Microscopic mechanism of carbon annihilation upon SiC oxidation due to phosphorus treatment: Density functional calculations combined with ion mass spectrometry

Abstract

We report first-principles static and dynamic calculations that describe the microscopic mechanism of carbon annihilation due to phosphorus treatment upon silicon carbide oxidation. We identify the most stable form of phosphorus in the oxide as being fourfold coordinated with the dangling PO unit and find that the unit attracts carbon ejected from the interface, thus operating as a carbon absorber. This finding provides a possible microscopic reasoning for the annihilation of C-related defects at the interface. The secondary ion mass spectrometry and electrical characterization of interface state density are also performed to corroborate the theoretical finding above.