OPTICAL INVESTIGATION OF STRUCTURES FORMED BY 2 MEV OXYGEN IMPLANTATION INTO SILICON

Silicon was implanted with 2 MeV O+ ions with doses covering the range from 2 x 10(17) cm(-2) to 1 x 10(18) cm(-2) at an implantation temper ature of not less than 600 degrees C. Subsequently, samples were annea led at 1300 degrees C for 6 h. Fourier transform infrared reflection s pectroscopy has been used in order to characterise the as-implanted an d annealed samples. The interference fringes observed in the transpare nt region (1500 cm(-1) to 7000 cm(-1)), are very sensitive to changes in the structure of the examined sample. Cross-correlation with H+ bea m Rutherford backscattering spectroscopy (RES)/channelling results, gi ves a good agreement within the depth resolution (100 nm) of the RES t echnique. No anomalous diffusion was observed during annealing and a b uried layer formed during annealing even for the lowest dose, IR spect roscopy constitutes the most suitable non-destructive method to invest igate structures formed by MeV implantation.