MANUFACTURE OF ACCELERATION SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a structure of an acceleration sensor which realizes improvement of yield of a beam formation process and improvement of perfor mance. SOLUTION: This device has a process for joining a first substrate 17 wherein a sacrificial layer is formed and a second substrate 22 and a process for etching and removing a sacrificial layer. The sacrificial layer is a high concentration impurity diffusion layer 20 which is formed in a polysilicon layer 19 formed on the first substrate 17. A sacrificial layer which is the high concentration impurity diffusion layer 20 alone is etched and removed by solution formed by mixing hydrofluoric acid : nitric acid : acetic acid =1:3:8 using the silicon layer 19 as an etching stop layer.