Monitoring and controlling cross-wafer and in-die variability has been recognized as the dominant and escalating factors for the successful commercialization of modern-day integrated circuit products utilizing advanced semiconductor manufacturing [1,2]. In this paper we present a Performance Based Metrology (PBM), a measurement technology for closing the information gap between the design, process integration, and manufacturing groups with respect to accounting for variability. PBM enables the "porting" of scribe-like and end-of-line contact tested measurements to within the product die active area to it provide the capability to significantly reduce the cycles of learning to obtain relevant and key process, device, and product metrics. This product-relevant information can then be used for process monitoring and control, performance optimization, and to enhance early bin-yield predictability. The technique would reduce or eliminate the need for send-ahead test wafers and other "disruptive" measurements by making possible in-die, non-contact characterization of product performance monitors and devices. We describe the in-line measurement system and review the design and implementation considerations for the non-contact test structures incorporated on product wafers. Experimental results from PBM measurements on several generations (90, 65, and 45nm) of bulk-Si and SOI product wafers and devices are presented to illustrate the capabilities of the technique.
We report on the first non-contact, non-destructive performance measurements of embedded Ring Oscillators. Measurements are made inside the die active area as early as Metal 1. 90-nm logic CMOS technology was used for this work. We have measured residual across-field performance process noise, and variation separate from and of opposite sense to wafer uniformity. This effect cannot be extrapolated from scribe measurements.
We report on a performance-based measurement (PBM) technique from a volume production 65-nm multi-product wafer (MPW) process that shows far more sensitivity than the standard physical gate-length (CD) measurements. The performance (the electrical "effective" gate length, L eff ) variation results measured by PBM can NOT be explained alone by CD (physical gate) measurement and show that the non-destructive (non-contact) PBM is able to monitor and control at first-level of electrical connectivity (≥ M1), the bin-yield determining in-die variation that are NOT captured or realized by physical CD measurement. Along with this higher sensitivity, we also show that the process-induced variation (excursion) has a distinct signature versus "nominal" expected behavior.
KeywordsNon-contact, in-die performance based metrology, process-induced variability, critical physical gate length (CD), and effective channel length (L eff ) Metrology, Inspection, and Process Control for Microlithography XXIII, edited
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.