GaN外延用蓝宝石衬底的图形化研究进展

因蓝宝石具有良好的稳定性能,且其生产技术成熟,是目前异质外延GaN应用最广泛的衬底材料之一.采用图形化蓝宝石衬底技术可以降低GaN外延层材料的位错密度,提高LED的内量子效率,同时提高LED出光效率提高,近年来引起了国内外的广泛关注.概述了图形化蓝宝石衬底的研究进展,包括图形化蓝宝石衬底的制备工艺、图形尺寸、图形形状及图形化蓝宝石衬底的作用机理;详细介绍了凹槽状、圆孔状、圆锥形、梯形和半球状5种图形形状,并分析了GaN材料在不同图形形状的图形化蓝宝石衬底上的生长机理及不同图形形状对GaN基LED器件性能的影响.对图形化蓝宝石衬底技术的研究方向进行了展望,提出了亟待研究和解决的问题.

Research Progress of Patterned Sapphire Substrates for GaN Epitaxial

Sapphire is one of the most widely used substrate materials for heteroepitaxial GaN due to its good stability and mature production technology.The patterned sapphire substrate technology can reduce the dislocation density of GaN epitaxial layer materials,improve the internal quantum efficiency and the luminous efficiency of LED.In recent years,it has attracted domestic and overseas attentions.The research progress of patterned sapphire substrate is reviewed,including the fabrication methods,patternsize,pattern-shape and mechanism for patterned sapphire substrate.Five kinds of shapes are introduced,such as groove-shaped,hole-shaped,cone-shaped,trapezoid-shaped and hemisphere-shaped.The growth mechanism of GaN material grown on different shapes of patterned sapphire substrate and the effects of different shapes on the performance of GaN-based LED devices are analyzed.The research direction of patterned sapphire substrate technology is prospected,and the research problems which need to be solved urgently are put forward.