Characteristics of low-k SiOC(-H) films deposited at various substrate temperature by PECVD using DMDMS/O-2 precursor

Abstract

We report on the influence of substrate temperature on SiOC(-H) thin films deposited on p-type Si(100) substrates by plasma enhanced chemical vapor deposition (PECVD) with dimethoxydimethylsilane (DMDMS) and oxygen gas as precursors. The films were deposited at various substrate temperatures with a radio frequency (rf) power of 500 Wand working pressure of 700 mTorr. Fourier transform infrared (FTIR) spectroscopy was used in the absorbance mode over the range of 400 to 4000 cm(-1) which showed the various bonding configurations such as Si-O-Si(C), Si-CH3,-OH, and CHn, bonds in the SiOC(-H) films. The X-ray photoelectron spectroscopy (XPS) was used to study the binding energies of Si-C, SiO-C-3, SiO2-C-2, SiO3-C, Si-O-2, C-C, C-H and C-O bonds in the SiOC(-H) films as a function of the substrate temperature. The dielectric constant of the SiOC(-H) films was measured using a metal insulator semiconductor (MIS, Al/SiOC(-H)/p-Si) structure at 1 MHz frequency. The lowest dielectric constant of the films deposited at room temperature was 2.22 and was achieved with DNMMS/O-2 precursor. (C) 2007 Elsevier B.V. All rights reserved.