DOI QR코드

DOI QR Code

The Characteristic Variation of Mask with Plasma Treatment

플라즈마 처리에 의한 마스크 특성 변화

  • Published : 2008.02.01

Abstract

We have studied surface roughness, contamination of impurity, bonding with some gas element, reflectance and zeta potential on masks to be generated or changed during photolithography/dry or wet etching process. Mask surface roughness was not changed after photolithography/dry etching process. But surface roughness was changed on some area under MoSi film of Cr/MoSi/Qz. There was not detected any impurity on mask surface after plasma dry etching process. Reflectance of mask was increased after variable plasma etching treatment, especially when mask was treated with plasma including $O_2$ gas. Blank mask was positively charged when the mask was treated with Cr plasma etching gas($Cl_2:250$ sccm/He:20 $sccm/O_2:29$ seem, source power:100 W/bias power:20 W, 300 sec). But this positive charge was changed to negative charge when the mask was treated with $CF_4$ gas for MoSi plasma etching, resulting better wet cleaning. There was appeared with negative charge on MoSi/Qz mask treated with Cr plasma etching process condition, and this mask was measured with more negative after SC-1 wet cleaning process, resulting better wet cleaning. This mask was charged with positive after treatment with $O_2$ plasma again, resulting bad wet cleaning condition.

References

  1. R. A. Lawea, 'Future trends in high-resolution lithography', Applied Surface Science 154-155, p. 519, 2000 https://doi.org/10.1016/S0169-4332(99)00478-X
  2. M. D. Levenson, N. S. Viswanathan, and R. A. Simpson, 'Improving resolution in photolithography with a phase-shifting mask', IEEE Trans. Electron. Devices ED-29, p. 1828, 1982
  3. K. Bhattacharyya and J. Ayala, 'Investigation of reticule defect formation at DUV lithography', Proceedings of SPIE, 22nd Annual BACUS Symposium on Photomask Technology, Vol. 4889, p. 478, 2002
  4. B. J Grenon, C. R. Peters, and K. Bhattacharyya, 'Tracking down cause of DUV sub-pellicle defects', Solid State Technology, p. 45, 2000
  5. R. Novak, I. Kashkoush, and G. S. Chen, 'Today's binary and EAPSMs need advanced mask cleaning methods', Solid State Technology, p. 55, 2004
  6. C. J. Cramer, 'Essentials of computational chemistry', John wiley & Sons inc. Chapter 9, 2004
  7. 박기채, 일반화학, 일신사, p. 468, 1974