Difficulties in deducing disordering mechanisms from experimental studies of disorder-ion fluence functions in ion irradiation of semiconductors

A detailed composite model of amorphousness production during ion irradiation of semiconductors at low temperatures and the stepwise approximation to the disorder density profile for disorder accumulation is presented. Numerical calculations of this and other models are performed and a series of comparisons are made. It is shown that all the models considered can result in numerically similar amorphousness-ion fluence curves and hence that interpretation of experimental data of this kind can be difficult. It is further shown that if in an experimental procedure disordered but not amorphous regions are also analysed then the resulting disorder-fluence curves can be misleading and almost impossible to interpret without further analyses of, for example, dose rate effects or direct observation of defect density. (author)