極薄Si酸化膜上Geナノドットの界面構造と閉じ込めポテンシャル [in Japanese] Interface-structure Dependent Confining Potential Height and Quantized Energy of Ge Nanodots Fabricated onto the Oxidized Si Substrate [in Japanese]
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Quantum confinement effect in the valence band of Ge nanodots, fabricated onto an ultrathin SiO<Sub>2</Sub> film on Si(111) substrate, was clearly measured by means of photoemission spectroscopy. Dot-size dependent shifts of the highest occupied state were well described by quantized energy levels of confined holes by the spherical parabolic potential. Two-types of Ge nanodots with different interface conditions, named as 'epitaxial' and 'non-epitaxial', can be fabricated depending on the growth temperature. The actual confining potentials for the quantum states in the two-types of Ge nanodots were evaluated, which clearly indicates drastic reduction of the confining potential barrier height for the epitaxial dots owing to voids formed in the interface SiO<Sub>2</Sub> layer just below the Ge nanodots.
- J. Surf. Sci. Soc. Jpn.
J. Surf. Sci. Soc. Jpn. 27(9), 523-529, 2006-09-10
The Surface Science Society of Japan