Reliability improvement in amorphous InGaZnO thin film transistors passivated by photosensitive polysilsesquioxane passivation layer

We report the fabrication of highly reliable amorphous InGaZnO (a-IGZO) passivated by a novel photosensitive polysilsesquioxane-based passivation layer using a simple solution process. Results show that the photosensitive passivation material is effective in improving the reliability of a-IGZO. a-IGZO thin film transistors (TFT) passivated by this photosensitive material exhibited a small threshold voltage (V_th) shift of ~ 0.4 V during positive bias stress (PBS), ~ -0.15 V during negative bias stress (NBS) and -2.3 V during negative bias illumination stress (NBIS). These results demonstrate the large potential of easy to fabricate photosensitive polysilsesquioxane passivation layers as effective passivation material.