REACTIVITY BETWEEN TI AND N2-C2H2 MIXED-GAS ON TI(C, N) FILM DEPOSITION BY ARC-LIKE PLASMA-ENHANCED ION PLATING

The reactivity of Ti with a gas mixture N2-C2H2 on Ti(C, N) films deposited by changing the reactive ion-plating parameters (gas composition ratio [N2]/[C2H2][N2-C2H2]; total pressure P(T) = 1 x 10(-5)-1 x 10(-3) Torr; negative substrate voltage V(s) = 0-920 V; source-substrate distance D(s-s) = 260-473 mm) was investigated. The composition was determined by electron probe microanalysis. The reactivity was evaluated from the composition ratio [N]/[C] of the film to [N2]/[C2H2], i.e. ([N]/[C])/([N2]/[C2H2]). The ratio ([N]/[C])/([N2]/[C2H2]) > 1 means that the reaction of Ti with N2 is faster than with C2H2. The reactivity depended strongly on P(T), on [N2]/[C2H2] and on the deposition rate R, but less markedly on V(s) and on the substrate temperature. At the impingement rate ratio Z(N2 + C2H2)/Z(Ti) < 3 (P(T) < 2 x 10(-4) Torr; [C + N] < 50 at.%), ([N]/[C])/([N2]/[C2H2) is much greater than unity. At Z(N2 + C2H2)/Z(Ti) > 3 (P(T) > 2 x 10(-4) Torr; [C + N] = 50 at.0/o), the reactivity depended strongly on Z(C2H2)/Z(Ti). At Z(C2H2)/Z(Ti) > 3.8, ([N]/[C])/([N2]/[C2H2]) tended to be less than unity.