Energy and angular distributions of ions backscattered from the sidewalls during the implantation into deep trenches

A characteristic feature of implantation into deep trenches is the grazing incidence bombardment of the trench sidewalls. This leads to a considerable backscattering of the incoming ions. Most of the backscattered particles are reimplanted into the opposite sidewalls of the trench. For grazing incidence implantation of As+ ions into Si we determine the backscattering yield and energy and angular distributions of the reflected ions using TRIM Monte Carlo simulations. Our investigations may be considered a first step in a semi-analytical calculation of the dopant profiles in the trench. Therefore, we fit the histograms obtained for the energy and directional distributions of the backscattered ions to analytical expressions. (author)