Factors influencing the nanostructure of obliquely deposited thin films

ABSTRACT

In this piece of work, silica thin films were deposited by RF magnetron reactive sputtering exploiting the mechanism of oblique angle deposition. Here, change in the structure of the films with a change in the oblique angle of deposition and target to substrate distance has been studied with some emphasis on the role of the atomic weight of silicon in influencing the collisional process and directionality of the sputtered atoms. The films deposited at a lower target to substrate distance are compact and possess a columnar structure when deposited at higher oblique angles. The films deposited at higher target to substrate distance do not show any change in the tilt angle of the nanocolumnar structure with change in the oblique angle of deposition. This shows that the mean free path of the sputtered atoms plays a major role in the evolution of the structures of the thin films.

KEYWORDS:

• Oblique angle deposition
• silica thin film
• sputtering
• self-shadowing effect
• mean free path
• effective thermalising collision theory

Acknowledgements

We would like to thank the Director, IMMT Bhubaneswar, for permitting to publish the results. We are thankful to Dr BB Nayak for his useful suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Satyajit Sarkar http://orcid.org/0000-0003-2107-5442