Influence of flow ratio of N_2 to (N_2+Ar) mixture on the structure and properties of zirconium nitride films prepared by radio frequency magnetron sputtering

摘要

Zr-N films were grown on glass and Si (100) substrate by radio-frequency magnetron sputtering using a mixture of high pure nitrogen and argon as sputtering gases. The structure and properties of Zr-N compounds in the films change with N_2/(N_2+Ar) flow ratio (R_(N2))- At low R_(N2), a ZrN alloy with the rocksalt structure (denoted as γ-ZrN_x) is formed. The N concentration x and lattice constant increases with increasing R_(N2), and x reaches 1 when the R_(N2) goes up to 20%. As the R_(N2) exceeds 20%, the film is composed of γ-ZrN and Zr_3N_4 phase with Th_3P_4 structure (denoted as c-Zr_3N_4). The relative content decreases for the γ-ZrN but increases for the c-Zr_3N_4 with increasing R_(N2), and a single phase of c-Zr_3N_4 was deposited on glass at R_(N2) of 100%. The c-Zr_3N_4 behaves with p-type conductivity with a band gap of 2.8 eV. The lattice constant of the c-Zr_3N_4 was measured to be ～0.674 nm. The mechanism of the phase transition from γ-ZrN to c-Zr_3N_4 with increasing R_(N2) was suggested.