Silicon on Sapphire (SOS) 薄膜の電気的性質—残留歪効果—

抄録

Silicon on sapphire (SOS) is subjected to a large lateral compressive strain (_??_4×10^-3) due to the thermal expansion coefficient difference between silicon and sapphire. In this paper, electrical properties of SOS influencd by this strain through the change of the band structure are reviewed. In the conduction band of (001) SOS, the energy of k_z valley is raised by _??_60 meV relative to those of k_x and k_y valleys, which reduces the electron mobility and produces elastoresistance and magnetoresistance anisotropies different from those for bulk n-type silicon. The compressive strain splits the quartet state J=3/2 at the top of the valence band into m_J=±3/2 and m_J=±1/2 states. Room-temperature magnetoresistance anisotropy of p-type (001) SOS and p-channel MOS Hall mobility which exceeds n-channel one below _??_130 K may be interpreted by the upper, anisotropic and non-parabolic m_J=±3/2 band.