Patent ID: 7045371

Claim:
A method for removing foreign material from a capacitance type dynamic quantity sensor comprised of a movable portion having a poise portion mounted on a semiconductor substrate through a spring portion to be displaced in accordance with application of a dynamic quantity to thereby detect the dynamic quantity, movable electrodes integrally formed with the poise portion so as to extend from the side surface of the poise portion, and a fixed portion having fixed portion anchors mounted on the semiconductor substrate and fixed electrodes, wherein each of the fixed electrodes has a detection face confronting to a detection face of each of the movable electrodes and extends from each of the fixed portion anchors, the dynamic quantity being detected on the basis of variation of electrostatic capacitance between each movable electrode and each fixed electrode when under the application of the dynamic quantity, the movable portion is displaced in a direction along which the distance between the detection faces of the movable electrode and the fixed electrode varies, the method comprising: applying a predetermined driving voltage between the movable portion and the fixed portion to displace the movable portion and thereby expose the foreign material in a hollow portion below the movable portion to the outside and removing the foreign material.