The 18O tracer diffusion method was used to investigate O diffusion in reactively dc-sputtered IrO2 films. The profile measurements were done by secondary ion mass spectrometry. For the investigation of O diffusivity in the samples, temperatures ranging from 600 to 765C were used (figure 25). The O tracer diffusion in IrO2 films was found to be described by:

D (m2/s) = 2.8 x 10-6 exp[-2.73(eV)/kT]

It was also shown that the extrinsic O diffusion was strongly influenced by the film preparation conditions, which was especially important for the application of IrO2 films as O barriers.

Oxygen Tracer Diffusion in IrO2 Barrier Films. C.U.Pinnow, I.Kasko, N.Nagel, T.Mikolajick, C.Dehm, F.Jahnel, M.Seibt, U.Geyer, K.Samwer: Journal of Applied Physics, 2002, 91[3], 1707-9

Figure 25

Diffusion of 18O in IrO2