Structural stability for UV irradiation and dielectric properties of a-CNxfilms

Two topics on amorphous carbon nitride (a-CN,) films prepared with 0.52 les s than or equal to x less than or equal to 0.86 are studied and discussed. (a) Structural stability for ultraviolet (UV) light irradiation is measured by X-ray photoelectron spectroscopy (XPS). The x at the surface increases after UV light irradiation in air. The amplitude of C-ls peak related to C- N bond increased. Its binding energy shifts to larger energy after irradiat ion as does the N-1s peak also. The photo-induced change in a-CN, is discus sed comparing with the properties of a-C:H. (b) Structural effect on the re fractive indices, n: is studied by Raman spectroscopy. The it decreases wit h increasing x, which properties could be applied to a low dielectric const ant insulators for ultra large-scale integrated (ULST) technology. However, n is not correlated with the D and G Raman peaks. The structural effect on n and an application of a-CN, to an insulator for ULSI are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.