Effects of substrate temperature on the device properties of pentacene-based thin film transistors using Al₂O_3+x gate dielectric

The effects of substrate temperature on the pentacene-based organic thin film transistor (OTFT) device properties were studied. The aluminum oxide gate dielectric films were deposited by magnetron sputtering at fixed deposition rate for various substrate temperature. The x-ray diffraction (XRD), atomic force microscopy (AFM), and spectroellipsometry (SE) techniques were used in the study. It was observed that the grain size of the pentacene layer increased with temperature and a phase transition occurred. No significant improvement of field-effect hole mobility was observed for varying temperature.