An In-Situ Transmission Electron Microscopy Study of the Oxidation of Clean Si Surfaces

The transformation of a clean Si surface to a buried Si/SiO sub 2 interface is observed directly in-situ in a UHV transmission electron microscope. The roughness of the buried interface can be probed directly in plan-view imaging and diffraction. We observe that interfaces resulting from native oxidation of atomically flat surfaces remain locally flat, whereas the chemically polished Si surface exhibits a very rough Si/SiO sub 2 interface after room temperature oxidation. Similar techniques can be used to probe the interfaces of high-temperature oxidized Si in a less ambiguous fashion than high resolution electron microscopy in cross-section.