Procedure for production of high purity molybdenum for sputtering target

FIELD: metallurgy.

SUBSTANCE: procedure consists in purification of solution of ammonia paramolybdate form impurities by ion exchange in neutral and sub-alkali mediums on hydrated oxide of tin and on sub-basic anionite AN-106. Further, ammonia paramolybdate is thermally decomposed at temperature 600-800°C to production of molybdenum oxide and is refined by zone sublimation at temperature 750-800°C in continuous flow of oxygen. Molybdenum oxide is heterogeneous reduced with hydrogen at temperature 700-750°C till production of powder of molybdenum. Powder is compressed to a rod which is subjected to electronic vacuum zone re-crystallisation till production of high purity molybdenum crystal. Molybdenum crystals are melt in electron vacuum in a flat crystalliser with melt of flat ingot of high purity molybdenum on each side at total depth not less, than twice. A molybdenum rod is treated with chlorine prior to zone re-crystallisation at rate of chlorine supply 100 ml/min and temperature 300°C during 1 hour.

EFFECT: great rise of molybdenum purity.

1 ex

 

The invention relates to the field of metallurgy of non-ferrous metals and can be used in the production of magnetron sputtered targets designed for thin-film metallization of silicon integrated circuits in microelectronics.

A method of obtaining high-purity molybdenum for sputtering targets, which includes cleaning solution paramolybdate ammonium from impurities ion exchange in neutral and alkaline environments hydrated tin oxide and the weakly basic anion exchange resin an-160. Thermal decomposition of paramolybdate ammonium carried out at a temperature of 600-800°C to obtain a molybdenum oxide. Purification of molybdenum oxide from volatile oxides of the impurities is performed using zone sublimation at a temperature of 750-800°C in a constant flow of oxygen. After sublimation spend heterogeneous recovery of molybdenum oxide with hydrogen at a temperature of 700-750°C prior to the formation of molybdenum powder with subsequent pressing of the powder of molybdenum in the rod. Then conduct electronic vacuum zone recrystallization of the rod to obtain a crystal of high-purity molybdenum and electronic vacuum melting crystals in a flat mold with a penetration of flat bar with each hand at the depth not less than twice [RF patent №2375479]. This method adopted by us for the prototype. In principle, Izv the STN method allows to obtain the target high-purity molybdenum, which satisfy the essential requirements on the purity of the obtained films. However, the presence of this material is relatively high concentrations of heavy metals (copper, iron, cobalt, Nickel, lead, vanadium, tungsten and others) has stimulated the search for methods to make extra deep cleaning of molybdenum.

Technical problem - increasing purity molybdenum for sputtering targets used for thin-film metallization, with the aim of improving the electrophysical parameters of the applied thin layers.

This is achieved in that in the method of production of high-purity molybdenum for sputtering targets, including cleaning solution paramolybdate ammonium from impurities ion exchange in neutral and alkaline environments hydrated tin oxide and the weakly basic anion exchange resin an-106, thermal decomposition of paramolybdate ammonia at a temperature of 600-800°C to obtain a molybdenum oxide, purification of molybdenum oxide zone sublimation at a temperature of 750-800°C in a constant oxygen flow, heterogeneous recovery of molybdenum oxide with hydrogen at a temperature of 700-750°C prior to the formation of molybdenum powder, pressing the powder of molybdenum to receive a rod, zone recrystallization rod of molybdenum to obtain a crystal of high-purity molybdenum and electronic vacuum melting crystals of molybdenum in flat Cree is talesfore with the penetration of flat ingot of high-purity molybdenum on each side on the depth of not less than two times moreover, the rod of molybdenum zone before the recrystallization process chlorine in the feed rate of chlorine 100 ml/min at a temperature of 300°C for 1 hour.

Method of production of high-purity molybdenum for sputtering targets is as follows. The solution paramolybdate ammonium cleanse from impurities in neutral and alkaline environments hydrated tin oxide and the weakly basic anion exchange resin an-106. Thermal decomposition of paramolybdate ammonium carried out at a temperature of 600-800°C to obtain a molybdenum oxide, which is subjected to zone sublimation at a temperature of 750-800°C. thereafter, the molybdenum oxide is subjected to zone cleaning and heterogeneous reduction with hydrogen at a temperature of 700-750°C to obtain a fine powder of molybdenum. The resulting powder was pressed into a rod of molybdenum, which is processed chlorine in the feed rate of chlorine in the reactor of 100 ml/min at a temperature of 300°C for 1 hour. As a result, saturation of the surface of the rod molybdenum chlorine and when passing zone on the rod in the pre-zone annealing and subsequent zone recrystallization of the dissolved chlorine interacts with impurities in the melt. The result is the formation of volatile chlorides of these impurities, which are removed from the purified molybdenum simple evaporation. This is riodic to significantly improve the efficiency of purification during zone refining. Crystals of high-purity molybdenum obtained vacuum zone recrystallization, melt in vacuum cooled flat mould by means of an axial electron gun, and a flat bar with each hand proplast on the depth of not less than two times.

An example implementation of the method

As the source materials used solution paramolybdate ammonium, which was purified from tungsten in neutral and alkaline environments hydrated tin oxide (IV) and the weakly basic anion exchange resin an-106. The resulting paramolybdate ammonium subjected to thermal decomposition at a temperature of 600-800°C to obtain a molybdenum oxide, which was subjected to zone sublimation at the facility with a quartz reactor zone heater is moved horizontally, the result of which has been purified molybdenum oxide. In the process zone sublimation occurred purification from volatile oxides of impurities. The highest volatile oxides of molybdenum was going to the far side of the reactor, and non-volatile oxides of impurities in the initial part of the reactor. The flow rate of oxygen 50-60 ml/min, the velocity of zone 20 mm/h, the temperature of 750-800°C. was Performed ten passes of the steam zone. Molybdenum oxide was subjected to heterogeneous reduction with hydrogen at a temperature of 700-750°C for 3-5 hours at a loading of 0.5-1 kg per financial p is Tata received a fine powder of molybdenum, which is extruded into rods. The rods were treated with chlorine at a feed rate of the chlorine in the reactor of 100 ml/min at a temperature of 300°C for 1 hour. When this happened the saturation of the surface of the rods molybdenum chlorine. Vacuum zone recrystallization was performed in the installation of electron-beam zone melting with pre-vacuum annealing of the molybdenum rod in the same setup. The required mass number of crystals of molybdenum was molded in a flat mold in vacuum e-beam melting, and flat ingot was Poplawski using axial electron gun with each hand on the depth of not less than two times. According to mass spectral analysis of the content of impurities in molybdenum was as follows (ppm): si<0,01; Pb<0,01; Fe<0,05; Ni<0,01;<0,05; Cr<0,01; Nb<0,05; V<0,05; W<0,1.

Thus, the introduction of additional purification steps in obtaining for molybdenum sputtering targets can significantly reduce the content of heavy metals, although somewhat complicates the process.

Method of production of high-purity molybdenum for sputtering targets, including cleaning solution paramolybdate ammonium from impurities ion exchange in neutral and alkaline environments hydrated tin oxide and the weakly basic anion exchange resin an-106, thermal decomposition of paramolybdate ammonia at a temperature of 600-800°C to obtain a molybdenum oxide, purification of molybdenum oxide zone sublimation at a temperature of 750-800°C in a constant oxygen flow, heterogeneous recovery of molybdenum oxide with hydrogen at a temperature of 700-750°C prior to the formation of molybdenum powder, pressing the powder of molybdenum to receive a rod, electronic vacuum zone recrystallization rod of molybdenum to obtain a crystal of high-purity molybdenum and electronic vacuum melting crystals in a flat mold with a penetration of flat ingot of high-purity molybdenum on each side on the depth of not less than two times, characterized in that the front zone recrystallization rod molybdenum is treated with chlorine at a feed rate of 100 ml/min at a temperature of 300°C for 1 h



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: invention refers to production of α-, pseudo α-, α+β-titanium alloys of secondary raw materials with specified strength characteristics mainly for fabrication of sheet work-pieces, items of structure purpose and structure armour and can be used in defence and civil branches of industry. Alloy contains, wt %: Al 0.01-6.5, V 0.01-5.5, Mo 0.05-2.0, Cr 0.01-1.5, Fe 0.1-2.5, Ni 0.01-0.5, Zr 0.01-0.5, Si 0.01-0.25, O ≤0.3, C ≤0.1, N ≤0.07 and Ti - the rest. Charge is composed depending on required value of ultimate strength of alloy. Contents of alloying elements in alloy are determined from calculated values of aluminium and molybdenum strength equivalents.

EFFECT: obtaining specified stable strength and process properties at implementation of wide spectre of titanium wastes.

