Applications of rapid thermal processing to silicon epitaxy

The growth of silicon epitaxy by chemical vapour deposition during a rapid thermal pulse is described, and compared with conventional CVD epitaxy. A thin hydrous oxide film was formed on the silicon substrate surface by a modified RCA process prior to loading into a radiantly heated reactor. Oxide removal and then silicon epitaxial growth was carried out during a rapid thermal pulse at reduced pressure in a hydrogen or argon atmosphere using trichlorosilane as a source gas. The layers grown were undoped and showed a very sharp interfacial dopant profile in comparison to conventional CVD silicon epitaxy. Experiments have also been carried out using rapid thermal processing as a step to remove the silicon native oxide layer from the substrate surface before reducing the temperature to the range 750-900 degrees C in order to carry out extended low-temperature epitaxial growth. This method is also capable of producing sharp interfacial dopant profiles. The two techniques described are compared with respect to the properties of the layers grown.