Evaluation device and circuit design method used for the same
First Claim
1. An evaluation apparatus, comprising:
- an AC input signal superimposing circuit for superimposing an AC input signal to a gate of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor);
an AC component measurement circuit for measuring an AC component of a current flowing between a source and a drain of the MOSFET when the AC input signal is superimposed to the gate; and
a mutual conductance calculation circuit for calculating a mutual conductance at a frequency of the AC input signal of the MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal,wherein the gate, the source, and the drain of the MOSFET are being applied a DC voltage.
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Abstract
There is provided an evaluation apparatus capable of measuring the I-V characteristic in the MOSFET AC operation with a high accuracy. There are also provided a circuit design method and a circuit design system used for the evaluation apparatus. In the evaluation apparatus (1), an AC input signal superimposing circuit (11) applies DC voltage to the MOSFET gate•source•drain•substrate and superimposes an AC input signal of very small voltage on the gate. An AC component measurement circuit (12) measures an AC component of the current flowing between the source and the drain at that time. A mutual conductance calculation circuit (13) compares the amplitude of the AC component of the current with the amplitude of the AC input signal and calculates, from this ratio, the mutual conductance in the frequency of the AC input signal of the MOSFET.
79 Citations
26 Claims
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1. An evaluation apparatus, comprising:
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an AC input signal superimposing circuit for superimposing an AC input signal to a gate of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor); an AC component measurement circuit for measuring an AC component of a current flowing between a source and a drain of the MOSFET when the AC input signal is superimposed to the gate; and a mutual conductance calculation circuit for calculating a mutual conductance at a frequency of the AC input signal of the MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal, wherein the gate, the source, and the drain of the MOSFET are being applied a DC voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An evaluation apparatus, comprising:
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an AC input signal superimposing circuit for superimposing an AC input signal to a drain of a SOT (Silicon On Insulator) MOSFET (Metal Oxide Semiconductor Field Effect Transistor); an AC component measurement circuit for measuring an AC component of a current flowing between a source and a drain of the S01 MOSFET when the AC input signal is superimposed to the drain; and a drain conductance calculation circuit for calculating a drain conductance at a frequency of the AC input signal of the SOT MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal, wherein the gate, the source, and the drain of the SOT MOSFET are being applied a DC voltage. - View Dependent Claims (9, 10, 11, 12)
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13. A circuit design method, comprising steps of:
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a step for superimposing an AC input signal to a gate of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor); a step for measuring an AC component of a current flowing between a source and a drain of the MOSFET when the AC input signal is superimposed to the gate; a step for calculating a mutual conductance at a frequency of the AC input signal of the MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal; a step for comparing a gate.source.drain voltage dependency of a frequency characteristic of the mutual conductance obtained as a result of measurement of the MOSFET with a gate•
source•
drain voltage dependency of a frequency characteristic of the mutual conductance obtained from circuit simulation for simulating the MOSFET; anda step for changing a parameter which is used for the circuit simulation so that a frequency characteristic of the mutual conductance obtained as a result of the circuit simulation approaches to a frequency characteristic of the mutual conductance obtained from a result of measurement of the MOSFET, wherein the gate, the source, and the drain of the MOSFET are being applied a DC voltage. - View Dependent Claims (14, 15, 16)
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17. A circuit design method, comprising steps of:
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a step for superimposing an AC input signal to a drain of a SOI (Silicon On Insulator) MOSFET (Metal Oxide Semiconductor Field Effect Transistor); a step for measuring an AC component of a current flowing between a source and a drain of the SOT MOSFET when the AC input signal is superimposed to the drain; a step for calculating a drain conductance at a frequency of the AC input signal of the SOT MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal; a step for comparing a gate•
source•
drain voltage dependency of a frequency characteristic of the drain conductance obtained as a result of measurement of the MOSFET with a gate•
source•
drain voltage dependency of a frequency characteristic of the drain conductance obtained from circuit simulation for simulating the SOI MOSFET; anda step for changing a parameter which is used for the circuit simulation so that a frequency characteristic of the drain conductance obtained as a result of the circuit simulation approaches to a frequency characteristic of the drain conductance obtained from a measurement result of the MOSFET, wherein the gate, the source, and the drain of the SOI MOSFET are being applied a DC voltage. - View Dependent Claims (18, 19)
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20. A circuit design system, comprising:
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a function block for superimposing an AC input signal to a gate of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor); a function block for measuring an AC component of a current flowing between a source and a drain of the MOSFET when the AC input signal is superimposed to the gate; a function block for calculating a mutual conductance at a frequency of the AC input signal of the MOSFET from a ratio of amplitude of an AC component of a measured current and amplitude of the AC input signal; a function block for comparing a gate•
source•
drain voltage dependency of a frequency characteristic of the mutual conductance obtained as a result of measurement of the MOSFET with a gate•
source•
drain voltage dependency of a frequency characteristic of the mutual conductance obtained from circuit simulation for simulating the MOSFET; anda function block for changing a parameter which is used for the circuit simulation so that a frequency characteristic of the mutual conductance obtained as a result of the circuit simulation approaches to a frequency characteristic of the mutual conductance obtained from a result of measurement of the MOSFET, wherein the gate, the source, and the drain of the MOSFET are being applied a DC voltage. - View Dependent Claims (21, 22, 23)
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24. A circuit design system, comprising:
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a function block for superimposing an AC input signal to a drain of a SOI (Silicon On Insulator) MOSFET (Metal Oxide Semiconductor Field Effect Transistor); a function block for measuring an AC component of a current flowing between a source and a drain of the SOI MOSFET when the AC input signal is superimposed to the drain; a function block for calculating a drain conductance at a frequency of the AC input signal of the SOI MOSFET from a ratio of amplitude of an AC component of the measured current and amplitude of the AC input signal; a function block for comparing a gate•
source•
drain voltage dependency of a frequency characteristic of the drain conductance obtained as a result of measurement of the MOSFET with a gate•
source•
drain voltage dependency of a frequency characteristic of the drain conductance obtained by circuit simulation for simulating the SOI MOSFET; anda function block for changing a parameter which is used for the circuit simulation so that a frequency characteristic of the drain conductance obtained as a result of the circuit simulation approaches to a frequency characteristic of the drain conductance obtained from a result of measurement of the MOSFET, wherein the gate, the source, and the drain of the SOI MOSFET are being applied a DC voltage. - View Dependent Claims (25, 26)
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Specification