Method and apparatus for use in improving linearity of MOSFETs using an accumulated charge sink
First Claim
1. A method of fabricating an RF switch comprising:
- fabricating an integrated circuit (IC) that includes the RF switch;
wherein the fabricating includes forming at least a plurality of N-type metal oxide semiconductor field effect transistors (NMOSFETs) by forming a source, a drain, a gate and a body for respective NMOSFETs of the plurality in a silicon layer of a substrate;
wherein the fabricating further includes fabricating one or more layers of metallization over the silicon layer;
wherein the one or more layers of metallization to couple the plurality of NMOSFETs into a stack to pass an RF signal through the stack of NMOSFETs in an ON state of the stack of NMOSFETs in accordance with RF switch operation;
wherein the one or more layers of metallization to couple the plurality of NMOSFETs of the stack to not pass an RF signal through the stack of NMOSFETs in an OFF state of the stack of NMOSFETs in accordance with RF switch operation; and
wherein the one or more layers of metallization to couple an electrical bias to the body of the respective NMOSFETs, in accordance with RF switch operation, at least in a portion of the OFF state of the stack to have a DC voltage level substantially more negative than a lowest voltage level of the following;
ground, a DC voltage level of the source of the respective NMOSFETs, and a DC voltage level of the drain of the respective NMOSFETs.
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Accused Products
Abstract
A method and apparatus for use in improving the linearity characteristics of MOSFET devices using an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to remove, reduce, or otherwise control accumulated charge in SOI MOSFETs, thereby yielding improvements in FET performance characteristics. In one exemplary embodiment, a circuit having at least one SOI MOSFET is configured to operate in an accumulated charge regime. An accumulated charge sink, operatively coupled to the body of the SOI MOSFET, eliminates, removes or otherwise controls accumulated charge when the FET is operated in the accumulated charge regime, thereby reducing the nonlinearity of the parasitic off-state source-to-drain capacitance of the SOI MOSFET. In RF switch circuits implemented with the improved SOI MOSFET devices, harmonic and intermodulation distortion is reduced by removing or otherwise controlling the accumulated charge when the SOI MOSFET operates in an accumulated charge regime.
651 Citations
13 Claims
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1. A method of fabricating an RF switch comprising:
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fabricating an integrated circuit (IC) that includes the RF switch; wherein the fabricating includes forming at least a plurality of N-type metal oxide semiconductor field effect transistors (NMOSFETs) by forming a source, a drain, a gate and a body for respective NMOSFETs of the plurality in a silicon layer of a substrate; wherein the fabricating further includes fabricating one or more layers of metallization over the silicon layer; wherein the one or more layers of metallization to couple the plurality of NMOSFETs into a stack to pass an RF signal through the stack of NMOSFETs in an ON state of the stack of NMOSFETs in accordance with RF switch operation; wherein the one or more layers of metallization to couple the plurality of NMOSFETs of the stack to not pass an RF signal through the stack of NMOSFETs in an OFF state of the stack of NMOSFETs in accordance with RF switch operation; and wherein the one or more layers of metallization to couple an electrical bias to the body of the respective NMOSFETs, in accordance with RF switch operation, at least in a portion of the OFF state of the stack to have a DC voltage level substantially more negative than a lowest voltage level of the following;
ground, a DC voltage level of the source of the respective NMOSFETs, and a DC voltage level of the drain of the respective NMOSFETs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification