AVS 52nd International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session EM2-TuM

Paper EM2-TuM8
The Effect of Surface Pre-treatment upon the Growth of Hafnium Dioxide Layers on Silicon

Tuesday, November 1, 2005, 10:40 am, Room 312

Session: High-k Dielectric Characterization
Presenter: J. Wolstenholme, Thermo Electron, UK
Authors: P. Mack, Thermo Electron, UK
R.G. White, Thermo Electron, UK
J. Wolstenholme, Thermo Electron, UK
T. Conard, IMEC, Belgium
Correspondent: Click to Email
Angle resolved XPS (ARXPS) has been shown to be a powerful tool for the determination of the thickness of ultra-thin films. In the case of high-k dielectric layers, the technique is capable of measuring the thickness of both the high-k layer and intermediate layers of silicon dioxide or metal silicate. The values for layer thickness are in close agreement with those generated by a variety of other techniques. As well as knowing the thickness of these layers, it is important to determine whether the layers are continuous or whether the coverage of the high-k layer is only partial. Using ARXPS, a method has been developed to determine whether the coverage of the high-k material is continuous and, if not, to calculate the fraction of the surface that is covered. The method has been applied to HfO@sub 2@ layers produced using atomic layer deposition (ALD) on silicon wafers whose surfaces had received three different types of surface treatment. The way in which the layers grow and the nature of the resulting layer were found to depend upon the pre-treatment method. For example, growth on a thermal silicon dioxide surface resulted in complete coverage of HfO@sub 2@ after fewer ALD cycles than layers grown on an HF last surface. The results from ARXPS will be compared with those obtained from ToF SIMS that have been shown earlier to be a valuable alternative to the LEIS analysis.