A highly sensitive CMOS compatible thermal-type microsensor

Abstract

A CMOS compatible thermal-type microsensor was fabricated with large sensitive area and ultra-low solid thermal-conductance. To reach high performance, a floating circular membrane with diameter, 460 mu m and lead length, 393 mu m, was formed after anisotropic etching the silicon substrate. The large membrane is well supported with four curved leads, which greatly release the residual stress. The highly sensitivity is reached by the extremely low solid conductance (10(-6) W/C), which is lower than the published data; the large active area give better response than other works. Output voltage versus frequency was measured and thermal conductance was characterized by DC method.