The hardness of iron (N) films sputtered in Ar-N/sub 2/ mixtures

RF sputtered iron films can be significantly hardened from about 13 GPa to about 19 GPa by adding nitrogen to the sputtering atmosphere. The dependencies of hardness on the operating parameters for RF diode sputtering are reported. At a fixed bias the hardness depends only on the ratio of nitrogen partial pressure to iron deposition rate. The hardness correlates well with grain size, increasing for decreasing grain size.<
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