High-aspect-ratio patterning by ClF3-Ar neutral cluster etching

Abstract

A new facile method is described for high-aspect-ratio patterning by a neutral cluster beam. In this study, we selected a ClF3-Ar neutral cluster beam in order to eliminate the charge-up damage caused by plasma etching. We succeeded in achieving features with high-aspect-ratio patterns, which is a 60nm line width on a 180nm pitch, by ClF3-Ar neutral cluster etching. We confirmed how small feature sizes with high aspect ratio can be fabricated using this neutral cluster beam. Moreover, we successfully presented features with an aspect ratio larger than 10 at less than 100nm feature size. These results indicated that high-speed anisotropic etching with low damage can be applied to the etching of less than 100nm feature size with a high aspect ratio. This etching method may enable the realization sub-10nm high-aspect-ratio etching if the process is further modified.