Method and Apparatus Improving Gate Oxide Reliability by Controlling Accumulated Charge
First Claim
1. A circuit, comprising:
- a) a semiconductor-on-insulator (SOI) metal-oxide-silicon field effect transistor (MOSFET) operating in an accumulated charge regime; and
b) a means for accumulated charge control (ACC) operatively coupled to the SOI MOSFET, wherein the means for ACC comprises a control circuit operatively coupled to a gate of the SOI MOSFET, wherein the control circuit applies a voltage pulse to the gate that switches the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for a selected interval.
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Accused Products
Abstract
A method and apparatus are disclosed for use in improving the gate oxide reliability of semiconductor-on-insulator (SOI) metal-oxide-silicon field effect transistor (MOSFET) devices using accumulated charge control (ACC) techniques. 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 embodiment, a circuit comprises a MOSFET, operating in an accumulated charge regime, and means for controlling the accumulated charge, operatively coupled to the SOI MOSFET. A first determination is made of the effects of an uncontrolled accumulated charge on time dependent dielectric breakdown (TDDB) of the gate oxide of the SOI MOSFET. A second determination is made of the effects of a controlled accumulated charge on TDDB of the gate oxide of the SOI MOSFET. The SOI MOSFET is adapted to have a selected average time-to-breakdown, responsive to the first and second determinations, and the circuit is operated using techniques for accumulated charge control operatively coupled to the SOI MOSFET. In one embodiment, the accumulated charge control techniques include using an accumulated charge sink operatively coupled to the SOI MOSFET body.
139 Citations
21 Claims
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1. A circuit, comprising:
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a) a semiconductor-on-insulator (SOI) metal-oxide-silicon field effect transistor (MOSFET) operating in an accumulated charge regime; and b) a means for accumulated charge control (ACC) operatively coupled to the SOI MOSFET, wherein the means for ACC comprises a control circuit operatively coupled to a gate of the SOI MOSFET, wherein the control circuit applies a voltage pulse to the gate that switches the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for a selected interval. - View Dependent Claims (2, 3, 4, 5)
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6. A circuit, comprising:
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a) a semiconductor-on-insulator (SOI) metal-oxide-silicon field effect transistor (MOSFET) operating in an accumulated charge regime; and b) a means for accumulated charge control (ACC) operatively coupled to the SOI MOSFET, wherein the means for ACC comprises a resistor electrically connected to a gate of the SOI MOSFET, wherein the resistance value of the resistor is sufficient to prevent attenuation of an induced RF voltage on the gate, and wherein an RF signal voltage having a selected frequency is applied to a drain of the SOI MOSFET thereby generating the induced RF voltage, and wherein the induced RF voltage transitions the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for at least part of a cycle of the RF signal voltage. - View Dependent Claims (7, 8, 9, 10)
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11. A method for controlling accumulated charge in a circuit comprising a semiconductor-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOSFET) operating in an accumulated charge regime, comprising the steps of:
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a) operatively coupling a control circuit to a gate of the SOI MOSFET; and b) applying a voltage pulse to the gate;
wherein the voltage pulse switches the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for a selected interval. - View Dependent Claims (12, 13, 14, 15)
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16. A method for controlling accumulated charge in a circuit comprising a semiconductor-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOSFET) operating in an accumulated charge regime, comprising the steps of:
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a) operatively coupling a resistor to a gate of the SOI MOSFET sufficient to prevent attenuation of an induced RF voltage on the gate; and b) applying an RF signal having a selected frequency to a drain of the SOI MOSFET thereby generating the induced RF voltage, wherein the induced RF voltage transitions the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for part of a cycle of the RF signal voltage. - View Dependent Claims (17, 18, 19, 20)
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21. A system for controlling accumulated charge in a circuit comprising a semiconductor-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOSFET) operating in an accumulated charge regime, comprising:
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a) means for operatively coupling a control circuit to a gate of the SOI MOSFET; and b) means for applying a voltage pulse to the gate that switches the SOI MOSFET from the accumulated charge regime to a non-accumulated charge regime for a selected interval.
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Specification