Zno Thin Films Based On The Pvd Method And Characteristics

The techniques of depositing zinc thin film on grass substrate by vacuum evaporation and direct-current sputtering were investigated with XRD, SEM and AFM in this paper.XRD patterns showed that thin film prepared by evaporation was consisted of only Zn element, there was no impurity, zinc film grew at (101) and (102)-preferred orientation, and thin film prepared by sputtering was amorphous.The effects of deposition conditions on crystalline topography were researched and the results showed that crystalline topography was shaped as leaf at low current or long source-to-substrate distance, triangle or quadrangle at high evaporation current or short source-to-substrate distance, symmetrical hexagon at optimal deposition conditions.The effects of deposition conditions on growth mode of crystals were researched and the results showed that zinc crystals grew in three-dimensional island mode at low evaporation current or long source-to-substrate distance, planar layer-by-layer mode at high current or short source-to-substrate distance.It was found that high deposition rate would result in compact zinc films, and high substrate temperature would result in big zinc crystals. Under optimal deposition conditions, the crystalline granularity of zinc film was about 400nm and 50nm respectively for vacuum evaporation and direct- current sputtering.The surface characteristics of Zn films deposited by evaporation were analyzed and the results showed that under the conditions of current 42 A and source-to-substrate distance 2.0cm, the average roughness was 30.0nm, the highest contour 306nm, the extraction average roughness 37.5nm and the ten-point average roughness 292nm. For zinc film prepared by direct-current sputtering under the conditions of voltage 1.6kV and target-to-substrate distance 4.0cm, the average roughness was 5.98nm, the highest contour 58.1nm, the extraction average roughness 7.49nm and the ten-point average roughness 56.8nm.The effects of deposition conditions on deposition rate and surfacetopography were researched and the results showed that for vacuum evaporation, the optimal conditions were as follow: current 42A, source-to-substrate 2.0cm and evaporation time 15s, then the deposition rate was 21nm-s"1. For direct-current sputtering, the optimal conditions were sputtering voltage 1.6kV, target-to-substrate distance 4.0cm, Ar pressure 5Pa and depositing time 60min, then the deposition rate was 0.018 nm-s'1.