Dual layer surface gate JFET having enhanced gate-channel breakdown voltage
First Claim
1. A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type having a first surface;
first and second semiconductor regions of a second conductivity type, opposite to said first conductivity type, respectively disposed in first and second spaced-apart surface portions of said substrate;
a third, channel, semiconductor region of said second conductivity type, disposed beneath a third surface portion of said substrate and bridging said first and second semiconductor regions; and
a fourth, gate, semiconductor region of said first conductivity type extending from said third surface portion of said substrate, bridging said first and second semiconductor regions and so as to be contiguous with said third semiconductor region, said fourth region containing a fifth semiconductor region of a first impurity concentration, extending from said third surface portion of said substrate to a sixth semiconductor region of a second impurity concentration, lower than said first impurity concentration, said sixth region being contiguous with said third region and being spaced apart from said third surface portion of said substrate.
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Accused Products
Abstract
Radiation insensitivity and breakdown voltage characteristics of a dual region top gate JFET are improved by a top gate structure in which the entirety of the lower concentration region of the top gate is separated from the oxide/silicon interface by the top surface high impurity concentration region. The dual region top gate extends from the substrate/insulator interface to a channel region beneath the top surface of the JFET substrate and extends laterally to bridge the source and drain regions. The lateral extent of the dual region top gate may be delimited by barrier regions, respectively separating the top gate regions from the source and drain regions. The barrier regions extend from the substrate/oxide interface to the channel and may comprise dielectric material or a combination of dielectric material and doped semiconductor material.
19 Citations
17 Claims
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1. A semiconductor device comprising:
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a semiconductor substrate of a first conductivity type having a first surface; first and second semiconductor regions of a second conductivity type, opposite to said first conductivity type, respectively disposed in first and second spaced-apart surface portions of said substrate; a third, channel, semiconductor region of said second conductivity type, disposed beneath a third surface portion of said substrate and bridging said first and second semiconductor regions; and a fourth, gate, semiconductor region of said first conductivity type extending from said third surface portion of said substrate, bridging said first and second semiconductor regions and so as to be contiguous with said third semiconductor region, said fourth region containing a fifth semiconductor region of a first impurity concentration, extending from said third surface portion of said substrate to a sixth semiconductor region of a second impurity concentration, lower than said first impurity concentration, said sixth region being contiguous with said third region and being spaced apart from said third surface portion of said substrate. - View Dependent Claims (2)
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3. A semiconductor device comprising:
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a semiconductor substrate of a first conductivity type having a first surface; first and second semiconductor regions of a second conductivity type, opposite to said first conductivity type, respectively disposed in first and second spaced-apart surface portions of said substrate; a third, channel, semiconductor region of said second conductivity type, disposed beneath a third surface portion of said substrate and bridging said first and second semiconductor regions; and a fourth surface gate region of said first conductivity type, extending from said third surface portion of said substrate, laterally between said first and second regions, so as to be contiguous with said channel region, said surface gate region including a fifth semiconductor region of a first impurity concentration extending from said third surface portion of said substrate to a sixth semiconductor region of a second impurity concentration, lower than said first impurity concentration, said sixth region being contiguous with said channel region, and wherein the entirety of said laterally extending sixth region is spaced apart from said first surface of said substrate. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification