MoS₂ doping by atomic layer deposition of high-k dielectrics using alcohol as process oxidants

We developed doping technique of transition metal dichalcogenides based on atomic layer deposition (ALD) of oxide thin films. In this study, we deposited ALD Al2O3 overlayer using various oxidant including iso-propyl alcohol (IPA) and ethanol and investigated the doping effects depending on the choice of oxidant for ALD process. The doping effects were investigated by the change in the performance of bottom-gated MoS2 field effect transistors. Experimental results indicate that Al2O3 overlayer deposited using IPA as ALD reactant produces more efficient n-type doping effect compared to ethanol. Moreover, doping was effectively controlled by modulating atomic layer deposition process. ALD process using effective oxidant material is expected to be practically used for realizing the fabrication of threshold voltage-controllable transistors or further applications such as diodes.