| Summary: | 碩士 === 國立交通大學 === 光電工程系所 === 97 === The stability of as-deposited a-IGZO TFTs was studied. The serious turn-on voltage shift under seven times sequent IDVG measurement of unstable as-deposited device was observed. It suggests that the atomic bonding of film was loose due to low temperature during sputter process. Hence, the defects were formed in the interface between channel and dielectric layer.
By varying the post-annealing ambiance, it was observed that the transfer characteristic of a-IGZO TFTs annealed in vacuum based furnace and atmosphere based furnace were totally opposite. The device annealed in vacuum based went toward to conductive with increasing temperature. In the contrary, the device annealed in atmosphere based went toward to insulate with increasing. The mechanism was investigated by the thermal desorption spectrometry (TDS) and X-ray photoelectron spectroscopy (XPS). It was confirmed that the post-annealing could introduce oxygen into IGZO film or extract oxygen from IGZO film depending on the annealing ambiance. Besides, this work was studied with my senior classmates, Cheng-Wei Chou and Wei-Tsung Chen.
|
|---|
