Generating ion implantation profiles in one and two dimensions. 2: depth-dependent moments and line-source responses

Abstract

In this, the second of two papers, various techniques and models are proposed for the extraction of depth-dependent lateral moments from the depth-independent mixed moments produced by transport equation solvers. These depth-dependent moments are then compared with those obtained directly from Monte Carlo simulations. A set of such comparisons, using consistent input quantities, is performed over a range of ion - target mass ratios and energies. The depth-dependent moments are then combined with Pearson and/or Johnson curves to form two-dimensional ion implantation profiles. Comparisons are made between these line-source responses (LSRs) and LSRs obtained directly from Monte Carlo simulations into a-Si for the various models over a range of energies and ion types. Selection of appropriate models leads to LSRs for the ions B, P and As implanted into a-Si which are in good agreement with Monte Carlo simulations over three orders of magnitude of profile concentration. The techniques described will enable two-dimensional profile information to be stored and regenerated, quickly and efficiently, within process simulators so that rapid optimization of processing parameters may be achieved.