SK hynix uses 13.5nm EUV technology to advance ultra-fine circuit patterns

SK hynix is utilizing 13.5nm EUV technology to overcome diffraction limits in semiconductor miniaturization, having already achieved the world's first certified 10nm-class LPDDR6 this year.

The core of the photo process, which draws minute circuits on semiconductor chips, lies in light-handling technology. As the AI era opens and the demand for rapid processing of massive data grows, the "miniaturization competition"—the race to pack more elements and memory cells into a single chip—has emerged as a major theme in the semiconductor industry.

According to the technical content "Invisibles" released by SK hynix, the photo process begins by applying light-sensitive photoresist (PR) onto a silicon wafer. Light passing through the fine patterns of a photomask containing the design travels through a lens to form a reduced image on the wafer. Sophisticated light and dark patterns are created depending on whether the areas exposed to light are removed (positive PR) or remain (negative PR).

Diffraction creates technical barriers; short-wavelength EUV is the solution

Technical difficulty increases sharply as patterns become denser. This is because as patterns become finer, the "diffraction phenomenon"—where light bends in multiple directions while passing through narrow gaps—intensifies. When diffracted light overlaps, it causes the boundaries of adjacent patterns to blur, or some light may fall outside the lens range, reducing the pattern information delivered to the wafer. Consequently, the process hits a limit where circuits become blurred or fail to form properly.

To overcome these physical limits, the Extreme Ultraviolet (EUV) process was introduced. The resolution of the lithography process (the minimum distance at which two close points can be distinguished) increases as the wavelength of light becomes shorter. By using EUV with a wavelength of 13.5nm, which is approximately 14 times shorter than the existing ArF process, more precise circuits can be implemented in a single step. This also reduces reliance on the complex "Multi Patterning" method, which required splitting patterns into two separate exposures.

From DRAM to LPDDR6, SK hynix optimizes ultra-fine processes

SK hynix has broken through the limits of memory miniaturization through EUV process optimization. Since first introducing EUV to the DRAM process in 2021, the company unveiled the world's first 10nm-class 6th generation DDR5 in 2024. Following this, the company is applying ultra-fine pattern technology to next-generation memory product lines, reaching the world's first certified 10nm-class LPDDR6 this year.

Industry attention is now turning toward "High NA (High Numerical Aperture) EUV," which can achieve even higher resolution. High NA EUV technology, which can collect light more precisely, is a key driver enabling ultra-fine processes at the single-digit nanometer (nm) scale. Based on these advancements in optical technology, SK hynix is focusing on implementing high-density memory capable of storing and processing more data.

Source: original video (YouTube)