Effect of thermalization distance on stochastic phenomena in 7-nm-half-pitch line-and-space pattern fabrication using chemically amplified extreme ultraviolet resists

摘要

The thermalization of secondary electrons is an important process in the radiation effects on a condensed matter. In the lithography using ionizing radiations, it is expected that the effects of thermalization distance will become prominent in the sub-10 nm resolution region. In this study, the effects of thermalization distance on the stochastic phenomena in the fabrication of line-and-space patterns with 7 nm half-pitch were investigated on the basis of the sensitization mechanisms of chemically amplified extreme ultraviolet resists. All three factors related to the stochastic phenomena [the stochastic generation of pinching and bridges and line edge roughness (LER)] were improved by decreasing the thermalization distance. It was found that the suppression of LER and bridge generation was a more serious problem than that of pinching. (C) 2016 The Japan Society of Applied Physics