Investigation of micro-array thermal actuator for MEMS

This paper proposes an insight view on the motion behavior of Micro-Array Thermal Actuator, MATA, applied in Micro-Electro-Mechanical Systems, MEMS. There are three basic kinds of {2 x 1}, MATA, opposite type, parallel type and orthogonal type. That will be analyzed in simulation and experiment. The effects of voltage, flexure length, connecting length and position on the variations of displacement and temperature distribution of devices will be investigated in this work. In this investigation, the longer the flexure length is, the greater the displacement is for the opposite type MATA. However, when the flexure length increases, the variation of displacement of the parallel type is against to that of opposite type. In addition, there is a little effect of connecting length on the variation of displacement for three kinds of MATA through the detailed analysis of simulation. Finally, there are many interesting phenomena which include suspension, sticking, side etching, undercut, and overly etching in surface micromachining engineering. These will be fully discussed through FE-SEM for MATAs. Mechanism of poly3 peeled off is systematically developed. First, poly3 can not be fully covered on poly2 due to side etching. Then, as releasing time increases, undercut is going in sequentially until poly3 is peeled off due to overly etching.