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

Abstract

BackgroundThe photolithography process in the semiconductor industry uses various chemicals with little information on their constitution. This study aimed to identify the chemical constituents of photoresist (PR) products and their by-products and to compare these constituents with material safety data sheets (MSDSs) and analytical results.MethodsA total of 51 PRs with 48 MSDSs were collected. Analysis consisted of two parts: First, the constituents of the chemical products were identified and analyzed using MSDS data; second, for verification of the by-products of PR, volatile organic compounds were analyzed. The chemical constituents were categorized according to hazards.ResultsForty-five of 48 products contained trade secrets in amounts ranging from 1 to 65%. A total of 238 ingredients with multiple counting (35 ingredients without multiple counting) were identified in the MSDS data, and 48.7% of ingredients were labeled as trade secrets under the Korea Occupational Safety and Health Act. The concordance rate between the MSDS data and the analytical result was 41.7%. The by-product analysis identified 129 chemicals classified according to Chemical Abstracts Service No., with 17 chemicals that are carcinogenic, mutagenic, and reprotoxic substances. Formaldehyde was found to be released from 12 of 21 products that use novolak resin.ConclusionWe confirmed that several PRs contain carcinogens, and some were not specified in the toxicological information in the MSDS. Hazardous chemicals, including benzene and formaldehyde, are released from PRs products as by-products. Therefore, it is necessary to establish a systematic management system for chemical compounds and the working environment.

Green Nanofabrication Opportunities in the Semiconductor Industry: A Life Cycle Perspective

“…Photolithography uses high volumes of chemicals at each of its processing stages, and is a cause for environmental concern [ 34 ]. Photoresists are light sensitive materials that undergo photochemical reactions on exposure to light [ 57 ].…”

“…It has relatively low environmental toxicity but all of the reactants required in its manufacture are from non-renewable sources [ 151 ]. Carcinogens used in photoresists (PR) products include cyclohexanone, ethylbenzene, pyridine, and 1,4 dioxane [ 34 ]. Cyclohexanone has central nervous system inhibitory and aesthetic reactions [ 152 ].…”

“…Lithography requires the greatest number of chemicals amongst the semiconductor fabrication processes [ 34 , 35 ]. The main set of chemicals used during photolithography are photoresists.…”

“…BCP and brush lithographic techniques do not require a sensitizer or these additional additives and therefore may reduce chemical wastes. Production costs will also be reduced if the need for a photolithographic mask is circumvented [ 34 ]. It has been suggested that BCP and brush lithography provide rapid processing, scalable synthesis, and reduced production costs when compared to current lithographic techniques [ 4 , 36 ].…”

Chemical Use and Associated Health Concerns in the Semiconductor Manufacturing Industry

“…The semiconductor industry itself also has concerns, leading to the introduction of key environmental priority indicators [ 24 , 25 ], but data about chemical use are very limited. In 2018, the use of chemicals at the one semiconductor industry was reported by our research group, and in 2019, a more detailed description of chemical uses in the photolithography process [ 23 , 26 ] The first study reported that more than 150 chemical constituents were used in more than 450 chemical products, more than 40% of which contained trade secrets and that safety and health information was very limited. In second study, we found that more than 90% of the chemicals in the photolithography process contain trade secrets, safety data sheets (SDSs) provides inadequate safety and health information, and has found that by-products such as benzene and formaldehyde may be produced at the photolithography process; however, no comprehensive study on the use of chemical products in the workplace exists.…”