Effective Interface Channel Control in IGZO/ITO Heterostructure-Channel Thin Film Transistors

During the investigation of amorphous oxide semiconductor thin film transistors (TFTs), researchers found that TFTs containing a heterostructure-channel demonstrate exceptional mobility. This study focuses on the physical insights into the interfacial channel formation and modulating the device performance. The InGaZnO / InSnO heterostructure-channel TFTs were utilized. The band structure of their interface channel was elucidated by Ultraviolet Photoelectron Spectroscopy and Reflection Electron Energy Loss Spectroscopy. Through the examination of the band structures of heterostructure -channel TFTs, we have discovered that the thickness of the InSnO layer can modify the interface band-edge via the quantum confinement effect. By that, the threshold voltage of the heterostructure-channel TFT was altered.