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.