Honda Giken Kogyo Kabushiki Kaisha

Katuhiko Takebe

Katsuki Ichinose

Satoshi Hiyama

A semiconductor sensor has a plurality of field-effect transistors disposed on a semiconductor substrate at spaced intervals. The field-effect transistors have respective drains electrically connected parallel to each other, respective sources electrically connected parallel to each other, and gates electrically connected parallel to each other. While a gate bias voltage is being applied to each of the field-effect transistors, a stress applied to the semiconductor substrate is detected based on a change in a combined output of the field-effect transistors. A single comb-shaped field-effect transistor or a single planar type field-effect transistor may be employed instead of the plurality of field-effect transistors.

Semiconductor sensor with plural gate electrodes

A semiconductor stress sensor includes a field-effect transistor for producing a drain current commensurate with a stress applied thereto. The gate of the field-effect transistor is supplied with a gate bias voltage from a gate bias voltage generator. The drain current from the field-effect transistor is converted into a detected output signal by a current-to-voltage converter. The gate-to-source voltage of the field-effect transistor can be varied to reduce the drain current in a standby mode when no stress is to be detected. To vary the gate-to-source voltage, the gate bias voltage applied to the gate of the field-effect transistor may be slightly varied or the source potential thereof may be slightly varied. The gate-to-source voltage of the field-effect transistor slightly differ from each other in the standby and stress sensing modes. Even in the standby mode, the field-effect transistor is supplied with substantially the same voltage as in the stress sensing mode. When the semiconductor stress sensor switches from the standby mode to the stress sensing mode, the drain current is subjected to an only small drift, allowing the semiconductor stress sensor to produce a highly accurate, stable detected output signal within a short period of time.

Semiconductor stress sensor

A semiconductor sensor has a plurality of field-effect transistors disposed on a semiconductor substrate at spaced intervals. The field-effect transistors have respective drains electrically connected parallel to each other, respective sources electrically connected parallel to each other, and gates electrically connected parallel to each other. While a gate bias voltage is being applied to each of the field-effect transistors, a stress applied to the semiconductor substrate is detected based on a change in a combined output of the field-effect transistors. A single comb-shaped field-effect transistor may be employed instead of the plurality of field effect transistors.

Semiconductor stress sensor MESFET or MESFET array

A semiconductor sensor for detecting physical quantities such as pressure, acceleration, mechanical vibration, etc. includes a semiconductor substrate, and a field-effect transistor on the semiconductor substrate, the field-effect transistor having a source, a drain, and a gate. A gate voltage is between the source and the gate to cause a drain current between the source and the drain, the drain current being variable with an external force applied to the field-effect transistor, whereby the external force can be detected on the basis of a change in the drain current. The drain current which flows when no external force is applied to the field-effect transistor is selected to be 1/3 or less of a drain current which flows when the gate and the source are shorted, or to be in the vicinity of a value that maximizes the ratio of a change in the drain current which flows when the external force is applied to the field-effect transistor to a change in the drain current which flows when no external force is applied to the field-effect transistor.

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Tokyo, Japan

Katuhiko Takebe