Analysis And Study Of Manufacture For MEMS

Micro-Electro-Mechanical Systems (MEMS) are highly sensitive about process technique, so, it is very important to consider the effect of possible error from process on yield when designers design MEMS products. To solve this problem, Design for Manufacture (DFM) in MEMS industry is put forward. It is a key method to increase yield by compensatory design, which is achieved by reducing the effect of process error on device performance. So how to realize compensatory design is an urgent matter which should be dealt with.This work mainly focused on the effect of process error on the performance of MEMS products. Fixed-fixed beam and comb-drive resonator were set as the pattern to explore how geometry size deviation and geometry shape error influence the devices. The methods we used here were finite element simulation and theoretical derivation.In view of fixed-fixed beam, the influence of the process error to the frequency and amplitude of the first five modes and pull-in voltage was analyzed by finite element simulation tool-ANSYS. The process errors we considered included the variety of geometry size, inclination profiles in DRIE process, footing effect in SOI structures, corrugated profiles in TMDE process, the corner arc in anisotropic etching process, etc. It is found that the length of fixed-fixed beam impacts the frequency most, geometry size and footing effect are the main sources of amplitude variation and pull-in voltage is sensitive to the thickness of fixed-fixed beam. The distribution of modes may change with the rate of width and thickness. Furthermore, we also revised the frequency formula with the influence of inclination profiles, footing effect, and corrugated files, and it proved to be appropriate.For comb-drive resonator, the effect of the process error on the frequency and amplitude was also simulated. The process errors we considered here were almost the same with the situation of fixed-fixed beam except the corner arc. In addition, the mechanical parameter error caused by process condition was included. It is discovered that the frequency of resonator is susceptible to the width of springs and inclination profiles. When the rate of spring width and thickness varies, the modes may be affected. What’s more, we revised the frequency formula with influence of inclination profiles, footing effect, and corrugated files, which got validated by means of comparing the finite element simulation results with theoretical results.Based on the analysis of common process error, a lot of calculation was carried out to study the effect of process error on the performance of MEMS devices. And the theory concerned was revised in this paper. So the work here establishes the foundation of design for manufacture in MEMS, and the next work will be conducted smoothly.