Breakthrough achieved in the purification technology of high-purity electronic-grade chlorine at Changzhou University

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Electronic-grade chlorine serves as the \"cutting tool\" and \"cleaning agent\" for constructing the microscopic structure of chips, yet China has long relied on imports for this key material in chip manufacturing. Reporters learned recently from Changzhou University that the team led by Wang Jun, an associate professor at the School of Petrochemical Engineering at the university, has made significant independent breakthroughs in the fields of electronic-grade chlorine purification and comprehensive safety control. By utilizing a precision distillation purification process developed by themselves, they have managed to produce high-purity electronic-grade chlorine with a purity of 99.9999% (6N grade). The key performance indicators of this product are at the international advanced level, thereby breaking the long-standing monopoly held by foreign countries in the field of purification technology for high-end electronic specialty gases. 　　Previously, China was entirely dependent on imports for 6N-grade electronic-grade chlorine required for high-end chip manufacturing, resulting in high procurement costs and poor supply chain stability. Wang Jun’s team focused on the pain points in this industry, developing a comprehensive purification process that transforms ordinary industrial chlorine into high-purity electronic-grade chlorine, thereby solving the problem of excessive impurities in ordinary industrial chlorine, which made it unsuitable for use in advanced chip manufacturing processes. 　　It is reported that this team has innovatively integrated precision distillation with targeted adsorption of organic impurities to develop a multi-stage purification system. The structure of the components within the purification tower was optimized to take into account the highly corrosive nature of chlorine, and specialized adsorbent combinations were carefully selected. By removing water, organic impurities, and metal impurities at each stage, a highly precise purification of chlorine is achieved. Compared to traditional processes, this technology not only produces 6N-grade high-purity chlorine stably but also significantly reduces energy consumption during the purification process. At present, this technology has successfully completed pilot-scale testing, providing a foundation for industrial deployment. 　　Chlorine is a highly toxic hazardous chemical, and strict safety controls are essential during its storage and transportation. Wang Jun’s team simultaneously overcame the shortcomings in the safe management of high-purity chlorine, establishing a safety control model that covers the entire process from chlorine production to purification and transportation. By utilizing computational fluid dynamics (CFD) techniques to simulate the flow of chlorine gas within equipment and pipelines, as well as its vaporization and the spatial and temporal distribution of nitrogen trichloride concentrations, they developed specialized safety assessment methods. These methods enabled the creation of a \"digital twin\" design for electronic specialty gas production plants, thus overcoming the \"last mile\" challenge in the industrialization of high-purity chlorine gas and establishing a solid safety barrier for the large-scale application of this technology. 　　It is understood that electronic specialty gases are essential materials for core processes such as wafer etching and cleaning. Among them, electronic-grade chlorine can be regarded as the “etching tool” and “cleaning agent” used to construct the microscopic structure of chips. Advanced manufacturing processes below 28 nanometers have extremely stringent requirements regarding chlorine purity. The levels of moisture and metallic impurities in the gas must be strictly controlled to the ppb (parts per billion) range, with a purity level reaching 6N. As a result, this type of specialty electronic gas is one of those most difficult to produce domestically and for which China relies the most on imports. This technological breakthrough will accelerate the localization of semiconductor specialty gases in China, and is expected to enhance the country’s ability to secure raw materials for high-end manufacturing industries.