Comparison of electrical and SEM CD measurements on binary and alternating aperture phase-shifting masks

摘要: Many of the recent advances in optical lithography have been driven by utilization complex photomasks using proximity correction (OPC) or phase-shifting technologies. These masks are difficult and expensive to manufacture so ability test characterize mask making process is very important. This paper examines issues involved use relatively low-cost electrical critical dimension (ECD) measurement features. Modified cross-bridge structures designed allow on-mask dense isolated, binary phase-shifted layouts. The results scanning electron microscope (CD-SEM) testing these presented indicate lower variability associated with ECD measurements. In particular adverse effect elements on accuracy SEM measurements highlighted.