AVS 46th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP25
Surface Morphology Analysis in Correlation with Crystallinity of CeO@sub 2@(110) Layers on Si(100) Substrates

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: T. Inoue, Iwaki Meisei University, Japan
Authors: T. Inoue, Iwaki Meisei University, Japan
T. Nakamura, Iwaki Meisei University, Japan
S. Nihei, Iwaki Meisei University, Japan
Y. Yamamoto, Hosei University, Japan
Correspondent: Click to Email
In the course of the study on epitaxial growth of CeO@sub 2@ layers on Si(100) substrates, it is found that the layer has (110) orientation and requires substrate temperature above 820°C. Recently, we have succeeded in lowering growth temperature by more than 100°C by using newly developed "electron beam assisted evaporation". In general, epitaxial growth needs enough migration energy for adsorbed atoms and/or molecules. In the vicinity of the critical condition for epitaxial growth, CeO@sub 2@ layers having various crystallinity are obtained depending on growth conditions such as growth temperature, pre-treatment of the Si surface, contents of residual gas in the vacuum atmosphere and so on. It is very important to understand the growth mechanism, which rules crystallinity of the layer. We will present surface morphology analysis by atomic force microscopy (AFM) in correlation with crystallinity of the layers determined by reflection high energy electron diffraction (RHEED). It is clearly observed that surface morphology changes with crystallinity of the CeO@sub 2@ layers. Single crystal samples show a nanometer-scale-periodically corrugated sturcture, which consists of (111)-facets. On the other hand, the surface of poly-crystalline samples with a strong tendency of <111> orientation consists of tetrahedral hillocks with irregular-rotational-orientations within the horizontal plane. Samples with a ring RHHED pattern show a very finely grained surface. These features clearly reflect the difference in the growth mechanism, especially at the early stage of the growth. Results on quantitative analysis of AFM data will be given.