Electron spin resonance study of a platinum-manganese complex in silicon

We observed ESR signals related to Pt and Mn in both n-type and p-type Si. The observed hyperfine structure clearly indicates that the Pt-Mn complex involves one Pt atom and one Mn atom. The anisotropic g-tensor obtained by analyzing the angular dependence of the ESR signals indicates the trigonal (C_3v) symmetry with the g-values of g_|| = 2.2, g_⊥ = 2.1, and the g_|| axis along the 〈1 1 1〉 direction. Since it has been known that isolated Pt and Mn atoms occupy substitutional and interstitial sites in Si, respectively, we expect that the Pt-Mn complex consists of a substitutional Pt and an interstitial Mn. In addition, we investigated the dissociation of the complex by thermal treatment at 350-400 °C. The activation energy for the dissociation was determined to be 0.96 eV, which was a little higher than that for the diffusion of interstitial Mn in Si. We assume that interstitial Mn diffuses away, leaving a substitutional Pt atom after the dissociation of the Pt-Mn complex.