Phonon transport properties depending on crystal orientation analyzed by nanoindentation using single-crystal silicon wafers
Oga Norimasa, Masataka Hase, Mai Hayamizu, Sho Nagata, S. Tanaka, Shugo Miyake, Tsuyoshi Nishi, Hiroshi Murotani, Masayuki Takashiri
Abstract
The influences of crystal orientation on phonon transport properties were analyzed by nanoindentation using single-crystal Si wafers. The elastic moduli and group velocities of [100]-oriented Si were lower than those of [111]-oriented Si. The phonon mean free path (MFP) exhibited the opposite trend. Phonon transport properties were calculated using Hooke's law with a stiffness tensor. The measured phonon MFP of the [100]-oriented Si were approximately 13% different from the corresponding semi-theoretical values, while those of the [111]-oriented Si were comparable to the corresponding semi-theoretical values, according to the difference in atomic density of each crystal plane of Si.