AVS 49th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP1
Origin of Crystalline Quality Deterioration in Epitaxial Growth of CeO@sub 2@ Layers on Si Substrates

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Poster Session
Presenter: T. Inoue, Iwaki Meisei University, Japan
Authors: T. Inoue, Iwaki Meisei University, Japan
S. Shida, Iwaki Meisei University, Japan
H. Takakura, Iwaki Meisei University, Japan
K. Takahashi, Iwaki Meisei University, Japan
A. Horikawa, Iwaki Meisei University, Japan
N. Sakamoto, Iwaki Meisei University, Japan
M. Ohashi, Iwaki Meisei University, Japan
Correspondent: Click to Email
Cerium dioxide (CeO@sub 2@) is a promising high K insulating material for microelecronic applications with chemical and mechanical stability. It is known that epitaxial CeO@sub 2@(110) layers grow on Si(100) substrates with a long range lattice ordering. It is reported that crystalline quality of the epitaxial layers varies from poly-crystalline to single-crystalline, in the vicinity of the critical temperature of the epitaxial growth. This is thought to be due to nucleus generation mode variation depending on surface asperity, contamination from the growth atmosphere and so on. In order to clarify the origin of the crystalline quality deterioration, it is strongly desired that the direct observation and structural analysis of the surface of epitaxial layers and the interface between the epitaxial layer and the substrate. This paper describes the results of microscopic analyses. AFM analyses indicate that there are three kinds of facets at the CeO@sub 2@ layer surfaces: gable roof shaped CeO@sub 2@(110) facets having excellent crystallinity, irregular shaped CeO@sub 2@(110) hillocks having poor crystallinity and tetrahedral hillocks with (111)-orientation. Cross-sectional TEM observations clarify that the shape and crystallographic structure of the irregular hillocks, whose increase in surface density leads to the deterioration of the epitaxial layer.