| 摘要 |
PURPOSE:To prevent a diaphragm from exceeding a yield limit when pressure within a reference chamber is increased by forming a silicon wafer in a triple structure where both surfaces of the silicon wafer are held by glass wafers and forming a mesa on either of a diaphragm or the glass wafer. CONSTITUTION:In a pressure sensor, a glass wafer (glass substrate) where an opposing electrode 7 is provided and a diffusion layer 6 and a junction prevention film 11 are provided on the surface and then a silicon wafer 10 with a diaphragm 2 where a mesa 3 is formed on the opposing rear surface and a glass wafer (stopper) 5 where an external air introducing hole 8 is provided are provided, thus forming a triple structure where the wafer 10 is sandwiched by a substrate 1 and the stopper 5. When the outer pressure is equal to or less than atmospheric pressure and then the diaphragm 2 is deflected and the reference chamber 3 is inflated, the mesa 3 collides with the stopper 5 in a specified inflation, thus preventing the diaphragm 2 from being damaged. When the sensor is pressurized to a preset pressure, the reference chamber 3 shrinks, the mesa 3 is separated from the stopper 5, and the diaphragm 2 is activated in response to pressure. |
