Generation, saturation, and annealing characteristics of metastable defects formed by electron beam irradiation at 20 keV and photon irradiation at 1.9 eV have been compared. Saturation density reached by electron irradiation is temperature independent over the range 225 K to 300 K, although a small activation energy of the generation rate may be present. This differs from observed temperature dependent light-induced saturation from 330 K to 470 K, although differences are expected because of the separate temperature ranges and dissimilar carrier excitation rates. The electron beam-induced saturated defect density is about 5 times larger than for light-induced saturation at 350 K and high light intensity (generation rate ≈ 1022cm-3s-1). Defects formed by electron irradiation anneal at 300 K with a stretched exponential time constant three orders of magnitude smaller than for light-induced defects. After electron irradiation, dark conductivity relaxes faster than photoconductivity. Once the dark Fermi level becomes constant during defect density relaxation, photoconductivity is inversely proportional to the defect density.