TIN NITRIDE THIN-FILMS PREPARED BY RADIOFREQUENCY REACTIVE SPUTTERING

Tin nitride thin films were obtained by the reactive sputtering method. The metallic tin target was sputtered by nitrogen gas with rf magnetron sputtering equipment. To prevent the re-evaporation of atomic nitrogen from the substrate, the depositions were made at the low substrate temperature of 60 °C. Polycrystalline films were obtained at an rf power lower than 90 W. The resistivity of polycrystalline film was 3-14×10-2 Ω cm, while the resistivity of amorphous film increased monotonically with decreasing sputtering pressure. For amorphous film, the change in resistivity is attributable to the change in carrier concentration. The decrease in carrier concentration is associated with an increase of -N=O combination in the film. The optical energy gap of tin nitride was 1.5 eV. © 1995 American Institute of Physics.