Abstract
One of the significant problems that we must challenge is that energy crisis in the near future. Concerning gallium nitride that has direct energy gap and wide bandgap, it has a decent photoelectric conversion efficiency and process stability. Currently in the market has produced light emitting diode (LED), ultraviolet photodetector (UV Photodetector), and other related devices with gallium nitride. In addition, another superiority of gallium nitride such as the electron saturation velocity, critical electric field, and good thermal conductivity etc., are beneficial for high-power or high-frequency devices. In the field of high power device, P-i-N junction diode, schottky barrier diode (SBD), and high electron mobility transistor (HEMT) are most promising device lately. This experiment is mainly used P-i-N junction diode with gallium nitride on sapphire to discuss. We currently make use of the Baliga's figure of merits to determine the characteristics of the power device, and it uses the reverse breakdown voltage squared divided by turn-on resistance obtained figure of merits. In this study, we utilize the improved inductively coupled plasma ion etching system to adjust the different process parameters to classify into six categories based on the severity of the sidewall damage. To sum up, we find out with the improved inductively coupled plasma ion etching system at the RF power 200 (W), DC bias 10 (W), chamber pressure 0.5 (Pa), and used aluminum oxide substrate, so that we can get the most smooth etching sidewall and the best electrical characteristics of performance. Keywords：power device, inductively coupled plasma ion etching, gallium nitride