Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
권호 표지

Optimum process conditions for supercritical fluid and co-solvents process for the etching, rinsing and drying of MEMS-wafers

초임계 유체와 공용매를 이용한 미세전자기계시스템 웨이퍼의 식각, 세정을 위한 최적공정조건

  • Noh, Seong Rae (School of Energy, Material and Chemical Engineering, Korea University Of Technology & Education) ;
  • You, Seong-sik (School of Energy, Material and Chemical Engineering, Korea University Of Technology & Education)
  • 노성래 (한국기술교육대학교 에너지 신소재 화학공학부) ;
  • 유성식 (한국기술교육대학교 에너지 신소재 화학공학부)
  • Received : 2017.08.18
  • Accepted : 2017.09.22
  • Published : 2017.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study aims to select suitable co-solvents and to obtain optimal process conditions in order to improve process efficiency and productivity through experimental results obtained under various experimental conditions for the etching and rinsing process using liquid carbon dioxide and supercritical carbon dioxide. Acetone was confirmed to be effective through basic experiments and used as the etching solution for MEMS-wafer etching in this study. In the case of using liquid carbon dioxide as the solvent and acetone as the etching solution, these two components were not mixed well and showed a phase separation. Liquid carbon dioxide in the lower layer interfered with contact between acetone and Mems-wafer during etching, and the results after rinsing and drying were not good. Based on the results obtained under various experimental conditions, the optimum process for treating MEMS-wafer using supercritical CO2 as the solvent, acetone as the etching solution, and methanol as the rinsing solution was set up, and MEMS-wafer without stiction can be obtained by continuous etching, rinsing and drying process. In addition, the amount of the etching solution (acetone) and the cleaning liquid (methanol) compared to the initial experimental values can be greatly reduced through optimization of process conditions.

Keywords

References

  1. Kazuo, S., "Perspective of Micro-Nano Science and Technology", Journal of the japan society of mechanical engineers, Vol. 116, pp. 12-15, 2013. https://doi.org/10.1299/jsmemag.116.1130_12
  2. Kim, T.H., Kim, D.Y., Chun, M.S., and Lee, S.S., "MEMS Fabrication of Microchannel with Poly-Si Layer for Application to Microchip Electrophoresis", Chem. Eng. Res., Vol. 44, pp. 513-519, 2006.
  3. Han, G.S., Lim,J.S., and Yoo, K.P., "Wafer Cleaning using Supercritical Carbon Dioxide", Prospectives of industrial chemistry, Vol.9, pp. 2-11, 2006.
  4. Jafri, I., Busta, H., and Walsh, S., "Critical Point Drying and Cleaning for MEMS Technology", Proc.-SPIE Int. Soc. Opt. Eng, Vol. 3880, pp. 51-58, 1999.
  5. Tas, N., Sonnenberg, T., Jansen, H., Legtenberg, R. and Elwenspoek, M., "Stiction in surface micromachining," J. Micromech. Microeng., Vol. 6, pp. 385, 1996. https://doi.org/10.1088/0960-1317/6/4/005
  6. Jincao,Y. and Matthews, M.A., "Prevention of Photoresist Pattern Collapse Using Liquid Carbon Dioxide," Ind. Eng. Chem. Res, Vol. 40, pp. 5858, 2001. https://doi.org/10.1021/ie010424h
  7. Jeon, B. Y., and Lee, C. M., "Dry cleaning for metallic contaminants removal after the chemical mechanical polishing(CMP) process", Journal of the Korean Vacuum Society, Vol.9, pp. 102-109, 2000.
  8. Rubin, J.B., Davenhall, L.B., Taylor, C.M.V., Sivils, L.D., Pierce, T. and Tiefert, K., "$CO_2$-Based Supercritical Fluids as Replacements for Photoresist-Stripping Solvents", Electronics Manufacturing Technology Symposium, Vol 23, pp. 308-314, 1998.
  9. Han, G.S., "Supercritical $CO_2$ dry cleaning of nanopattern semiconductor", Ph.D. Dissertation, Sogang University, Korea, 2009.
  10. You, S.-S., "Removal of Post Etch/Ash Residue on an Aluminum Patterned Wafer Using Supercritical $CO_2$ Mixtures with Co-solvents and Surfactants: sc-$CO_2$ Mixture for the Removal of Post Etch/Ash Residue", J. the Semiconductor & Display Technology, Vol.16, pp. 22-28, 2017.
  11. Min, S.K., Han, G.S. and You, S.-S., "Continuous Process for the Etching, Rinsing and Drying of MEMS Using Supercritical Carbon Dioxide", Korean Chem. Eng. Res., Vol. 53, pp. 557-564, 2015. https://doi.org/10.9713/kcer.2015.53.5.557
  12. Lee, Y.W., "Design of Particles using Supercritical Fluids", Korean Chem. Eng. Res., Vol. 41, pp. 679-688, 2004.
  13. Jones, C.A., Zweber, A., Deyoung, J.P., Carbonell, R. and Desimon, J.M., "Applications of Dry Processing in the Microelectronics Industry Using Carbon Dioxide", Crit. Rev. Solid State Mater. Sci., Vol. 29, pp. 97, 2004. https://doi.org/10.1080/10408430490888968