Proceedings Article | 29 March 2006
Proc. SPIE. 6153, Advances in Resist Technology and Processing XXIII
KEYWORDS: Semiconductors, Carbon, Polymers, Manufacturing, Adsorption, Semiconductor manufacturing, Photoresist processing, Semiconducting wafers, Contamination control, 193nm lithography
While the current standard for NA (Numerical Aperture) for the semiconductor resist process is 193 nm High NA, use of the 193 nm immersion exposure process is growing and almost ready for application in mass production. With the growing trend toward the use of finer line processes in the manufacture of semiconductor devices, the need for cleanliness of the ambient atmosphere surrounding the silicon wafer has also been increasing. In addition to ammonia, that has hitherto been the main target for elimination, the concentration of other chemicals, such as amines and N-methyl-2-pyrrolidone (NMP), need to be kept sufficiently low for the new processes. Therefore, the role of chemical filters has become an essential one. We conducted a study on the dependency of chemical filters on the molecular diffusivity of target gas species, and, based on this data, developed a filter that eliminates amines. The filter has a honeycomb structure with a wide gas-contacting area, and consists of an ion-exchange resin that has received special treatment. The filter has a greatly improved gas capture efficiency (>99.8% for ammonia, >98% for triethylamine and NMP) and a very large adsorption capacity, which enables a 50% reduction of the filter volume compared with currently available chemical filters.
