Pressure-induced changes in the conductivity of AlGaN∕GaN high-electron mobility-transistor membranes

• Published in: Applied physics letters Vol. 85; no. 14; pp. 2962 - 2964
• Main Authors: Kang, B. S., Kim, S., Ren, F., Johnson, J. W., Therrien, R. J., Rajagopal, P., Roberts, J. C., Piner, E. L., Linthicum, K. J., Chu, S. N.G., Baik, K., Gila, B. P., Abernathy, C. R., Pearton, S. J.
• Format: Journal Article
• Language: English
• Published: 04-10-2004
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1800282

AlGaN ∕ GaN high-electron-mobility transistors (HEMTs) show a strong dependence of source∕drain current on the piezoelectric-polarization-induced two-dimensional electron gas. The spontaneous and piezoelectric-polarization-induced surface and interface charges can be used to develop very sensitive but robust sensors for the detection of pressure changes. The changes in the conductance of the channel of a AlGaN∕GaN high electron mobility transistor (HEMT) membrane structure fabricated on a Si substrate were measured during the application of both tensile and compressive strain through changes in the ambient pressure. The conductivity of the channel shows a linear change of −(+)6.4×10−2mS∕bar for application of compressive (tensile) strain. The AlGaN∕GaN HEMT membrane-based sensors appear to be promising for pressure sensing applications.