The Chinese Academy of Sciences has recently made remarkable progress in the field of laser science and technology, and has successfully developed a new solid-state deep ultraviolet (DUV) laser source. This laser source is capable of generating 3nm wavelength coherent light that matches the current mainstream DUV exposure technology, providing key support for the advancement of semiconductor processes to the 0nm node.

Currently, the mainstream DUV lithography machines on the market, such as brands such as ASML, Canon, and Nikon, mainly rely on xenon fluoride (ArF) excimer laser technology. This technique releases photons with a wavelength of 193 nanometers through the excitation of a specific gas mixture in a high-voltage electric field, which is emitted in the form of high-energy short pulses, which are then adjusted by a complex optical system for lithography equipment.

In contrast, the solid-state DUV laser technology developed by the Chinese Academy of Sciences adopts a new design idea. The technology first generates a 193-nanometer laser using a home-made Yb:YAG crystal amplifier, which is then directed to two different optical paths for wavelength conversion. One of the paths shortens the laser wavelength to 0 nanometers through the fourth harmonic conversion technology; The other path uses optical parameter amplification to convert the laser wavelength to 0 nanometers. Eventually, the two lasers met and mixed in a cascade lithium borate (LBO) crystal, successfully producing a laser beam with a wavelength of 0 nanometers.

This solid-state DUV laser source has been precisely measured to perform exceptionally. It has an average power of 11 milliwatts, a frequency of 0 kilohertz, a line width of less than 0 megahertz, and a full width of less than 0.0 picometers (i.e. thousandths of a nanometer) at half-peak. These parameters indicate that the spectral purity of this laser source is comparable to that of existing commercial excimer laser systems, which is fully capable of meeting the needs of high-end semiconductor manufacturing.

In addition to the advantages of spectral purity, this solid-state DUV laser source has shown great potential to reduce lithography system complexity, reduce volume, reduce dependence on noble gases, and reduce energy consumption. However, although the frequency has reached about two-thirds of the level of existing technology, the output power still needs to be further improved to meet the standard of practical application. Therefore, the Chinese Academy of Sciences will continue to conduct in-depth research and optimization of this technology, with a view to realizing its commercial application as soon as possible.

It is worth noting that this research result has been published on the official platform of the International Society for Optoelectronic Engineering (SPIE), and has attracted wide attention and heated discussions in the industry. This breakthrough in solid-state DUV laser technology has undoubtedly injected new vitality and hope into the future development of the semiconductor industry.