Conformal damage-free encapsulation of chalcogenide materials

Methods and apparatuses for forming an encapsulation bilayer over a chalcogenide material on a semiconductor substrate are provided. Methods involve forming a bilayer including a barrier layer directly on chalcogenide material deposited using pulsed plasma plasma-enhanced chemical vapor deposition (PP-PECVD) and an encapsulation layer over the barrier layer deposited using plasma-enhanced atomic layer deposition (PEALD). In various embodiments, the barrier layer is formed using a halogen-free silicon precursor and the encapsulation layer deposited by PEALD is formed using a halogen-containing silicon precursor and a hydrogen-free nitrogen-containing reactant.