Tailoring of optical and wetting properties of sputter deposited silica thin films by glancing angle deposition

Synthesis of silica thin films by RF magnetron sputtering using glancing angle deposition (GLAD) has been reported here. Films deposited at four different oblique angles (45°, 60°, 75°, 85°) show transition from featureless to columnar structure. The silica films have been characterized for their optical and wetting properties and they exhibit potential for use in applications such as antireflection coatings, self-cleaning coatings, antifogging coatings, etc. The reflectance decreases to a minimum of 3.15% whereas transmittance increases to a maximum of 93.43% when the films have been deposited at an oblique angle of 85°. Water contact angle measurements were done to show the hydrophilic nature of the films. The hydrophilicity of the films gets enhanced and a minimum water contact angle of 20° is achieved with increase in the oblique angle of deposition owing to the increase in the values of roughness.