A non-uniform voltage distribution across a driven electrode results in inhomogeneous film deposition in large-area, very high-frequency (VHF) plasma reactors. Here we perform experimental and numerical studies on the voltage distribution across the electrode. Two kinds of dedicated vacuum chambers are prepared for one-and two-dimensional observations of the voltage and the plasma distributions. A comparison between the measured voltage and the plasma distribution clearly shows a good agreement between the two. In principle the plasma distribution is governed by the standing wave of the voltage on the driven electrode for an at least one-dimensional electrode. A numerical model based on transmission-line modelling is presented for calculating the voltage distribution. The influence of plasma conditions such as the electron density and the sheath length included in the model on the voltage distribution is investigated through comparison of the model predictions with the experimental results. The correlation between the plasma conditions and the propagation constant of the model suggests that the sheath length dominates the wavelength; in contrast, the electron density dominates the decay of the wave propagation. Using the parameters of the plasma conditions estimated from the experimental results, the model can predict the voltage distribution across a ladder electrode of size 45 cm × 55 cm in a large-area VHF plasma reactor.

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Dynamic Monte Carlo ͑DMC͒ simulations are carried out on silicon ͑001͒2ϫ1 surface under 100% silane gas chemical vapor deposition condition as a function of surface temperature ͑600-800°C͒ and pressure ͑6 and 12 mTorr͒. The reactant on the surface from gas-phase is assumed to be the silane molecule. The rates and probabilities of surface reactions are determined a priori by recent ab initio calculation results in the literature. The DMC method can reveal not only the short-time microscopic mechanism but also predict the macroscopic phenomena such as deposition. The calculated growth rate and Arrhenius activation energy of growth depending on temperature show good agreement with experimental results. The results suggest that the low activation energy regime above 700°C is associated with a process controlled by silane dissociative adsorption. In contrast, the higher activation energy regime below 700°C is supposed to be governed by hydrogen desorption. The periodic change of surface structure that is similar to reflection high-energy electron diffraction intensity oscillation in the process of molecular beam epitaxy is observed. The periodic behavior results from the repeat of a series of hydrogen desorption, silane adsorption, surface incorporation, and adatom diffusion on the growing surface.

Two very-high-frequency powers between which the phase difference is varying in split of time are supplied to a ladder-shaped electrode through multiple feeding points located at symmetrical positions of the electrode to generate a large-area uniform plasma. Theoretical calculations of the voltage distribution at several phase difference show good agreement with experiments. Plasma emission uniformity within ±15% is demonstrated at 60MHz for the substrate size of 1.4×1.1m, with nitrogen gas of 10Pa.

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