AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Tuesday Sessions
       Session DI-TuM

Paper DI-TuM8
The Effect of Surface Preparation and Post Growth Annealing on the Thickness and Composition of High-k Layers Grown on Silicon

Tuesday, November 4, 2003, 10:40 am, Room 317

Session: High-k Dielectric Growth and Processing
Presenter: J. Wolstenholme, Thermo Electron, UK
Authors: T. Conard, IMEC, Belgium
R.K. Champaneria, Thermo Electron, UK
P. Mack, Thermo Electron, UK
R.G. Vitchev, Facultes Universitaires Notre-Dame De La Paix (FUNDP), Belgium
R.G. White, Thermo Electron, UK
J. Wolstenholme, Thermo Electron, UK
Correspondent: Click to Email
The move to high-k materials for gate dielectrics brings with it a new set of parameters that require characterisation. As with silicon dioxide, the thickness of the layer must be measured but, in addition, the thickness of any intermediate layer must be measured also. The chemistry of the intermediate layer is likely to affect the electrical properties of the layer and therefore needs to be understood along with the factors that affect this chemistry. XPS has an information depth that is similar to the thickness of the layers and, therefore, can be used to characterise them. If the information depth is controlled by varying the photoelectron emission angle (angle resolved XPS or ARXPS) more information becomes available. Thickness of surface and subsurface layers can be measured with accuracy and precision. The chemical state of each component of the material can also be determined and the distribution of chemical states within the layer can be measured. Since no material is removed during the measurements, ARXPS can be regarded as a non-destructive technique. This technique has been used to analyse HfO2 and Al2O3 layers on silicon prepared by ALD or MOCVD. A comparison will be made of the layers grown on relatively thick (up to ~1 nm) silicon oxide with those grown on thin oxide layers and on layers containing nitrided SiO2. It will be shown how XPS and ARXPS can determine the effect of the preparative method on the thickness of the layers and the chemical states of the component materials. The results will be presented in the context of those on the same materials from other techniques.