The changes in the capacitance of the channel of an 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 capacitance of the channel displays a change of 7.19±0.45 × 10 -3 pF/μm as a function of the radius of the membrane at a fixed pressure of +9.5 bar and exhibits a linear characteristic response between -0.5 and +1 bar with a sensitivity of 0.86 pF/bar for a 600 μm radius membrane. The hysteresis was 0.4% in the linear range. These AlGaN/GaN HEMT membrane-based sensors appear to be promising for both room-temperature and elevated-temperature pressure-sensing applications.
Bibliographical noteFunding Information:
The work at UF is partially supported by AFOSR (F49620-02-1-0366, G. Witt, and F49620-03-1-0370), NSF (CTS-0301178, monitored by Dr. M. Burka and Dr. D. Senich), by NASA Kennedy Space Center Grant NAG 10-316 monitored by Mr. Daniel E. Fitch, ONR (N00014-98-1-02-04, H. B. Dietrich), and NSF DMR 0400416 (L. Hess).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)