Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (06): 841-845.doi: 10.3866/PKU.WHXB20070609

• ARTICLE • Previous Articles     Next Articles

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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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