中国物理B ›› 2014, Vol. 23 ›› Issue (4): 47804-047804.doi: 10.1088/1674-1056/23/4/047804

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Improvement in a-plane GaN crystalline quality using wet etching method

曹荣涛, 许晟瑞, 张进成, 赵一, 薛军帅, 哈微, 张帅, 崔培水, 温慧娟, 陈兴   

  1. Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2013-05-04 修回日期:2013-08-22 出版日期:2014-04-15 发布日期:2014-04-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 61204006), the Fundamental Research Funds for the Central Universities, China (Grant No. K50511250002), and the National Key Science & Technology SpecialProject, China (Grant No. 2008ZX01002-002).

Improvement in a-plane GaN crystalline quality using wet etching method

Cao Rong-Tao (曹荣涛), Xu Sheng-Rui (许晟瑞), Zhang Jin-Cheng (张进成), Zhao Yi (赵一), Xue Jun-Shuai (薛军帅), Ha Wei (哈微), Zhang Shuai (张帅), Cui Pei-Shui (崔培水), Wen Hui-Juan (温慧娟), Chen Xing (陈兴)   

  1. Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2013-05-04 Revised:2013-08-22 Online:2014-04-15 Published:2014-04-15
  • Contact: Zhang Jin-Cheng E-mail:jchzhang@xidian.edu.cn
  • About author:78.55.Cr; 81.15.Kk
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 61204006), the Fundamental Research Funds for the Central Universities, China (Grant No. K50511250002), and the National Key Science & Technology SpecialProject, China (Grant No. 2008ZX01002-002).

摘要: Nonpolar (112 0) GaN films are grown on the etched a-plane GaN substrates via metalorganic vapor phase epitaxy. High-resolution X-ray diffraction analysis shows great decreases in the full width at half maximum of the samples grown on etched substrates compared with those of the sample without etching, both on-axis and off-axis, indicating the reduced dislocation densities and improved crystalline quality of these samples. The spatial mapping of the E2 (high) phonon mode demonstrates the smaller line width with a black background in the wing region, which testifies the reduced dislocation densities and enhanced crystalline quality of the epitaxial lateral overgrowth areas. Raman scattering spectra of the E2 (high) peaks exhibit in-plane compressive stress for all the overgrowth samples, and the E2 (high) peaks of samples grown on etched substrates shift toward the lower frequency range, indicating the relaxations of in-plane stress in these GaN films. Furthermore, room temperature photoluminescence measurement demonstrates a significant decrease in the yellow-band emission intensity of a-plane GaN grown on etched templates, which also illustrates the better optical properties of these samples.

关键词: nonpolar GaN, wet etching, metal-organic chemical vapor deposition, crystalline quality

Abstract: Nonpolar (112 0) GaN films are grown on the etched a-plane GaN substrates via metalorganic vapor phase epitaxy. High-resolution X-ray diffraction analysis shows great decreases in the full width at half maximum of the samples grown on etched substrates compared with those of the sample without etching, both on-axis and off-axis, indicating the reduced dislocation densities and improved crystalline quality of these samples. The spatial mapping of the E2 (high) phonon mode demonstrates the smaller line width with a black background in the wing region, which testifies the reduced dislocation densities and enhanced crystalline quality of the epitaxial lateral overgrowth areas. Raman scattering spectra of the E2 (high) peaks exhibit in-plane compressive stress for all the overgrowth samples, and the E2 (high) peaks of samples grown on etched substrates shift toward the lower frequency range, indicating the relaxations of in-plane stress in these GaN films. Furthermore, room temperature photoluminescence measurement demonstrates a significant decrease in the yellow-band emission intensity of a-plane GaN grown on etched templates, which also illustrates the better optical properties of these samples.

Key words: nonpolar GaN, wet etching, metal-organic chemical vapor deposition, crystalline quality

中图分类号:  (III-V semiconductors)

  • 78.55.Cr
81.15.Kk (Vapor phase epitaxy; growth from vapor phase)