Journal of Vacuum Science & Technology B, Vol.20, No.1, 71-75, 2002
Stencil reticle cleaning using an Ar aerosol cleaning technique
Reticle cleaning is one of the important issues in all next-generation lithography (NGL) systems. In this article, an Ar aerosol cleaning technique, which is a cryogenic cleaning technique, is described for cleaning a stencil-type reticle for an electron beam stepper. The cleaning efficiency and the redeposition rate depend on the pressure of the process chamber of cleaning. The Al2O3 particles of average size 0.1 mum on the reticle surface and inside the through-hole pattern were effectively removed. The gas flow conditions for damage-free cleaning were limited by the size of the stencil pattern. In the reticle made of a silicon-on-insulator (SOI) wafer, the thermal distortion of the reticle in the cleaning at low temperature was expected. However, after cleaning, the distortion measurement results did not show residual distortion of the reticle.