AVS 51st International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP24
High-density Plasma in Low-pressure will Cast a Bright Foresight in a 45 nm Node Etching Process

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

Session: Poster Session
Presenter: T. Hayashi, ULVAC, Inc., Japan
Authors: Y. Morikawa, ULVAC, Inc., Japan
T. Hayashi, ULVAC, Inc., Japan
K. Suu, ULVAC, Inc., Japan
M. Ishikawa, ULVAC, Inc., Japan
Correspondent: Click to Email
For the next-generation lithography, whose target dimensions are below the 100 nm realm, ArF lithography is considered to be a promising technique. However, an ArF resist has poor etching resistance, which brings on low mask selectivity and results in striation or pitting by resist degradation. This is a serious problem in a future device fabrication. We have studied etching characteristics of organic materials in view of pressure dependence and relations of etching species. Obtained results suggest organic materials are very reactive with atomic hydrogen, oxygen, halogen and other molecular radicals, and therefore, high density plasma in low pressure below 1 Pa is very useful to achieve anisotropic etching of organic films and porous dielectric materials with ArF resist mask without striation. Organic materials including ArF resist may react with radicals, so chemical / physical properties of the organic films may change and resulting degradation may occur under the energetic particle irradiation in the etching plasma. An important issue in the porous low-k etching process is the film damage(ref.1) (degradation of the etched sidewall). If the thick sidewall protective film is formed, this damage may be suppressed. However, it is necessitated that a thin protective film is formed on the sidewall in the finely patterned holes and lines below 100 nm. Nitrogen additive plasma may answer this problem. Under a certain etching condition, it was deduced that the protective thin film formed in the nitrogen additive plasma was composed by some kinds of fluorinated acrylonitrile polymer. 1) Y. Morikawa, N. Mizutani, M. Ozawa, T. Hayashi, W. Chen, and T. Uchida, J. Vac. Sci. Technol., B 21 (2003) 1334.