COMPARATIVE INVESTIGATION OF DAMAGE-INDUCED BY DIATOMIC AND MONOATOMIC ION-IMPLANTATION IN SILICON

The damaging effect of mono- and diatomic phosphorus and arsenic ions implanted into silicon was investigated by spectroscopic ellipsometry (SE) and high-depth-resolution Rutherford backscattering and channelin g techniques. A comparison was made between the two methods to check t he capability of ellipsometry to examine the damage formed by room tem perature implantation into silicon. For the analysis of the spectrosco pic ellipsometry data we used the conventional method of assuming appr opriate optical models and fitting the model parameters (layer thickne sses and volume fractions of the amorphous silicon component in the la yers) by linear regression. The depth dependence of the damage was det ermined by both methods. It was revealed that SE can be used to invest igate the radiation damage of semiconductors together with appropriate optical model construction which can be supported or independently ch ecked by the channeling method. However, in case of low level damage ( consisting mainly of isolated point defects) ellipsometry can give fal se results, overestimating the damage using inappropriate dielectric f unctions. In that case checking by other methods like channeling is de sirable.