Removal of Post Etch/Ash Residue on an Aluminum Patterned Wafer Using Supercritical CO2 Mixtures with Co-solvents and Surfactants: sc-CO2 Mixture for the Removal of Post Etch/Ash Residue

  • You, Seong-sik (School of Energy, Material & Chemical engineering, Korea University of Technology and Education)
  • Received : 2017.02.28
  • Accepted : 2017.03.24
  • Published : 2017.03.31

Abstract

The result of stripping process for the removal of the post etch/ash Photoresist (PR) residue on an aluminum patterned wafer by using supercritical $CO_2$ ($sc-CO_2$) mixture, was investigated by scanning of electron microscope (SEM) inspection of wafer, measuring the cloud points and visual observation of the state of $sc-CO_2$ mixtures. It was found that $sc-CO_2$ mixtures were made by mixing additives and $sc-CO_2$ should form homogeneous and transparent phase (HTP) in order to effectively and uniformly remove the post etch/ash PR residue on the aluminum patterned wafer using them. The additives were formulated by mixing and co-solvents like an amine compound and fluorosurfactants used as HTP agents, and the PR residue on the wafer were able to be rapidly and effectively removed using the $sc-CO_2$ mixture of HTP. The five kinds of additives were formulated by the recipe of mixing co-solvents and surfactants, which were able to remove PR residue on the wafer by mixing with $sc-CO_2$ at the stripping temperature range from 40 to $80^{\circ}C$. The five kinds of $sc-CO_2$ mixtures which were named as PR removers were made, which were able to form HTP within the above described stripping temperature. The cloud points of $sc-CO_2$ mixtures were measured to find correlation between them and HTP.

Keywords

References

  1. Rubin, J.B., Davenhall, L.B., Taylor, C.M.V., Sivils, L.D. and Pierce, T., "$CO_2$-based supercritical fluids as replacements for PR stripping solvents", Internal LANL paper, 1998.
  2. Rubin, J.B., Davenhall, L.B., Barton, J., Taylor, C.M.V. and Tiefert, K.,"A comparison of chilled DI water/ozone and $CO_2$-based supercritical fluids as replacements for PR-stripping solvents", Internal LANL paper, 1998.
  3. Banerjee, S., Cross, P., Borade, R., Raghavan, S., and Stevens, R.,"Non-ashing high dose implant strip in IC manufacturing", SEMATECH wafer clean and surface preparation conference, April, 2005.
  4. Joseph, M.D., and Keiper, J.S., "Surfactants and selfassembly in carbon dioxide.", Current opinion in solid and materials science, Vol. 5, pp. 333-341, 2001. https://doi.org/10.1016/S1359-0286(00)00041-3
  5. Shi, J.,"Damage Reduction in Dry Resist Stripping Systems," Solid State Technology, Vol. 38, pp. 75-82, 1995. https://doi.org/10.1016/0038-1101(94)E0047-I
  6. Okuyama, Y., Hashimoto, T., and Koguchi, T., "High Dose Ion-Implantation into PR," Journal of the Electrochemical Society, Vol. 125, pp. 1293-1298 1978. https://doi.org/10.1149/1.2131665
  7. Flamm, D.,"Dry Plasma Resist Stripping. Part II: Physical Processes," Solid State Technology, Vol. 35, pp. 43-48. 1992. https://doi.org/10.1016/0038-1101(92)90301-R
  8. Dopp, D.,"Manufacturing Qualification of an All-Dry Via DeVeil Plasma Process" (paper presented at the Third International Symposium on Environmental Issues with Materials and Processes for the Electronics Semiconductor Industries, Toronto, May 14-18, 2000.
  9. Weibel, G.L., and Ober, C.K., "An overview of supercritical CO2 applications in microelectronics processing", Microelectronics Engineering, Vol. 65, pp. 145-152, 2003. https://doi.org/10.1016/S0167-9317(02)00747-5
  10. Baik, J.H., WO0114934, Dongjin Semichem Co., Ltd., KR, 2001.