The effect of exposure of Si Si-SiO₂ structure to atomic H by PECVD reactor

The effect of H plasma exposure parameters, such as power, pressure and temperature, on the Si-SiO₂ interface is investigated. Inductively coupled photoconductivity decay measurements indicate an increase in carrier recombination at the surfaces following atomic hydrogen exposure, as measured by an increase in the emitter saturation current density. This increase is chiefly due to the generation of additional, recombination active defects. These defects are not thermally stable and are removed by subsequent thermal treatments above 300°C in N₂. In addition, atomic hydrogen results in the passivation of a certain fraction of thermally stable interface defects. However, the fraction of defects passivated is always lower than can be achieved by exposure to molecular hydrogen. Variation of sample temperature during atomic H exposure in the range 25-400°C does not have a significant impact on the passivation efficiency.