Electrical properties of SiO2 films deposited by photon-assisted CVD with vacuum-ultraviolet excimer lamp

Abstract

R&D is proceeding in various countries on Vacuum-Ultraviolet Chemical Vapor Deposition (VUV-CVD) as the CVD technique for next-generation semiconductor fabrication. Deposition becomes possible at room temperature because the precursor of the film is photodissociated by vacuum-ultraviolet light, which is short-wavelength ultraviolet light. VUV-CVD is a promising damage-free CVD system in processes where charged particles and neutral particles having kinetic energies above the theoretical photon energy do not exist, and process damage such as high heat, impurity injection, and electrical charges of the semiconductor fabrication process are a concern. The authors fabricated silica film by VUV-CVD using an Xe2 excimer lamp and tetraethylorthosilicate [TEOS, Si(OC2H5)4], which has many uses in the fabrication of interlayer insulating film, and octamethylcyclotetrasiloxane [OMCTS, ((CH3)2SiO)4], which has a cyclic Si-O skeleton. The result of evaluating the leakage current characteristics and the relative dielectric constant, which are electrical characteristics of these films, showed that the OMCTS having a cyclic Si-O skeleton is effective as the silica film precursor in VUV-CVD. This paper reports the electrical characteristics of these silica films formed by VUV-CVD. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(3): 36–43, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10196