基于氮化镓单晶的垂直p-i-n二极管性能研究

Study on Vertical GaN p-i-n Diode Based on Free-standing GaN Substrates

摘要:

利用高质量自支撑GaN衬底,通过外延方法制备了垂直结构的GaN基p-i-n型二极管结构。通过对材料结构、杂质浓度分布以及对器件整流特性的研究,探究了影响垂直结构器件特性的关键因素。结果表明,在同质外延的制备过程中,衬底表面的粗糙程度将使制备的环形结构具有不规则形状,这种不规则电极对垂直结构器件的性能将产生不利影响；此外,多种杂质在界面处聚集,进而形成平面漏电通道,是降低器件耐压值的主要因素。

Abstract:

A GaN-based p-i-n diode with vertical structure was fabricated with epitaxial method by using high quality free-standing GaN substrate. Based on studing the material structure, impurity concentration and current-voltage characteristics, the key factors affecting the performance of the vertical structure device were analyzed. Experimental results indicate that the roughness of the surface will cause the irregular shape of the annular structure, which plats a negative effect on the ohmic contact and performance of the vertical structure device. In addition, during the growth process, a variety of impurities will gather at the interface and form a planar leakage channel, which will dominantly limit the performance of the device.