Temperature Sensitivity of Silicon Cantilevers with the Pull-in Instability Method

Abstract

In this paper the temperature effect on [110] Silicon cantilevers is analyzed and measured in the range of 25 - 100°C. The quasi-static electrostatic pull-in instability method developed recently for ultra-thin cantilevers ["Characterizing Size-dependent Effective Elastic Modulus of Silicon Nanocantilevers Using Electrostatic Pull-in Instability", Applied Physics Letters, Vol. 94 (22), p. 221903, 2009] is employed to measure the temperature sensitivity of ultra-thin cantilevers. A temperature sensitivity of 81.3°C/V is obtained. the temperature sensitivity is mostly due to the temperature dependence of the effective Young's Modulus of silicon. It is shown that changes in geometrical dimensions due to the change in temperature can be neglected. The changes in the effective Young's Modulus due to the changes in temperture are extracted using an electromechanical-coupled system. The pull-in method showed substantial advantages over other methods used for the study of the thermal effects on micron and sub-micron structures. The results demonstrate a new concept for a temperature sensor with ultra high sensitivity.

Keywords: temperature sensitivity, pull-in instability, cantilever, nanoelectromechanical systems.