Temperature dependence of electrical characteristics of n-InxGa1 − xN/p-Si hetero-junctions made totally by RF magnetron sputtering

Abstract

The n-InxGa1−xN/p-Si hetero-junction diodes including their semiconductors and electrodes were grown directly on p-Si (100) wafer by magnetron sputtering. Targets for n-InxGa1−xN films with x=0, 0.15, and 0.4 were made by hot pressing with the mixture of metallic and nitride powders. SEM, AFM, and Hall measurement were carried out to analyze the surface morphology, topography, and electrical property of the n-InxGa1−xN films. Temperature dependent transport behavior of n-InxGa1−xN/p-Si hetero-junction diodes was determined by the I–V analyses. After measurements at room temperature, the turn-on voltage and ideality factor were determined to be 2.1V, 6.2 for n-GaN/p-Si, 1.8V, 5.2 for n-In0.15Ga0.85N/p-Si, and 1.4V, 4.3 for n-In0.4Ga0.6N/p-Si, respectively. In addition, with a 1mm2 contact of all devices, the current densities at 20V and the leakage current densities at −5V were calculated to be 0.183 and 5.96×10−5A·cm−2 for n-GaN/p-Si, 0.303 and 8.05×10−5A·cm−2 for n-In0.15Ga0.85N/p-Si, and 0.513 and 2.81×10−4A·cm−2 for n-In0.4Ga0.6N/p-Si. Our three devices strongly sustained under reverse bias and showed the breakdown voltage beyond 20V. The variations of electrical properties with the test temperature were also investigated up to 150°C. The barrier height, ideality factor, and series resistance of all hetero-junction diodes were also calculated by using equations based on the standard thermionic-emission (TE) mode and Cheung's method.