MEMS device and method of forming MEMS device

Abstract

The invention relates to a MEMS device and a method of forming an MEMS device. In the MEMS device, a back plate comprises a first dielectric layer, a second dielectric layer and a conductive layer which are sequentially stacked. The stress level of the first dielectric layer is higher than that of the second dielectric layer, the overall stress and rigidity of the back plate can be improved by utilizing the first dielectric layer, the improvement of the sensitivity and accuracy of the test is facilitated when the pull-in voltage test is carried out, and the tensile property of the back plate is ensured while the larger size of the back plate is realized. In addition, since the conductive layer is still in contact with the second dielectric layer, the influence of the first dielectric layeron the contact performance of the conductive layer is small. In the MEMS device, a third dielectric layer can be arranged on the side, far away from the second dielectric layer, of the first dielectric layer so as to protect the first dielectric layer from being corroded. The method of forming an MEMS device can be used for forming the MEMS device.

Description

technical field [0001] The present invention relates to the field of micro-electromechanical technology, in particular to a MEMS device and a method for forming the MEMS device. Background technique [0002] Micro Electro Mechanical System (MEMS) integrates micro sensors, micro actuators, micro mechanical structures, micro power sources (micro energy sources), signal processing and control circuits, high-performance electronic integrated devices, interfaces, communications and other components. It can be regarded as an independent intelligent system, and its overall size is usually a few millimeters or even smaller. With the development trend of miniaturization of electronic devices, electronic devices including MEMS (hereinafter referred to as MEMS devices) such as MEMS microphones, MEMS accelerometers, MEMS gyroscopes, etc. have also made great progress and have broad development prospects. [0003] The manufacture of MEMS is different from traditional mechanical processi...

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Problems solved by technology

[0005] In the existing process, the backplane is usually composed of low-stress nitride and a low-stress conductive layer covering it. However, for other considerations (such as in order to improve the signal-to-noise ratio of the chip), the MEMS backplane will be designed However, larger size backsheets made with low stress nitrides have poorer tensile properties that interfere with the sensitivity and accuracy of the pull-in voltage test

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