Small angle X-ray scattering from microvoids in the a-SiC:H alloy

Small-angle X-ray scattering (SAXS) measurements on a series of a-SiC:H alloy films deposited in a glow discharge reactor using SiH₄/CH₄ gas mixtures are discussed. It was found that the introduction of C into the a-Si matrix produces a large SAXS signal, which suggests a sizable microvoid density, and which further increases with increasing C content. A Guinier analysis shows that these microvoids are spherical and have an average radius of approximately 6 Å, which increases only slightly with C content. Other measurements (infrared, photoconductivity, film density, optical) made on identically prepared material are included to identify the possible origins of these microvoids and to determine how they affect material quality