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

• The first n-InGaN/p-Si hetero-junction diode with InGaN grown by sputtering w/o AlN
• The smallest turn-on voltage of 1.4 V was found for n-In0.4Ga0.6N/p-Si diode.
• The largest breakdown voltages above 20 V were observed for all n-InGaN/p-Si diode.
• The thermal stability in electrical properties of diodes was tested up to 150 °C.
• Our n-InGaN/p-Si diodes have the potential for cost-effective power electronics.

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 2.1 V, 6.2 for n-GaN/p-Si, 1.8 V, 5.2 for n-In0.15Ga0.85N/p-Si, and 1.4 V, 4.3 for n-In0.4Ga0.6N/p-Si, respectively. In addition, with a 1 mm2 contact of all devices, the current densities at 20 V and the leakage current densities at − 5 V were calculated to be 0.183 and 5.96 × 10− 5 A·cm− 2 for n-GaN/p-Si, 0.303 and 8.05 × 10− 5 A·cm− 2 for n-In0.15Ga0.85N/p-Si, and 0.513 and 2.81 × 10− 4 A·cm− 2 for n-In0.4Ga0.6N/p-Si. Our three devices strongly sustained under reverse bias and showed the breakdown voltage beyond 20 V. 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.