Tunneling of X-ray photons through a thin film under total internal reflection conditions

Tunneling of 0.154-and 0.139-nm x-ray photons through a thin film under total internal reflection conditions has been experimentally demonstrated. The NiSi₂ film 13 nm thick is deposited by magnetron sputtering on a polished Si substrate. A beam with an angular spread of 20″ is directed to the Si/NiSi₂ interface from the inside through the lateral surface of a sample. A peak associated with tunneling of photons from Si to air through the NiSi₂ film is observed at grazing angles of θ₁ > 0.4θ_c, where θ_c is the critical angle of total internal reflection at the Si/NiSi₂ interface. The integral intensity of tunneling peaks that is measured for various θ₁ angles agrees with the calculations.