Acceleration sensor

摘要

An acceleration sensor can ensure rigidity of its movable electrode despite a large number of through-holes formed in the movable electrode. The acceleration sensor has an SOI substrate in which a silicon oxide layer is formed on a silicon support layer and an active silicon layer is formed on the silicon oxide layer, wherein the active silicon layer of the SOI substrate has a movable electrode supported by elastic beams and configured with a weight, and also has fixed electrodes disposed in a fixed manner around the movable electrode to face the movable electrode, and wherein through-holes penetrating in a Z-axis direction are formed over the entire surface on the inner side of an outer circumference to which the elastic beams of the movable electrode are connected.

主权项

1. An acceleration sensor, comprising an SOI substrate in which a silicon oxide layer is formed on a silicon support layer and an active silicon layer is formed on the silicon oxide layer,
the active silicon layer of the SOI substrate being formed to have a movable electrode supported by elastic beams and configured with a weight, and also have fixed electrodes disposed in a fixed manner around the movable electrode to face the movable electrode, and through-holes penetrating in a Z-axis direction being formed over a surface on an inner side of an outer border to which the elastic beams of the movable electrode are connected, and the through-holes extending in different directions in a pattern that repeats in each of quadrants of an area defined by the border; wherein the pattern that repeats includes the through-holes alternately disposed in a first block-shaped area and a second block-shaped area in a two-dimensional manner, the first block-shaped area having a predetermined number of long through-holes formed in parallel, and the second block-shaped area having a predetermined number of long through-holes formed in parallel in a direction perpendicular to a direction of the long through-holes of the first block-shaped areas.