Active solid-state devices (e.g. – transistors – solid-state diode – Schottky barrier
Reexamination Certificate
2005-03-11
2008-12-30
Lewis, Monica (Department: 2894)
Active solid-state devices (e.g., transistors, solid-state diode
Schottky barrier
C257SE29148, C257SE29265, C257S077000
Reexamination Certificate
active
07470967
ABSTRACT:
A self-aligned silicon carbide power MESFET with improved current stability and a method of making the device are described. The device, which includes raised source and drain regions separated by a gate recess, has improved current stability as a result of reduced surface trapping effects even at low gate biases. The device can be made using a self-aligned process in which a substrate comprising an n+-doped SiC layer on an n-doped SiC channel layer is etched to define raised source and drain regions (e.g., raised fingers) using a metal etch mask. The metal etch mask is then annealed to form source and drain ohmic contacts. A single- or multilayer dielectric film is then grown or deposited and anisotropically etched. A Schottky contact layer and a final metal layer are subsequently deposited using evaporation or another anisotropic deposition technique followed by an optional isotropic etch of dielectric layer or layers.
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Casady Janna B.
Merrett Joseph N.
Sankin Igor
Lewis Monica
Morris Manning & Martin LLP
Raimund Christopher W.
SemiSouth Laboratories, Inc.
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