Properties of SOI-SIMNI films

SOI-SIMNI films were formed by different methods. The wafers were evaluated by means of IR, X-ray, SR, Hall-effect and DLTS studies. The three peak coefficients of IR spectra were calculated using our experimental data. A new nondestructive method is suggested to determine the thickness of a buried Si₃N₄ layer in a SOI-SIMNI film with IR spectra measurements. The X-ray diffraction lines were used to analyse the structure of the SOI-SIMNI films. The X-ray results proved that the buried silicon nitride layers are partly polycrystal α-Si₃N₄. The unit-cell contents are Si₁₂N₁₆ (28 atoms with hexagonal structure). Hall-effect measurements (4-300 K) show that in some SIMNI films, the carrier concentration of the surface silicon layers is much higher than the virgin substrate silicon; and the DLTS results indicated that there are some deep level defects E_t=0.152 or 0.392 eV in the n-Si(100) surface layers of SOI-SIMNI films