A protective coating is provided for components of an immersion lithography tool, in which at least a portion of a component exposed to the immersion fluid is protected by a thin, hard protective coating, comprising materials such as silicon carbide, diamond, diamond-like carbon, boron nitride, boron carbide, tungsten carbide, aluminum oxide, sapphire, titanium nitride, titanium carbonitride, titanium aluminum nitride and titanium carbide. The protective coating may be formed by methods such as CVD, PECVD, APCVD, LPCVD, LECVD, PVD, thin-film evaporation, sputtering, and thermal annealing in the presence of a gas. The protective coating preferably has a hardness greater than a Knoop hardness of about 1000 and more preferably greater than about 2000, or a Moh hardness greater than about 7, more preferably greater than about 9. The protective coating minimizes defects due to mechanical wear of scanner components.