Accession Number : ADD004746

Title :   Technique for Threshold Control over Edges of Devices on Silicon-on-Sapphire.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Harari,Eliyahou

Report Date : 24 Jan 1978

Pagination or Media Count : 4

Abstract : This patent describes a self-aligning technique for doping the edges of metal-oxide-semiconductor devices fabricated on silicon-on-sapphire to eliminate channel-edge conduction at voltages lower than the device threshold voltage without unnecessarily doping the top conducting surface of the device. A thick masking layer is deposited on the silicon layer. The masking layer is etched locally to expose the silicon in the regions between the devices and the exposed silicon is etched to form islands on the sapphire substrate. In a new step, a partial etch of the masking layer is conducted to expose a narrow frame on the top surface and edges of the silicon island. The resulting structure may be doped by any conventional method to ensure heavier doping at the edges than in the transistor channel region.

Descriptors :   *Patents, *Processing, *Threshold effects, *Integrated circuits, Silicon, Sapphire, Metal oxide semiconductors, Doping, Edges

Subject Categories : Electrical and Electronic Equipment
      Mfg & Industrial Eng & Control of Product Sys
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE