SiO[sub 2]/Gd[sub 2]O[sub 3]/GaN Metal Oxide Semiconductor Field Effect Transistors

Abstract

GaN-based metal oxide semiconductor field effect transistors ͑MOSFETs͒ were demonstrated using a stacked gate oxide consisting of single-crystal Gd 2 O 3 and amorphous SiO 2 . Gd 2 O 3 provides a good oxide/semiconductor interface and SiO 2 reduces the gate leakage current and enhances oxide breakdown voltage. Charge modulation of the n-channel depletion mode MOSFET was achieved for gate voltage from ϩ2 to Ϫ4 V. The source-drain breakdown voltage exceeded 80 V. An intrinsic transconductance of 61 mS/mm was obtained at a gate-source and drain-source bias of Ϫ0.5 and 20 V, respectively. This is the first demonstration of epitaxial Gd 2 O 3 growth on GaN and the first use of Gd 2 O 3 as an insulating layer for nitride electronic device applications.

Recent advances in wide bandgap semiconductor-based gas sensors

“…The gate area of the HEMT can be used to modulate the drain current in the FET mode or for use as the electrode for the Schottky diode. A variety of gas, chemical and health-related sensors based on HEMT technology have been demonstrated with proper surface functionalization on the gate area of the HEMTs, including the detection of hydrogen, mercury ion, prostate specifi c antigen (PSA), DNA and glucose (Lothian et al, 1992;Luther et al, 1999;Johnson et al, 2000;Schalwig et al, 2002b;Eickhoff et al, 2003;Kim et al, 2003a;Mehandru et al, 2004;Pearton et al, 2004;Shen et al, 2004;Kang et al, 2004aKang et al, , 2004bKouche et al, 2005;Kryliouk et al, 2005;Tien et al, 2005aTien et al, , 2005bWang et al, 2005aWang et al, , 2005bWang et al, , 2005cKang et al, 2005bKang et al, , 2005cKang et al, 2006;Wang et al, 2006;Gangwani et al, 2007;Jun et al, 2007;Pearton et al, 2007;Kang et al, 2007aKang et al, , 2007bKang et al, , 2007cWang et al, , 2007cChen et al, 2008;Johnson et al, 2009;Yu et al, 2008;Wright et al, 2009).…”

High-Performance 1-$\mu\hbox{m}$ GaN n-MOSFET With MgO/MgO–$\hbox{TiO}_{2}$ Stacked Gate Dielectrics

“…MgO with a dielectric constant of 9.8, a large bandgap of 8 eV, a small lattice mismatch of 6.5% on GaN, and a lower interface trap density of 4 × 10 11 eV −1 cm −2 derived by the conductance method [4] is promising. Meanwhile, the normally off GaN MOSFETs with gate dielectrics as Gd 2 O 3 [5], MgO [6], and SiO 2 [7] show high OFF-state leakage current and nonsaturating behavior. It could be from the positive charges at the dielectrics/GaN interface [8], which in turn could be associated with the fixed charges induced by the native oxide on GaN surface.…”

Effect of Proton Irradiation on Interface State Density in Sc2O3/GaN and Sc2O3/MgO/GaN Diodes

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The use of high-quality oxide or dielectric films can reduce high gate leakage at elevated temperatures and current collapse in HEMTs. [18][19][20][21][22][23][24][25][26] This metal-oxide semiconductor-heterostructure field effect transistor (MOS-HFET) approach is attractive, but the stability of the structures to radiation environments must be established because some of the proposed applications include nuclear industry monitoring and satellite-based, broad-band communication in weather forecasting systems. The EarthÕs magnetosphere is bombarded by a nearly isotropic flux of energetic charged particles-85% protons, 14% alpha-particles, and 1% heavier ions covering the full range of elements.…”