Research On Self-Destructive Device Based On MEMS Technology

With the advent of the information age,in order to protect the information security in the chip and prevent the high-tech carried by the chip itself from being reused or developed by others,self-destructible electronic devices have become a research hotspot.In this thesis,a self-destructive device based on MEMS technology is designed,and the mechanical-electrical triggered,chemical etching method is used to realize the complete self-destruction of silicon-based microstructures.The theoretic analysis and structural optimization of the MEMS membrane,MEMS hammer,electrostatic drive structure and electrostatic latch structure in the self-destructive device were carried out respectively,and the processing flow and layout were designed.The main research contents of this thesis are as follows:The energy storage beam of MEMS membrane and MEMS hammer are theoretically analyzed and verified by simulation.The energy storage beam with the maximum deflection of 37 ?m and the elastic force of 180 m N is designed.The lever balance structure of MEMS is designed.The contact situation and torque balance situation when the MEMS balance structure rotates at different angles are analyzed.Then the dynamics of the hammer after released is analyzed.The results show that when the energy storage beam deflection is 35 ?m,the hammer touches the MEMS membrane within 11 ?s after release,the velocity reaches 13 m/s and the kinetic energy reaches 1.54 ?J.In order to realize the automatic energy storage loading of the MEMS hammer,the structure of the MEMS electrostatic inchworm motor is designed,and its maximum load capacity reaches 1.8 m N.Based on the realization principle of the inchworm motor and the MEMS lever force balance structure,an inchworm transmission system is designed,through the two-stage lever amplify,the motor can drive the hammer to load a force of 200 m N.In view of the problem that traditional mechanical latch requires manual operation,and the latch voltage required by MEMS electrostatic holding latch is too large,two low voltage latch methods based on gap-closed comb arrays are proposed: electrostatic friction latch and electrostatic support latch,the impact hammer with a force of 180 m N can be locked,and an electrostatic latch release structure controlled by the voltage signal of the microcontroller is given.Design the process flow and layout of the self-destructive device,analyze the key processes and technologies,including SOI material selection,VPE-HF release of the sacrificial layer,and two scratch-free processing schemes,and finally give the entire MEMS self-destructive device integration solution.