R.F Sputtering으로 제조한 ZnO박막의 미세구조와 광학적 특성에 미치는 잔류응력의 영향

Abstract

ZnO films were produced on the Si(100) and sapphire(0001) wafers by RF magnetron sputtering in terms of processing variables such as substrate temperature and RF power. The stress in films was obtained from the Stoney’s formula using a laser scanning device. The stress levels in the films showed the range from ~40 MPa to ~ -1100 MPa depending on processing variables. The specimens were thermally cycled from R.T. to 250oC to investigate the stress variation as a function of temperature. SEM was employed to characterize the microstructure of the films. As the substrate temperature increased, the film surface became rougher and the films showed coarser grains. The optical property of the films was studied by PL measurements. At the highest substrate temperature 800oC the film exhibited sharper UV peaks unlike other conditions.