Gold Atom Implantation into α-SiC by High-Energy Electron Irradiation and State Analysis of the Resultant Phase

Abstract

Bilayer films of Au (target atom)/α-SiC (substrate) were irradiated with 2MeV electrons in an ultra-high voltage electron microscope. By irradiation, gold atoms in the upper layer were implanted into the SiC substrate. Changes in the microstructures and bonding state associated with the implantation were studied by ultra-high voltage electron microscopy and scanning Auger valence electron spectroscopy, respectively. The results obtained are as follows; (1) Irradiation with 2MeV electrons first induces a crystalline-to-amorphous transition in α-SiC. (2) Gold atoms which have been knocked-off from the gold layer by the collision with 2MeV electrons are recoil-implanted into the resultant amorphous SiC. (3) The implanted gold makes preferential bonding with silicon having dangling bonds, and new bonding states are formed between them. (4) During continued irradiation, the gold atoms repeat displacement towards the beam direction, which is induced by the collision with electrons and subsequent bonding with silicon atoms having dangling bonds. The repetition results in the deep implantation of gold into the SiC substrate.