Topography Simulation of Reactive Ion Etching Combined with Plasma Simulation, Sheath Model, and Surface Reaction Model

We developed an oxide-film reactive ion etching (RIE) topography simulation which consists of a plasma simulation, a sheath model, and a surface reaction model. In the plasma simulation, the plasma parameters were calculated in two dimensions using the particle-in-cell/Monte Carlo collision (PIC/MCC) method. In the surface reaction model, the motion of particles in the etching trench was simulated by the Monte Carlo method. This topography simulation was applied to the etching by a capacitively coupled plasma (CCP). Etching conditions were as follows:gas pressure 5.3–10.6 Pa and RF power 1.1–1.7 kW in the gas mixture of C4F8, CO, O2, and Ar. The calibration method for such simulation parameters as the ion reflection ratio, the etch rate and the polymer etch rate was established based on the experimental results. As a result, the change of the etching profile was reproduced according to the change of the gas pressure and RF power with high accuracy. Furthermore, it was shown that the simulator can predict the profile change corresponding to the process change.