Deposition of GaV₄S₈ thin films by H₂S/Ar reactive sputtering for ReRAM applications

The chalcogenide compound GaV₄S₈ is promising for applications as active materials in non-volatile memory applications. We report here a comprehensive study on the thin-film deposition of this compound using a stoichiometric GaV₄S₈ target and H₂S/Ar reactive sputtering. We show that a fraction of 0.5% to 1% of H₂S in the reactive plasma is sufficient to compensate the sulfur deficiency that appears in films deposited in pure Ar plasma. This reactive plasma method allows avoiding the addition of elemental sulfur during the annealing treatment required to obtain a crystallized and stoichiometric GaV₄S₈ layer. A simple Au/GaV₄S₈/Au structure presents a resistive switching behaviour well suited for non-volatile memory applications. (paper)