Deep-level transient spectroscopy measurements were performed in order to investigate the effects of substrate growth temperature and dopant species on deep levels in Si layers during low-temperature molecular beam epitaxial growth. The structures studied were n+-p junctions using B doping for the p layer and p+-n junctions using P doping for the n layer. While the density of hole traps H1 (0.38–0.41 eV) in the B-doped p layers showed a clear increase with decreasing growth temperature from 600 to 370 °C, the electron trap density was relatively constant. Interestingly, the minority carrier electron traps E1 (0.42–0.45 eV) and E2 (0.257 eV), found in the B-doped p layers, are similar to the majority carrier electron traps E11 (0.48 eV) and E22 (0.269 eV) observed in P-doped n layers grown at 600 °C. It is hypothesized that these dominating electron traps are associated with pure divacancy defects and are independent of the dopant species. © 2003 American Institute of Physics.