CDU prediction based on in-situ image measurements

摘要

Control of CD uniformity is a key aspect of IC manufacturing. Ability to accurately predict wafer-measured CD prior toexposure is critical to CDU control. In this paper we present a method to calculate a predicted CD value based on in-situmeasurements, and estimate CD uniformity across the field of an exposure tool. This method is based on directmeasurements of aerial image using a sensor built into the wafer stage of SMEE SSA600-series exposure scanners.Using this sensor to measure image of several features at 9 points across the exposure field, we compare predicted CDand ADI CD obtained using a standard wafer process and CD-SEM.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.