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:
Nov. 03, 1981
Filed:
Feb. 28, 1980
John E Davey, Alexandria, VA (US);
Aristos Christou, Springfield, VA (US);
Other;
Abstract
A method of forming a single, reliable n.sup.+ contact for discrete GaAs devices. A film of p-type Ge is deposited uniformly over the surface of a n-type GaAs substrate. Ions of phosphorous or arsenic are implanted to 5.times.10.sup.18 ions/cc at a depth of 1500 A. The ends and the sides of the substrate and Ge layer are capped by a CVD oxide and annealed at 450.degree.-500.degree. C. for about one hour. This process over-compensates the initial p-type layers which results in the Ge layer becoming n.sup.+. The oxide is removed by an etch process and the n.sup.+ Ge is etched to form two separate contact sections of n.sup.+ Ge. The n.sup.+ Ge is then metalized to form ohmic contacts by use of NiAu. A CVD oxide overcoat may again be applied and annealed at about 500.degree. C. to drive a shallow 200-500 A, n.sup.+ germanium diffusion into the substrate.