Plasma etch rates: The impact of mask transmittance

摘要

The relationship between plasma etch rates and the area to be etched is described as a "loading effect." This can be theoretically explained and is typically taken into account for both fixed-time and endpoint-etch processes. In particular, transmittance-related mask features determine the size of the exposed areas, thus directly contributing to the loading effect both globally (macroloading) and locally (microloading). This article discusses the impact of mask characteristics on plasma-etching performance when endpoint detection is used. Also discussed is how mask suppliers can perform transmittance characterization by properly extracting information from standard layout data.