Effect of hydrogen on hot electron noise in short samples of GaAs

Abstract

We present experimental results on hot electron noise in untreated and hydrogenated samples of silicon-doped GaAs. Short n+-n-n+ structures are used to resolve noise sources arising from different mechanisms which dominate electron scattering. Passivation of centres of impurity scattering by hydrogen and the resultant effect on noise temperature and spectral density of current fluctuations are clearly observed at intermediate hydrogen doses (1017 cm-2): low-field mobility of electrons increases, electron heating by electric field is favoured, noise sources due to Gamma -L and Gamma -X intervalley transfer and resonant scattering of hot electrons are better resolved, especially at low temperatures. The effects at a hydrogen dose of 1018 cm-2 suggest that the impurity passivation is accompanied by formation of new scattering centres.