Boron redistribution in a shallow δ-doped Si structure after solid phase epitaxial growth

Abstract

A combination of nuclear reaction analysis, high-resolution sectioning methods, and time-resolved reflectivity have been used to study the boron redistribution from a shallow δ-doped layer in silicon, following deep amorphization and subsequent solid phase epitaxial growth (SPEG). A significant fraction of the boron was found to move into the top 20 nm undoped Si cap layer after SPEG. Over the temperature range of 550–600 °C, the fraction of boron accumulating in the cap layer is increased with the SPEG temperatures. Boron redistribution was enhanced in the sample which was etched in HF prior to SPEG. Possible contributing factors are discussed.