Temperature dependence of the structural properties of amorphous silicon oxynitride layers

Amorphous silicon oxynitride, a-SiOxNy, layers were prepared by nitridation of 7-nm thick thermally grown silicon dioxide, a-SiO2, layers on n-type crystalline Si substrates, in NH3 plasma with different temperatures (<f>TP=300</f>–500 °C). The compositional and structural properties for the a-SiOxNy layers were examined using current–voltage (<f>I–V</f>), capacitance–voltage (<f>C–V</f>), 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 <f>C–V</f> characteristics with varying <f>TP</f>. These results were interpreted as indicating a change in the compressive strain. The <f>I–V</f> characteristics showed that the breakdown strength monotonically decreased with increasing <f>TP</f>. In the distribution of the constituent atoms, the AES profiles were roughly independent of <f>TP</f>. 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 <f>C–V</f> results. [Copyright &y& Elsevier]