Influence of surface topography on ion trajectories in low-pressure plasma etching

The transport of ions through a collisionless rf glow-discharge sheath is simulated with a Monte Carlo method in order to determine the influence of surface topography on ion trajectories. The simulation results indicate that the perturbation of the local electric field by the geometric shape of the trench has very little influence on ion trajectories, and as such cannot be considered as the origin of reactive ion etching lag in low-pressure rf plasmas. These results are in sharp disagreement with the model proposed by Lee and Zhou [J. Electrochem. Soc. 138, 2439 (1991)] and with the calculations by Ingram [J. Appl. Phys. 68, 500 (1990)].