The authors have studied photoluminescence (PL) from Er-doped Si-rich Si oxide (SRSO) films deposited by magnetron sputtering of an Er+Si+SiO2 composite target in Ar or Ar+H-2 ambients. When the samples were annealed in N-2, for the film grown in an Ar ambient, the PL annealing behaviors reveal that the emissions from the film are defect-related and that the Er3+ PL at 1.54 mu m is possibly triggered by a defect-mediated energy transfer process; while for the films grown in an Ar+H-2 ambient, the emissions from the SRSO matrix are suppressed and the Er PL intensities increase significantly but differently dependent on the Ar:H-2 ratios during sputtering. After annealing the samples in an Ar+5%H-2 (FG) ambient, however, almost no Er PL was observed from the film grown in the Ar ambient, while the Er PL intensities of the films grown in the Ar+H-2 ambient increase further compared to those annealed in N-2. Fourier transform infrared spectroscopy shows that the absorption of the samples after FG annealing is weaker than after annealing in N-2. The PL properties have also been compared to those of a sample grown by plasma enhanced chemical vapor deposition. The roles of hydrogen during sputtering and postdeposition annealing are discussed.