Effect of size on eutectic temperature lowering in Ag-Ge layered films

Abstract

We report the results of the systematic experimental investigation of the eutectic temperature size dependence for Ag-Ge binary system. The Ag-Ge layered films have been produced by sequential deposition of components in vacuum at room temperature. The eutectic temperature TE as a function of Ag film thickness has been measured in a wide range of film thicknesses with use of in situ and ex situ TEM techniques. The significant lowering of TE with the film thickness reduction was registered. In particular, the lowest thickness of the Ag film required for the liquid phase formation at the metalsemiconductor interface was estimated to be ≈1.2 nm, while the onset temperature of this process was found to be ≈200 °C.