蓝宝石基无极性GaN薄膜外延生长及LED器件研究

项目名称： 蓝宝石基无极性GaN薄膜外延生长及LED器件研究

项目编号： No.60806017

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 彭冬生

作者单位： 深圳大学

项目金额： 21万元

中文摘要： 本项目从发展高发光功率GaN基LED出发，为了消除C面GaN材料的极化效应，围绕在R面蓝宝石衬底上，无极性GaN薄膜材料外延生长的技术问题，研究、探索提高无极性GaN薄膜材料生长质量的新方法、新技术以及光电器件制备中的关键基础技术。 由于在R面蓝宝石衬底生长的A面GaN薄膜的位错密度和堆垛层错密度较高，结晶质量较差。如何进一步降低无极性GaN外延膜的位错密度，提高其晶体质量是本项目的研究重点。针对无极性GaN外延膜高位错密度的问题，基于横向外延生长原理，并结合MOCVD薄膜生长技术，采用化学方法处理R面蓝宝石衬底表面，以形成一定的图案，然后在此一定图案的R面蓝宝石衬底上外延生长出高质量的无极性GaN薄膜；随后，优化外延生长工艺参数，进一步降低位错密度，生长出更高质量的无极性GaN薄膜，并在此基础上外延生长出高效无极性GaN基LED外延片。

中文关键词： 表面处理；R面蓝宝石；无极性GaN；LED

英文摘要： Generally, GaN films are grown on the c-plane substrate, which leads to the huge built-in electrostatic field resulted from intrinsic spontaneous and extrinsic piezoelectric polarization. The study focuses mainly on the non-polar GaN films growth on the r-plane substrate in order to improve the luminescence power of GaN based light-emitting diodes (LEDs). The new method, new technology and key basic technique are explored to improve the quality of non-polar GaN films. Unlike conventional epitaxial growth of c-plane GaN, a-plane GaN films grown on r-plane sapphire contain high densities of dislocation and stacking faults. High quality non-polar GaN films with low dislocation density grown on the r-plane sapphire substrate are the emphasis of the study. In the study, high quality non-polar GaN films with low dislocation density have been successfully grown on the r-plane sapphire substrate by metal-organic chemical vapor-phase deposition (MOCVD) based on the mechanism of the epitaxial lateral overgrowth (ELO), which the substrate is treated chemically. The dislocation density of non-polar GaN films is decreased again by optimizing epitaxial parameter. The high brightness non-polar GaN-based LEDs can be successfully grown on the r-plane sapphire substrate on the study.

英文关键词： Surface treated; R-plane sapphire; Non-polar GaN; LED