A novel method for suppressing B penetration was reported. The co-implantation of Sb and BF2 into metal-oxide semiconductors was found to diminish the B penetration which was enhanced by the presence of F. The B penetration in BF2-implanted devices was seen to be significantly reduced with increasing dose of co-implanted Sb. Fourier transform infra-red spectroscopic and X-ray photoelectron spectroscopic analyses suggested that the suppression of B penetration was perhaps due to the formation of an Sb-F compound. The latter would reduce F-enhanced B diffusion.

W.T.Sun, C.S.Yang, M.C.Liaw, C.C.H.Hsu: Japanese Journal of Applied Physics, 1996, 35[2-3B], L377-9