GAS DISTRIBUTION SHOWERHEAD SKIRT

摘要

The present invention generally includes an extension or skirt that extends from a gas distribution showerhead in a processing chamber. When processing substrates, the gas distribution showerhead may be electrically biased. The electrically biased showerhead may, in some cases, ignite the processing gas into a plasma state. The walls of the processing chamber and the susceptor, may be grounded relative to the showerhead. Thus, the edges of the substrate may have a greater surface area of ground contacts as compared to the electrically biased showerhead. Due to the increase in grounding near the edges, the material deposited on the substrate may have different properties as compared to the middle of the substrate. By extending the showerhead edges down closer toward the substrate, substantially uniform properties of the material may be obtained.