Research on the influence of stamping materials on resist flow and the residual layer in thermal nanoimprint lithography

Various stamp materials can significantly affect the filling quality of nanoimprint lithography (NIL). The effects of different stamp materials on the imprinting process were investigated from the angles of residual layer (RL) thickness, contact pressure, and filling proportion. The selection of various stamp materials affects the thickness and uniformity of the RL. Soft stamps (PDMS, PU) leave a thin but uneven RL distribution, while the RL imprinted by hard stamps (Si, Ni) is thicker but more uniform. The contact pressure using soft stamps is relatively more evenly distributed than hard stamps. The uneven distribution of contact pressure leads to poor cavity-filling proportion, especially for hard stamps. This study offers guidance for choosing proper nanoimprint stamp materials for different NIL applications.