Invited - Characteristics of oxide TFT using atomic-layer deposited InOx-based metal oxide channel

InOx-based metal oxide semiconductors (InOx-OSs) including In-Ga-Zn-O (IGZO) [1,2] have been investigated as active channel materials in oxide thin film transistors (TFTs) for flat-panel display applications. These InOx-OSs have recently attracted attention for n-channel field effect transistor (n-FET) in back-end of line [3-5] and ferroelectric FET with HfO2-based ferroelectric gate insulator [6] First, InOx-OS films were deposited vis sputtering method. Considering to the growth of ultra-thin films, atomic layer deposition (ALD) technique is of great interest in the angstrom-scale thickness controllability, atomically smooth surface and composition control of multicomponent films as well as excellent step coverage on three-dimensional structure. The superior transistor performance of TFTs with ALD-In2O3 and IGZO channels and n-FET with ALD-In2O3 channel have been demonstrated [3,4,7]. Here, In2O3 films have been deposited via ALD with a combination of various precursors and oxidant gases such as trimethyl indium-O2, O3, H2O, or H2O2, and ethylcycropentadienyl indium (InEtCp)-H2O/O3 [8-10]. Please click Download on the upper right corner to see the full abstract

Unipolar transport in bilayer graphene controlled by multiple p-n interfaces

Unipolar transport is demonstrated in a bilayer graphene with a series of p-n junctions and is controlled by electrostatic biasing by a comb-shaped top gate. The OFF state is induced by multiple barriers in the p-n junctions, where the band gap is generated by applying a perpendicular electric field to the bilayer graphene, and the ON state is induced by the p-p or n-n configurations of the junctions. As the number of the junction increases, current suppression in the OFF state is pronounced. The multiple p-n junctions also realize the saturation of the drain current under relatively high source-drain voltages.Comment: 18 pages, 4 figures, Applied Physics Letters, in printin