Inorganic Acid Emission Factors of Semiconductor Manufacturing Processes

• Published in: Journal of the Air & Waste Management Association (1995) Vol. 54; no. 2; pp. 218 - 228
• Main Authors: Chein, HungMin, Chen, Tzu Ming, Aggarwal, Shankar Gopala, Tsai, Chuen-Jinn, Huang, Chun-Chao
• Format: Journal Article
• Language: English
• Published: Pittsburgh, PA Taylor & Francis Group 01.02.2004; Air & Waste Management Association; Air and Waste Management Association; Taylor & Francis Ltd
• Subjects: Acids; Acids - analysis; Air Pollutants - analysis; Applied sciences; Emissions; Environmental Monitoring; Exact sciences and technology; Industry; Inorganic Chemicals - analysis; Ion chromatography; Manufacturing; Pollution; Regression analysis; Semiconductors; Taiwan; Taiwan; Correlation coefficient; Linear regression; Samplings; Emission content; Cleaning; Droplet; Pollutant emission; Ion chromatography; Manufacturing process; Air pollution; Regulation; Sampling; Environmental protection
• ISSN: 1096-2247; 2162-2906
• DOI: 10.1080/10473289.2004.10470898

A huge amount of inorganic acids can be produced and emitted with waste gases from integrated circuit manufacturing processes such as cleaning and etching. Emission of inorganic acids from selected semiconductor factories was measured in this study. The sampling of the inorganic acids was based on the porous metal denuders, and samples were then analyzed by ion chromatography. The amount of chemical usage was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County according to the Taiwan Environmental Protection Agency regulation. The emission factor is defined as the emission rate (kg/month) divided by the amount of chemical usage (L/month). Emission factors of three inorganic acids (i.e., hydrofluoric acid [HF], hydrochloric acid [HQ], and sulfuric acid [H 2 SO 4 ]) were estimated by the same method. The emission factors of HF and HCl were determined to be 0.0075 kg/L (coefficient of variation [CV] = 60.7%, n = 80) and 0.0096 kg/L (CV = 68.2%, n = 91), respectively. Linear regression equations are proposed to fit the data with correlation coefficient square (R 2 ) = 0.82 and 0.9, respectively. The emission factor of H 2 SO 4 , which is in the droplet form, was determined to be 0.0016 kg/L (CV = 99.2%, n = 107), and its R 2 was 0.84. The emission profiles of gaseous inorganic acids show that HF is the dominant chemical in most of the fabricators.