| 摘要 |
PURPOSE:To make symmetric non-linearity the sensitivity in positive and negative of a differential pressure by forming a recess at the center of a diaphragm so as to have a swell in comparison with the periphery. CONSTITUTION:Diffused resistant layer 20 are diffusion-formed on one main surface of an Si single crystal substrate 17, and an Si3N4 layer 21 is formed on the other main surface. When the Si single crystal substrate 17 is ground by means of a grinding stone which revolves to the direction of the arrow 24 while it rotates to the direction of the arrow 23, and whose rotation axis inclines at 0.05-0.3 deg. with respect to the revolution axis, a round hole 25 having the conical swell whose inclination angle from the peripheral edge at the bottom to the center is 0.05-0.3 deg. is formed. Next, a photo resist, etc. are adhered on the lower bottom, the outer peripheral surface, and the upper end surface of the single crystal Si, and then the inner surface of the round hole 25 is etched. |
