发明授权
- 专利标题: Method for making an all-silicon capacitive pressure sensor
- 专利标题(中): 制造全硅电容式压力传感器的方法
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申请号: US707107申请日: 1996-09-03
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公开(公告)号: US5706565A公开(公告)日: 1998-01-13
- 发明人: Douglas Ray Sparks , William J. Baney , Steven Edward Staller , Dan Wesley Chilcott , James Werstler Siekkinen
- 申请人: Douglas Ray Sparks , William J. Baney , Steven Edward Staller , Dan Wesley Chilcott , James Werstler Siekkinen
- 申请人地址: IN Kokomo
- 专利权人: Delco Electronics Corporation
- 当前专利权人: Delco Electronics Corporation
- 当前专利权人地址: IN Kokomo
- 主分类号: G01L9/00
- IPC分类号: G01L9/00 ; H01G7/00
摘要:
An all-silicon monolithic capacitive absolute pressure-sensing device and method for making the same. The device employs a single-crystal silicon diaphragm that serves at a flexible capacitor plate of a variable capacitor. The diaphragm is bonded to a single-crystal silicon wafer to overlie a cavity etched into the wafer. A fixed capacitor plate of the variable capacitor is formed by a heavily-doped region at the bottom of the cavity. A thin dielectric layer is grown on the fixed capacitor plate to complete the capacitor. The cavity has a minimal depth such that the fixed capacitor plate provides overpressure protection for the diaphragm. At least a portion of the operating range of the pressure sensor occurs while the diaphragm is contacting the doped region. As a result, the capacitive output signal of the pressure sensor is produced by changes in contact area between the diaphragm and a thin dielectric situated on the doped region in response to pressure applied to the diaphragm.