Shot noise limit of sensitivity of chemically amplified resists used for extreme ultraviolet lithography

With the improvement of resolution, the shot noise effect becomes a serious concern in the lithography used for high-volume production of semiconductor devices. In this study, the shot noise limit of the sensitivity of chemically amplified resists was investigated from the viewpoint of sensitivity enhancement, assuming extreme ultraviolet lithography. The latent images of line-and-space patterns with 11 nm half-pitch were calculated using a Monte Carlo method. The effect of secondary electron blur was eliminated to clarify the shot noise limit of line edge roughness (LER). When the requirement for line width roughness (LWR) was assumed to be 10% critical dimension (CD), the shot noise limit of sensitivity was >100 mJ cm −2 . For the 20% CD LWR, the shot noise limits of sensitivity for the 10, 20, and 30 wt % acid generator concentrations were 20, 9, and 7 mJ cm −2 , respectively.