Preferential refilling and planarization of grooves with amorphous carbon by using gas cluster ion beam irradiations

Abstract

Surface planarization is important for fabrication of patterned media. One of the methods is smoothing of the patterned surface after deposition of refilling materials. However it requires two process steps. In this study, we studied planarization of patterned media by formation of refilling films with gas cluster ion beam (GCIB) assisted deposition to reduce the process step. Hard amorphous carbon films were deposited on line‐and‐space pattern (100 nm pitch, 20 nm in depth) by using Ar‐GCIB assisted deposition. From the atomic force microscope and the cross‐sectional transmission electron microscope observations, the line‐and‐space patterns were refilled with amorphous carbon films with Ar‐GCIB assisted deposition and smooth surface was obtained. The thickness of the amorphous carbon film required for surface planarization was 32 nm, which was very small compared to the initial peak to valley (20 nm). By using this method, sputtering process for planarization can be omitted.