Catalytic oxidation of (001)Si in the presence of Cu3Si at room temperature

Room temperature oxidation of (001)Si catalyzed by Cu3Si has been investigated by transmission electron microscopy (TEM) and x-ray diffractometry (XRD). For η″-Cu3Si thin layer on (001)Si, XRD analysis showed that volume fractions η″-Cu3Si and Cu decrease and increase with the exposure time in air, respectively. TEM revealed the presence of a high density of Cu precipitates in the SiO2 layer. After prolonged exposure in air, the Cu precipitates were observed to form an irregular network. The thickness of starting Cu, hence Cu3Si, layer on silicon was found to be a critical factor in determining the oxidation behavior. Based on the microstructural evolution data, a partial reconstitution of catalytic Cu3Si mechanism is proposed to be the dominant process for the room-temperature oxidation of silicon catalyzed by Cu3Si.