Simulation of trench homogeneity in plasma immersion ion implantation

The time-dependent evolution of the potential, the electrical field, and th e particle movement surrounding two-dimensional trenches during a high volt age pulse in the context of plasma immersion ion implantation is studied by a particle-in-cell simulation. The numerical procedure is based on the sol ution of Poisson's equation on a grid and the determination of the movement of the particles on the grid. This simulation is combined with simulation codes for the calculation of depth profiles and sputtering yields. The reta ined ion dose and the depth resolved concentration distribution were determ ined in dependence on the rise time of the pulse between 0.1 and 2 mu s, pu lse durations between 1 and 10 mu s and the ion mass (m=20-131, i.e., Ne,.. .,Xe) for trenches with two different aspect ratios (eta=3:1 and 3:2). The results are discussed on the basis of the temporal evolution of the energy of the ions and the impact angle of the ions during the pulse. (C) 2000 Ame rican Institute of Physics. [S0021-8979(00)05314-7].