DAMAGE PROFILES IN AS-IMPLANTED [100]SI CRYSTALS - STRAIN BY X-RAY-DIFFRACTOMETRY VERSUS INTERSTITIALS BY RBS-CHANNELING

The strain versus interstitials correlation for as-implanted [100] sil icon crystal was studied comparing the strain profiles with the displa ced atom profiles and the strain integral with the total fraction of d isplaced atoms as measured by X-ray diffractometry and Rutherford back scattering-channeling spectrometry, respectively. Light/medium (B, N a nd O) and heavy (Si and As) mass ions at low (50 keV) and high (0.7 or 0.8 MeV) energy, low dose rate (less than or equal to 3 x 10(12) ion/ cm(2)/s) and fluences between 2 x 10(12) and 3 x 10(15) ion/cm(2) were implanted at room temperature and random incidence in [100] Si wafers . Independently of the ion energy two correlations between strain and displaced atoms can be given depending on the ion mass and the damage level. For light mass ions at low damage level (less than or equal to similar to 6%) a linear relation exists between strain and interstitia ls. For heavy mass ions at any damage level and for low mass ions at d amage level > similar to 6%, the correlation between strain and displa ced atoms is sublinear. Isochronal annealing treatments show that the predominant defects produced by high mass ions are different from thos e produced by low mass ions. Once interpreted in the frame of the elas tic theory of solid, the linear relation between strain and interstiti als may allow an evaluation of the relative volume increase per inters titial in silicon.