Enhancing the Performance of MEMS Piezoresistive Pressure Sensor Using Germanium Nanowire

Abstract

Microelectromechanical systems (MEMS) have gained tremendous interest among researchers because of rapid development and wide variety of applications. The microsensors are the upcoming field that demand high sensitive devices which respond to the environmental changes. The paper describes the fabrication, designing and the performance analysis of a germanium material as a Piezoresistive MEMS pressure sensor. This pressure sensor uses double polysilicon germanium nanowires to increase the sensitivity of the pressure sensor. The pressure sensor uses circular diaphragm which was fabricated using Reactive Ion Etching method. The pressure sensor has a radius of about 500nm and thickness of about 10nm.The polysilicon nanowires form a bridge like appearance between the diaphragm and the substrate.Intellisuite software is extensively used to carry out the finite element analysis. Finite element method (FEM) is adopted to optimize the sensor output and to improve the sensitivity of the circular shaped diaphragm polysilicon germanium nano wire is used in place of the conventional piezoresistors. The optimum position is also analyzed to place the nanowire to get maximum output. The proposed double polysilicon germanium nanowire pressure sensor gave a sensitivity of about 9.1V/VK