2 cl, 8 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to procedure of ingot vacuum arc melting surface of liquid metal bath is influenced with arc discharge of modulated frequency. Frequency modulation of arc discharge is carried out with reverse source of current of arc with frequency of 0.1-10 Hz by reversing its polarity. Frequency modulation of arc discharge with low current is carried out by effecting electric arc with magnetic field generated with solenoid wound on crystalliser and with its current source. Modulations of surface of liquid bath of a formed ingot are produced by modulation of arc discharge with magnetic field of solenoid.

EFFECT: increased output of accepted product due to improved melting side surface of ingots and reduced defects of liquation origin.

5 cl, 2 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in measurement of voltage on arc at moment of arc presence in central part of end surface of electrode and in influencing electric arc and melt with axial magnetic field. Also, position of consumable electrode relative to a melted ingot is controlled. Electric arc and melt are influenced with radial rotating magnetic field with switching frequency of 0.1-0.3 Hz and intensity 60-80 oersted. Radial rotating magnetic field is generated by means of at least six parallel metal rods connected to a control current source; also, the rods are arranged coaxial to axis of a crystalliser on its external surface.

EFFECT: increased output of acceptable product.

2 cl

FIELD: metallurgy.

SUBSTANCE: procedure for control of process of vacuum arc weld consists in synchronous measurement of voltage on arc and pressure in furnace, and in correction of these values considering rate of transfer of consumable electrode relative to padded ingot. Internal surface of a crystalliser is cleaned from fusible sublimates by means of effect of cathode spots occurring on reverse polarity of arc discharge current in the region of the padded ingot and a wall of the crystalliser. Simultaneously arc gap is increased at 0.15-0.5 diametre of the crystalliser. Arc discharge is additionally effected with magnetic field.

EFFECT: elimination of sublimates on walls of crystalliser with successive evaporation of sublimates into volume of chamber of vacuum arc furnace and their evacuation with vacuum system.

2 cl, 3 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: there is prepared mixture of niobium and silicon powders which is successively compressed. Compressed mixture is adjoined to an electrode containing niobium. During following vacuum-arc re-melting the mixture is merged with the electrode. The melted electrode is cooled and there is formed an ingot of alloy. The ingot is thermo-mechanically processed and annealed at 950-1150 °C facilitating at least 75 % of re-crystallisation. The ingot can be produced by melting niobium, by introduction from 0.1 to 100 ppm (part per million) of silicon into melt and by melt cooling. Cups of deep drawing and targets of ion sputtering are produced from this ingot.

EFFECT: fabrication of totally re-crystallised semi-finished product of niobium with fine and uniform by size grain.

22 cl, 11 dwg, 1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: phlegmatisation of steam-gas mixture is performed in the method at its emergency formation in working area. As phlegmatiser there used is water vapour; at that, pressure excluding the operation of return valve is kept in furnace working area for the period equal to the ingot cooling time.

EFFECT: invention allows neutralising explosive mixture formed as a result of contact of water from crystalliser cooling system with molten reaction metal, avoiding detonation of explosive mixture.

1 dwg

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, particularly to rust less process for steel of transient class in vacuum installations. According to the procedure there is used source steel with indices of magnetic induction at a low limit. Charge is melt at temperature 1400-1420°C and in high vacuum 1.10-1 -1.10-2 mm of m.c. whereupon melt is heated to temperature of skin disperse 1700-1730°C at relatively low pressure of 20-50 mm of m.c. in medium of inert gas. Deoxidisation with alloy containing rare earth element is performed 2-3 minutes before tapping in vacuum or in medium of inert gas.

EFFECT: upgraded level of mechanic properties of steel required for production of thin walled large size casts.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to specific electro-metallurgy, particularly to vacuum arc re-melting of high reaction metals and alloys and can be implemented at melting ingots out of titanium alloys. The procedure for control consists in determination of actual value of a spark gap and in adjusting position of a consumable electrode relative to a melted ingot by results of arc voltage measurements, in successive selection of current pulses of reverse polarity and in measuring their duration. An interface and normalising block regulating an input signal to a specified value at bandwidth 50 kHz is arranged in the installation. A computer recognises voltage pulses of reverse polarity and duration in a specified range at sampling frequency not less, than 40 kHz.

EFFECT: upgraded accuracy of measurement.

