With the continuous development of chip technology, the lithography machine as a key equipment for chip manufacturing has also continued to evolve. From ordinary DUV lithography to immersion DUV lithography to the current EUV lithography machine, every improvement has promoted the progress of chip technology. However, with the introduction of EUV lithography machines, we are faced with a question: in which direction will the development of lithography machines break through?Van den Brink said that the road ahead of EUV lithography seems to have come to an end, whether it is the change of the wavelength of the light source, the increase of the numerical aperture or the increase of the lithography process factor, it is close to the limit of technology. Therefore, the next development of lithography machines may need to find disruptive ideas or turn to other types of lithography machines.
The EUV lithography machine currently uses 13A light source with a wavelength of 5 nm. It has been suggested that if the wavelength of the light source is further reduced, the resolution of the lithography machine can be improvedHowever, current experiments have shown that light, even at lower wavelengths, is absorbed by almost all materials, so it needs to be reflected through mirrors. However, after many reflections, the light is severely weakened and does not provide enough energy for lithography. Therefore, changing the wavelength of the light source is not a feasible direction.
However, we cannot rule out that there will be new technological breakthroughs in the future that will solve the current problems and make it possible to further change the wavelength of the light source.
The numerical aperture (NA) is a measure of the focusing ability of a lithography machine, and the larger it is, the better the focusing of light. The current NA of the EUV lithography machine has reached 055, ASML believes that under the current level of technology, it can not be further improved. Therefore, the increase in numerical aperture seems to be a dead end.
However, historically, people have always been able to overcome technical difficulties and push the limits. Perhaps in the future, new technologies will emerge that will make it possible to increase the numerical aperture.
The lithography process factor is the ratio of the smallest detail size to wavelength that can be achieved under specific optical conditions. Current EUV lithography machines have reached their physical limits in terms of lithography process factors. This means that the lithography machine can no longer increase resolution by adjusting the process factor.
However, there are many technologies in history that were thought to have reached their limits, but have since been pushed through. Therefore, we cannot rule out the possibility of a breakthrough in the lithography process factor, and perhaps new methods will emerge in the future to make it possible to improve the process factor.
The development of EUV lithography machines seems to have come to an end, and Van Den Brink believes that when the NA reaches 0After 55, the resolution can no longer be increased. Changing the wavelength of the light source, increasing the numerical aperture and improving the lithography process factor seem to have reached the limit of technology. Although it seems that the road ahead of the lithography machine is a dead end, there are many similar situations in history that have been broken through, and the development of technology is indispensable. Maybe in the next development, we will have new breakthroughs, or there will be a new type of lithography machine. Following the retirement of ASML co-presidents Wennink and Van den Brink, their successors will continue to explore breakthroughs in this area.
As the core equipment of chip manufacturing, the development of lithography machine is of great significance to the entire technology industry. The current EUV lithography machine is facing a bottleneck in development, whether it is the change of the wavelength of the light source, the increase of the numerical aperture or the increase of the lithography process factor, it seems that it has reached the limit of technology. However, the development of technology is incomprehensible, and many technical problems in history that were once thought to be impossible to break through have finally been overcome, bringing surprises to mankind. Therefore, although it seems that the road ahead of the lithography machine seems to be a dead end, we cannot give up the exploration of technological breakthroughs, and believe that new breakthroughs will appear in the future.