V. G. Bespalov

Energy effective dual-pulse bispectral laser for EUV lithography

The power consumption in the two-pulse bispectral primary source could be substantially decreased by replacing the SRS converters from 1.06 μm into 10.6 μm wavelength as the preamplifier cascades in СО2 laser channel at the same efficiency radiation of EUV source. The creation of high volume manufacturing lithography facilities with the technological standard of 10-20 nm is related to the implementation of resist exposure modes with pulse repetition rate of 100 kHz. Low power consumption of the proposed scheme makes it promising for the creation of LPP EUV sources.

Monitoring radioactive contamination by hyperspectral lidar

There are already significant amounts of hazardous radioactive substances in the world. It, potentially, leads to a major damage and contamination of large areas. Laser sensing can serve as a highly effective method of searching and monitoring of radioactive contamination. We developed a laser system to detect accidental leakage of radioactive materials. Methods of fluorescence spectroscopy and Raman spectroscopy allow to detect a concentration of uranyl U235O2 and U238O2 at 500 ppb, and Sr90 and Cs137 at the level of 1 ppm at 100 m distance from the object.

Remote laser spectroscopy of oil and gas deposits

We developed a Raman lidar with ultraspectral resolution for automatic airborne monitoring of pipeline leaks and for oil and gas exploration. Test flights indicate that a sensitivity of 6 ppm for methane and 2 ppm for hydrogen sulfide has been reached for leakage detection. The lidar is based on the CARS method with a Ti:Sapphire pump laser and a frequencydoubled YLF:Nd probe beam whose frequency is displaced by a BBO crystal. In ground-based experiments, a detection level of 3 to 10 molecules has been reached.

CARS technique for geological exploration of hydrocarbons deposits

We developed a Raman lidar with ultraspectral resolution for automatic airborne monitoring of pipeline leaks and for oil and gas exploration. Experiments were carried out under the CARS circuit. Minimal concentrations of 200 ppb of heavy hydrocarbon gas have been remotely measured in laboratory tests. Test flights indicate that a sensitivity of 6 ppm for methane and 2 ppm for hydrogen sulfide has been reached for leakage detection. As estimations have shown the reliability of heavy hydrocarbon gas detection by the integration method of seismic prospecting and remote laser sensing in CARS circuit can exceed 80%.

Laser remote spectroscopy for geological exploration of hydrocarbons deposits

We have developed airborn lidar system to detect pipeline leakage and explore oil and gas deposits. Test flights indicate that a sensitivity of 6 ppm for methane and 3 ppm for hydrogen sulfide has been reached for leakage detection. As estimations have shown the reliability of HHG detection can exceed 80% at the integration method of seismic prospecting and laser remote sensing.

High-NA EUV projection lens with central obscuration

The lenses with coaxial mirrors allow obtain NA values up to of 0.8 and demagnification β ≥10. The larger β value leads to the mask cost reducing, as in this case, the elements of the IC pattern template can be made bigger and, therefore, with fewer defects. Сoaxial schemes can engender a problem of the image plane shift beyond the projection lens element boundaries near the wafer. The projection lens consisting of four coaxial mirrors with NA= 0.485 and s = 12 combined with the ”Vanguard” imaging subsystem have been designed. According to the computation the circuit features at 10 nm in center and 20 nm on the edge of 12.4 mm field of view can be imaged.

High-efficiency bispectral laser source for EUV lithography

New concept of EUV radiation power scaling in the intermediate focus of the illumination system is proposed. The multiplex source scheme based on combination of several sources with acceptable level power allows to concentrate EUV light on the total power level of 1kW and more have been developed. The experimental results showed that the power consumption in the double-pulse bi-spectral primary source for EUV lithography can be substantially decrease by replacing pre-amplifiers in power CO2 laser on the SRS converters wavelength 1.06 μm to 10.6 μm while maintaining efficiency of EUV radiation output of illuminated plasma.

Oil and gas deposits determination by ultraspectral lidar

We have demonstrated airborne lidar possessing spectral resolution λ/Δλ ≥ 1000. Its ultraspectral resolution is provided by the dual polychromator based on large-sized stigmatic holographic gratings. The lidar was tested in a real-life flight conditions at the transcontinental gas pipeline. It has performed aero search of leaks and measurements of the leaked gas concentration.

High-efficiency bispectral laser for EUV

The results of experimental and theoretical modeling of multistage Raman conversion in compressed hydrogen with a buffer gas under using the lasing of neodymium-crystalline mediums to obtain the seed radiation for CO2 power amplifier in the double-pulse and bispectral primary laser while maintaining efficiency of LPP EUV source are presented. This scheme allows as significantly decrease level of pumping consumption and tune a delay time up to 820 ns between a weak power (initiating a plasma cloud) and main power pulses irradiated the converter target. The lasing intensity in the focal spots was 0.2 GW/cm2 and 5TW/cm2 respectively for wavelengths of 1.064 μm and 9.2 μm.

Lidar for monitoring methane hydrate in the arctic permafrost

Over the past 100 years, the rate of temperature in the Arctic increases almost twice higher than the average rate of warming of the planet. Identifying methane anomalies responsible for the temperature increase, by hiking trails in the Arctic requires great human labor. It is necessary to use lidar methods for search and identification of methane from permafrost. Necessary to create a Raman lidar for monitoring of emissions of methane hydrate from the permafrost. Hyperspectral resolution would resolve the isotope shifts in the Stokes spectra, thereby to determine the isotopic composition of methane ratio C14/C12 CH4 carbon emissions and identify the source for study (permafrost or oil deposits)