The effects of Xe irradiation on He and H co-implanted Si

Abstract

A combination of X-ray diffraction, cross-sectional transmission electron microscopy (XTEM), and Raman spectroscopy was used to study the effects of irradiation with swift heavy ions on helium and hydrogen co-implanted silicon.<100>-oriented silicon wafers were co-implanted with 30 keV helium to a dose of 3×10¹⁶He⁺/cm² and 24 keV protons to a dose of 2×10¹⁶ H⁺/cm². Moreover, selected helium and hydrogen co-implanted Si wafers were irradiated with 94 MeV xenon. After He and H co-implantation and Xe-irradiation, the wafers were annealed at a temperature of 673 K for 30 min. The damage region of the wafers was examined by the XTEM analysis. The results reveal that most of the platelets are aligned parallel to the (100) plane in the He and H co-implanted Si. However, majority of the platelets lie in<texlscub>111</texlscub>planes after Xe irradiation. Blisters do not occur on the sample surface after Xe irradiation. Raman results reveal that the intensities of both SiH₂ and V₂H₆ modes increase with the increase in the dose of Xe. A possible explanation is that strong electronic excitation during Xe irradiation produces annealing effect, which reduces both lattice damage and the out-of-plane tensile strain.

Keywords:

• H and He co-implantation
• Xe irradiation
• platelet
• strong electronic excitation

PACS :

• 61.80Jh
• 61.72Jd
• 61.72Uf

Acknowledgements

The authors acknowledge the support from National Natural Science Foundation of China (Grant Nos. 10979063 and 11015130) and National Basic Research Program of China (Grant No. 2010 CB832904).