Temperature dependence of the structural properties of amorphous silicon oxynitride layers

摘要

Amorphous silicon oxynitride, a-SiO_xN_y, layers were prepared by nitridation of 7-nm thick thermally grown silicon dioxide, a-SiO_2, layers on n-type crystalline Si substrates, in NH_3 plasma with different temperatures (T_p = 300-500℃). The compositional and structural properties for the a-SiO_xN_y layers were examined using current-voltage (Ⅰ-Ⅴ), capacitance-voltage (C-V), electron spin resonance (ESR), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy and Fourier transform infrared measurements. We found a strong correlation between the change in the ESR spin density and that in the C-V characteristics with varying T_p. These results were interpreted as indicating a change in the compressive strain. The Ⅰ-Ⅴ characteristics showed that the breakdown strength monotonically decreased with increasing T_p. In the distribution of the constituent atoms, the AES profiles were roughly independent of T_p. The changes in the 800 and 1070 cm~(-1) IR absorption bands were also examined based on those in the compressive strain, as well as a proposal for interpreting the ESR and C-V results.