8-BEAM PIEZORESISTIVE ACCELEROMETER FABRICATED BY USING A SELECTIVE POROUS-SILICON ETCHING METHOD

This paper presents the first experimental results of a piezoresistive silicon accelerometer with eight beams fabricated by a unique silicon micromachining technique using selective porous-silicon etching. This technique is capable of precisely constructing a microstructure witho ut any lateral etching or undercutting. By the use of this eight-beam structure, the mechanical strength of the accelerometer can be highly improved due to smaller shear stress. The lower sensitivity of the sen sor can be simply solved by combining the four output signals of the h alf-bridge. The effectiveness of the sensor is confirmed through an ex periment in which the accelerometer is characterized. (C) 1998 Elsevie r Science S.A. All rights reserved.