Structural studies of 20 keV oxygen-implanted silicon

Silicon wafers were implanted with 20 keV O-2(+) up to total fluence of 1 x 10(18) O-2(+) cm(-2) to synthesize SiO2 layers. The FTIR, ESR and C-V studies of as-implanted samples and samples nitrogen-annealed at 500 degrees C and 800 degrees C are reported. The FTIR spectrum of the as-implanted sample shows absorption bands corresponding to the stretching (1050 cm-L strong), the bending (800 cm(-1), weak) and the rocking (415 cm(-1), weak) modes of SiO2, The peaks shift towards higher wave number on annealing. The ESR signal of the as-implanted sample exhibits an isotropic g-value 2.0028, the line width 3.75 G and the spin density 1.1 x 10(16) cm-2 which disappears on annealing at 800 degrees C. The interface state density distribution as a U-shape and a minimum value of similar to 7-8 x 10(11) cm(-2) eV(-1). (C) 2000 Elsevier Science B.V. All rights reserved.