Redefining Resource Efficiency in Lithography: The Future of Excimer Laser Gas Management

Kanken Techno Co., Ltd. Develops World’s First On-Site Neon Gas Recycler for Excimer Lasers

Kanken Techno Co., Ltd. has achieved a world-first by successfully developing an on-site neon (Ne) gas recycling system for excimer lasers used in semiconductor lithography equipment. This groundbreaking technology enables Ne gas—an essential and costly component of excimer lasers—to be recycled directly at the production site, reducing both cost and environmental impact.

The system is currently operating at a semiconductor fabrication plant, where a single recycler is connected to three ArF excimer lasers. The lasers and recycler are functioning stably while continuously recycling process gas, achieving a recycling rate of over 90%.

Excimer lasers are categorized into two types—ArF and KrF—and Kanken Techno has developed dedicated recyclers for both. This marks the first time that an on-site Ne gas recycling system for excimer lasers has reached mass production anywhere in the world.

Globally, only two companies manufacture excimer lasers, and Kanken Techno is working individually with both through collaborative partnerships. The company is currently undergoing the certification process with each manufacturer and expects official approval in the near future.

This innovation positions Kanken Techno as a pioneer in sustainable gas recycling for advanced semiconductor manufacturing, offering both technological value and cost-saving potential to the industry.

Key Technologies Covered

• The exhaust gas from excimer lasers contains impurities such as H₂O and O₂, originating from air contamination. Our system is equipped with mechanisms to reliably remove these impurities.
• The exhaust gas also includes CF₄, a difficult-to-decompose gas that can affect laser performance. Despite its persistent nature, our system is equipped with a decomposition mechanism capable of removing CF₄ effectively.
• In ArF excimer lasers, xenon (Xe) is added in trace amounts (10 ppm ± 2 ppm) to the laser gas. Through repeated recycling, Xe concentration tends to diminish. To address this, we have developed and implemented a precision mechanism that reintroduces Xe at 10 ppm ± 2 ppm.
• To achieve the precise removal of air components and CF₄, as well as the controlled reintroduction of Xe, the recycler is equipped with a built-in Quadrupole Mass Spectrometer (QMS).The system automatically analyzes gas composition using QMS to determine the necessary Xe addition and confirm purification results after impurity removal.
• The system achieves a neon gas recycling rate of over 90%. Notably, for the “injection” portion of gas supply—which accounts for more than 90% of gas usage in excimer lasers—the effective recycling rate reaches 100%. The remaining less than 10% comes from “refill” gas supply. With further optimization of the gas recovery method for refills, the system has the potential to approach a true 100% recycling rate.
• A single recycler can be connected to up to five high-usage excimer lasers. Depending on the laser duty cycle and usage patterns, it is technically possible to support more than five lasers per unit.