MONTE-CARLO PROGRAM MODEX - SIMULATION OF POINT-DEFECT CLUSTERING DURING IRRADIATION AND, SUBSEQUENT ANNEALING

A Monte Carlo program MODEX is presented, capable of simulating the de fect clustering process during ion implantation and subsequent anneali ng. The program considers four different types of point defects, e.g. implanted ions, vacancies, self-interstitials and impurities, as mobil e. Depending on the mobility of the point defect the diffusion equatio ns are solved in the stationary or non-stationary form. The clustering process of point defects is described by a set of rate equations and is simulated; through a number of elementary trapping and dissociation events. The use of the program is demonstrated in examples of helium implantation in molybdenum, vanadium and silicon and the simulation re sults are discussed in relation to the results of helium desorption ex periments. (C) 1998 Elsevier Science B.V.