There is a strong need to protect current and future thin film devices from the effects of moisture attack from the environment in which they operate. Typically, such barriers are also required to be transparent as part of their functionality. This paper will illustrate a method to create single and multilayer barrier structures that can offer a high degree of protection of the underlying devices. These structures are created by a mixture of vacuum plasma processes – both physical vapour deposition (PVD) and chemical vapour deposition (CVD). The effectiveness of the structures has been assessed by an acid vapour etching of a sacrificial layer to mimic the underlying device. A mode of hybrid PVD/PECVD deposition has been developed that can create a single layer coating structure with enhanced levels of protection normally only associated with multi-layer structures. The key to the effectiveness of a single layer is ability to ‘heal’ itself during deposition so that through layer defects are not present in the structure. This ability has been termed a ‘self-healing’ moisture barrier due to the unusual ability to prevent defects during deposition.