The relationship of etching behavior and crystal orientation of aluminum doped zinc oxide films

Aluminum doped zinc oxide (AZO) transparent conducting films were dynamically deposited on corning glass substrates in an in-line sputtering system operated at mid-frequency sputtering mode with excitation frequency of 40 kHz. This study addressed the surface structure as well as the electrical and optical properties after wet-chemical etching. With the increase of substrate temperature, the dominant orientation of the as-deposited films changes from (0 0 2) to (1 0 3). After wet-chemical etching, due to the quick etching rate of the (0 0 2) plane relative to the (1 0 3) plane, the surface morphology of the films deposited at different temperatures show a transition from craterlike to granular surface morphology. The experimental results demonstrate that the crystal orientation of the as-deposited films plays an important role for the etching behavior of the films.