School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI 48202, USA
School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
: Received: 13 August 2016 / Approved: 13 August 2016 / Online: 13 August 2016 (10:47:16 CEST)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
How to cite:
Cao, G.; Wang, X.; Xu, Y.; Liu, S. A Micromachined Piezoresistive Pressure Sensor with a Shield Layer. Preprints2016, 2016080140 (doi: 10.20944/preprints201608.0140.v1).
Cao, G.; Wang, X.; Xu, Y.; Liu, S. A Micromachined Piezoresistive Pressure Sensor with a Shield Layer. Preprints 2016, 2016080140 (doi: 10.20944/preprints201608.0140.v1).
This paper presents a piezoresistive pressure sensor with a shield layer for improved stability. Compared with the conventional piezoresistive pressure sensors, p-type piezoresistors are covered by an n-type shield layer, which is formed by ion implantation. The proposed pressure sensors have been successfully fabricated by bulk micromachining techniques. The impact of electrical field on piezoresistors is studied by simulation. The temperature drift of the pressure sensor has been investigated by both simulation and experimental measurement. Characteristics of developed pressure sensors are tested from -40 C to 125 C. A sensitivity of 0.022 mV/V/KPa and a maximum non-linearity of 0.085% FS are measured for the fabricated sensor in a pressure range of 1 MPa. The temperature coefficients of resistance of shielded piezoresistors are found to be smaller than those of un-shielded ones. It is demonstrated that the shield layer is able to reduce the drift caused by electrical field and ambient temperature variation.