Conversion of sputtering time into depth in depth profiles of oxidized CuNi alloys obtained by glow discharge spectroscopy

Depth analyses of oxidized Cu–Ni alloys were performed in the constant voltage mode by glow discharge optical emission spectroscopy. A Cu‐rich oxide was segregated on the surface of Cu–Ni oxidized layer and, moreover, the discharge current varied strongly with the sputtering time. Therefore, it is presumed that the sputtering rate varied with the sputtering time. The dependence of the sputtering rate on the composition of samples was investigated for oxidized Cu–Ni layers in order to convert intensity vs. sputtering time to intensity vs. depth. The region of the Cu‐rich oxide layers in the corrected depth profiles was larger than that in the uncorrected sputtering time profile.