Seed injection ArF excimer laser device

Abstract

The invention provides a seed injection ArF excimer laser device. The device comprises an all solid state seed laser and an ArF excimer laser, wherein the all solid state seed laser comprises an all solid state laser, a nonlinear optical crystal converter and a KBe2BO3F2 crystal frequency multiplier; the all solid state laser is used for generating basic frequency laser; the nonlinear optical crystal converter is used for receiving the basic frequency laser and performing frequency conversion on the basic frequency laser until the wavelength is 386.8 nanometers; the KBe2BO3F2 crystal frequency multiplier is used for receiving laser of 386.8 nanometers and performing frequency multiplication on the laser until the laser becomes seed laser with the wavelength of 193.4 nanometers; the all solid state seed laser injects the seed laser into the ArF excimer laser; and the ArF excimer laser receives and amplifies the seed laser. The seed injection ArF excimer laser device of the invention has the advantages of simple structure, easier practicability and engineering and capability of realizing 193.4-nanometer output of laser with high power, high light beam quality and small line width.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a seed injection type ArF excimer laser device. Background technique [0002] Excimer laser is a kind of gas laser with excimer as the working substance. The most important feature of excimer lasers is that they can efficiently output high-power ultraviolet or deep ultraviolet lasers, so they have gained important applications in the fields of microelectronics, micro-nano processing, photochemistry, photobiology, isotope separation, and nuclear fusion. Especially in semiconductor lithography, the ArF excimer laser with an output wavelength of 193.4nm is the mainstream light source for the new generation of lithography systems currently under development. In the lithography system, the laser beam reflected or transmitted by the mask needs to be imaged to the photosensitive layer by a complex and expensive optical imaging system. In order to obtain a high-resolution image, the lase...

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Problems solved by technology

[0004] The seed laser adopts the scheme of excimer laser. Since the excimer laser is generated by gas discharge pumping, the gas is highly corrosive and has a short service life, the discharge thyratron is easily damaged, and the optical window is easy to be polluted. Therefore, there is a system Complexity, high technical difficulty, poor stability, and short lifespan

The seed laser uses BBO, KB5 (KB 5 o 8 4H 2 O)[Generation of femtosecond pulses down to 166nm by sum-frequency mixing in KB 5 o 8 4H 2 O, Electron Letter 34, 1748], CLBO (CsLiB 6 o 10 )[A Quasi-Continuous-Wave Deep Ultraviolet Laser Source, IEEE J.Quant.Elect.39:1160] and LBO (LiB 3 o 5 ) [Generation of tunable femtosecond pulses to as low as 172.7nm by sum-frequency mixing in lithium triborate, Optics Letter 19, 1538] and other non-linear optical crystal all-solid-state laser sum-frequency technical solutions, because these crystals can only use two The 193.4nm laser output is realized by the method of beam laser sum frequency, the technology is more complex, it is difficult to achieve high frequency conversion efficiency, short life and other shortcomings, which is not conducive to the realization of engineering; moreover, the nonlinear crystals used in sum frequency technology have their own Inadequacies, for example: the BBO crystal needs to be cooled to 226K to reduce absorption loss and improve the stability of the sum frequency; the CLBO crystal has strong deliquescence; the LBO crystal cannot achieve the phase matching of the sum frequency of the 1um fundamental solid-state laser; the KB5 crystal The effective nonlinear coefficient is very small (0.04pm / V)

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