SEMICONDUCTOR ACCELERATION SENSOR AND ITS MANUFACTURE
Document Type and Number:
Japanese Patent JP3427462
PURPOSE: To provide a semiconductor acceleration sensor whose beam portions resist deflection and a method for manufacturing the same.
CONSTITUTION: Silicon substrates are machined to form thin beam portions 2 and weight portions 3 inside a frame-shaped support 1, the weight portions 3 being supported by the beam portions 2 in such a way as to freely rock. A plurality of piezoresistances Rx1... are formed on the surface of the beam portions 2. Silicon oxide films 24 for insulating the plurality of piezoresistances Rx1... from one another are formed on the surface of the beam portions 2 and on that of the support 1. A silicon oxide film 21 is formed over the reverse side of each beam portion 2. The silicon oxide film 21 on the reverse side is initially formed on that side of one of the silicon substrates where the weight portions 3 are formed, and is joined to the other silicon substrate that is formed into the beam portions 2. Since the silicon oxide films 21, 24 are formed respectively on the right and reverse sides of each beam portion 2, internal stress generated in each beam portion 2 by thermal expansion is canceled out and so the beam portions 2 can be prevented from deflecting.
May 16, 2003
February 23, 1994
MATSUSHITA ELECTRIC WORKS LTD
G01P15/12; H01L29/84; G01P15/12; H01L29/66; (IPC1-7): G01P15/12; H01L29/84