Accession Number : ADD009152

Title :   Ion-Implanted Evaporated Germanium Layers as N+ Contacts to GaAs.

Descriptive Note : Patent,


Personal Author(s) : Davey,John E ; Christou,Aristos

Report Date : 03 Nov 1981

Pagination or Media Count : 4

Abstract : A method of forming a single, reliable n+ 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 phophorous or arsenic are implanted to 5 x 10 to the 18th power 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 450-500 C. for about one hour. This process over-compensates the initial p-type layers which results in the Ge layer becoming n+. The oxide is removed by an etch process and then n+ Ge is etched to form two separate contact sections of n+ Ge. The n+ 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 C. to drive a shallow 200-500 A, n+ germanium diffusion into the substrate. (Author)

Descriptors :   *Patents, *Semiconductors, *Ion implantation, *Evaporation, *Layers, Germanium, Gallium arsenides, N type semiconductors, Substrates, Oxides, Inventions, P type semiconductors, Electric contacts, Gold alloys, Etching, Films

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE