The gap is far, the light source is a generation.
The 90nm lithography machine is still far away from 7nm, at least a generation lower in light source technology. The 9nm lithography machine uses a deep ultraviolet light source, which is roughly a 193nm light source generated by laser bombardment of mercury lamps, and then compressed to 90nm by purified water medium and lens group technology. The so-called 7nm is actually 13.5nm extreme ultraviolet light source, is to use laser bombardment tin drop particles to produce extreme ultraviolet light, the current tin drop generator is only a company in the United States can manufacture, the difficulty is very high. Therefore, 90nm and 7nm are not only different in the wavelength of the light source, but also very different in the way the light source is generated and the technical difficulty.