The analysis of plasma etching processes has been explored for the etching of polysilicon films with CF3Cl/Ar discharges. The etching rate is well fit as a function of the macroscopic plasma parameters (power input, pressure, and composition) using Response Surface Methodology. The parametric expression obtained can be used to examine the sensitivity of the process to the operating conditions, and to optimize the process. The parametric expression also permits comparison of the experimental data with physically meaningful kinetic models.
The Response Surface Method allows characterization of a wide parameter space with few experiments. The design of the experimental set is critical to the success of the parametric fit. The parametric expression must account for interactions between parameters, and the expected curvature of the response surface will dictate the required number of data points.