Patent ID: 8241923
Filing Date: 2012-08-14
Classification: G01C,G01P

Abstract:
1. A method for manufacturing an acceleration sensor or an angular velocity sensor, comprising: dividing an SOI wafer having a three-layer structure composed of an active-layer silicon layer, a silicon-oxide layer and a base silicon layer, into multiple faces, and then providing a first frame, a plurality of beams respectively projecting inward from the first frame and a weight junction supported by the beams, in the active-layer silicon layer, for each divided face of the SOI wafer; forming a second frame and a weight in the base silicon layer, the weight being positioned inside the second frame, in a non-contact manner to the second frame, and joined to and held by the weight junction via the silicon-oxide layer; removing the silicon-oxide layer exposed to the outside; and joining a supporting substrate to the second frame of the base silicon layer, in a non-contact manner to the weight, wherein, in forming the second frame and weight in the base silicon layer, the second frame and weight are formed, respectively, by forming an opening, by dry-etching the base silicon layer, via a mask pattern having a corresponding opening, until the silicon-oxide layer is exposed, wherein the mask pattern has been corrected, in advance, to have a desired width of the opening thereof, and wherein the correction of the mask pattern comprises: dry-etching at least a portion of the base silicon layer with a desired etching apparatus using a reference mask pattern which is not yet corrected, and then measuring a distribution of a size of expansion of a tapered portion formed in a surface of a remaining portion of the base silicon layer after being etched; and approximating the measured distribution by using a quadratic curve (Y=AX