Toughness and adhesion of atomic layer deposited alumina films on polycarbonate substrates

A study is made of the cracking and interfacial adhesion characteristics of atomic layer deposited alumina films on as-received and water–plasma-treated polycarbonate using tensile testing. Optical microscopy was used to observe the initial cracking and subsequent evolution of multiple cracks and film delamination from the substrate during loading. The strength and toughness of the alumina film was determined to be 140 MPa and 0.23 MPa m1/2, respectively. Adhesion of the alumina films was improved for substrates pre-treated with water–plasma.