Characteristics of inorganic acid emission from various generation semiconductor manufacturing factories

Abstract

With advancements in semiconductor industry technology, the gas emissions per wafer have decreased, but the emission compositions have shown significant differences. This study analyzed nine semiconductor plants representing different generations of process technologies, ranging from 3 μm to 12 nm technology nodes. Stack inspections were conducted on the acid, alkali, and organic exhaust systems to understand the characteristics of inorganic acid emissions in plants in different process technologies. The analysis showed that with technological process and air pollution control equipment advancements, the emissions of inorganic acids per wafer decreased by 38% compared to the first generation. It is worth noting that both hydrofluoric acid and nitric acid are identified as the primary pollutants in traditional semiconductor process plants. At the same time, H₂SO₄ was instead the primary pollutant in advanced process plants. Based on these characteristics, each plant has established relevant improvement strategies. After two years of improvement, the emissions of inorganic acids per wafer in each generation of plants are evidenced to have further decreased by 15-56%. Hence, it is shown that these initiatives and studies have successfully helped to reduce air pollution emissions and promote advanced green manufacturing.

Keywords: Air pollution prevention and control; Exhaust gas composition in the stack; Inorganic acid emission; Semiconductor manufacturing emission.