Bistable microelectrothermal actuator in a standard complementary metal-oxide-semiconductor process

A new kind of bistable microelectrothermal actuator is designed and fabrica ted in a standard complementary metal-oxide-semiconductor technology. This actuator is designed to be the basic element of an N by N switching matrix that enables the connection of an input signal among N outputs. A microelec tronic addressing circuit integrated on the same substrate can control this matrix. Bulk micromachining processes release SiO2 and Al cantilever beams , each having two bilayer actuators. When the Al is resistance heated, stre sses are generated leading to deflections of the cantilever. By proper sequ encing of heating and cooling of the heaters, complex motion of the beam is possible, including two stable positions. A combination of anisotropic and isotropic etching techniques using tetramethyl ammonium hydroxide and XeF2 are used to realize these structures. (C) 2000 American Vacuum Society. [S 0734-2101(00)03802-1].