| 摘要 |
PROBLEM TO BE SOLVED: To reduce a parasitic resistance caused by p/n junction and to improve sensitivity/temperature characteristics when achieving a capacitive acceleration sensor for controlling a beam thickness using an anode oxidation method. SOLUTION: A capacitive acceleration sensor has a sensor substrate 1 where a ring part 2, a thinned beam part 7, and a weight part 6 with vertically movable electrodes 14 and 15 are formed by executing anisotropic etching to n/p type semiconductor substrate and upper and lower stoppers 5 and 4 which are stuck and fixed to the upper and lower surfaces of the substrate 1, have gaps 12 and 13 for moving the weight part 6, and have fixed electrodes 10 and 9 at positions opposing the electrodes 14 and 15 of the weight part 6. Also, the electrodes 14 and 15 and a tapered part 18 are formed by mutually connected n<+> diffusion layer. Namely, by changing the conduction type of the beam part 7 from n/p junction type to a n type, a pad 11 and the electrodes 14 and 15 can be wired by an n-type impurity, thus improving beam thickness and sensitivity. |
