Accession Number : ADD014995

Title :   Insulator Assisted Self-Aligned Gate Junction.

Descriptive Note : Patent, filed 30 Oct 90, patented 30 Apr 91,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Nguyen, Richard

Report Date : 30 Apr 1991

Pagination or Media Count : 8

Abstract : A high transconductance, low capacitance, low leakage compound semiconductor junction field effect transistor (JFET) enhances the low leakage current while having the advantages of a self-aligned JFET including low capacitance and low source-drain resistance. the diffused junction of the JFET is totally covered during the process of manufacture. An n channel on a substrate has a layer of photoresist placed over it and exposed to leave a predefined pattern of photoresist. The patterned photoresist is used as a mask so that part of the n-channel layer is etched down to a desired depth leaving a wedge-shaped region. A layer of insulator, such as silicon dioxide, is deposited over the entire substrate and sides of the w edge-shaped region in insulator regions. Next, the photoresist is then removed. A p (+) diffusion or implant is performed in the wedge-shaped region to create a p (+) n-junction system which is the gate region of the JFET. The p (+) n junction system sides are covered the insulator regions of silicon dioxide unlike the opened-junction of the conventional self-aligned gate JFET. Next, the gate patterned metal is deposited on top of the p (+) n junction system and partially on the silicon dioxide insulator regions. Using the patterned gate metal as a mask, the silicon dioxide layer is removed. Source and drain metals are then self-aligned evaporated. The JFET has potential use in microwave, millimeter-wave and optical electronic circuits. (Author)

Descriptors :   ALIGNMENT, CAPACITANCE, CHANNELS, CIRCUITS, DIFFUSION, DRAINAGE, ELECTRIC CURRENT, ELECTRONIC EQUIPMENT, GATES(CIRCUITS), JUNCTIONS, LAYERS, LEAKAGE(ELECTRICAL), LOW RATE, METALS, N TYPE SEMICONDUCTORS, OPTICAL CIRCUITS, PHOTORESISTORS, REGIONS, RESISTANCE, SELF OPERATION, SIDES, SILICON DIOXIDE, SOURCES, SUBSTRATES, TRANSCONDUCTANCE, WEDGES

Subject Categories : Electrical and Electronic Equipment
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE