Procedure for evaluating measurement system performance: a case study

This paper presents the methodology used to perform an evaluation of automated CD metrology SEMs for sub-half micron process control. The paper describes the evaluation strategy, the procedure used to collect and analyze the evaluation data and concludes with recommendations on how the procedure can be improved. The evaluation process was designed to estimate metrology capability and review specific application requirements envisioned for a leading edge semiconductor development and manufacturing facility at Motorola. The evaluation process consisted of a quantitative evaluation of measurement performance specifically examining the reproducibility, linearity, automation success rate, and throughput of the instrument. In addition, capabilities such as user interface, computer integration, job transportability, and technology roadmap were assessed qualitatively. Although a particular evaluation of automated CD SEMs is considered here, the principles used to develop the evaluation procedure can be applied to metrology tools in general. A discussion of the application and desired functionality of CD metrology instrumentation including performance criteria is presented for completeness.