Morphology and interdiffusion behavior of evaporated metal films on crystalline diindenoperylene thin films

We present a transmission electron microscopy (TEM)/Rutherford backscattering spectrometry (RBS)/x-ray-diffraction (XRD) study of Au evaporated on crystalline organic thin films of diindenoperylene (DIP). Cross-sectional TEM shows that the preparation conditions of the Au film (evaporation rate and substrate temperature) strongly determine the interfacial morphology. In situ XRD during annealing reveals that the organic layer is thermally stable up to about 150 degreesC, a temperature sufficient for most electronic applications. The x-ray measurements show that the as-grown Au layer exhibits a large mosaicity of around 10degrees. Upon annealing above approximate to120 degreesC the Au film starts to reorder and shows sharp (111)-diffraction features. In addition, temperature dependent RBS measurements indicate that the Au/DIP interface is thermally essentially stable against diffusion of Au in the DIP layer up to approximate to100 degreesC on the time scale of hours, dependent on the Au thickness. (C) 2003 American Institute of Physics.