| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a semiconductor accelerometer in which a flexure part can be formed with good accuracy. SOLUTION: A P<+> -type embedded sacrificial layer 3a is formed inside a single-crystal silicon substrate 1. An epitaxial layer 4 is formed on the side of a face, on which the p<+> -type buried sacrificial layer 3a is formed inside the single-crystal silicon substrate 1. In succession, a piezoresistance 5 and a diffusion interconnection 6 are formed in the epitaxial layer 4. Then, a p<+> -type impurity layer 7 which reaches the p<+> -type embedded sacrificial layer 3a is formed inside the epitaxial layer 4. Silicon oxide films 8 are formed on the single-crystal silicon substrate 1 and on the epitaxial layer 4. Protective films 9 are formed on the silicon oxide films 8. Then, a part which corresponds to the outer peripheral edge of a bob part 15 in the single-crystal silicon substrate 1 is etched anisotropically. As a result, cutout parts 11 which reach the p<+> -type embedded sacrificial layer are formed. Then, the p<+> -type impurity layer 7 is etched and removed. An etchant inlet port 12 is formed. An etchant is introduced from the etchant inlet port 12. The p<+> -type embedded sacrificial layer 3a is etched and removed, and then a cutout groove 3 is formed. |
