To where do silicon atoms go? Still mysterious thermal oxidation

Abstract

The thermal oxidation process of Si consists of four processes: (1) diffusion of oxidizing molecules in the oxide film, (2) reaction of oxidizing molecules and Si at the interface, (3) generation and transport of interstitial Si atoms at the interface associated with the reaction, and (4) volume expansion, viscous flow and deformation of the oxidized region. Such complexity is not noticeable in the thermal oxidation of flat Si, and at first glance it seems that it can be easily understood only by (1) and (2). But in the thermal oxidation of Si three-dimensional nanostructures, the complexity is immediately revealed. We introduce the overall microscopic picture of thermal oxidation process mainly based on our research.