IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Wednesday Sessions
       Session PS1-WeM

Paper PS1-WeM3
Organic Low-k Film Etching in Inductively Coupled Plasma Employing N@sub 2@/H@sub 2@ and N@sub 2@/NH@sub 3@ Gases

Wednesday, October 31, 2001, 9:00 am, Room 103

Session: Dielectric Etch II
Presenter: H. Nagai, Nagoya University, Japan
Authors: H. Nagai, Nagoya University, Japan
M. Hiramatsu, Meijo University, Japan
M. Hori, Nagoya University, Japan
T. Goto, Nagoya University, Japan
Correspondent: Click to Email
An organic low-k film, FLARE, is one of the most prospective candidates for interlayer films with lower dielectric constants (low-k). N@sub 2@/H@sub 2@ and N@sub 2@/NH@sub 3@ plasmas have been used for etching organic low-k film without degrading the film quality and etch profile. In this study, the organic low-k film was etched in inductively coupled high-density plasmas (ICP) employing N@sub 2@/H@sub 2@ and N@sub 2@/NH@sub 2@ gases. By changing the mixing ratio of these gases, the anistropic etching profile was obtained. The etching plasmas were evaluated by quadruple mass spectroscopy (QMS), optical emission spectroscopy (OES) technique and microwave interferometer. Furthermore, absolute densities of H and N radicals were measured using the vacuum ultraviolet absorption spectroscopy (VUVAS) employing micro-plasma as light source. N and H radical densities were estimated on the order of 10@super 11@ - 10@super 12@ cm@super -3@ and 10@super 12@ - 10@super 13@ cm@super -3@, respectively. It was found that the behaviors of H and N radical densities were dependent on H and N atom ratio of feed gases, and were not related to the kind of gases in N@sub 2@/H@sub 2@, N@sub 2@/NH@sub 3@. The behavior of etch rate corresponded to that of H radical density. The correlation between the behavior of radical, ion and electron densities and the etching characteristics of organic low-k film is investigated. On the basis of these results, the mechanism for anisotropic etching and the surface reaction of radicals on organic low-k film are discussed.