Large-area deposition of thin crystalline MoS2 films on 200 mm wafers using plasma-assisted atomic layer deposition.

Abstract:
We demonstrate direct polycrystalline growth of molybdenum disulphide (MoS2) via atomic layer deposition (ALD) on 200 mm Si/SiO2 substrates. The synthesis of MoS2 in wafer-scale is a first critical step for future 2D technology implemented by industry. Substantial progress has already been taken for films grown via chemical vapour deposition (CVD). Typically, as-deposited MoS2 films by ALD at low temperatures are amorphous and show different characteristics and a non-ideal stoichiometry in comparison to CVD or high temperature ALD deposited crystalline counterparts. However, low temperature ALD is still indispensable for direct synthesis on for example polymeric or glass substrates for flexible electronics. Using an industrial ALD-reactor, this work proves the capability to combine both low temperature (T < 300 °C) and wafer-scale deposition of direct crystalline and continuous MoS2 films with good morphology.