Quantitative Analysis of MEMS Piezoresistive Pressure Sensors Based on Wide Band Gap Materials

Abstract

Wide band gap materials such as silicon carbide and diamond are considered more suitable compared to silicon for the fabrication of piezoresistive pressure sensors for operation at high temperatures. We have carried out extensive FEM simulation study for theoretically assessing the response of pressure sensors incorporating these wide band gap materials. Response of sensors incorporating silicon micromachined diaphragm with oxide isolated piezoresistors of diamond or silicon carbide was studied using FEM simulations. The study was further extended for sensors incorporating diaphragm as well as piezoresistors of diamond or silicon carbide. The results in both cases were compared with those obtained for a single crystal or polycrystalline piezoresistor-based silicon pressure sensor. The results presented in this paper demonstrate that among the materials studied in this work, diamond-based sensors will have the least pressure sensitivity compared to silicon carbide or silicon-based sensors. However, considering the nonlinearity of response, diamond-based sensors will have the minimum nonlinearity of pressure response compared to silicon-based pressure sensors. Hence for the same nonlinearity, it would be possible to operate the diamond-based sensors up to much higher pressures.

KEYWORDS:

• High temperature sensors
• MEMS pressure sensors
• MEMS technology
• MEMS
• Piezoresistivity
• Wide band gap materials

Additional information

Notes on contributors

Vinod Belwanshi

Vinod Belwanshi received MTech degree in instrumentation engineering from Department of Electrical Engineering, Indian Institute of Technology, Kharagpur, West Bengal, India, in 2012. He is currently pursuing PhD degree in instrumentation engineering from Homi Bhabha National Institute, Mumbai, India. His current research is focused on design, optimization, simulation, and characterization of MEMS devices. Email: [email protected]

Anita Topkar

Anita Topkar received MTech (Control & Instrumentation) degree in 1987 and PhD in microelectronics in electrical engineering in 1995 from Indian Institute of Technology, Bombay. She is working as a scientific officer at Electronics Division, Bhabha Atomic Research Centre, Mumbai, India, and is also a faculty at Homi Bhabha National Institute, Mumbai, India. Her research interests include design, fabrication technology, and instrumentation for semiconductor-based sensors and MEMS.