Study on Induced Stress and Strain in Direct Nanoimprint Lithography

Abstract

Induced stress and strains in direct nanoimprint process are investigated by computational works. Impact of the mold pressing velocity, the polymer thickness, and the side wall angle of the mold are studied for the model polymer and PMMA. The shear stress distribution in pattern cavity is strongly affected by the polymer thickness and the side wall angle of the mold. By inclination of the side wall, the shear stress is spread into pattern cavity in triangular shaped cavity due to polymer flow along the side wall, which may induce molecular ordering. On the other hand, stress and strain distributions are hardly affected by the mold pressing velocity under investigated conditions.

Study on induced strain in direct nanoimprint lithography

“…The mold is pressed to the polymer with velocity v. In our previous work, the effect of the mold velocity is not significant for the sheer stress distribution. 25) In this work, the mold velocity is fixed to 0.01 m=s. The mold is a rigid body.…”

“…4,[15][16][17][18][19][20][21][22][23][24] The investigation of shear strain in polymer materials is one of the key issues for a successful direct nanoimprint process to utilize material features. In our pervious study, the effects of mold pressing velocity and mold pattern variation were briefly investigated by computational work 25) without considering the friction between the mold and the polymer. In this study, the effects of the friction between the mold surface and the polymer, and the crosssectional profile of the mold were examined.…”