Effect of hydrostatic pressure on the dc characteristics of AlGaN∕GaN heterojunction field effect transistors

We report the effect of compressive hydrostatic pressure on the current-voltage characteristics of AlGaN∕GaN heterojunction field effect transistors (HFETs) on a sapphire substrate. The drain current increases with hydrostatic pressure and the maximum relative increase occurs when the gate bias is near threshold and drain bias is slightly larger than saturation bias. The increase of the drain current is associated with a pressure induced shift of the threshold voltage by −8.0mV∕kbar that is attributed to an increase of the polarization charge density at the AlGaN∕GaN interface due to the piezoelectric effect. The results demonstrate the considerable potential of AlGaN∕GaN HFETs for strain sensor applications.

[1]  S. Denbaars,et al.  Polarization effects in AlGaN/GaN and GaN/AlGaN/GaN heterostructures , 2003 .

[2]  Wayne R. McKinney,et al.  Dependence of the fundamental band gap of AlxGa1−xN on alloy composition and pressure , 1999 .

[3]  K. Y. Tong,et al.  Numerical simulation of current–voltage characteristics of AlGaN/GaN HEMTs at high temperatures , 2005 .

[4]  Stephen J. Pearton,et al.  Gateless AlGaN/GaN HEMT response to block co-polymers , 2004 .

[5]  Mario G. Ancona,et al.  AlGaN/GaN heterostructure field-effect transistor model including thermal effects , 2000 .

[6]  Martin Eickhoff,et al.  Group III-nitride-based gas sensors for combustion monitoring , 2002 .

[7]  S. S. Park,et al.  Effects of hydrostatic and uniaxial stress on the Schottky barrier heights of Ga-polarity and N-polarity n-GaN , 2004 .

[8]  Oliver Ambacher,et al.  Evidence for nonlinear macroscopic polarization in III-V nitride alloy heterostructures , 2002 .

[9]  Fan Ren,et al.  Wide energy bandgap electronic devices , 2003 .

[10]  F. Bernardini,et al.  First-principles prediction of structure, energetics, formation enthalpy, elastic constants, polarization, and piezoelectric constants of AlN, GaN, and InN: Comparison of local and gradient-corrected density-functional theory , 2001 .

[11]  John C. Roberts,et al.  Pressure-induced changes in the conductivity of AlGaN∕GaN high-electron mobility-transistor membranes , 2004 .

[12]  C. Gaquière,et al.  Effects of high temperature on the electrical behavior of AlGaN/GaN HEMTs , 2002 .

[13]  Michael S. Shur,et al.  Gaas Devices And Circuits , 1987 .

[14]  Martin Eickhoff,et al.  Piezoresistivity of AlxGa1−xN layers and AlxGa1−xN/GaN heterostructures , 2001 .