Investigation of Gas Phase Species and Deposition of SiO₂ Films from HMDSO/O₂ Plasmas

Abstract

Abstract Summary: SiO x C y H z films are deposited by radio frequency plasma enhanced chemical vapor deposition (PECVD) using a mixture of HMDSO and oxygen as source gases. The gas phase species produced in HMDSO and HMDSO/O 2 plasmas are investigated by optical emission spectroscopy (OES) and mass spectrometry (MS). These data reveal that oxygen dilution causes strong dissociation of the HMDSO monomer. The film composition was investigated with X‐ray photoelectron spectroscopy (XPS) and Fourier‐transform infrared (FT‐IR) spectroscopy. Low O 2 dilution (≤50%) results in the deposition of polymer‐like SiO x C y H z films while higher O 2 dilution (≥80%) results in the deposition of inorganic SiO 2 ‐like films. Surface energy measurements show that the SiO 2 films have higher surface energy than the polymer‐like SiO x C y H z films. Deposition rates are measured with variable angle spectroscopic ellipsometry and are strongly dependent on the percentage of O 2 dilution in the feed mixture. Si 2p high‐resolution XPS spectra of films deposited in 50 W HMDSO/O 2 plasmas with different gas ratios in the feed. magnified image Si 2p high‐resolution XPS spectra of films deposited in 50 W HMDSO/O 2 plasmas with different gas ratios in the feed.