Evaluating apparatus for thermal boundary conductance using acoustic phonon waves

An apparatus for evaluating thermal conductance of a semiconductor interface, the apparatus comprising:

• a spectrometer exciting acoustic phonons in a semiconductor by irradiating a laser beam to the semiconductor;
• and
• a processor evaluating thermal conductance of an interface of the semiconductor in accordance with a phase difference of an ascending acoustic phonon propagating toward the interface and reflecting from the interface and a descending acoustic phonon propagating in an opposite direction to the interface,
• wherein the processor is configured to calculate the phase difference before and after an acoustic reflection of ascending acoustic phonons based on a reflectivity ΔR/R, which has a relationship to the phase difference in [Equation 1],
• Δ
• ⁢
• R
• R
• ∼
• sin
• ⁡
• (
• 2
• ⁢
• nk
• probe
• ⁢
• v
• AC
• ⁢
• t
• +
• ϕ
• 0
• +
• ϕ
• C
• /
• T
• )
• [
• Equation
• ⁢
• 1
• ]
• where n is a refractive index of medium at a probe beam wavelength, kprobe is a wavenumber of a probe beam, vAC is a velocity of acoustic phonons, t is a time delay, φ0 is a phase at a production position of an acoustic phonon, and φC/T is the phase difference between before and after the acoustic reflection of the ascending acoustic phonons.