Positron beam study of low-temperature-grown GaAs with aluminum delta layers
文献类型：期刊论文
| 作者 | Fleischer, S; Hu, YF; Beling, CD; Fung, S; Smith, TL; Moulding, KM; Weng, HM; Missous, M |
| 刊名 | APPLIED SURFACE SCIENCE
 |
| 出版日期 | 1999-08-01 |
| 卷号 | 149页码:159-164 |
| 关键词 | positron beam low-temperature-grown GaAs aluminum delta layers |
| ISSN号 | 0169-4332 |
| 英文摘要 | We report on the use of a slow-positron beam to examine aluminium delta layers in GaAs grown at low substrate temperature (250 degrees C) by molecular beam epitaxy (LTMBE). It is now established that LTMBE-GaAs contains an excess of arsenic which causes an increase in the lattice parameter. After annealing, this arsenic is redistributed and forms precipitates resulting in the relaxation of the lattice. Previous positron beam studies have shown that the as-grown material has a large concentration of gallium vacancies, and after annealing the S-parameter increases above the as-grown value indicating that vacancy clusters have formed. A region depleted of arsenic precipitates has been shown to form near to aluminium delta layers, and this work is the first to study the vacancy distribution associated with this depletion region. We observe that the as-grown material has a peak value of the normalized S-parameter that is similar to 3.5% higher than the substrate, which is much larger than that for a single layer LT-GaAs structure (0.8-1.5%). After annealing in the range 600-800 degrees C the S-parameter collapses down to the substrate, value, which again is opposite to the LT-GaAs case and indicates that few precipitates have formed. We correlate these findings with SIMS and TEM data and propose a mechanism involving compositional disordering due to the aluminium layers. (C) 1999 Elsevier Science B.V. All rights reserved. |
| WOS关键词 | EPITAXY ; DEFECTS |
| WOS研究方向 | Chemistry ; Materials Science ; Physics |
| 语种 | 英语 |
| WOS记录号 | WOS:000082445300032 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://119.78.100.186/handle/113462/35912]  |
| 专题 | 中国科学院近代物理研究所 |
| 通讯作者 | Fleischer, S |
| 作者单位 | 1.Univ Hong Kong, Dept Phys, Hong Kong, Peoples R China 2.Hong Kong Univ Sci & Technol, Mat Characterisat & Preparat Facil, Hong Kong, Peoples R China 3.Univ Sci & Technol China, Acad Sinica, Dept Modern Phys, Hefei, Peoples R China 4.Univ Manchester, Inst Sci & Technol, Ctr Elect Mat, Manchester M60 1QD, Lancs, England 5.Univ Manchester, Inst Sci & Technol, Dept Elect Engn & Elect, Manchester M60 1QD, Lancs, England |
| 推荐引用方式 GB/T 7714 | Fleischer, S,Hu, YF,Beling, CD,et al. Positron beam study of low-temperature-grown GaAs with aluminum delta layers[J]. APPLIED SURFACE SCIENCE,1999,149:159-164. |
| APA | Fleischer, S.,Hu, YF.,Beling, CD.,Fung, S.,Smith, TL.,...&Missous, M.(1999).Positron beam study of low-temperature-grown GaAs with aluminum delta layers.APPLIED SURFACE SCIENCE,149,159-164. |
| MLA | Fleischer, S,et al."Positron beam study of low-temperature-grown GaAs with aluminum delta layers".APPLIED SURFACE SCIENCE 149(1999):159-164. |
入库方式： OAI收割
来源：近代物理研究所
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