Pressure and temperature dependence of GaN/AlGaN high electron mobility transistor based sensors on a sapphire membrane

M.J. Edwards (1) , S. Vittoz (2) , E. Le Boulbar (1) , G. Vanko (3, 4) , K. Brinkfeldt (5) , Libor Rufer (2) , P. Johander (5) , T. Lalinsky (4) , C.R. Bowen (1) , D.W.E. Allsopp (1)

1 University of Bath [Bath]
2 TIMA - Techniques de l'Informatique et de la Microélectronique pour l'Architecture des systèmes intégrés
3 Institute of Electrical Engineering, SAS Bratislava
4 Institute of Electrical Engineering
5 Swerea IVF

This paper reports a high pressure sensor based on a GaN/AlGaN High Electron Mobility Transistor (HEMT) that uses its 375 mm thick sapphire substrate to provide a robust base and enables device operation up to at least 60 bar (6 MPa). Transduction of changes in ambient pressure occurs via piezoelectric and pyroelectric effects on the channel conductance. The HEMTs were strategically placed along an 8 mm2 GaN/AlGaN/GaN/sapphire chip; where the central 4 mm diameter behaves as a pressure sensitive 'drumskin'. The location of peak response lies in the HEMT at the geometric centre of the drumskin, demonstrated by the change in IDS when the pressure was increased from 0 to 60 bar. The response of six strategically placed HEMTs along the chip's surface, were compared to a finite element model to predict sensor behaviour.

Mots clés: sensors; temperature-sensors; piezoelectricity; AlGaN/GaN

Domaines: Micro et nanotechnologies/Microélectronique

M.J. Edwards, S. Vittoz, E. Le Boulbar, G. Vanko, K. Brinkfeldt, et al.. Pressure and temperature dependence of GaN/AlGaN high electron mobility transistor based sensors on a sapphire membrane. physica status solidi (c), 2012, 9 (3-4), pp.960-963. ⟨10.1002/pssc.201100371⟩. ⟨hal-00817852⟩