Patent ID: 7046028

Claim:
A method of inspecting a semiconductor dynamic quantity sensor comprising: a peripheral fixed portion of a semiconductor fixed and supported on a support substrate along the periphery of the support substrate; movable electrodes of a semiconductor supported on the support substrate on the inside of the peripheral fixed portion and displaceable in a horizontal direction relative to the surface of the substrate; and first fixed electrodes and second fixed electrodes of a semiconductor fixed and supported on the support substrate on the inside of the peripheral fixed portion and that are opposed to the movable electrodes maintaining detection gaps; wherein a first capacitance is formed between the movable electrodes and the first fixed electrodes, a second capacitance is formed between the movable electrodes and the second fixed electrodes; wherein the applied dynamic quantity is detected based on a change in the differential capacitance between the first capacitance and the second capacitance that accompanies the displacement of the movable electrodes when a dynamic quantity is applied; the method comprising: applying a potential (V 1 ) to the first fixed electrodes, a potential (V 2 ) is to the second fixed electrodes, a potential (V 3 ) to the movable electrodes, and a potential (V 4 ) to the peripheral fixed portion, and whereby a potential (V 5 ) of the support substrate is expressed by the following numerical formula 1, V 5=( CK 1· V 1+ CK 2· V 2+ CK 3· V 3+ CK 4· V 4)/( CK 1+ CK 2+ CK 3+ CK 4) (1) wherein (CK 1 ) denotes a parasitic capacitance between the first fixed electrodes and the support substrates, (CK 2 ) denotes a parasitic capacitance between the second fixed electrodes and the support substrate, (CK 3 ) denotes a parasitic capacitance between the movable electrodes and the support substrate, and (CK 4 ) denotes a parasitic capacitance between the peripheral fixed portion and the support substrate, and by utilizing the relationship of the numerical formula 1, the voltage (V 4 ) applied to the peripheral fixed portion is varied while maintaining constant the voltage (V 1 ) applied to the first fixed electrodes, the voltage (V 2 ) applied to the second fixed electrodes and the voltage (V 3 ) applied to the movable electrodes, to vary a potential difference between the movable electrodes and the support substrate to thereby displace the movable electrodes in a direction perpendicular to the surface of the substrate.