Abstract
In this thesis, aluminum nitride is used as gate dielectric in organic thin film transistor, the main content can be divided into two parts: the aging effect on AlN and the substrate thermal effect during evaporation of pentacene. Taking the as-deposited AlN thin films to undergo the aging process can lead to the rise of the field effect mobility, after 7 days the highest field effect mobility can reach 1.806 cm2/Vs. In addition to the aging effect, the increase of substrate temperature during evaporation of pentacene results in the decrease of field effect mobility. As the temperature increases from RT, 50℃ to 70℃, the field effect mobility decreases from 1.002 cm2/Vs, 0.178 cm2/Vs to 0.058 cm2/Vs. AFM and GIXD were used to analyze the material properties of pentacene/AlN. An in-situ Raman analysis was used to analyze the molecular vibration during the operation of OTFT. Different from the previous perspective where the mobility enhancement is mainly caused by enlarging the pentacene grain size, the experimental results suggest that the pentacene molecular stacking and the intermolecular interaction dominate the carrier transport properties. The preparation of AlN thin films was applied by RF reactive magnetron sputter system, then by thermal evaporation to deposit pentacene thin films. Throughout the whole process, the temperature is under 150℃. Therefore, it is suitable for the requirement of the flexible display. Moreover, the field effect mobility surpasses the field effect mobility of a-Si TFTs, and it increases the potential of using the OTFTs with AlN dielectric.