Characterization of High Quality Continuous GaN Films Grown on Si-Doped Cracked GaN Template

Author:

Soh C. B.,Zhang J.,Chi D.Z.,Chua S. J.

Abstract

AbstractIn this paper, deep level defects in high quality continuous GaN films grown over a cracked Si-doped GaN template has been studied using digital deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). From TEM observation, it is found that the density of pure screw dislocations have been effectively suppressed while pure edge dislocations remained in substantial quantity. From DLTS measurement, trap levels at Ec -ET ∼ 0.11-0.12 eV, 0.24-0.27 eV, 0.60-0.63 eV were detected in the high quality GaN layer. DLTS measurement was also carried out on the underlying cracked Si-doped GaN template after the top high quality continuous GaN film was removed by plasma etching. An additional defect level at Ec-Et ∼ 0.37 eV was detected which we attributed to defect decoration at screw dislocation. Both the trap levels Ec-ET ∼ 0.24–0.27 eV, 0.60-0.63 eV are believed to originate from mixed screw/edge dislocation based on observation of the logarithmic capture behavior. Trap level at Ec -ET ∼ 0.24-0.27eV, however, experiences a more drastic increase in transient capacitance (i.e. in trap concentration) compared to that of Ec -ET ∼ 0.60-0.63 eV after plasma etching, illustrating that the latter is related to a higher proportion of edge dislocation. The 0.11-0.12 eV trap level, which exhibits an exponential capture kinetic, is believed to be related to nitrogen vacancies. This high quality continuous GaN layer can be used as a template to grow any device structure and the underneath cracked Si-doped GaN layer may help to release stress for the top continuous GaN layer. This can bring about a cracked free epilayer for subsequent device fabrication.

Publisher

Springer Science and Business Media LLC

Subject

General Engineering

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3