Interfacial reactions in the Zr–Si system studied by in situ transmission electron microscopy

Abstract

The interfacial reactions in the Zr–Si system have been studied by in situ cross-section transmission electron microscopy (TEM) including high-resolution-mode energy-dispersive spectroscopy (EDS) and nanobeam electron diffraction (nanodiffraction). The as-deposited Zr film has a columnar structure and an amorphous interlayer is observed at the Zr/Si interface. The amorphous layer is found to grow during annealing at 400 °C. The growth of the amorphous layer consists of three stages: a rapid increase in the early stage, a gradual increase in the intermediate metastable stage, and saturation in the final stage. The kinetics at each stage are discussed with in situ TEM observation and ex situ EDS analysis. Annealing at 500 °C creates a ZrSi2 layer at the amorphous layer/Si interface. The phase and orientation relationship are determined from the nanodiffraction patterns. The ZrSi2 is found to grow layer by layer into the Si substrate via a ledge mechanism.