Acoustic Phonon Scattering in Free‐Standing Anisotropic Silicon Plates

The electron–acoustic‐phonon interaction in a free‐standing anisotropic Si plate with (001) surface is studied taking into account the elastic anisotropy of the Si crystal and the modulated phonon modes. The interaction potential is derived from the modulated phonon modes and the anisotropic deformation potential constants. The effective deformation potential constant D ac is then calculated considering only the lowest electronic sub‐band. In the quantum well model for the electronic states, it is shown that the effective deformation potential for the modulated phonons in an anisotropic Si plate becomes D ac ≈ 13 eV in the thinner region of the plate thickness . It is also shown that both the phonon modulation and the crystal anisotropy have non‐negligible effects on the effective deformation potential and electron mobility.