Structure stability of high aspect ratio Ti/Au two-layer cantilevers for applications in MEMS accelerometers

Abstract

This paper reports the structure stability of Ti/Au two-layer micro-cantilevers with various aspect ratios based on the results obtained from a 3D optical microscope and FEM simulation. The cantilevers were fabricated by MEMS fabrication process. The movable structure stability was investigated by observing the shape of the Ti/Au two-layer micro-cantilevers with the Ti layer thickness of 0.1μm, and the Au layer thicknesses of 3μm, 10μm and 12μm. The length was varied from 100 to 1000μm. The results of the tip deflection observed from the 3D optical microscope were similar to those of the FEM simulation. The experimental results of the micro-cantilevers with the Au thickness of 12μm indicated the highest structure stability. In conclusion, these results revealed that the Ti/Au two-layer structure can enhance the stability and reliability of the movable structure.