Deuterium passivation of grain-boundary dangling bonds in silicon thin films

Abstract
Hydrogen passivation of silicon grain boundaries has been investigated by using deuterium as a readily identifiable isotope which duplicates hydrogen chemistry. Deuterium detection with high sensitivity was achieved with secondary-ion mass spectrometry. Diffusion of deuterium in single- crystal silicon and polycrystalline silicon thin films at low temperatures (e.g., 350 °C) clearly demonstrates enhanced diffusion along grain boundaries. Defects at grain boundaries were detected by electron-spin resonance and identified as silicon-dangling bonds. Deuterium passivation of grain boundaries is revealed by correlated deuterium diffusion and dangling-bond annihilation in polycrystalline silicon films.