Data for Direct thermal atomic layer deposition of high-κ dielectrics on monolayer MoS2 : nucleation and growth

With high carrier mobility and relatively strong visible light emission, monolayer molybdenum disulfide (1L MoS2) is a promising candidate for optoelectronic applications and is commonly synthesised via chemical vapour deposition (CVD) to enable large-area device production.

The growth of uniform high-κ dielectrics on bulk materials is routinely achieved via thermal atomic layer deposition (ALD), but continuous deposition on MoS2 is notoriously challenging due to the absence of dangling bonds on the basal plane. The resulting unique nucleation and growth characteristics of high-κ dielectrics on 1L MoS2 are not fully understood, particularly on large-area CVD-1L MoS2. In this work, we investigate the nucleation and growth of aluminium oxide (Al2O3) and hafnium dioxide (HfO2) on CVD-1L MoS2 films via direct thermal ALD at 200 °C. We vary the number of ALD cycles and monitor the morphology of the deposited high-κ layer via atomic force microscopy, observing ALD-Al2O3 and ALD-HfO2 films on CVD-1L MoS2 to exhibit island features for all cycle numbers investigated (up to 200 cycles).