Solution of the kinetic equation for the deposited momentum distribution. II. Threshold energy effects

Abstract

The p a p continues an investigation of the depth distribution of momenNm deposited in solids by ion bombardment. finite-threshold-energy effects being discussed. It is shown that, for a wide set of system parameters, existing semianalytical techniques lead to a qualitatively inoarreet description of momentum deposition, especially in the target surface region. The most important qualitative -res of the deposited momentum distribution are considered, which cannot be ignored when finding solutions of the kinetic equation by analytiwlly based methods or interpreting numerical simulation data. Corresponding analytical and numerical results nre presented.

Recollections of fifty years with sputtering

“…In particular, pertinent quantities showed a divergence at m = 1/4, a value that could not be excluded as being unphysical. The solution to the problem turned out to be a third term in the expansion that is related to the gradient of the distribution of deposited energy, which likewise shows a divergence at m = 1/4, but which cancels the divergence in the momentum-related term [66,67,56]. This term was also neglected in a successful semiempirical approach [68], but the effect of the omission was limited due to the use of adjustable parameters.…”