Electrical Characterization of RF Reactive Sputtered p–Mg-In_xGa_1−xN/n–Si Hetero-Junction Diodes without Using Buffer Layer

The modeling of p–In_xGa_1−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-In_0.05Ga_0.95N were deposited directly on the n–Si (100) wafer by the RF reactive sputtering at 400 °C with single cermet targets. Al and Pt with the square size of 1 mm² were used for electrodes of p–In_xGa_1−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 × 10¹⁶ cm⁻³ and µ = 145 cm²/V·s for p–GaN film, N_p = 2.53 × 10¹⁷ cm⁻³, and µ = 45 cm²/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 × 10⁻⁷ A and 2.4 V for p–GaN/n–Si and 3.38 × 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 °C. By calculating based on the TE mode, Cheungs’ and Norde methods, and other parameters of diodes were also determined and compared. View Full-Text