China’s Breakthrough Solid-State Deep Ultraviolet Laser Could Transform Chipmaking

Scientists from the Chinese Academy of Sciences (CAS) have reportedly achieved a significant milestone in the field of solid-state deep ultraviolet (DUV) lasers. According to a study published in Advanced Photonics Nexus, a journal affiliated with the International Society for Optics and Photonics (SPIE), Chinese researchers have successfully developed a 193-nanometer (nm) coherent laser beam.

Currently, the semiconductor industry relies on DUV lithography machines that utilize gas-based excimer lasers to generate a 193 nm wavelength beam. These systems use a mixture of gases—such as Argon (Ar), Fluorine (F), and Neon (Ne)—which are excited by high-voltage pulses to produce short-lived Argon Fluoride (ArF) molecules. As these molecules return to their stable state, they emit ultraviolet (UV) photons at precisely 193 nm.

The new solid-state laser developed by CAS scientists offers a potential alternative to this traditional gas-based approach. Unlike excimer lasers, which require the careful handling of toxic gases like fluorine, the solid-state laser relies solely on crystals and optics. The research team used a Yb:YAG crystal amplifier to generate an infrared laser at 1030 nm. Through a series of optical processes—specifically Fourth-Harmonic Generation (FHG) and Optical Parametric Amplification (OPA)—they successfully combined different wavelengths using nonlinear crystals to produce a coherent 193 nm beam.

A major advantage of this solid-state approach is its potential to eliminate the need for hazardous gases, making the technology safer, more compact, and potentially easier to maintain. Additionally, solid-state lasers are generally more reliable and have lower operational complexity compared to their gas-based counterparts.

However, despite its promise, the technology is far from being ready for commercial semiconductor production. The newly developed CAS laser currently produces only 70 milliwatts (mW) of power, significantly lower than the 100–120 Watts typically required in commercial lithography systems. This power gap—several hundred times weaker—presents a major engineering challenge.

The research is still in its early experimental phase, and scaling up the power output to match industry standards will require years of further development. Scientists will need to overcome significant hurdles in enhancing power efficiency and ensuring long-term reliability before this new solid-state laser technology can compete with existing commercial solutions.