Analysis of Etching Mechanism and Etched Slope Control of Silicon for Nanoimprinting Lithography

Abstract

In the nanoimprint lithography (NIL) process, profile control of imprint masters is a very important task. Therefore, we attempted to control the etched slope of imprint masters as a function of adding O(2) to CF(4) plasma. Etched profile mechanisms and relationships between the etch kinetics and plasma chemistry were explored using zero-dimensional-based modeling. O(2) flow rate increased to 24 sccm, the Si etch rate increased in the range of 186-393 nm/min, while the etch rate rapidly decreased as the O(2) flow rate increases beyond 24 sccm. Meanwhile, change in the etch rate of SiO(2) followed a similar tendency as the etch rate of Si as a function of O(2) flow rate in the CF(4)/O(2) mixing gases. The Si and SiO(2) etch rate were expected to be closely dependent on the F radical intensity in CF(4)/O(2) mixing gases. Moreover, the results of simulated normalized lateral etch critical dimension (NLECD) are in agreement with the measured NLECD as a function of O(2) flow rate in the CF(4)/O(2) mixing gases.