Nanoimprinting of Ti–Cu-based thin-film metallic glasses deposited by unbalanced magnetron sputtering

Thin-film metallic glasses (TFMGs) are an optimal material for nanoimprint technology. In this study, we prepared Ti–Cu–Zr–Ni–Hf–Si TFMG films by Ar ion bombardment using unbalanced magnetron sputtering (UBMS) and investigated the effect of nanoimprint temperature and deposition bias voltage on the thermal formability during nanoimprinting. The supercooled liquid region of the films increased with increasing Ar ion bombardment intensity. During nanoimprinting of the films deposited at −200 V using a Si mold with a pillar pattern, the hole depth of the nanoimprinted films increased with increasing nanoimprint temperature. During nanoimprinting of the films deposited with different bias voltages using a Si mold with a line and space pattern at 723 K, the line height of the nanoimprinted films increased with increasing bias voltage. This enhancement in the thermal formability was probably due to the decreasing viscosity of the film by Ar ion bombardment. In addition, the surfaces of the nanoimprinted films deposited using intense Ar ion bombardment were very smooth. Thus, Ar ion bombardment by UBMS is an effective method for fabricating TFMGs for nanoimprint technology.