Sputtered Amorphous Silicon Thin Films Exhibiting Low Argon Working Gas Content and High Film Density

Abstract

To achieve high-quality sputtered amorphous silicon (a-Si) thin films with low argon (Ar) working gas atom content and high film density, the effects of \(\:{P}_{Ar}{D}_{TS}\) on Ar gas content and film density is investigated. Here, \(\:{P}_{Ar}\) is Ar working pressure and \(\:{D}_{TS}\) is target-to-substrate. The findings from this work indicate that the Ar gas content in the films primarily arises from highly energetic reflected Ar ions that bombard growing a-Si thin films at low \(\:{P}_{Ar}{D}_{TS}\:\) values (< 50 Pa·mm). As \(\:{P}_{Ar}{D}_{TS}\) increases, a monotonic decrease in film density is observed. This results well correlates with the declining average energy of sputtered silicon atoms reaching the substrate. Optimal conditions for fabricating sputtered a-Si thin films with both low Ar content and high film density were identified within the \(\:{P}_{Ar}{D}_{TS}\) range of 30–40 Pa·mm. This research could provide valuable insights for researchers seeking to optimize the balance between low working gas content and high film density in sputtered thin films.

Graphical Abstract