Review on Potential Risk Factors in Wafer Fabrication Process of Semiconductor Industry

Evaluation of Hazardous Chemicals with Material Safety Data Sheet and By-products of a Photoresist Used in the Semiconductor-Manufacturing Industry

“…For example, the high-molecular-weight compound used for determining mechanical properties was specified using a number of terms such as a resin, polymer, and monomer. Also, ingredients that control the photochemical reaction during exposure to light were denoted with various names, including sensitizer, photoactive, initiator, and generator [7] , [14] Thus, unification of the names of individual ingredients is required for systematic management. Also, we suggest that resin type should be informed in MSDS at least because a previous study [9] has shown that novolak resin could release aromatic compounds such as benzene, toluene, phenol, and cresol through thermal energy.…”

“…In addition, analytical results from a thermal decomposition experiment detected aromatic compounds such as benzene, toluene, and cresol; however, the temperature conditions in that experiment were higher than the operating temperature [8] , [9] . Hence, analysis was performed at 110°C in accordance with the operating temperature for the photolithography process: soft baking between 70 and 90°C and hard baking between 120 and 135°C [5] , [7] . Table 8 shows that various chemical compounds were released as the by-product at actual operative temperature.…”

“…Photoresists (PRs), the main set of chemicals used in photolithography, consist of a polymer, solvent, sensitizer, and additives. A PR can be classified as positive or negative depending on its response to light, and most chemical constituents are specified as trade secrets [1] , [5] , [6] , [7] . In addition, by-products can be released by ultraviolet (UV) light and heat during the development process [8] , [9] .…”

“…Detailed chemical information is difficult to obtain due to lack of sufficient data, trade secrecy, and fast-changing technology. However, it is necessary to evaluate past exposure information, such as transitions in chemicals, process technologies, and management techniques, for the investigation of exposure to hazards [3] , [7] , [10] .…”

“…The general chemical constituents used in photolithography are known, but information regarding specific and real chemical use is insufficient [5] . For example, xylene, ethylene glycol monoethyl ether acetate (EGMEA), toluene, hexamethyldisilazane, and propylene glycol ether (PGE) have been used as coating agents in PR chemical products [1] , [7] . Because of its reproductive toxicity, EGMEA was replaced with PGE in the 1990s [11] .…”