SiO_(2)图形化蓝宝石衬底对GaN生长及LED发光性能的影响

Effect of SiO_(2)Patterned Sapphire Substrate on GaN Growth and LED Luminescence Performance

为了提高氮化镓(GaN)基发光二极管(LEDs)的发光性能,采用等离子体增强化学气相沉积(PECVD)在蓝宝石衬底上沉积SiO_(2)薄膜,经过光刻和干法刻蚀技术制备了SiO_(2)图形化蓝宝石衬底(SiO_(2)patterned sapphire substrate,SPSS),利用LED器件的外延生长和微纳加工技术获得了基于SPSS的GaN基LED器件。通过分析GaN外延层晶体质量、光提取效率和LED器件性能,重点研究了SPSS对GaN生长及LED发光性能的影响。实验及模拟仿真结果表明,与常规图形化蓝宝石衬底(Conventional patterned sapphire substrate,CPSS)相比,SPSS上生长的GaN外延层位错密度较低,晶体质量较高,SPSS-LED的光提取效率提高26%、光输出功率和亮度均提高约5%。

To improve the luminescence performance of gallium nitride(GaN)-based light-emitting diodes(LEDs),a SiO_(2)film was deposited on sapphire substrates by the plasma-enhanced chemical vapor deposition(PECVD)in this study.After depositing the SiO_(2)film,a SiO_(2)patterned sapphire substrate(SPSS)was prepared through photolithography and dry etching,and a GaN-based LED device with SPSS was obtained by using epitaxial growth and micro-nano processing technology of the LED device.The effect of SPSS on the crystal quality of the GaN epitaxial layer,the light extraction efficiency,and the performance of the LED device were investigated.The experimental and simulation results show that,compared to the conventional patterned sapphire substrates(CPSS),the GaN epitaxial layer grown on SPSS had lower dislocation density and higher crystal quality,and the light extraction efficiency of SPSS-LED was increased by 26%,as well as that the light output power and brightness of SPSS-LED were both increased by about 5%.