11:45 〜 12:00
[16a-F203-10] 溶液プロセスによるMoS2の作製と薄膜トランジスタ応用に関する研究
キーワード：MoS2、半導体、high-k
In this work, TFTs with the chemical solution processed MoS2 channel which was directly deposited on the high-k oxide film was investigated. The (NH4)2MoS4 powder was dissolved in N-methyl-2-pyrrolidone (NMP) for MoS2 precursor solution. To investigate the appropriate gate oxide for spin-coating of MoS2, we first examined coating property of the source solution on various kinds of dielectric oxide films as well as thermal stability at 1000ºC with sulfur atmosphere, and selected Nb-doped ZrO2(NZO). The 0.05 mol/kg MoS2 solution were spin-coated on NZO/Si substrates and annealed by a two-step annealing process, where the first annealing is performed at 450 ºC in H2/Ar (5:95) atmosphere for 20 min and the second annealing at 1000 ºC in Ar atmosphere with S vapor for 20 min. It is confirmed by Raman scattering spectroscopy that the MoS2 layers were grown on the NZO film. In addition, although the NZO film shows rough surface, the conformal growth of a MoS2 layered structure on the curved surface of the oxide film was confirmed by transmission electron microscope. Normal n-type transistor operation was observed. The on/off drain current ratio was 4.5x104 and the estimated field effect mobility was 0.32~0.71 cm2/Vs.