Wolfgang Fricke

Analysis of the Vistec LMS IPRO3 performance and accuracy enhancement techniques

Following the international technology roadmap for semiconductors the image placement precision for the 65nm technology node has to be 7nm. In order to be measurement capable, the measurement error of a 2D coordinate measurement system has to be close to 2nm. For those products, we are using the latest Vistec registration metrology tool, the LMS IPRO3. In this publication we focus on the tool performance analysis and compare different methodologies. Beside the well-established ones, we are demonstrating the statistical method of the analysis of variance (ANOVA) as a powerful tool to quantify different measurement error contributors. Here we deal with short-term, long-term, orientation-dependent and tool matching errors. For comparison reasons we also present some results based on LMS IPRO2 and LMS IPRO1 measurements. Whereas the short-term repeatability and long-term reproducibility are more or less given by the tool set up and physical facts, the orientation dependant part is a result of a software correction algorithm. We finally analyse that kind of residual tool systematics and test some improvement strategies.