Patent ID: 7135749
Filing Date: 2006-11-14
Classification: G01L

Abstract:
1. A capacitive pressure sensor for measuring pressure according to changes in interelectrode capacitance, the pressure sensor comprising: a silicon-on-insulator (SOI) substrate having a pressure-sensitive diaphragm portion that deflects in response to the pressure to be measured; a glass substrate bonded to the SOI substrate by anode bonding; a reference pressure chamber, for providing a reference value for the pressure to be measured, formed by sealing a microgap between the bonding sides of the two substrates in the position corresponding to the position where the pressure-sensitive diaphragm portion is formed; a first electrode formed on a surface of a silicon layer of the SOI substrate; a second electrode comprising a conductive material and being formed on the surface of the glass substrate facing the pressure-sensitive diaphragm portion in the reference pressure chamber; a silicon island formed on a part of the silicon layer of the SOI substrate bonded to the glass substrate, the silicon island being surrounded by a groove extending to an insulating layer of the SOI substrate; a second through hole formed in the glass substrate in the vicinity of the reference pressure chamber; and a second output electrode comprising a conductive material and being disposed inside the second through hole and electrically connected to the second electrode via the silicon island.