The disclosed technology generally relates to semiconductor devices, and more particularly to an encapsulation layer for a semiconductor device having a chalcogenide material, and methods of forming the same. In one aspect, a method of fabricating a semiconductor device comprises providing a substrate having an exposed surface comprising a chalcogenide material. The method additionally comprises forming a low-electronegativity (low-χ) metal oxide layer on the chalcogenide material by cyclically exposing the substrate to a low-χ metal precursor and an oxygen precursor comprising O2, wherein the low-χ metal of the metal precursor has an electronegativity of 1.6 or lower.