THERMAL SPRAY COATINGS FOR SEMICONDUCTOR APPLICATIONS

This invention relates to thermal spray coatings on a metal or non-metal substrate. The thermal spray coating comprises a ceramic coating having a functionally graded porosity across the ceramic coating thickness. The ceramic coating includes an inner layer and an outer layer. The inner layer has a porosity at or near the interface of the inner layer and the metal or non-metal substrate sufficient to provide a compliant ceramic coating capable of straining under thermal expansion mismatch between the ceramic coating and the metal or non-metal substrate at elevated temperature. The outer layer has a decreasing porosity extending from the surface of the inner layer to the surface of the ceramic coating sufficient to provide corrosion resistance and/or plasma erosion resistance to said ceramic coating. This invention also relates to methods of protecting metal and non-metal substrates by applying the thermal spray coatings. The coatings are useful, for example, in the protection of semiconductor manufacturing equipment, e.g., integrated circuit, light emitting diode, display, and photovoltaic, internal chamber components, and electrostatic chuck manufacture.