A wafer processing apparatus characterized by having corrosion resistant connections for its electrical connections, gas feed-through channels, recessed areas, raised areas, MESA, through-holes such as lift-pin holes, threaded bolt holes, blind holes, and the like, with the special configurations employing connectors and fillers having excellent chemical resistant properties and optimized CTEs, i.e., having a coefficient of thermal expansion (CTE) that closely matches the CTE of the base substrate layer, the electrode(s), as well as the CTE of coating layer. In one embodiment, a filler composition comprising a glass-ceramic material is employed.