A. P. Zhevlakov

Simulation of the EUV-lithography projection system and nanometer features imaging

The illumination system presented in the paper consists of an elliptical mirror collecting light in the solid angle over 103 and two plane mirrors (one of them is a grazing incidence mirror). The projection lens consists of two 4th-order aspherical mirrors with the diminished obscuration 0.36. The simultaneous exposure wafer area is 0.82 x 0.82 mm2 and NA = 0.36. The obscuration of the projection lens and obscured aperture of the illumination system influence the contrast of nanometer features of image. Mathematical simulation of imaging by the partially coherent theory is performed for target bars with L&S 15, 30, and 45 nanometers. The results of computer simulation give the reliable values of contrast 0.50, 0.58 and 0.6 correspondingly.

Optically (solar) pumped oxygen-iodine lasers

We present the results of theoretical and experimental studies demonstrating the possibility of developing an oxygen-iodine laser (OIL) with direct optical pumping of molecular oxygen involving inter-molecular interaction with charge transfer from donor molecule (buffer gas) to acceptor molecule (oxygen). This interaction lifts degeneracy of the lower energy states of molecular oxygen and increases its absorption cross section in the visible spectral region and the UV Herzberg band, where high quantum yield of singlet oxygen is achieved (QY ∼ 1 and QY ∼ 2, respectively) at the same time. A pulse-periodic optical pump sources with pulse energy of ∼50 kJ, pulse duration of ∼25 μs, and repetition rate of ∼10 Hz, which are synchronized with the mechanism of singlet oxygen generation, are developed. This allows implementation of a pulse-periodic oxygen-iodine laser with an efficiency of ∼25%, optical efficiency of ∼40%, and parameter L/T ∼ 1/1.5, where T is the thermal energy released in the laser active medium upon generation of energy L. It is demonstrated that, under direct solar pumping of molecular oxygen, the efficiency parameter of the OIL can reach L/T ∼ 1/0.8 in a wide range of scaling factors.

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.

Lidar for monitoring methane emission in Siberian permafrost

Identifying methane anomalies responsible for the temperature increase, by hiking trails in the Arctic requires great human labor .According to the tentative forecast by the year 2100 Arctic permafrost will greatly deteriorate, which will have numerous consequences. Indeed, release of less than 0.1% of the organic carbon stored in the upper 100-meter permafrost level (approximately 10000 ppm of carbon in the СН4 form) can double concentration of atmospheric methane, which is roughly 20 times more potent greenhouse gas than the CO2. Necessary to create a Raman lidar for monitoring of emissions of methane hydrate from the permafrost.

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.

Hydrocarbon halo-laser spectroscopy for oil exploration needs

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.

Interference inspection of the aspherical components of an objective for nanolithography

Methods and schemes to inspect the EUV mirror shape are developed on the basis of a point diffraction interferometer with computer processing of interferograms. A measurement accuracy to within 0.001 of a wavelength in the visual range is achieved.

Selection of spectral lines of a CW chemical HF laser

The spectral distribution of laser radiation power generated in two (initial and final) regions of the flow of an active medium formed by a three-jet nozzle array of a supersonic cw chemical HF laser embodying the nozzle-nozzle-nozzle mixing scheme is investigated experimentally. It is demonstrated that the spectral lines can be selected by merely varying laser operating parameters, such as the feedback factor of the cavity, the orientation of the optical axis of the cavity with respect to the exit plane of the nozzle array, and the degree of secondary dilution of the active medium with helium. This method results in the selection of one line P1−0 (6) with a power as high as 80% of the total radiation power and two lines P1−0 (5) and P1−0 (6) with a power of 100%.

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.

Influence of laser radiation on the growth and development of seeds of agricultural plants

The experimental results presented in this study focused on the study of biological processes caused by exposure to the coating layers of the laser green light seed (λ = 532 nm) range for the larch, violet (λ = 405 nm) and red (λ = 640 nm) for spruce. Spend a series of experiments to study the dependence of crop seed quality (spruce and larch from the pine family) from exposure to laser radiation under different conditions. In all the analyzed groups studied seed germination and growth of seedlings exposed to laser exposure, compared with the control group. The results showed that the higher percentage of germination than seeds of the control group.