With Samsung's announcement of mass production of the 7nm EUV process, the EUV lithography process was finally commercialized in 2018, which is a milestone in the 30 years of EUV process development. However, there are still many technical challenges for the mass production of the EUV process. The current light source power and wafer capacity output have not yet reached the ideal state. The EUV process still has a long way to go.
In addition to the existing EUV, ASML and IMEC Belgium Microelectronics Center also reached a new cooperation agreement. The two parties will jointly develop a new generation of EUV lithography machines. The NA numerical aperture is increased from the existing 0.33 to 0.5, which can further enhance the optical Engraving the micro-level of the process, making smaller transistors.
What does NA numerical aperture mean for lithography machines? We have explained this question in a previous Super Class: a lithography machine with a unit price of 120 million US dollars. Only one company in the world produced a simple explanation. The formula for determining the resolution of a lithography machine is as follows:
k1 is a constant, different lithography machines k1 are different, λ refers to the wavelength of the light source, NA is the numerical aperture of the objective lens, so the resolution of the lithography machine depends on the wavelength of the light source and the numerical aperture of the objective lens. The shorter the wavelength, the better. The larger NA is, the better the resolution of the lithography machine is, and the more advanced the process technology is.
The current EUV lithography machine uses extreme ultraviolet light with a wavelength of 13.5nm, while the ordinary DUV lithography machine uses deep ultraviolet light at 193nm, so upgrading to an EUV lithography machine can greatly improve the semiconductor process level, achieving 7nm and Following process.
However, after changing the wavelength to further improve the resolution of the EUV lithography machine, it is necessary to start from the NA index. The current lithography machine uses an objective lens system with NA = 0.33. The next generation goal is optical with NA = 0.5 and above. System.
Now, the cooperation between ASML and IMEC is the high NA EUV process. The two sides will set up a joint laboratory to use the optical system of NA = 0.55 on the EXE: 5000 lithography machine. Higher NA will help project the EVU light source to Wider wafers to increase semiconductor process resolution and reduce transistor size.
Now this research has just begun, so the new generation of EUV lithography is still early. ASML invested US $ 2 billion to invest in Zeiss. The goal is to cooperate in the development of NA = 0.5 objective lens system. The previously announced mass production time is 2024. At this point in time, the semiconductor company's process technology should be able to reach the 3nm node.