Characterization of hydrogen and oxygen atoms in SiN films produced by plasma‐enhanced reactive sputtering

Silicon nitride films are prepared by helium‐excited magnetron radio‐frequency sputtering. Excitation energy transfer from He to N₂ and existence of hydrogenation and oxidation source (O⁺ and OH⋅) in the plasmas are confirmed by optical emission spectroscopy. The structure and characteristics of the resultant films depend on the gas pressure during sputtering: Films produced at pressures above 5 Pa are etched rapidly in a buffered hydrogen fluoride solution and have low refractive indices because their structure is coarse and rich in oxygen and hydrogen or both.