The Beneficial Effects of Thin Film Stress in the Fabrication of a MEMS Device

Microelectromechanical systems (MEMS) are playing an increasing role in the semiconductor industry today. The modeling and manufacturing of mechanical devices on a microscopic level have made their way from the area of singularly fabricated devices for research into the bulk processing of the commercial market Many of these commercial devices are of the optical variety. And there has also been successful work done in combining integrated circuits with MEMS. Presented here is a process for the fabrication of an optical device called a microshutter. The device consists of a moveable electrode constructed of a stack of Si02/Al/SiO2. The key to the successful micromachining of this device lays in the stress characteristics of the stacked layer. The physical qualities and methods of obtaining these stresses will also be discussed