| 摘要 |
PROBLEM TO BE SOLVED: To reduce fluctuations in the sensitivity of a sensor, caused by the fluctuations in electrostatic capacity between movable and stationary electrodes. SOLUTION: Anisotropic reactive ion etching is carried out from an upper surface of a silicon substrate 1 to make grooves 4a and 4b extended in a vertical direction to define a rectangular frame part 5, a beam structure 6 and stationary electrodes 17a and 23a thereby. Ice 53 as electrically insulating material is provided only in bottoms of the grooves 4a and 4b, reactive etching is again carried out for the grooves 4a and 4b so that the trajectory of an incident ion is bent in the vicinity of the bottom surfaces of the grooves by an electrical repulsive force to the ice 53 to realize anisotropic etching only in this vicinity to locally proceed in horizontal directions. Thereby a cavity 2 is formed extended in the direction horizontal to the bottom surface of the grooves 4a and 4b to define a support (rectangular frame part + beam structure), a beam structure 6 and stationary electrodes 17a and 23a. |
