STUDIES OF PROCESSES OF THE PRECURSOR FORMATION FOR PRODUCTION OF CuAlO NANOCERAMICS AT THE EFFECT OF DOUBLE LASER PULSES ON AD1 AND M2 ALLOYS IN THE AIR ATMOSPHERE

Проведено исследование процессов образования смешанных нанопорошков Al, оксидов меди и алюминия, прекурсоров для получения нанокерамик типа CuAlO и CuAlO при воздействии сдвоенных лазерных импульсов энергией 53 мДж и между импульсным интервалом 10 мкс на мишень, состоящую из пластинок алюминия марки АД1 и меди марки М2, склеенных между собой и помещенную в закрытую стеклянную прямоугольную кювету. Установлено, что последовательное воздействие серий сдвоенных лазерных на мишень из алюминия, а затем на мишень из меди приводит к многократному увеличению выхода субоксидов AlO, ионов и атомов алюминия и меди в лазерном факеле, направляемом на подложку, при напылении пленок, по сравнению с воздействием одиночными лазерными импульсами. Изучены процессы, происходящие на поверхности подложки при напылении пленок. Показана возможность получения прекурсоров для получения нанокерамик типа CuAlO и CuAlO. A study of formation of mixed Al nanopowders, copper and aluminum oxides, and precursors for production of CuAlO and CuAlO nanoceramics under the influence of double laser pulses with energy of 53 mJ and the interpulse interval of 10 microseconds on a target consisting of plates of aluminum grade AD1 and copper grade M2, 0,4 mm thick, glued together and placed in a closed rectangular glass cuvette. It is found that the successive exposure of a series of double laser beams to an aluminum target and then to a copper target leads to a multiple increase in the yield of AlO suboxides, aluminum and copper ions and atoms in the laser torch, compared with the exposure to single laser pulses. To better understand the hidden mechanisms of this dependence, we study the processes occurring both on the surface and in the near-surface laser plasma inside the resulting microchannel when the target is broken by a series of single and double laser pulses. The possibility of obtaining precursors for the production of nanoceramics such as CuAlO, CuAlO is shown.

Prospects for using two-phase micro-size systems for high heat flux removal

Heat transfer in active systems for high heat removal based on the micro-channels and hybrid micro-channel/micro-jet is considered. The application of these systems allows significantly increasing the critical heat flux for a dense arrangement of the heat stressed equipment. The characteristics of heat transfer and critical heat flux during subcooled flow boiling of water in the micro-channel heat sink and during micro-jet impingement in narrow channel are obtained. The experiments are performed for the horizontal segmented microchannels with a cross section of 340×2000 μm2 made on the top of copper target and for impingement micro-jet cooling of the copper target in the gap of 1000 μm. It has been found that, compared with impingement micro-jet cooling in similar condition, the micro-channel cooling is more effective for high heat flux removal although it creates the considerably high wall temperature.

Diffusion Bonding Performance of Copper Target for 300mm Integrated Circuit

Ultra-pure copper sputtering target is a key material widely used in large-scale integrated circuits with 90-28 nm feature size. The copper target for 300 mm integrated circuit requires a reliable diffusion bonding between the ultra-pure copper target and the copper alloy backplate. The bonding ratio and bonding strength of diffusion bonding should reach over 99% and 80 MPa respectively. In this paper, the ascendant structure of electron beam welding united diffusion bonding with high quality was designed. The ultra-pure copper target and the C18000 copper alloy backplate were machined to coordinating size, meanwhile the backplate underwent surface treatment of toothed/smooth, ion cleaning, magnetron sputtering coating, then the combination of target and the backplate was proceeded electron beam welding and diffusion bonding. Metallographic microscope, scanning electron microscope (SEM), mechanical tensile machine, C-scan flaw detector were used to analyze the bonding properties including interface microstructure, bonding strength and bonding ratio. The results show that the bonding ratio of copper target was above 99%, and the bonding strength was up to 80-160 MPa.

EXPRESS: Feasibility of Using Boltzmann Plots to Evaluate the Stark Broadening Parameters of Cu(I) Lines

A linear Boltzmann plot was constructed using Cu I-lines of well-known atomic parameters. Aligning other spectral lines to the plot was adopted as a viable way to estimate the most probable values of Stark broadening parameters of Cu I-lines at 330.79, 359.91, and 360.2 nm. Plasma was generated by focusing of Nd: YAG laser radiation at wavelength 532 nm on a pure copper target in open air. Plasma emission was recorded at delay times of 3, 4, 5, 7, and 10 μs. The in situ optically thin H_α-line was used to determine the plasma reference electron density over the entire experiment. Following this method, the missing values of the Stark broadening parameters of the three Cu-I lines turn out to be about 0.15 ± 0.05 à (for 330.79 nm transition) and 0.17 ± 0.05 à (for 359.91, and 360.20 nm transition) at reference electron density of (1 ± 0.09)×10¹⁷ cm^-3 and temperature of 10800 ± 630 K. The apparent variation in plasma parameters at different delay times was found to scale with electron density and temperature as <i>~ n_e.T_e^0.166</i>.