Superadditivity in the Implantation of Molecular Ions

This paper deals with the implantation of molecular ions in silicon. The ‘molecular’ effect, i.e. the increase of the displacement yield compared with the sum of the atomic yields, is weak for light molecules (e.g., H2) and for heavy diatomic molecules (e.g., Sb2 and Bi2), but, for instance, it is strong for C6H6 at energy per atomic mass of the order of 1 keV/amu. Binary collision calculations are used to give a pictorial view of the phenomena occurring along the ion path, and to predict superadditivity and damage columnarity. The increase of pressure and temperature to extreme conditions by implantation of molecular ions is discussed.