AVS 53rd International Symposium
    Plasma Science and Technology Friday Sessions
       Session PS1-FrM

Paper PS1-FrM5
Study of Downstream NH@sub 3@ Plasma Damage to Low k Dielectrics

Friday, November 17, 2006, 9:20 am, Room 2009

Session: Plasma-Surface Interactions III
Presenter: J. Bao, The University of Texas at Austin
Authors: J. Bao, The University of Texas at Austin
H. Shi, The University of Texas at Austin
J. Liu, The University of Texas at Austin
P.S. Ho, The University of Texas at Austin
Correspondent: Click to Email
Carbon Doped Oxide (CDO) films were treated by downstream NH@sub 3@ plasma. The effects of film porosity, ion energy, process time, substrate temperature on carbon depletion and nitrogen incorporation were studied by In-situ angle resolved X-ray photoelectron spectroscopy. Transmission electron microscopy, Fourier transform infrared spectroscopy, Spectroscopic ellipsometry and Atomic force microscopy were employed to evaluate the extent of damage to the films. NH@sub x@ reacted with the surface weakly bonded groups to form a densification layer. It was observed that this structural modification concentrated mainly within 10 nm at the surface region with the underlying film being undamaged. Mechanism of this plasma damage was investigated by analyzing the residual gas during the process. Hybrid beams damaged low k dielectrics more severely due to the combination of ions and neutrals. Roles of ions and neutrals in the plasma to cause carbon depletion will be compared and discussed. Moisture uptake after the plasma treatment was found to be a major reason to induce dielectric constant increase.