Moisture Related Instability In P-Type Low Temperature Polycrystalline Silicon Thin Film Transistors

The unreliable behaviors of low temperature polycrystalline silicon (LTPS) thin film transistors (TFTs) after a period of storage are confirmed to be related to the moisture by the observation of enhanced negative bias temperature instability (NBTI) after humidity treatments and the observation of decreased NBTI degradation after hard bake treatment. PECVD passivation layers of combined SiO2 and Si3N4 deposited on the top of low temperature LTPS TFT structure can effectively prevent the moisture from penetrating into the TFT structure and improve the device reliability.