Manufacturing method of convective acceleration sensor chip based on temperature sensitive resistor

Abstract

The invention provides a manufacturing method of convective acceleration sensor chip based on a temperature sensitive resistor. The method comprises the following steps: firstly, forming an oxide layer and a low stress silicon nitride layer on the surface of a mono-crystalline silicon wafer; manufacturing the polycrystalline silicon temperature sensitive resistor and a polycrystalline silicon heating resistor on the low stress silicon nitride layer; manufacturing metal interconnection lines to form an acceleration sensor output circuit; corroding the mono-crystalline silicon wafer to form a concave cavity, releasing a cantilever; bonding a cover on the silicon wafer by a BCB (benzo cyclobutene) adhesive to form a sealed cavity, finally the acceleration sensor chip is obtained. The method of the invention uses the low stress silicon nitride layer deposited by LPCVD (low pressure chemical vapor deposition) as a supporting layer of the heating resistor and the temperature sensitive resistor, and manufactures the polycrystalline silicon heating resistor and the polycrystalline silicon temperature sensitive resistor by an LPCVD and doping technology; the manufactured convective acceleration sensor chip has the advantages of high detection precision, high reliability and good stability; and the manufacturing technology is compatible with IC (integrated circuit) technology. In this way, the method of the invention is helpful for realizing chip microminiaturization and low cost.

Description

technical field [0001] The invention relates to a method for manufacturing a thermal convection acceleration sensor chip, in particular to a method for manufacturing a thermal convection acceleration sensor chip based on a temperature-sensitive resistor, and belongs to the technical field of silicon micromechanical sensors. Background technique [0002] Accelerometers based on silicon micromachining technology have the advantages of small size, light weight, high performance, and low cost due to mass production. They have been used in many testing occasions, such as automotive airbags, crash tests, and consumer electronics. , seismic wave detection, military inertial technology navigation, etc. Explosion, shock test and penetrating bomb fuze are one of the very special applications. The acceleration to be detected can be as high as tens of thousands of g or even hundreds of thousands of g. Accelerometers are required not only to have high sensitivity, but also to have high r...

AI Technical Summary

Problems solved by technology

However, the heating wire and temperature sensor of the accelerometer are supported by ordinary silicon dioxide or silicon nitride, suspended above the inner cavity formed by the single crystal silicon wafer, and packaged in the outer cavity formed by the tube shell and the shell cap. In the body, this structural design enables gas heat convection to occur between the inner and outer chambers; and it is also necessary to connect the pins of each temperature sensor outside the tube shell to form a more complex detection circuit

Images