Study of Cleaning Method for Si Substrate Using High-Speed Shear Flow of Ultrapure Water

Abstract

Since organic contaminants, which adhere on the silicon substrate surface, have an adverse impact on the quality of the gate oxide films, it is very highly required for the current semiconductor fabrication processes to take them off the surface before producing the films. Therefore, some kinds of cleaning method for silicon substrate, such as SPM (Sulfuric acid-hydrogen Peroxide Mixture) cleaning, ozone water cleaning and ultraviolet exposure cleaning, have applied to remove organic contaminants from the substrate surface. But these cleaning methods exert a bad influence of the global environment and spend high cost for the semiconductor fabrication. On the contrary, we have developed the new cleaning method for the silicon substrate using the high-speed shear flow of only ultrapure water and composed the new cleaning system. In the result of cleaning the silicon substrata surface contaminated by dioctyl phthalate at 1×1015atoms/cm2, we demonstrated that DOP(dioctyl phthalate) concentration on the substrate reduced at the level of 1013atoms/cm2 using our cleaning system. Moreover, we showed that our cleaning method possessed oxidizing property to Si substrate surface and supposed that DOP removal mechanism from Si substrate surface and this oxidizing property were related.