%0 Journal Article
%T Investigation of temperature dependent threshold voltage variation of Gd2O3/AlGaN/GaN metal-oxide-semiconductor heterostructure
%A Atanu Das
%A Liann Be Chang
%A Ray Ming Lin
%J AIP Advances
%D 2012
%I AIP Publishing LLC
%R 10.1063/1.4750481
%X Temperature dependent threshold voltage (Vth) variation of GaN/AlGaN/Gd2O3/Ni-Au structure is investigated by capacitance-voltage measurement with temperature varying from 25¡ãC to 150¡ãC. The Vth of the Schottky device without oxide layer is slightly changed with respect to temperature. However, variation of Vth is observed for both as-deposited and annealed device owing to electron capture by the interface traps or bulk traps. The Vth shifts of 0.4V and 3.2V are obtained for as-deposited and annealed device respectively. For annealed device, electron capture process is not only restricted in the interface region but also extended into the crystalline Gd2O3 layer through Frenkel-Poole emission and hooping conduction, resulting in a larger Vth shift. The calculated trap density for as-deposited and annealed device is 3.28¡Á1011¡«1.12¡Á1011 eV 1cm 2 and 1.74¡Á1012¡«7.33¡Á1011 eV 1cm 2 respectively in measured temperature range. These results indicate that elevated temperature measurement is necessary to characterize GaN/AlGaN heterostructure based devices with oxide as gate dielectric.
%U http://link.aip.org/link/doi/10.1063/1.4750481