KAIST, Samsung Electronics develop catalyst to neutralize greenhouse gas 6,000 times more potent than CO₂

South Korean researchers have developed a technology capable of eliminating a semiconductor exhaust gas more than 6,000 times as potent as carbon dioxide.

KAIST announced Thursday that a research team led by Professor Choi Min-ki of the Department of Chemical and Biomolecular Engineering, working jointly with researchers from Samsung Electronics, has developed a new catalyst that can efficiently and durably break down carbon tetrafluoride (CF₄) — a greenhouse gas used in semiconductor fabrication processes such as dry etching to create microscopic circuits on wafers.

CF₄ is used in dry etching, a process that selectively removes material from semiconductor wafers to form fine circuit patterns. The problem lies in the trace amounts of CF₄ that remain after use. Because carbon and fluorine bond extremely tightly, the compound resists decomposition and, once released into the atmosphere, can persist for roughly 50,000 years. Its global warming potential is more than 6,000 times that of carbon dioxide.

Semiconductor manufacturing facilities currently decompose CF₄ using high-temperature steam and catalysts to prevent it from being released directly into the atmosphere. Existing catalysts, however, have long suffered from performance degradation over time.

The research team addressed this problem by applying the principle of "entropy stabilization" — a method that evenly mixes multiple types of atoms within a catalyst to prevent it from agglomerating or transforming into a different structure.

The team uniformly distributed several metals — aluminum (Al), zinc (Zn), gallium (Ga), nickel (Ni) and cobalt (Co) — within a single aluminate crystal structure. Aluminate is a material in which various metals bond to a base framework of aluminum and oxygen. The result was an "entropy-stabilized aluminate catalyst" that resists clumping and structural change even under the harsh conditions of high temperature, moisture and fluorine exposure that characterize semiconductor processing environments.

The performance gap was clear. The new catalyst showed approximately 2.3 times greater CF₄ decomposition activity than conventional alumina catalysts. In a stress test conducted at around 800 degrees Celsius over 150 hours, the CF₄ conversion rate of the conventional alumina catalyst dropped from 93 percent to 48 percent. The new catalyst held steady, declining only marginally from 98 percent to 92 percent — demonstrating that it can sustain high-efficiency CF₄ removal over extended periods.

The significance of the research extends beyond the development of a single high-performing catalyst. The team has proposed a new catalyst design methodology capable of simultaneously achieving high decomposition performance and long operational life. The approach is expected to be applied to the development of catalysts for treating a range of other process gases used in semiconductor manufacturing, by varying the types and combinations of metals used.

"We applied the principle that disorder in nature can actually stabilize a structure to catalyst design, achieving both high CF₄ decomposition performance and long-term stability at the same time," Choi said. "The technology also has potential applications in reducing fluorine-based greenhouse gas emissions generated during the manufacture of LCD and OLED displays."

The findings were published in June in the international chemistry journal Angewandte Chemie International Edition.