半极性面GaN基偏振光LED外延技术及性能研究

项目名称： 半极性面GaN基偏振光LED外延技术及性能研究

项目编号： No.61274041

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 汪连山

作者单位： 中国科学院半导体研究所

项目金额： 80万元

中文摘要： 随着宽带隙GaN基材料生长技术和芯片制造技术的突破，以GaN基蓝光LED激发黄色荧光粉制成的白光LED已经成为主要半导体照明光源。为了进一步提高白光LED发光效率，需要大幅减少材料内的缺陷密度和消除极化电场对LED发光效率的影响,为此，制造非极性或半极性面GaN基LED是其选项之一。本项目旨在利用m面图形蓝宝石衬底的凸凹结构抑制缺陷生成和提高LED取光效率，实现低成本(11-22) 半极性面GaN基偏振光LED。通过衬底表面处理和AlN缓冲层的协同作用，控制半极性面GaN的外延生长取向，通过分步外延生长，揭示图形衬底外延生长过程以及图形尺寸、形状对缺陷生成及抑制机理。研究LED外延层结构设计、外延各工艺因素对半极性面LED性能的影响机理，揭示半极性面LED的偏振特性。这种偏振光LED因其更节能，将极具潜力作为液晶显示背光源。

中文关键词： (11-22)半极性氮化物；各项异性；微结构缺陷；蓝;绿光LED；光偏振特性

英文摘要： With the breakthrough of III-nitrides' growth and chip fabrication technologies, white light emitting diodes (LEDs), based on the GaN-based blue LEDs exciting the yellow phosphors, become gradually an important illumination source. In order to further enhance the luminous efficacy of white LEDs, it is necessary to largely cut down the defect density in materials and to lower down or avoid influence of the polarization electric field on the LED performance. Therefore, it is one choice to fabricate the nonpolar or semipolar GaN-based LEDs. This project will focus on the achievement about the (11-22) semi-polar polarized GaN-based LEDs on m-plane patterned sapphire substrate (PSS) with the cost-effectiveness. We will take an advantage of the microstructures on PSS surfaces to reduce the defect formation during the GaN growth and to enhance the extraction efficiency of GaN-based LEDs. The (11-22) growth orientation will be controlled by the combination of the treatment to sapphire substrate surfaces and the utilities of AlN buffer layers. We will aslo study the growth process of the semipolar GaN via the stepwise growth, and show the influence of the pattern sizes and shapes on the formation and suppression of micro-structural defects. At the same time, we will also investigate the effects of LED layer structures an

英文关键词： (11-22) semiploar nitrides；in-plane anisotropy；microstructural defects；blue and green LED；light polarized properties