Low-temperature native oxide removal from silicon using nitrogen trifluoride prior to low-temperature silicon epitaxy

Abstract

The native oxide of silicon has been shown to be removed in situ within a radiantly heated epitaxial reactor by passing a gas mixture of nitrogen trifluoride and hydrogen over a silicon substrate at a temperature of 580 °C. After oxide removal, silicon epitaxy has been grown from silane at temperatures between 750 and 850 °C forming abrupt dopant profiles at the substrate/layer interface of arsenic-, boron-, and antimony-doped substrates. It has been demonstrated that this epitaxial process may be adapted to a closely spaced, vertically stacked substrate geometry with the consequent large increase in reactor loading.