摘要
采用两种不同的方法分别确定了在c面蓝宝石上用氢化物气相外延(HVPE)法生长的六方相的GaN厚膜中的位错密度。首先,利用选择性化学腐蚀方法研究了GaN膜中的晶体缺陷,研究区分了位错的不同类型,发现在HVPEGaN贯通位错占主导地位。由腐蚀后形成的腐蚀坑数量可以直接来确定膜中的位错密度。此外,研究了用特定的X射线衍射峰半峰宽数据计算得到位错密度的方法。结果表明,HVPE生长的六方相的GaN厚膜中的位错密度为109～1010cm-2,而且两种方法所得到的结果相符合。
The dislocation density in hexagonal GaN epitaxial layers grown on c-plane sapphire substrates by hydride vapor phase epitaxy(HVPE)was measured by two different methods.By means of defect-selective etching(orthodox etching in molten KOH),the dislocation defects in GaN epitaxial films were studied.From surface morphology pictures and cross-sectional images,these defects could be divided into various types.Among all the defects,threading dislocations(TDs)dominated in the GaN epilayers.The density of TDs could be directly determined by accounting the different etching pits after the specimen etched.On the other hand,the dislocation density was also derived from the full-width half-maximum(FWHM)of certain X-ray diffraction(XRD)peaks.The results show that the two individual methods are in good agreement with each other and the density of wurtizite GaN epitaxial layers grown by HVPE is in the order from 109 cm-2 to 1010 cm-2.
出处
《半导体技术》
CAS
CSCD
北大核心
2008年第S1期190-192,201,共4页
Semiconductor Technology
基金
国家"973"重点基础研究项目(2006CB6049)
国家"863"高技术研究发展计划(2006AA03A103
2006AA03A118
2006AA03Z411)
国家自然科学基金(60721063
60676057
60731160628
60710085
60776001
60820106003)
江苏省创新学者攀登项目(BK2008019)
南京大学研究生科研创新基金资助
