Evolution of vacancy-like defects in helium-implanted (100) silicon studied by thermal desorption spectrometry

Thermal desorption spectrometry (TDS) has been applied to investigate the t hermal evolution of vacancy-like defects in helium-implanted (100) silicon samples with a dose of 2 x 10(16) cm(-2) at 20 keV. The measured spectra pr esent features which can be interpreted as fingerprints of the modification s occurring in the sample. The defects that are recognized which affect the desorption are: thermally unstable helium-vacancy complexes, pressurized g as bubbles organized in planar structures (cracks) and thermally stable cav ities. The attribution is supported by the results obtained by complementar y techniques, such elastic recoil detection, channeling Rutherford backscat tering spectrometry, cross sectional transmission electron microscopy and p ositron annihilation spectroscopy which have been employed on isothermally preannealed samples in the range 100-800 degrees C (C) 2000 Elsevier Scienc e S.A. All rights reserved.