Research Progress: Extreme Ultraviolet Photolithography

Recently, the semiconductor industry has adopted Extreme Ultraviolet Lithography (EUVL) technology. This cutting-edge photolithography technology is used for the continuous miniaturization of semiconductor devices to comply with Moore's Law. Extreme ultraviolet lithography (EUVL) has become a key technology that utilizes shorter wavelengths to achieve nanoscale feature sizes with higher accuracy and lower defect rates than previous lithography methods.

Recently, Dimitrios Kazazis, Yasin Ekinci, and others from the Paul Scherrer Institute in Switzerland published an article in Nature Reviews Methods Primers, comprehensively exploring the technological evolution from deep ultraviolet to extreme ultraviolet (EUV) lithography, with a focus on innovative methods for source technology, resist materials, and optical systems developed to meet the strict requirements of mass production.

Starting from the basic principles of photolithography, the main components and functions of extreme ultraviolet EUV scanners are described. It also covers exposure tools that support research and early development stages. Key themes such as image formation, photoresist platforms, and pattern transfer were explained, with a focus on improving resolution and yield. In addition, ongoing challenges such as random effects and resist sensitivity have been addressed, providing insights into the future development direction of extreme ultraviolet lithography EUVL, including high numerical aperture systems and novel resist platforms.

The article aims to provide a detailed review of the current extreme ultraviolet lithography EUVL capabilities and predict the future development and evolution of extreme ultraviolet lithography EUVL in semiconductor manufacturing.

Figure 1: Basic steps of photolithography process.

Figure 2: Extreme ultraviolet scanner and its main components.

Figure 3: Process window of photoresist.

Figure 4: Contrast curve of chemically amplified resist exposed to extreme ultraviolet light.

Figure 5: Typical faults in photolithography patterning of dense line/spacing patterns and contact hole arrays.

Figure 6: In 2025-2026, with the high numerical aperture, NA systems will enter mass production of high-volume manufacturing (HVM). In the next decade, lithography density scaling will continue to increase.

Figure 7: Chip yield curves plotted as a function of source power divided by dose for high numerical aperture NA and low numerical aperture NA extreme ultraviolet scanners.

Source: Yangtze River Delta Laser Alliance