Electric-field-assisted migration and accumulation of hydrogen in silicon carbide

Abstract

The diffusion of deuterium (Formula presented) in epitaxial (Formula presented) layers with buried highly Al-acceptor doped regions has been studied by secondary ion mass spectrometry. (Formula presented) was introduced in the near surface region by the use of 20-keV implantation after which the samples were thermally annealed. As a result, an anomalous accumulation of (Formula presented) in the high doped layers was observed. To explain the accumulation kinetics, a model is proposed where positively charged (Formula presented) ions are driven into the high doped layer and become trapped there by the strong electric field at the edges. This effect is important for other semiconductors as well, since hydrogen is a common impurity present at high concentrations in many semiconductors. © 2000 The American Physical Society.