MEMS多晶硅纳米膜压力传感器过载能力设计

Design of overload capacity for MEMS polysilicon nanomembrane pressure sensor

针对MEMS压力传感器感压膜片受较大压力易发生断裂而导致传感器性能失效问题,提出了MEMS多晶硅纳米膜压力传感器过载能力设计的方法。采用厚度为80 nm多晶硅薄膜构建感压膜片结构,利用静态大变形和接触非线性有限元分析方法,分析感压膜片触底保护的腔体高度,在此基础上,进一步得出感压膜片尺寸与过载能力的关系,并重点讨论了不同传感器量程下改变膜片尺寸对过载能力的影响。仿真结果表明,所设计的1 MPa量程MEMS多晶硅纳米膜压力传感器,其过载能力8 MPa,为传感器量程8倍。本次研究为MEMS压力传感器的实际生产制备提供了新思路。

Aiming at the problem that the diaphragm of MEMS pressure sensor is prone to breakage under high pressure,which readily brings about the disability of its performance,a method for designing the overload capacity of MEMS polysilicon nanomembrane pressure sensor is proposed.A pressure sensitive diaphragm structure is constructed by using polysilicon film with a thickness of 80 nm,and the classical finite element methods,such as static large deformation and contact nonlinear,are introduced.First,the cavity height on bottom protection for a pressure sensitive diaphragm is analyzed.The relationship was then determined between the sizes of a pressure sensitive diaphragm and overload capacity.Particularly,the effects of the diaphragm size on overload capacity under different sensor ranges are mainly discussed.For the designed MEMS polysilicon pressure sensor with a range of 1 MPa,the simulation results show that its overload pressure is up to 8 MPa,which is 8 times the range of the sensor.The studies on its overload capacity furnishes a novel scheme for the practical application of MEMS pressure sensors.