Room Temperature Oxidation of Silicon Catalyzed by Cu3Si

Abstract

ABSTRACTThe dependence of room temperature oxidation of silicon catalyzed by Cu3Si on silicide thickness, silicide grain size and the substrate orientation has been investigated by transmission electron microscopy and x—ray diffractometry.The extent of oxidation was found to depend critically on the thickness of starting Cu3Si film. The oxidation was found to be more restricted on (lll)Si than that of (001)Si samples. The thickness of SiO2 layer was found to decrease with the average grain size of the starting Cu3Si layer. HRTEM revealed that the oxidation is initiated at the grain boundaries. Oxide film as thick as 4.5 μm was grown at room temperature over a period of two weeks in (001) samples. The growth of thick oxide film was achieved by minimizing the grain size of Cu3Si through a reaction between Cu and an intermediate amorphous silicon layer at 200 °C.