Curtailing the Ambient Air Ageing Effect on Mechanical Properties of Vacuum Evaporated Al2O3 Thin Films Using Vapor Chopping Technique

Abstract

Here, we studied the 30-day ambient air exposed vacuum evaporated Al2O3 thin films. The ageing effect on mechanical properties like intrinsic stress as well as adhesion was studied. Vapor chopping technique (VCT) was used during deposition. To find ageing effect in vapor chopped (VC) and as deposited i.e. nonchopped (NC) Al2O3 thin films comparative study was done. VC and NC Al2O3 thin films’ X-ray diffraction (XRD) patterns remain the same even after 30 days ageing, i.e., no structural variation was found due to ageing. Adhesion degradation was observed in deposited films i.e. NC films showed reduction from 266±5×103 to 189±5×103 N/m2 whereas VC thin films showed 355±5×103 to 332±5×103 N/m2. Intrinsic stress increased from 41±2×107 to 61±2×107 N/m2 in NC and 31±2×107 to 39±2×107 N/m2 in VC Al2O3 thin films. Even though, overall VC films showed higher adhesion and smaller intrinsic stress than NC Al2O3 thin films i.e., curtailing ambient air ageing effect in VC thin films was perceptible.