物理化学学报 >> 2007, Vol. 23 >> Issue (06): 841-845.doi: 10.3866/PKU.WHXB20070609

研究论文 上一篇    下一篇

Si(001)表面分子束外延生长的小尺寸Ge量子点

王科范; 刘金锋; 刘忠良; 徐彭寿; 韦世强   

  1. 河南大学物理与电子学院微系统物理研究所, 河南 开封 475001; 中国科学技术大学国家同步辐射实验室, 合肥 230029

  • 收稿日期:2006-12-18 修回日期:2007-01-15 发布日期:2007-06-04
  • 通讯作者: 徐彭寿 E-mail:psxu@ustc.edu.cn

Small-size Ge/Si(001) Quantum Dots Grown by Molecular Beam Epitaxy

WANG Ke-Fan; LIU Jin-Feng; LIU Zhong-Liang; XU Peng-Shou; WEI Shi-Qiang   

  1. Institute of Physics for Microsystem, School of Physics and Electronics, Henan University, Kaifeng 475001, Henan Province, P. R. China; National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China

  • Received:2006-12-18 Revised:2007-01-15 Published:2007-06-04
  • Contact: XU Peng-Shou E-mail:psxu@ustc.edu.cn

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摘要：

通过调节生长参数, 在Si(001)衬底表面利用分子束外延(MBE)方法生长得到尺寸小于10 nm的高密度Ge量子点. 扩展的X射线吸收精细结构(EXAFS)的研究结果表明, 在500 ℃和550 ℃制备的小尺寸量子点内, GeSi合金的含量分别为75%和80%. 经热力学分析, 在量子点生长完成后的退火过程中, 可能存在Si原子从衬底表面向量子点表面扩散, 并和Ge原子通过表面偏析发生混合的过程. 另一方面, 小尺寸量子点较高的高宽比, 也会导致形成较高含量的GeSi合金.

关键词: Ge量子点, 扩展的X射线精细吸收结构, 互扩散

Abstract:

High density of Ge quantumdots (QDs) with size of less than 10 nmwere obtained on Si(001) surface by optimizing the growth parameters. The results of extended X-ray absorption fine structure (EXAFS) showed that the contents of GeSi alloy in these QDs fabricated at 500 ℃ and 550 ℃ were 75% and 80%, respectively. According to thermodynamics analysis, it was believed that during the annealing process after the QDs’ growth, Si atoms might diffuse fromthe substrate surface to the QDs surface, then intermix with Ge atoms by surface segregation. On the other hand, the higher height/diameter ratio might also induce high content of GeSi alloy in small size of Ge QDs.

Key words: Ge quantumdots, Extended X-ray absorption fine structure, Diffusing