Step and flash imprint lithography template characterization, from an etch perspective

As a means of studying process windows with short, turnaround time while avoiding substrate-to-substrate, repeatability issues, Step and Flash Imprint Lithography templates were fabricated with physical masking of quadrants during dry etching used to introduce process perturbations. For every 20 s of descum (Ar/O-2 etch) time, critical dimensions (CD) were observed to change approximately 2.6 nm on sub- 100. nm features. Similarly,,increasing Cr overetch time by 20% resulted in a positive CD change of 3.8 nm. Line edge roughness decreased with increasing descum and Cr overetch times. Best overall performance was observed, for a 20 s descum used in. conjunction with a 110% Cr overetch. Of four tip types studied, sharpened silicon atomic force microscopy tips were able to accurately measure etch depth of 80 nm trenches, but geometrical considerations limited sidewall angle determination to greater than 100degrees. Cross-sectioning of features on 6 x 6 x 0.25 in quartz plates was successfully accomplished using a focused ion beam technique with typical sidewall angles of about 95degrees observed on 150 nm features. Finally, minimal microloading was observed for the ICP-based quartz etch process. Feature sizes ranging from 70 nm up to 8 mum possessed an average etch depth of 88.8 nm with a 1.2 nm (1 sigma) variation. (C) 2003 American Vacuum Society.