MICROMACHINING METHOD ENABLING IMPROVEMENT OF Z-AXIS MOVEMENT PERFORMANCE AND MINIMIZING OF DEPTH DEVIATION OF STRUCTURE, AND ACCELERATION SENSOR USING SAME

摘要

A micromachining method, which enables improvement of z-axis movement performance and minimizing of the depth deviation of a structure, comprises: a step (S100) for preparing a silicon-on-insulator (SOI) wafer comprising an upper silicon layer, a support substrate which is formed from silicon, and an insulating layer between the support substrate and upper silicon layer; a step (S200) for etching by applying on the upper silicon layer a first photoresist and a second photoresist; a step (S300) for, by using the part which is opened by means of the etching of the step (S200), first deep etching by etching the upper silicon layer such that the insulating layer is exposed; a step (S400) for forming an oxide layer on the lateral side of the upper silicon layer which has been deep etched in the step (S300) and etching in the depth direction the insulating layer that is exposed on the lower part of the upper silicon layer; a step (S500) for second deep etching the support substrate that is exposed by means of the etching of the step (S400); and a step for removing the support substrate, which is a sacrificial layer, such that a MEMS portion is released by means of the support plate which is exposed by means of the second deep etching of the step (S500).