Method of improving the wafer-to-wafer thickness uniformity of silicon nitride layers

摘要

Wafer-to-wafer thickness uniformity may be improved significantly in a process for depositing a silicon nitride layer in that the flow rate of the reactant and the chamber pressure are varied during a deposition cycle. By correspondingly adapting the flow rate and/or the chamber pressure before and after the actual deposition step, the process conditions may be more effectively stabilized, thereby reducing process variations, even after non-deposition phases of the deposition tool, such as a preceding plasma clean process or an idle period of the tool.