As semiconductor devices become smaller and more complex, eliminating device-degrading contamination (i.e. metal ions, particulate, etc.) becomes more significant. At the same time, material removal (etch) has become increasingly important and has led to the introduction of more aggressive chemicals for both creation of the needed geometries and the need to maintain clean processing chambers. These chemicals require clean and inert pathways with minimal impact to the process. Amorphous silicon (a-Si:H) applied by a thermal chemical vapor deposition (CVD) process is an attractive candidate material for providing the necessary barrier between the corrosive process gases and the gas supply piping.