PURPOSE: To eliminate the influence of temperature on a semiconductor capacitor type pressure sensor by a method wherein an amplifier is provided at a part of the upper face of an Si substrate, and a concave notch part at another part, capacitor electrodes are provided on the face of an insulating cap to be joined to the substrate facing with the concave notch part, and pressure is detected and amplified as electric capacity.
CONSTITUTION: B ions are made to diffuse in a part of the Si substrate 20 to provide an IC amplifier 21, and another part of the substrate is etched with alkali to form the concave notch part 22. An oxide film 23 and a polycrystalline Si layer 24 are formed in order on the whole surface of the substrate excluding the concave notch part 22, and the cap 25 consisted of Pyrex glass is adhered on the polycrystalline Si layer 24 to seal. The electrodes 27, 28 are provided on the face of the cap 25 facing with the concave notch part to form capacitance between substrate 20, deformation of the substrate 20 by pressure A is detected as capacitance, and is amplified to be outputted to outside terminals 36, 37. Accordingly because no component of P-N junction capacitance is contained in the detected value of capacitance, variation of capacitance to be caused by the circumferential temperature can be reduced, and the sensor having high accuracy can be obtained.
| JPH0431729 | SEMICONDUCTOR PRESSURE CONVERTER |
| JPH1137858 | PRESSURE SENSOR |
NISHIHARA MOTOHISA
YAMADA KAZUJI
KATOU KAZUO
TANABE MASANORI
