In the present study, the thermal conductivity of a silicon nitride(Si3N4) thin-film is evaluated using the dualwavelength pump-probe technique. A 100-nm thick Si3N4 film is deposited on a silicon (100) wafer using the radio frequency plasma enhanced chemical vapor deposition technique and film structural characteristics are observed using the X-ray reflectivity technique. The film’s thermal conductivity is measured using a pump-probe setup powered by a femtosecond laser system of which pump-beam wavelength is frequency-doubled using a beta barium borate crystal. A multilayer transient heat conduction equation is numerically solved to quantify the film property. A finite difference method based on the Crank-Nicolson scheme is employed for the computation so that the experimental data can be curve-fitted. Results show that the thermal conductivity value of the film is lower than that of its bulk status by an order of magnitude. This investigation offers an effective way to evaluate thermophysical properties of nanoscale ceramic and dielectric materials with high temporal and spatial resolutions.

Abstracts
1.서 론
2. 실험방법
    2.1. 시험시편
    2.2. 2파장 펌프-프로브 측정
3. 이론 및 해석
4. 결과 및 토의
    4.1 X-선 반사율 측정
    4.2 2파장 펌프-프로브 측정
    4.3 결과 비교 분석
5.결 론
References

• 김윤영(충남대학교 기계공학부) | Yun Young Kim (School of Mechanical Engineering, Chungnam National University) Corresponding author