| 摘要 |
PROBLEM TO BE SOLVED: To prevent short-circuiting between the wiring for etching and the p<+> impurity diffusion layer in electrochemical etching in an integrated pressure sensor having a diaphragm section formed by the electrochemical etching and an integrated circuit section in a silicon chip. SOLUTION: In a silicon chip 10 where an n-type epitaxial layer is laminated on a p-type single crystal silicon substrate, one portion of the p-type single crystal silicon substrate is removed by electrochemical etching to form a diaphragm section 14, at the same time, a p<+> impurity diffusion layer 27 as isolation that reaches the p-type single crystal silicon substrate from the surface of the n-type epitaxial layer is formed, and an integrated circuit section 16 is formed at a site other than the diaphragm section 14. Wiring 28 for etching is arranged between one end section 28a that is electrically connected to the n-type epitaxial layer on a chip inner circumference and the other 28b extended to a tip end section without straddling the p<+> impurity diffusion layer 27.
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