Minitype silicon accelerometer having functions of measuring pressure intensity and temperature variation and its machining method

Abstract

The invention provides a micro-silicon accelerometer which has the functions of measuring pressure and temperature. The micro-silicon accelerometer not only can measure the change of the pressure and the environment temperature of a system, but also can measure the acceleration; the invention also provides a processing method. The micro-silicon accelerometer comprises a silicon single-crystal underlay (1) of single crystallographic orientation; the two surfaces of the silicon underlay (1) are covered by a composite film insulation layer (2); the two cantilever beam areas of the frontal surface of the silicon single-crystal underlay (1) are provided with four heat diffusion resistances (3) so as to assemble a wheatstone bridge. The micro-silicon accelerometer is characterized in that a mass area which is connected with the two cantilever beams is a silicon mass block (4); furthermore, the frontal surface of the mass block (4) is provided with a multi-layer structure of silicon dioxide/PSG/polycrystalline silicon/silicon dioxide/polycrystalline silicon; wherein, the polycrystalline silicon on the top is prepared to be four force-sensitive resistances (5) with longitudinal piezoresistive effect; a middle polycrystalline film is an elastic film (6) of a pressure sensor; furthermore, the PSG and a phosphorosilicate glass layer which is arranged below the polycrystalline elastic film form a hollow chamber (11); an internal aluminium wire is connected with four force-sensitive resistances (5) with the longitudinal piezoresistive effect so as to assemble the wheatstone bridge used for measuring the pressure change; furthermore, a boron-phosphorus area is arranged on the frame of the accelerometer so as to assemble the EB-junction (7) of an n-p-n triode.

Description

(1) Technical field [0001] The invention relates to a micro-silicon accelerometer with the functions of measuring pressure and temperature changes, and also relates to a processing method of the micro-silicon accelerometer. (2) Background technology [0002] Typically an accelerometer is a stand-alone device that measures acceleration. The pressure sensor and the temperature-sensitive element have a device made together. Such a device can not only measure the pressure of the system, but also measure the change of the ambient temperature. Scholars in the industry have applied for a micro-silicon accelerometer in the eighth five-year national key scientific and technological research. The project has completed the acceptance indicators stipulated by the state, and completed hundreds of sample tubes. Among them, the second beam, the fourth beam, and the fifth beam each have more than one hundred sample tubes. On August 6, 1988, it applied for a utility model patent "Double Is...

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