Microstructural and Chemical Evolution of –CH[sub 3]-Incorporated (Low-k) SiCO(H) Films Prepared by Dielectric Barrier Discharge Plasma

Abstract

The present work focuses on the incorporation of radicals in organic SiCO(H) films with low dielectric constant . The SiCO(H) films were deposited by dielectric barrier discharge plasma method using a mixture of and Ar gases at different conditions (varying the frequency and pressure). The evolution of the film microstructure was investigated by means of X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) absorption spectroscopy, and atomic force microscopy (AFM). Various bonds, C–C, C–O, Si–O, and , were observed in XPS. In XPS analysis, it is observed that at higher frequency range (from ), radicals (in the form of ) increase significantly. FTIR absorption spectra consist of several vibrational bands: namely, Si–O–Si asymmetric stretching at , symmetric deformation of the group in configuration at , C–H stretching of ( and 3) groups in the region between 3050 and , and –OH related vibrational bands in the range between 3700 and . The change in various deposition parameters causes the change in different Si–O–Si vibrational band ratio, and the intensity of and . The film roughness was verified by AFM measurement.