AVS 47th International Symposium
    Dielectrics Wednesday Sessions
       Session DI+EL+MS-WeM

Paper DI+EL+MS-WeM4
Impact of Hydrogen Addition on the Deposition Rate of SiOF Films Prepared by High Density Plasma CVD

Wednesday, October 4, 2000, 9:20 am, Room 312

Session: Low K Dielectrics
Presenter: K.S. Wong, Nanyang Technological University, Singapore
Authors: Y.W. Teh, Nanyang Technological University, Singapore
T.C. Ang, Chartered Semiconductor Manufacturing, Singapore
K.S. Wong, Nanyang Technological University, Singapore
K.H. See, Chartered Semiconductor Manufacturing, Singapore
S.Y. Loong, Chartered Semiconductor Manufacturing, Singapore
Y.C. Wong, Chartered Semiconductor Manufacturing, Singapore
Correspondent: Click to Email
Fluorinated Silicon Dioxide film (SiOF) has been considered as the more successful first generation interlevel low-k dielectric material. However, the impact of hydrogen addition on SiOF film properties are not extensively studied. In this paper, we present a spectroscopic study of the chemical bonding in SiOF film grown with silane gas added to the standard precursors using the techniques of ellipsometry and infrared (IR) absorption spectroscopy. These SiOF films have been prepared by high density plasma (HDP) chemical vapor deposition at substrate temperature at about 420°C. Addition of hydrogen through silane gas feed is found to control deposition rate and the fluorine doping concentration of the SiOF films. The addition of SiH4 does not lead to the incorporation of hydrogen in detectable quantities in the SiOF films. This phenomenon may be attributed to the strong mutual attraction between hydrogen and fluorine radicals in the HDP. The decrease of refraction index at 632.8nm and the frequency decrease of the dominant IR active bond-stretching vibration at ~1085cm@super -@@super 1@ were found to be approximately linear with increase in fluorine concentrations. The silane added to the process gas mixture has been found to play an active role in the SiOF film formation process both in the surface reactions and the chemical bonding properties. Our results show that with an optimized silane flow rate, the film stability of the SiOF towards moisture attack is significantly improved. In addition, a high deposition rate can be achieved together with comparable fluorine incorporation in the film as compared to the standard non-silane precursors.