AVS 51st International Symposium
    Applied Surface Science Monday Sessions
       Session AS-MoP

Paper AS-MoP17
Photoelectron Spectroscopy Study of the Aging and Plasma Treatments Effects on PECVD a-SiC:H Films for Advanced Interconnects

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: V. Jousseaume, CEA-DRT-LETI, France
Authors: V. Jousseaume, CEA-DRT-LETI, France
O. Renault, CEA-DRT-LETI, France
G. Passemard, ST-Microelectronics, France
Correspondent: Click to Email
The ageing of amorphous hydrogenated SiC (a-SiC:H) films grown by PECVD and used as potential low k dielectric barrier materials in advanced interconnects was investigated by x-ray photoelectron spectroscopy. Very thin layers (20-60 nm) and a special sample holder were used in order to minimize detrimental charging effects during analysis. It is shown that ageing on non-treated films proceeds by the introduction of up to 20at.% of oxygen into the film after 15 days of air exposure in the clean room, and that O is present in relatively high concentration at the very early stages of air exposure@footnote 1@. By XPS is evidenced the benefits of both He and H2 plasma treatments in term of drastic limitation of the reoxidation upon ageing, with an atomic percentage of O being stable at around 7at.% after 15 days. At the same time, on untreated samples, the Si/(Si+C) ratio is remaining constant and both Si2p and C1s core-level profiles show up a constant evolution as a function of ageing time, with a decrease of the relative intensity of Si-C bonds and an increase of oxycarbide and C-C, C-H groups. This evolution will be compared with the case of plasma treated samples and possible mechanisms of ageing will be proposed taking into account results from FTIR analysis, stress and dielectric constant measurements@footnote 2@. @FootnoteText@ @footnote 1@McCurdy et al., J. Electrochem. Soc., 145-9 (1998) 3271).@footnote 2@Jousseaume et al., E-MRS Meeting 2004.