DOI QR코드

DOI QR Code

Molecular Dynamics Simulation on the Thermal Boundary Resistance of a Thin-film and Experimental Validation

분자동역학을 이용한 박막의 열경계저항 예측 및 실험적 검증

  • Suk, Myung Eun (Division of Mechanical, Automotive, and Robot Components Engineering, Dong-eui Univ.) ;
  • Kim, Yun Young (School of Mechanical Engineering, Chungnam National University)
  • 석명은 (동의대학교 기계자동차로봇부품공학부) ;
  • 김윤영 (충남대학교 기계공학부)
  • Received : 2018.11.06
  • Accepted : 2019.01.16
  • Published : 2019.04.30

Abstract

Non-equilibrium molecular dynamics simulation on the thermal boundary resistance(TBR) of an aluminum(Al)/silicon(Si) interface was performed in the present study. The constant heat flux across the Si/Al interface was simulated by adding the kinetic energy in hot Si region and removing the same amount of the energy from the cold Al region. The TBR estimated from the sharp temperature drop at the interface was independent of heat flux and equal to $5.13{\pm}0.17K{\cdot}m^2/GW$ at 300K. The simulation result was experimentally confirmed by the time-domain thermoreflectance technique. A 90nm thick Al film was deposited on a Si(100) wafer using an e-beam evaporator and the TBR on the film/substrate interface was measured using the time-domain thermoreflectance technique based on a femtosecond laser system. A numerical solution of the transient heat conduction equation was obtained using the finite difference method to estimate the TBR value. Experimental results were compared to the prediction and discussions on the nanoscale thermal transport phenomena were made.

본 논문에서는 비평형 분자동역학 시뮬레이션 기법을 사용하여 알루미늄 박막과 실리콘 웨이퍼 간 열경계저항을 예측하였다. 실리콘의 끝 단 고온부에 열을 공급하고, 같은 양의 열을 알루미늄 끝 단 저온부에서 제거하여 경계면을 통한 열전달이 일어나도록 하였으며, 실리콘 내부와 알루미늄 내부의 선형 온도 변화를 계산함으로써 경계면에서의 온도 차이에 따른 열저항 값을 구하였다. 300K 온도에서 $5.13{\pm}0.17m^2{\cdot}K/GW$의 결과를 얻었으며, 이는 열유속 조건의 변화와 무관함을 확인하였다. 아울러, 펨토초 레이저 기반의 시간영역 열반사율 기법을 사용하여 열경계저항 값을 실험적으로 구하였으며, 시뮬레이션 결과와 비교 검증하였다. 전자빔 증착기를 사용하여 90nm 두께의 알루미늄 박막을 실리콘(100) 웨이퍼 표면에 증착하였으며, 유한차분법을 이용한 수치해석을 통해 열전도 방정식의 해를 구해 실험결과와 곡선맞춤 함으로써 열경계저항을 정량적으로 평가하고 나노스케일에서의 열전달 현상에 관한 특징을 살펴보았다.

Keywords

References

  1. Antonelli, G.A., Perrin, B., Daly, B.C., Cahill D.G. (2006) Characterization of Mechanical and Thermal Properties Using Ultrafast Optical Metrology, MRS Bulletin, 31, pp.607-613. https://doi.org/10.1557/mrs2006.157
  2. Cho, M., Choi, J., Jung, K. (2007) Multi-scale Analysis of Thin Film Considering Surface Effects, J. Comput. Struct. Eng. Inst. Korea, 20, pp. 287-292.
  3. Feng, B., Li, Z., Zhang, X. (2009) Prediction of Size Effect on Thermal Conductivity of Nanoscale Metallic Films, Thin Solid Films, 517, pp. 2803-2807. https://doi.org/10.1016/j.tsf.2008.10.116
  4. Frenkel, D., Smit, B. (1996) Understanding Molecular Simulation, San Diego, USA: Academic Press Inc.
  5. Hopkins, P.E. (2013) Thermal Transport across Solid Interfaces with Nanoscale Imperfections: Effects of Roughness, Disorder, Dislocations, and Bonding on Thermal Boundary Conductance, ISRN Mech. Eng., 2013.
  6. Ikeshoji, T., Hafskjold, B. (1993) Non-equilibrium Molecular Dynamics Calculation of Heat Conduction in Liquid and Through Liquid-gas Interface, Mol. Phys., 81, pp.251-261. https://doi.org/10.1080/00268979400100171
  7. Jelinek, B., Groh, S., Horstemeyer, M.F., Houze, J., Kim, S.G., Wagner, J.G., Moitra, A., Baskes, M.I. (2012) Modified Embedded Atom Method Potential for Al, Si, Mg, Cu, and Fe Alloys, Phys. Rev. B, 85(24), p.245102. https://doi.org/10.1103/PhysRevB.85.245102
  8. Jung, G., Zhou, M., Cho, M. (2012) Analysis on Thermomechanical Response to Tensile Deformation of GaN Nanowires, J. Comput. Struct. Eng. Inst. Korea, 25, pp.301-305. https://doi.org/10.7734/COSEIK.2012.25.4.301
  9. Kim, Y.Y., Krishnaswamy, S. (2012) Non-destructive Evaluation of Material Properties of Nanoscale Thin-films Using Ultrafast Optical Pump-probe Methods, J. Korean Soc. Nondestruct. Test., 35, pp.115-121.
  10. Muller-Plathe, F. (1997) A Simple Nonequilibrium Molecular Dynamics Method for Calculating the Thermal Conductivity, J. Chem. Phys., 106, p. 6082. https://doi.org/10.1063/1.473271
  11. Plimpton, S. (1995) Fast Pparallel Algorithms for Short-Range Molecular Dynamics, J. Comput. Phys., 117, pp.1-19. https://doi.org/10.1006/jcph.1995.1039
  12. Richardson, C.J.K., Spicer, J.B. (2003) Characterization of Heat-treated Tungsten Thin Films Using Picosecond Duration Thermoelastic Transients, Optics & Lasers Eng., 40, pp. 379-391. https://doi.org/10.1016/S0143-8166(02)00090-8
  13. Shin, H., Yang, S., Yu, S., Chang, S., Cho, M. (2012) A Study on the Sequential Multiscale Homogenization Method to Predict the Thermal Conductivity of Polymer Nanocomposites with Kapitza Thermal Resistance, J. Comput. Struct. Eng. Inst. Korea, 25, pp.315-321. https://doi.org/10.7734/COSEIK.2012.25.4.315
  14. Stevens, R.J., Smith, A.N., Norris, P.M. (2005) Measurement of Thermal Boundary Conductance of a Series of Metal-Dielectric Interfaces by the Transient Thermoreflectance Technique, J. Heat Transf., 127, pp. 315-322. https://doi.org/10.1115/1.1857944
  15. Stoner, R.J., Maris, H.J. (1993) Kapitza Conductance and Heat Flow Between Solids at Temperatures From 50 to 300K, Phys. Rev.B, 48, pp.16373-16387. https://doi.org/10.1103/PhysRevB.48.16373
  16. Yang, N., Luo, T., Esfarjani, K., Henry, A., Tian, Z., Shiomi, J., Chalopin, Y., Li, B., Chen, G. (2015) Thermal Interface Conductance Between Aluminum and Silicon by Molecular Dynamics Simulations, J. Comput. & Theor. Nanosci., 12, pp.168-174. https://doi.org/10.1166/jctn.2015.3710