The method of prevent footing effect in making SOI micro-mechanical structure

A novel method to apply thin metal film for preventing footing effect in making micro-mechanical structure on SOI wafer is presented. The handle wafer of the SOI wafer was etched to form cavity by KOH solution, and followed by removing the buried oxide from backside. Then a thin aluminum film was sputtered in the cavity to prevent footing effect. The experimental results showed that the SOI micro-mechanical structure was well protected from footing effect. We applied this method to make the SOI micro-accelerometer, and the linearity, sensitivity, resolution and bandwidth of the SOI micro-accelerometer were measured respectively. The performances of the fabricated SOI micro-accelerometer indicated that the method can improve the fabrication capability of SOI process.