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

Paper DI-WeM7
Radical Enhanced Atomic Layer Deposition of TiN Diffusion Barriers

Wednesday, October 31, 2001, 10:20 am, Room 130

Session: Atomic Layer Deposition for Silicon Devices
Presenter: F. Greer, University of California, Berkeley
Authors: F. Greer, University of California, Berkeley
D. Fraser, University of California, Berkeley
J.W. Coburn, University of California, Berkeley
D.B. Graves, University of California, Berkeley
Correspondent: Click to Email
Atomic Layer Deposition (ALD) has been proposed as one way to deposit highly conformal thin films for copper diffusion barriers due to the self-limiting, layer-by-layer growth that can be achieved with this technology. One problem with thermally activated ALD is that the deposition temperatures that are required to achieve reasonable growth rates and good quality films with low impurity concentrations can be relatively high. This may make the integration of these barrier films with temperature-sensitive films, such as organic low-k films, impossible. One potential alternative to thermal ALD is to use more reactive species such as radicals to catalyze film deposition at lower substrate temperatures. In this work, TiN films are deposited using Radical Enhanced Atomic Layer Deposition (RE-ALD) using separate, alternating pulses of TiCl@sub 4@ and various combinations of hydrogen and/or nitrogen radicals with or without additional pulses of NH@sub 3@. By directing independent beams of each of these species at a given surface (in this case, silicon dioxide coated on Quartz Crystal Microbalances), kinetic parameters of interest such as the sticking and reaction probabilities of these species have been measured as a function of surface temperature, and will be used to predict the conformality of films deposited using RE-ALD in features of arbitrary aspect ratio. Ex-situ XPS analysis of the deposited films will be presented, paying particular attention to the low residual chlorine content that can be achieved with sufficient hydrogen radical exposure (~0.3%) at deposition temperatures as low as 100°C. In-vacuo Auger Electron Spectroscopy film composition measurements will be presented from different stages during the deposition process. Various measurements of the film quality will also be presented including the dependence of the films' resistivity and crystallinity on deposition conditions.