Post-hydrogenation anneals of shallow Si(Ga) donors in GaAs indicate t
hat their reactivation rate is enhanced in the presence of an applied
electric field. We show that existing data are consistent with the Si(
Ga)-H complex being a deep donor dissociating only via its ionized sta
te. The 0/+ level of this deep donor is found to be at E(C)-0.75 eV. T
here is no need to appeal to the existence of negatively charged hydro
gen to account for the reactivation of Si(Ga) donors.