INTERFACIAL PROPERTIES OF A-SI-H A-SINX-H MULTILAYERS STUDIED BY ELECTROABSORPTION SPECTROSCOPY

By using electroabsorption method, we find that the built-in field (approximately 10(5) V.cm-1) in the a-Si sublayers of a-Si:H/a-SiNx:H multilayers points towards the sample surfaces. We ascribe the internal field to the asymmetric distribution of defect states which exist primarily in the silicon side of the silicon-on-nitride interfaces, owing to the large repellent lattice stress there. We also find that the built-in potential depends strongly on x, with a maximum value near x = 1.0. We intend to explain it as a result of structural softening as more N atoms are introduced into Si networks in the range of x > 1.0.