Pentacene thin film transistors on large area compatible gate dielectrics

Abstract

The properties of polycrystalline pentacene thin film transistors (TFT) are reported, showing the influence of the deposition conditions with different inorganic and organic dielectrics. Dielectrics compatible with large area fabrication were explored to facilitate low cost electronics on glass or flexible plastic substrates. Transistors were realized on plasma-enhanced chemical vapor deposited (PECVD) silicon nitride, silicon oxide and spin casted poly vinyl phenol (PVP). The physical and chemical properties of the dielectric have a distinct influence on the morphology and the structural properties of the pentacene films. Polycrystalline films with large crystals and high structural order can be grown on smooth dielectrics. For rougher dielectrics the crystal size is reduced and the films exhibit no structural order. Furthermore, the growth is affected by the surface wetting properties of the dielectric. The surface chemistry can be controlled by a treatment of the dielectric with self-assembled monolayers (SAMS). The impact of the different dielectrics on the device parameters like mobility and subthreshold slope will be discussed.