Tribology and Lubricants

Korean Tribology Society (한국트라이볼로지학회)
권호 표지
DOI QR코드

DOI QR Code

Stick-slip in Chemical Mechanical Polishing Using Multi-Particle Simulation Models

다수의 연마입자를 고려한 CMP 공정의 Stick-Slip 고찰

  • Jung, Soyoung (Dept. of Mechanical Engineering, Hannam University) ;
  • Sung, In-Ha (Dept. of Mechanical Engineering, Hannam University)
  • 정소영 (한남대학교 기계공학과) ;
  • 성인하 (한남대학교 기계공학과)
  • Received : 2018.09.28
  • Accepted : 2018.10.27
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, we investigate the behavior of abrasive particles and change of the stick-slip pattern according to chemical mechanical polishing (CMP) process parameters when a large number of abrasive particles are fixed on a pad. The CMP process is simulated using the finite element method. In the simulation, the abrasive grains are composed of those used in the actual CMP process. Considering the cohesion of the abrasive grains with the start of the CMP process, abrasive particles with various sizes are fixed onto the pad at different intervals so that stick-slip could occur. In this analysis, we determine that when the abrasive particle size is relatively large, the stick-slip period does not change as the pressure increases while the moving speed is constant. However, if the size of the abrasive grains is relatively small, the amount of deformation of the grains increases due to the elasticity of the pad. Therefore, the stick-slip pattern may not be observed. As the number of abrasive particles increases, the stick-slip period and displacement decrease. This is consistent with the decrease in the von Mises yield stress value on the surface of the wafer as the number of abrasive grains increases. We determine that when the number of the abrasive grains increases, the polishing rate, and characteristics are improved, and scratches are reduced. Moreover, we establish that the period of stick-slip increases and the change of the stick-slip size was not large when the abrasive particle size was relatively small.

Keywords

OHHHB9_2018_v34n6_279_f0001.png 이미지

Fig. 1. Finite element models used for FEM.

OHHHB9_2018_v34n6_279_f0001.png 이미지

Fig. 1. Finite element models used for FEM.

OHHHB9_2018_v34n6_279_f0002.png 이미지

Fig. 2. Effect of number of particles on stick-slip.

OHHHB9_2018_v34n6_279_f0002.png 이미지

Fig. 2. Effect of number of particles on stick-slip.

OHHHB9_2018_v34n6_279_f0003.png 이미지

Fig. 3. Effect of applied pressure on stick-slip (1).

OHHHB9_2018_v34n6_279_f0003.png 이미지

Fig. 3. Effect of applied pressure on stick-slip (1).

OHHHB9_2018_v34n6_279_f0004.png 이미지

Fig. 4. Effect of applied pressure on stick-slip (2).

OHHHB9_2018_v34n6_279_f0004.png 이미지

Fig. 4. Effect of applied pressure on stick-slip (2).

Table 1. Simulation conditions for FEM

OHHHB9_2018_v34n6_279_t0001.png 이미지

Table 1. Simulation conditions for FEM

OHHHB9_2018_v34n6_279_t0001.png 이미지

Table 2. Mechanical properties of the materials used in the simulation

OHHHB9_2018_v34n6_279_t0002.png 이미지

Table 2. Mechanical properties of the materials used in the simulation

OHHHB9_2018_v34n6_279_t0002.png 이미지

Table 3. Stress values obtained from FE analysis

OHHHB9_2018_v34n6_279_t0003.png 이미지

Table 3. Stress values obtained from FE analysis

OHHHB9_2018_v34n6_279_t0003.png 이미지

References

  1. Kim, H. J., "Effect of brush treatment and brush contact sequence on cross contaminated defects during CMP in-situ cleaning," J. Korean Soc. Tribol. Lubr. Eng., Vol. 31, No. 6, pp. 239-244, 2015. https://doi.org/10.9725/kstle.2015.31.6.239
  2. Park, S., Im, S., Lee, H., "Effect of pressure on edge delamination in chemical mechanical polishing of SU-8 film on silicon wafer," J. Korean Soc. Tribol. Lubr. Eng., Vol. 33, No. 6, pp. 282-287, 2017.
  3. Wang, Y. G., Zhang, L. C., Biddut, A., "Chemical effect on the material removal rate in the CMP of silicon wafers," Wear, Vol. 270, No. 3-4, pp. 312-316, 2011. https://doi.org/10.1016/j.wear.2010.11.006
  4. Kwon, T.-Y., Cho, B.-J., Ramachandran, M., Busnaina, A, A., Park, J.-G., "Investigation of source-based scratch formation during oxide chemical mechanical planarization," Tribol, Lett., Vol. 50, No. 2, pp. 169-175, 2013. https://doi.org/10.1007/s11249-012-0098-2
  5. Kim, H.-J., Yang, J. C., Yoon, B. U., Lee, H.-D., Kim, T. S., "Nano-scale stick-slip friction model for the chatter scratch generated by chemical mechanical polishing process," J. Nanosci. Nanotechnol., Vol. 12, No. 7, pp. 5683-5686, 2012. https://doi.org/10.1166/jnn.2012.6389
  6. Yang, W. Y., Sung, I.-H., "abrasive particle behavior and the change in the material properties of a pad used in chemical mechanical polishing (CMP)," Journal of the KSME, pp. 113-114, 2012.
  7. Wang, Y., Zhao, Y., Li, X., "Modeling the effects of abrasive size, surface oxidizer concentration and binding energy on chemical mechanical polishing at molecular scale," Tribol. Int., Vol. 41, No. 3, pp. 202-210, 2008. https://doi.org/10.1016/j.triboint.2007.08.004
  8. Park, C. W., Shin, M. W., Jang, H., "Friction-induced stick-slip intensified by corrosion of gray iron brake disc," Wear, Vol. 309, pp. 89-95, 2014. https://doi.org/10.1016/j.wear.2013.11.008
  9. Cho, W., Ahn, Y. M., Baek, C.-W., Kim, Y.-K., "Effect of mechanical process parameter on chemical mechanical polishing of Al thin films," Microelectron. Eng., Vol. 65, pp. 13-23, 2003. https://doi.org/10.1016/S0167-9317(02)00726-8
  10. Lee, H. S., Park, B. Y., Seo, H. D., Park, K. H., Jeong, H. D., "A study on the characteristics of stick-slip friction in CMP", J. Korean Inst. Electr. Electron. Mater. Eng., Vol. 18, No. 4, pp. 313-320, 2005. https://doi.org/10.4313/JKEM.2005.18.4.313

Cited by

  1. 화학기계적 연마기술 연구개발 동향: 입자 거동과 기판소재를 중심으로 vol.35, pp.5, 2019, https://doi.org/10.9725/kts.2019.35.5.274