| 摘要 |
PROBLEM TO BE SOLVED: To improve electric conductivity and light emitting and receiving characteristics of a isotope superlattice semiconductor device by reducing the scattering between conduction bands in a semiconductor. SOLUTION: In an isotope superlattice semiconductor device, first layers which are formed by growing 28Si in the direction of one crystal axis, which is not parallel with 100}-crystal plane, for example, in the <111>-direction by five atomic layers and second layers formed, by growing 30Si in the <111>- direction by five atomic layers are alternately laminated upon one another. When an isotope supperlattice is constituted by alternately laminating layers respectively formed by growing the 28Si and 30Si isotopes by five atomic layers, the maximum wave number of lattice vibrations is reduced to 1/5, which is smaller than the wave number vector between conduction bands, and transition is prevented. Therefore, the electric conductivity and light emitting and receiving characteristics of the semiconductor device can be improved by suppressing the scattering between conduction bands by phonons. Even when such a multi- valley semiconductor as the Ge, SiGe mixed crystal, etc., is used, the characteristics of the semiconductor device can be improved significantly, by suppressing the scattering between conduction bands. |
