The first pulse 1 1 is output before the second pulse 12, and the delay between the first pulse 1 1 and the second pulse 12 is adjustable; The energy of the first pulse is enough to bombard the target droplets into an ideal geometric distribution, and the energy of the second pulse 12 is enough to convert the target treated by the first pulse into plasma emitting EUV light.
abstract:
The invention relates to the technical field of lasers, and discloses a dual-pulse driving light source of a high-power EUV lithography light source, the wavelength range is 1800-2500 nm, Tm-doped materials are used as laser gain media, and the dual-pulse driving light source comprises a pulse seed source, a pulse selector, a pulse beam splitter, a pulse retarder, a pulse shaper and a laser pulse amplification system, wherein the pulse seed source comprises a mode-locked oscillator and a nanosecond pulse seed source.
The double pulse driving the light source can be generated by the same pulse seed source, and the double pulse output with adjustable time delay can be realized through the pulse beam splitter and pulse delay. The laser pulse amplification system for driving the light source includes at least one pulse amplifier, and the pulse width can be adjusted by a pulse stretcher and a pulse compressor.
The double pulses output by the driving source can also be generated by different pulse seed sources respectively. After the pulse selector reduces the pulse sequence to an appropriate repetition rate, the pulse delayer realizes the delayed output of double pulses. The laser pulse amplification system includes at least one stage of pulse amplifier, and the pulse width can be adjusted by pulse stretcher and pulse compressor.
According to the invention, the characteristics of high-power 2mum band all-solid-state laser, such as high average power, high wall insertion efficiency, small device volume and the like, are utilized to replace the CO2 laser as a driving light source at present, so that higher average power output is obtained, the power for exciting EUV radiation is improved, and the problem of increasing the output of EUV mask aligner chips is solved.
On May 26th, the Shanghai Science and Technology Awards Conference was held in Shanghai. At the meeting, various science and technology awards were awarded in 2022. Four scientific research achievements of Shanghai Institute of Optics and Mechanics won the first prize of Shanghai Science and Technology Award in 2022, among which the project "Key Technology and Application of High Power Polarization-Independent Spectral Beam Combining Grating" won the first prize of Shanghai Technological Invention Award.
Spectral beam combining technology is one of the fastest developing technical routes to realize high power fiber laser. Based on the principle of grating inverse dispersion, this technology combines hundreds of kilowatt sub-beam lasers with different wavelengths into a high-power laser. However, due to polarization independence, high spectral efficiency and low temperature rise distortion, it is extremely difficult to develop spectral beam combining gratings, and there has been no effective breakthrough for many years.
After years of joint research, Livermore National Laboratory, Advanced Film Company and Lockheed Martin Company of the United States have developed a spectral R& combined beam grating that can support a 30 kW high-energy laser system, and won the 20 14 American Science and Technology Award "R&: D 100" innovation award. In 2022, 300 kW synthetic laser output will be further realized.
This project has effectively promoted the rapid development of high-power spectral synthesis laser technology in China, making the synthetic output power jump by 4~5 orders of magnitude, and ensuring the construction of a series of high-power laser equipment in related fields in China. Related achievements have also been applied to laser applications such as laser Doppler velocimetry radar, semiconductor laser, ultrashort laser and blue-green laser processing, and some products have been exported abroad. In addition, it has promoted the progress of ultra-precision optical processing, high-power laser thin film preparation, photoresist spin coating, ion beam etching and other related technologies in China, and achieved remarkable social and economic benefits.
With the strong support of relevant state units, the project has broken through a series of key technologies such as grating structure system design and engineering evaluation, grating structure precision control, thermal deformation detection and temperature rise suppression, and formed a set of grating production process equipment with independent intellectual property rights. Authorized invention patents 15 and published 26 papers. More than a dozen experts in the field pointed out that "the project is technically complex, difficult and innovative, and the overall technology has reached the international advanced level in the field of high-power laser fiber combination gratings, among which the spectral bandwidth and diffraction efficiency are internationally leading".
The focus is on these two paragraphs:
After years of joint research, Livermore National Laboratory, Advanced Film Company and Lockheed Martin Company of the United States have developed a spectral R& combined beam grating that can support a 30 kW high-energy laser system, and won the 20 14 American Science and Technology Award "R&: D 100" innovation award. In 2022, 300 kW synthetic laser output will be further realized.
This project has effectively promoted the rapid development of high-power spectral synthetic laser technology in China, and made the synthetic output power jump by 4~5 orders of magnitude (that is, 1 10,000 times to 1 10,000 times! ), which guarantees the construction of a series of high-power laser equipment in related fields in China.
Recently, the polarization-independent beam combining grating developed by Shanghai Institute of Optics and Mechanics has made a breakthrough. The High Intensity Laser Materials Laboratory of Chinese Academy of Sciences took the lead in developing polarization-independent all-dielectric combined beam grating in China. The diffraction efficiency of the developed 50mm×50mm grating is over 94% in the range of unbiased laser 1040nm- 1070nm, and it can withstand several kilowatts of power.
Based on the high-intensity laser thin film technology and grating design, combined with the high-intensity laser thin film manufacturing technology and flexible grating structure design, the researchers of Shanghai Institute of Optics and Mechanics skillfully improved the manufacturing tolerance of each link in grating manufacturing, and achieved a breakthrough in the development of polarization-independent all-dielectric combined beam grating in China.
The synthesis technology of high-power fiber laser has become a hot research topic in the world, among which incoherent spectral synthesis is a rapidly developing synthesis method in recent years, and its core component is polarization-independent all-dielectric beam-combining grating, which can only be provided by the United States in the world.