Shallow thermal donors (STDs), generated in Czochralski silicon, annealed at 470°C in a hydrogen plasma, and detected by their infrared (IR) electronic absorption, have ground states that shift slightly (∼0.1 ${\mathrm{cm}}^{-1\mathrm{}}$) to smaller binding energies, when deuterium is introduced instead of hydrogen, demonstrating the presence of a hydrogen atom in the donor core. No other IR spectrum is detected apart from that from neutral double thermal donors (TDs). The same optical transitions are observed in three annealed samples given a preheat treatment in water vapor. These latter samples show the NL10 electron-paramagnetic-resonance (EPR) spectrum, recently attributed to hydrogen passivated TDs. The relative strengths of the EPR NL10 spectra correlate with those of the STD IR spectra, providing a strong indication that both spectra arise from the same defects.

• Received 14 February 1996

DOI:https://doi.org/10.1103/PhysRevB.54.R6803