Effect of photodecomposable quencher on latent image quality in extreme ultraviolet lithography

A basic compound, called a quencher, plays an important role in the formation of latent images in chemically amplified resists. In this study, the effect of photodecomposable quenchers on latent image quality was investigated using a simulation on the basis of the reaction mechanisms of chemically amplified extreme ultraviolet (EUV) resists. When the concentration of photodecomposable quenchers was relatively low (∼10% of the acid generator concentration), the effect of photodecomposable quenchers was negligible because of the competition between acid generators and photodecomposable quenchers for thermalized electrons. When the concentration of photodecomposable quenchers was increased, latent image quality was improved, compared with that in the resist with non-photodecomposable quenchers. The concentration of photodecomposable quenchers relative to that of acid generators has to be increased to some degree for photodecomposable quenchers to enhance latent image quality.