Characteristics of multilayered plasma-polymer thin films using toluene and TEOS by PECVD

Abstract

This study investigated the interaction of alternate multilayer ultralow-k TEOS (tetraethoxysilane)-toluene plasma-polymer thin films, as well as their electrical and chemical properties. Multilayered plasma-polymer thin films were deposited on silicon (1 0 0) substrates with the alternate injection of each precursor at room temperature via the plasma enhanced chemical vapor deposition (PECVD) method. Toluene and TEOS were prepared as the organic and inorganic precursors, and hydrogen and argon gases were used as the bubbler and carrier gases, respectively. To compare differences in the electrical and chemical properties of the multilayer plasma-polymer thin films, the hybrid polymer thin films were grown under 30 W of RF (radio frequency using 13.56 MHz) power with different proportions of toluene and TEOS polymer layer in the same total thickness. The as-grown plasma polymer thin films were in first analyzed by using FT-IR (Fourier transform infrared) and FE-SEM (field emission scanning electron microscopy). FT-IR results showed that the hybrid polymer thin films were totally fragmented and polymerized by PECVD. SEM cross sectional images showed alternate TEOS-toluene plasma polymer thin films. Plasma-polymer thin film capacitances were measured to determine the dielectric constant at 1 MHz.