TRAPPING OF IMPURITY ATOMS BY DEFECTS AND THE DISTRIBUTION OF CLUSTERS DURING ION BOMBARDMENT OF GROWING FILMS.

Trapping of gaseous impurity atoms by defects during film growth is treated from a theoretical standpoint when ion implantation is accompanied by simultaneous diffusion. Density profiles are determined analytically and by numerical analysis for the impurity-defect clusters as a function of distance in the film and substrate, and the main features of trapping impurity particles by defects are determined over a wide range of experimental parameters. The effects of impurity trapping by defects on the magnitude and distribution of the total impurity atom density and on the total rate at which the bombarding ions are absorbed in the film are studied. It is shown how to obtain films with a high and nearly uniform impurity-defect cluster density under typical experimental conditions and how to increase the total absorption of gas impurity by using films with an increased density of impurity-trapping defects.