Non-destructive Raman evaluation of a heavily doped surface layer fabricated by laser doping with B-doped Si nanoparticles

The heavy B-doping of an intrinsic Si(1 0 0) wafer has been performed by irradiating a B-doped Si nanoparticle film on the surface of the Si(1 0 0) substrate with energy densities of 8.0 and 16.0 J/cm² by 532-nm laser light. The thicknesses of the heavily doped surface layers were investigated using Raman spectroscopy. The observed 488.0-nm-excited Raman bands were decomposed into two bands: a Fano-type band due to the heavily doped Si surface layer and a Voigt band due to the lightly doped, intrinsic Si region. The analysis of the Fano-type band indicated that the carrier concentration of the heavily doped region was larger than approximately 10¹⁹ cm^-3. Based on the two-state model, the thicknesses of the heavily doped surface layers were 480 and 630 nm for the samples prepared with energy densities of 8.0 and 16.0 J/cm², respectively. These values were consistent with those obtained by secondary ion mass spectroscopy (SIMS).