Solid state RF switch with high cutoff frequency
AssigneeNorthrop Grumman Corporation
InventorsHarvey C. Nathanson, Philip C. Smith, R. Chris Clarke, David M. Krafcsik, Lawrence E. Dickens
Life of this patent
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Abstract
A solid state microwave switch having a plurality of adjacent parallel fingers covered with an oxide layer. One end of a finger is an N+ source region while the other end is an N+ drain region, with a current conducting N region between them. The oxide layer is covered with a gate layer to which a gate signal is applied for control of current between the N+ regions through the N region. The gate layer is highly resistive and has a sheet resistance on the order of millions of ohms per square. The length from the source to drain region is around 2 μm, and the fingers are spaced with a pitch of around 1 μm.
Claims15
An RF solid state switch, comprising:
- (A) a plurality of adjacent semiconductor fingers each having first and second ends and an intermediate body portion, with one of said ends constituting a source region and the other of said ends constituting a drain region;
- (B) each said finger having a width W, where W is less than around 5000 Å;
- (C) each said finger having an oxide layer on the surface thereof;
- (D) each said finger having a resistive gate layer on said oxide layer;
- (E) said resistive gate layer having a sheet resistance ρg in the range of 100,000 to on the order of 5×106 ohms per square;
- and
- (F) respective electrical contacts in electrical communication with said gate layer, and said source and drain regions.
An RF solid state switch, comprising:
- (A) a plurality of adjacent vertical semiconductor fingers each having first, second and third layers with said first layer constituting one of a source or drain region and said third layer constituting the other of a source or drain region;
- (B) said fingers extending from, and having a common one of said source or drain regions, so as to define fingers having distal ends, as well as horizontal interfinger portions;
- (C) each said finger having a width W, where W is less than around 5000 Å;
- (D) each said finger having an oxide layer on the vertical surfaces thereof and in said horizontal interfinger portions;
- (E) each said finger having a resistive gate layer on said oxide layer so as to extend along said vertical surfaces, as well as along said horizontal interfinger portions;
- (F) said resistive gate layer which extends along said vertical surfaces having a sheet resistance μg in the range of 100,000 to on the order of 5×106 ohms per square;
- (G) said resistive gate layer which extends along said horizontal interfinger portions constitutes a gate pad having a sheet resistance lower than said resistive gate layer which extends along said vertical surfaces;
- and
- (H) respective electrical contacts in electrical communication with said gate layer, and said source and drain regions.
Dependencies are inferred from the claim text.