Efficient high-harmonic-generation-based EUV source driven by short wavelength light
Extreme ultraviolet radiation is generated based on high-order harmonic generation. First, a driver pulse is generated from a drive laser. Second, the infrared driver pulse is passed through a second harmonic generator with an output wavelength in the range from 400 to 700 nm. Third, the pulse is then passed through a gas medium, which can be inside a resonant cavity, to generate a high-order harmonic in the form of extreme ultraviolet radiation.
1. A method for efficient generation of extreme ultraviolet radiation based on high-order harmonic generation, comprising:
generating an infrared driver pulse from a drive laser;
passing the infrared driver pulse through a second harmonic generator with an output wavelength in a range from 400 to 700 nm; and then
passing the pulse through a gas medium that comprises at least one gas selected from neon and helium inside a Bessel-Gauss resonator to generate a high-order harmonic in the form of extreme ultraviolet radiation.
2. The method of claim 1 , wherein the driver pulse has an energy in a range from 100 μJ to 100 mJ inside the resonant cavity.
3. The method of claim 1 , wherein the driver pulse has a repetition rate greater than 100 kHz.
4. The method of claim 1 , wherein the driver pulse has an energy in a range from 1-10 μj before entering the resonant cavity.
5. The method of claim 1 , wherein the driver pulse has a repetition rate in a range from 50-100 MHz.
6. The method of claim 1 , wherein the wavelength of the driver pulse is about 1 μm, and wherein the second harmonic generator produces a wavelength of about 500 nm.
7. The method of claim 6 , wherein the generated high-order harmonic has a wavelength of about 13.5 nm.
8. The method of claim 1 , wherein the extreme ultraviolet radiation is spatially and temporally fully coherent.
9. The method of claim 1 , further comprising directing a pattern of the extreme ultraviolet radiation onto a photosensitive surface to perform lithography.
10. The method of claim 1 , wherein the wavelength of the driver pulse is about 1300 nm delivered from a Cr:Forsterite laser, and wherein the second harmonic generator produces a wavelength of about 650 nm.
11. An efficient high-harmonic-generation-based extreme ultraviolet radiation source driven by short wavelength light comprising:
a laser configured to emit optical pulses along a path;
a second harmonic generator positioned in the path of the optical pulses with output wavelength in a range from 400 to 700 nm; and
an extreme ultraviolet radiation generator including a Bessel-Gauss cavity containing a gas medium comprising at least one gas selected from neon and helium positioned in the path of the optical pulses on an opposite side of the second harmonic generator from the laser.
12. The extreme ultraviolet radiation source of claim 11 , wherein the laser is selected from a titanium:sapphire laser, an ytterbium-based solid-state or fiber laser, and a Cr:Forsterite laser.
13. The extreme ultraviolet radiation source of claim 11 , wherein the second harmonic generator includes β-BaB 2 O 4 .