This work investigates the effect of Cl 2 / Ar dry etching on p-GaN. The root-mean-square ͑rms͒ surface roughness is measured, and the depth display ͑Bearing analysis͒ is monitored. The current-voltage characteristics of etched p-GaN with Ni ͑20 nm͒ /Au ͑20 nm͒ metallization are studied. Experimental results indicate that the etching rate does not increase significantly with the Cl 2 flow rate at a constant power or chamber pressure. The Bearing ratio data exhibit a much stronger variation with etch conditions, the rms displays the same trend but to a lesser extent.

This work investigates the temperature dependence of the current-voltage (I-V) characteristics of n-ZnO∕p-GaN junction diodes. The n-ZnO films were deposited on top of the p-GaN by dc sputtering with subsequent annealings at 500, 600, 700, and 800°C for 60s. The Hall measurement and the x-ray diffraction pattern are measured to study the n-ZnO films. The temperature sensitivity coefficients of the I-V characterizations are obtained by different substrate temperatures (25, 50, 100, and 150°C) and the extracted values are 2.10, 1.93, 3.22, and 1.36mV∕°C in the forward bias and 8.7, 8.0, 4.6, and 2.3mV∕°C in the reverse bias, respectively. The fabricated n-ZnO∕p-GaN diode with ZnO annealing temperatures at 800°C demonstrates the lowest temperature dependence.

This study investigated the temperature dependence of the current-voltage (I-V) characteristics of Al-doped MgxZn1-xO/p-AlGaN junction diodes. The n-type Al-doped MgxZn1-xO (AMZO) films were deposited on p-AlGaN using a radio-frequency (rf) magnetron sputtering system followed by annealing at 700, 800, and 900°C in a nitrogen ambient for 60 s. The n-AMZO/p-AlGaN diode at a substrate temperature of 25°C showed the lowest leakage current in reverse bias. The n-AMZO/p-AlGaN diode with an AMZO annealed at 900°C demonstrated the lowest reverse leakage current. The temperature sensitivity coefficients of the I-V characterizations were obtained at different substrate temperatures (25, 50, 75 100, and 125°C), providing extracted values of 6.4, 7.6, and 5.6 mV/°C in forward bias and −20, 5.6, and 0.8 mV/°C in reverse bias for the AMZO films annealed at 700, 800, and 900°C, respectively. The n-AMZO/p-AlGaN junction diode fabricated with AMZO annealed at 900°C demonstrated the lowest temperature dependence. In addition, the light emission was derived from the forward-biased junction, and near-ultraviolet light emission was evident at all of the p-n diodes. Based on these findings, the n-AMZO/p-AlGaN diodes are suitable for GaN-based heterojunction bipolar transistors (HBTs) and near-ultraviolet light-emitting diodes (LEDs).

No abstract

No abstract