| 摘要 |
PURPOSE:To restrain the dispersion of the thickness of a diaphragm very small by a method wherein the etching of an Si substrate is completely stopped at the point of reaching an oxide single crystal thin film so as to accurately control the thickness of the formed Si diaphragm. CONSTITUTION:An oxide single crystal thin film 22 and an Si single crystal thin film 23 are successively epitaxially grown on an Si substrate 21. Next, resistance regions 24 are formed in said film 23 by diffusion or ion implantation. Then, etching protection films 25 of Si nitride, etc. are formed on both surfaces of the substrate, and the part of said substrate is etched in EDP solution or KOH solution. At this time, the etching automatically stops at the point of reaching the thin film 22 by using an oxide material as said film 22. Thereafter, the protection film 25 and the thin film 22 are removed with etchant, forming an insulation film 26 and electrodes 27, and thus obtaining an Si diaphragm type pressure sensor. |
