CMOS electrothermal microactuators

Fabrication of electrothermal microactuators using a commercial CMOS technology is presented. The effect of differential thermal expansion of adjacent insulating layers is used to produce the mechanical deflection. The field oxide and CVD oxide of the CMOS process form the micromechanical structure. A heating element required to raise the temperature is formed by the polysilicon layer available in the CMOS process. A typical cantilever microactuator exhibits an elastic deflection of 4 mu m above the chip surface, and a suspended plate microactuator 1 mu m above the chip surface. Maximum frequency response is measured at 1.5 kHz and 2.0 kHz for the cantilever and the suspended plate microactuators, respectively.<
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