Atomic configuration and charge state of hydrogen at dislocations in silicon

The effect of the introduction of hydrogen upon the vibration spectra and electrical characteristics of samples with dislocation networks at the interface of bonded silicon wafers was studied. In order to improve the sensitivity of measurements and to distinguish the signal from dislocation networks in Raman spectra, thin foils conventionally prepared for transmission electron microscopy were used as the sample under investigation. In the samples with dislocation networks, a Raman peak at 2000 cm$^{-1}$ was observed. This peak survived after annealing at a temperature of $T$ = 500$^\circ$C and was not observed in reference samples. Comparison of the experimental data with currently available theoretical calculations allowed one to attribute the observed peak to neutral hydrogen atoms $H^0$ at the center of Si–Si bonds. The peak is metastable in the ideal lattice, but becomes stable in the vicinity of dislocations.