Simultaneous realization of stabilized temperature characteristics and low-voltage driving of a micromirror using the thin-film torsion bar of tensile poly-Si

The tense thin-film torsion bar of polycrystalline (poly-) Si has been recently introduced into a micromirror. A tensile stress is obtained by the crystallization of amorphous Si. The poly-Si has almost the same coefficient of thermal expansion as that of Si substrate. An electrical connection is obtained with doping without the use of metal overlayer. The thin-film torsion bar of poly-Si is fabricated with a revised process so as to protect against the crystalline Si etching. Considering the earlier advantages and techniques, the stabilized temperature characteristics and the low-voltage driving are simultaneously realized.