With the continuous progress of chip technology, lithography machines, as indispensable key equipment in chip manufacturing, are also evolving and improving. In the past, ordinary DUV lithography machines could only produce chips as low as 65 nanometers, while immersion DUV lithography machines could produce chips as low as 7 nanometers. Today, EUV lithography machines are capable of producing chips of 5 nanometers and below. The advancement and precision of the lithography machine largely determine the improvement of the chip process. With more advanced lithography machines, more advanced chips can be manufactured, and at the same time, advanced chips have promoted the development of lithography machines. According to experts, the current EUV lithography machine can theoretically manufacture chips of about 2 nanometers, while the next generation of EUV lithography machines can theoretically manufacture chips of about 1 nanometers. However, with the continuous progress of chip technology, EUV lithography machines are also facing challenges to move forward.
1.Wavelength limit: will 13Replacing a 5nm wavelength light source with a smaller wavelength light source is a breakthrough direction. However, current experiments have shown that light sources with even smaller wavelengths are absorbed by almost all materials and must therefore be reflected through mirrors. However, harvesting the reflected light results in a severe loss of energy, preventing sufficient energy from being obtained for lithography.
Amplification: In lithography, shortening the wavelength is important to improve resolution and the ability to capture details. Despite the fact that the existing EUV lithography machine used 135 nm wavelength light source, but this wave length is affected by material absorption during lithography and needs to be reflected through a mirror. However, energy loss occurs when light is reflected through it, limiting the amount of energy available during lithography. Therefore, finding a light source with a smaller wavelength and overcoming the problem of energy loss is an important direction for the development of EUV lithography machine.
2.Numerical Aperture Limit: Increasing the numerical aperture (NA) value increases the amount of light that can be collected and focused, which improves the effectiveness of lithography. However, according to ASML, after reaching 0With a numerical aperture of 55, it is difficult to further improve. This limitation limits the possibility of further increasing lithography resolution.
Expanding: The numerical aperture is an indicator used to describe the focusing ability of the light source of the lithography machine, and its size is directly related to whether it can effectively focus the light. A larger numerical aperture means that the lithography machine can collect more light, which improves the resolution in the lithography process. However, according to ASML, once the numerical aperture reaches 055, the possibility of further increasing the numerical aperture becomes very limited. This limitation makes lithography machines constrained in terms of increasing resolution.
3.Lithography Process Factor Limit: Increasing the lithography process factor can increase the resolution of lithography, thereby improving the accuracy and detail capture ability of the chip. However, ASML believes that the current lithography process factor is close to the physical limit and is difficult to further improve.
Expansion: The lithography process factor is an important indicator to measure the ability of the lithography process, which can determine the resolution and accuracy in the lithography process. The increase in lithography process factor can increase the detail and accuracy that can be captured during the lithography process, thereby improving the yield and performance of the chip. However, ASML believes that the current lithography process factors are close to the physical limit, and the room for further improvement is very limited.
In the opinion of Van Den Brink, co-president of ASML, when the EUV lithography machine was introduced, na=0After the 55 high numerical aperture lithography machine, there will be no further breakthrough, which will be the last generation of EUV lithography machine. He believes that the current technology has reached its limits and cannot be further breakthroughs. In other words, the three directions in which the EUV lithography machine is moving forward are already a dead end, and there can be no new breakthroughs.
However, there are still some unknowns about the future prospects of the lithography field. Perhaps, we can learn from the subversive idea of immersion lithography proposed by Lin Benjian, or turn to other types of lithography machines. In addition, ASML's successor will continue to take on the task and responsibility of breakthrough and contribute to the future development of lithography machines.
As one of the important driving forces for the development of chip technology, EUV lithography machine has attracted much attention for its technical prospects. However, in Van den Brink's view, the three directions in which the EUV lithography machine is advancing are already dead ends, and there can be no new breakthroughs. Whether it's changing the wavelength of the light source to a smaller wavelength, increasing the numerical aperture, or increasing the lithography process factor, the current technology is close to the physical limit. This point of view has led to thinking and discussion on the future development direction of lithography machines. While no specific solution has yet been identified, it is still crucial for the industry to find new breakthroughs and technological innovations. Only the continuous pursuit of innovation can promote the development of lithography machine technology and provide strong support for the continuous progress of chip technology.