as to form a uniform fine distribution of InGaAs layer at the metal/gallium arsenide interface which results in low contact resistance. A contact resistance of 0.3 ohm-millimeters is obtained at elevated temperature in the range of 700.degree.-1200.degree. C. The resistance is stable after annealing at 400.degree. C. for 100 hours.