Patent ID: 6441450
Filing Date: 2002-08-27
Classification: B81B,B81C,G01P

Abstract:
An acceleration sensor in which a base portion and a cap portion are bonded to each other and a sensor portion is sealed off between said base portion and said cap portion, comprising:a) a base portion comprising: a semiconductor substrate; a sensor portion and a frame portion surrounding a periphery of said sensor portion, which are formed by a polycrystalline silicon layer deposited on said semiconductor substrate and doped with an impurity; and a diffusion preventing layer and a non-doped polycrystalline silicon layer which are stacked one atop the other on said frame portion; and b) a cap portion comprising: a base unit; and a nickel layer formed on said base unit so as to be in contact with said non-doped polycrystalline silicon layer of said base portion, wherein said non-doped polycrystalline silicon layer of said base portion and said nickel layer of said cap portion are bonded to each other by eutectic bonding, and said sensor portion is sealed off between said base portion and said cap portion.