Test And Analysis Of Performance Of AlGaN/Gan HEMT Micro-cantilever-accelerometer Device And Optimization Design

In recent years, due to the characteristics of the material excellent in GaN, forexample, mechanical, thermal, chemical stability and biological compatibility,GaN-based micro-electromechanical systems （MEMS） has been widespread concernin academic circles. AlGaN/GaN heterostructure material system having a large bandlevel difference and a high melting point, so that it has a great potential for applicationin high-temperature, high-frequency, high-power microwave electronic devices. Atpresent, the devices are widely used in the micro inertial measurement unit cantileverstructure with field-effect transistor integrated structure to achieve inertialmeasurement signal. High electron mobility transistors （High Electron MobilityTransistor） as a field-effect transistor, have been widely used in communications,electronics and other fields, it has the characteristics of high-power, low-noise,high-frequency, high-speed. The use of electromechanical coupling principle preparedAlGaN/GaN-based HEMT micro-accelerometer structure, static characteristics ofdetection, analysis, given the parameters of the static characteristics of theaccelerometer, according to the parameters to optimize the design of the structure, inorder to get a higher sensitivity, linearity, and laid the foundation for a greater range ofaccelerometers.Firstly, application of AlGaN/GaN HEMT micro-cantilever structure of thedevice electromechanical coupling principle, reasonable experimental programdesigned to test the static characteristics of AlGaN/GaN HEMT micro-accelerometer.On the AlGaN/GaN HEMT acceleration of0to10g of the static friction test, thesensitivity of the accelerometer obtained0.12mA/g, indicating that the structuresensitivity smaller; Second, the analysis of the process of micro-accelerometer,summed up the causes of the micro-structure of residual stress, and the use of the Raman stress tester on the residual stress of the micro-structure were tested, drawresidual stress on the device structure and propertiesthe impact of the foundation forthe next step to improve the structure; Third, on this basis, re-optimize the structure ofthe accelerometer sensitive components of the acceleration sensor dimensions on theperformance of the sensitivity, linearity and frequency response range, combined withthe finite element static analysis and modal analyzesthe specific parameters of thestructure, and compared with the original structure. After the calculation and analysis,that the optimized structure sensitivity from4.13×10^-3um/g to improve to3.07×10^-2um/g, increases an order of magnitude. Able to withstand the longitudinalimpact of350g and500g of the lateral impact, the frequency response range between0³000Hz, in theory, meet the basic requirements of the high sensitivity of themicro-accelerometer. Accelerometer in the Frequency Range lacking.