An electron paramagnetic resonance study was made of B-doped or P-doped oxide films on Si. It was found that the principal defects were the B-O-hole and P-O-hole centers, which involved electrons on O atoms; with nearby B or P. The results demonstrated that the centers were activated by hole capture. Holes were trapped very efficiently in both B-doped and P-doped materials. However, electrons were more efficiently trapped in B-doped material. The electrical data could be explained by assuming that the precursor to the B-O-hole center was negatively charged and that the precursor to the P-O-hole center was electrically neutral.

W.L.Warren, M.R.Shaneyfelt, D.M.Fleetwood, P.S.Winokur: Applied Physics Letters, 1995, 67[7], 995-7