Focusing and leveling mechanism for Litho machines proposed by SMEE and IMECAS
And the prospect for EUV lithography.
EUV lithography machine is the core equipment for integrated circuit manufacturing at 7 nm and below technology nodes in the future. Due to the 13.5 nm exposure wavelength, it can only propagate in a vacuum. Therefore, the focusing and leveling measurement system of EUV lithography machine must be placed in a high vacuum environment [ ] . Compared with traditional dry and immersion lithography machines, in addition to the various technologies mentioned above, the focusing and leveling measurement system in a vacuum environment also needs to consider issues such as particle/gas pollution and heat dissipation control, and has a Make corresponding improvements to achieve higher measurement accuracy.
In order to control the temperature of the focusing and leveling measurement system in the vacuum chamber, Nikon Company proposed to set up a thermally conductive substrate and an active cooling device to dissipate heat by adding flowing gas between the optical element and the substrate [ ] . ASML Company proposed a method for thermal regulation of optical components operating in a vacuum environment, using gas as the medium to achieve the desired temperature by dynamically adjusting the position or direction of the cooling device [ ] . Focusing and leveling measurement systems for EUV lithography machines typically have multiple reflective optical elements, and reducing contamination on each element improves overall reflectivity. Carl Zeiss Company proposed a method for measuring the residual gas in the vacuum chamber of EUV lithography equipment, which can monitor the concentration of polluted gas, and interrupt the operation of the equipment for cleaning if necessary, and proposed a method for cleaning the pollutants in EUV lithography equipment. method, by reacting a stream of hydrogen atoms with the molecules to be cleaned to form volatile compounds that can be pumped away by a vacuum pump [ ] .
The Institute of Microelectronics, Chinese Academy of Sciences has carried out preliminary research on the adaptability of the focusing and leveling measurement system to the vacuum environment and proposed an electronic device, which places the electronic system (such as a photodetector) in a sealed shell in the vacuum chamber , effectively blocking the pollutants [ ] . Chen Jinxin et al. [ ] proposed a vacuum temperature field measurement device and method, which can not only realize the measurement in vacuum, but also improve the measurement accuracy of the temperature field. Xu Tianwei et al. [ ] proposed to place the light source of the EUV focusing and leveling measurement system outside the vacuum chamber, and transmit the light outside the vacuum chamber into the vacuum chamber through a fiber optic transmission device to supply the sensor to work, which can effectively reduce heat dissipation and vacuum. Cavity contamination [ ] .
And the prospect for EUV lithography.
4 Improvement of EUV lithography focusing and leveling measurement system
EUV lithography machine is the core equipment for integrated circuit manufacturing at 7 nm and below technology nodes in the future. Due to the 13.5 nm exposure wavelength, it can only propagate in a vacuum. Therefore, the focusing and leveling measurement system of EUV lithography machine must be placed in a high vacuum environment [ ] . Compared with traditional dry and immersion lithography machines, in addition to the various technologies mentioned above, the focusing and leveling measurement system in a vacuum environment also needs to consider issues such as particle/gas pollution and heat dissipation control, and has a Make corresponding improvements to achieve higher measurement accuracy.
In order to control the temperature of the focusing and leveling measurement system in the vacuum chamber, Nikon Company proposed to set up a thermally conductive substrate and an active cooling device to dissipate heat by adding flowing gas between the optical element and the substrate [ ] . ASML Company proposed a method for thermal regulation of optical components operating in a vacuum environment, using gas as the medium to achieve the desired temperature by dynamically adjusting the position or direction of the cooling device [ ] . Focusing and leveling measurement systems for EUV lithography machines typically have multiple reflective optical elements, and reducing contamination on each element improves overall reflectivity. Carl Zeiss Company proposed a method for measuring the residual gas in the vacuum chamber of EUV lithography equipment, which can monitor the concentration of polluted gas, and interrupt the operation of the equipment for cleaning if necessary, and proposed a method for cleaning the pollutants in EUV lithography equipment. method, by reacting a stream of hydrogen atoms with the molecules to be cleaned to form volatile compounds that can be pumped away by a vacuum pump [ ] .
The Institute of Microelectronics, Chinese Academy of Sciences has carried out preliminary research on the adaptability of the focusing and leveling measurement system to the vacuum environment and proposed an electronic device, which places the electronic system (such as a photodetector) in a sealed shell in the vacuum chamber , effectively blocking the pollutants [ ] . Chen Jinxin et al. [ ] proposed a vacuum temperature field measurement device and method, which can not only realize the measurement in vacuum, but also improve the measurement accuracy of the temperature field. Xu Tianwei et al. [ ] proposed to place the light source of the EUV focusing and leveling measurement system outside the vacuum chamber, and transmit the light outside the vacuum chamber into the vacuum chamber through a fiber optic transmission device to supply the sensor to work, which can effectively reduce heat dissipation and vacuum. Cavity contamination [ ] .
