Electrical Characterization of RF Reactive Sputtered p-Mg-InxGa1-xN/n-Si Hetero-Junction Diodes without Using Buffer Layer

The modeling of p-InxGa1-xN/n-Si hetero junction diodes without using the buffer layer were investigated with the "top-top" electrode. The p-Mg-GaN and p-Mg-In0.05Ga0.95N were deposited directly on the n-Si (100) wafer by the RF reactive sputtering at 400 degrees C with single cermet targets. Al and Pt with the square size of 1 mm(2) were used for electrodes of p-InxGa1-xN/n-Si diodes. Both devices had been designed to prove the p-type performance of 10% Mg-doped in GaN and InGaN films. By Hall measurement at the room temperature (RT), the holes concentration and mobility were determined to be N-p = 3.45 x 10(16) cm(-3) and mu = 145 cm(2)/V.s for p-GaN film, N-p = 2.53 x 10(17) cm(-3), and mu = 45 cm(2)/V.s for p-InGaN film. By the I-V measurement at RT, the leakage currents at -5 V and turn-on voltages were found to be 9.31 x 10(-7) A and 2.4 V for p-GaN/n-Si and 3.38 x 10(-6) A and 1.5 V for p-InGaN/n-Si diode. The current densities at the forward bias of 20 V were 0.421 and 0.814 A.cm(-2) for p-GaN/n-Si and p-InGaN/n-Si devices. The electrical properties were measured at the temperature range of 25 to 150 degrees C. By calculating based on the TE mode, Cheungs' and Norde methods, and other parameters of diodes were also determined and compared.