Method for improving the process uniformity in a reactor by asymmetrically adjusting the reactant gas flow

摘要

A method for improving the etch rate uniformity and the chemical vapor deposition uniformity in a single-wafer reaction chamber was achieved. The method utilizes an asymmetric gas distribution system to increase the reactant gas flow over regions of the wafer in an etcher where the etch rates are low, and increases the reactant gas flow in CVD deposition reactors over regions of the wafer where the deposition rates are low. More specifically, a modified shower head having an array of orifices that are varied in size and spacing across the shower face are proposed to optimize the uniformity. The method is particularly useful for improving the uniformity near the wafer flat where the uniformity is known to be exceptionally poor in conventional single-wafer reactors.