2 cl, 2 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: method involves consumable electrode manufacturing by shaping and compression of charge containing rutile, aluminium grit and fluidised glass as binding agent in a steel shell, and further feed of compressed consumable electrode by lifting device to fixation unit on horizontal bar of vertical stand of electric arc plant. Before feed to the said fixation unit, compressed consumable electrode is dried in drying chamber to dehydratise it. Before the end of consumable electrode drying, flux is loaded and melted into fluid state in crystallising tank by inconsumable graphite electrode mounted on additional horizontal bar of vertical stand. Further the inconsumable graphite electrode is retracted from the crystallising tank, and electric arc is excited between consumable electrode and lower eklectrode of crystallising tank under protective slag layer made of fluidised flux. Lime for melting in slag cover is fed to crystallising tank continuously.

EFFECT: improved quality of consumable electrode, obtainment of ferrotitanium ingot with improved titanium content, automated process of consumable electrode preparation and fusion.

13 cl, 1 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to electrometallurgy and can be used at vacuum arc remelting of ingots of high-melting and high reactivity metals and molten metals. Method of obtaining solid ingots-electrodes from high-melting and high-reactivity metals and molten metals involves the first remelting of extruded consumable electrode with formation of ingot-electrode consisting of cylindrical part and shank, intermediate remeltings of cast electrodes with further mechanical treatment of their shanks and the second remelting in vacuum arc furnace. At that, the first remelting of extruded electrode and formation of an ingot consisting of cylindrical part and conical shank at the bottom is performed in vacuum arc furnace with water-cooled crystalliser tank with a tray having a central conical cavity Initial melting stage is performed above the crystalliser tank tray by arcing in circular sector around central cavity in two steps. The first step is performed at 4÷10 kA during 15÷40 minutes, and the second step - at 10÷25 kA during 2÷10 minutes.

EFFECT: possible use of vacuum arc furnaces during production process of solid ingots-electrodes, increasing efficiency of vacuum arc furnaces owing to eliminating welding operations of electrode to stub end, as well as reducing labour input of mechanical treatment of reverse stub end.

1 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: according to the first version there is used preliminary mixed charge containing components at following ratio, wt %: molybdenum concentrate 69, reducer 31. Thermal treatment is carried out in a graphite can at temperature of combustion 1400-1600°C during 10-15 min. According to the second version there is used preliminary mixed charge containing components at following ratio, wt %: molybdenite concentrate 53-55, reducer 15-17, iron containing compounds 25-27, slag forming components 3-5. Thermal treatment is performed in the graphite can at temperature of combustion 2000-2200°C during 30-40 min.

EFFECT: efficient and ecologically safe thermal process of production of molybdenum and its alloys.

6 cl, 1 tbl

FIELD: metallurgy.

SUBSTANCE: procedure for extraction of molybdenum (VI) from solutions of cations of heavy metals consists in sorption of molybdenum (VI) at value of pH of solution less, than value of pH of hydrolytic sedimentation of cations of heavy metals. As sorbent at sorption there is used activated bone coal.

EFFECT: raised efficiency of procedure.

2 tbl, 2 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: procedure for production of metal powder of molybdenum consists in reduction of molybdenum oxide (MoO3) with metal-reducer in melt of sodium chloride of potassium chloride or their mixture at ratio 1:1 at temperature 770-850°C. Upon reduction metal phase of molybdenum powder is separated from reaction mass. Reduction is performed with aluminium powder at ratio of source molybdenum oxide (MoO3) to melt equal to 1:3-5.

EFFECT: reduced temperature of melting at sufficiently complete extraction of molybdenum from oxide in form of metal high dispersed powder of molybdenum and reduced consumption of reagents.

2 ex

FIELD: metallurgy.

SUBSTANCE: production of Mo-99 consists in filling solution reactor with fuel solution of uranyl-sulphate, in starting reactor up to specified power, in forming Mo-99 in fuel solution, in reactor shut-down, in conditioning fuel solution for decay of short-lived radionuclide and in sorption of Mo-99 from solution. Also, after reactor shut-down fuel solution is poured out of the reactor into at least one nuclear-safe reservoir; fuel solution is conditioned in this nuclear-safe reservoir. An empty reactor is repeatedly filled with fuel solution, is started up to specified power and Mo-99 is repeatedly generated in fuel solution. For the period of Mo-99 generation in the fuel reactor poured fuel solution in the nuclear-safe reservoir is conditioned. Mo-99 is sorbed from conditioned fuel solution by pumping it through at least one sorption column wherefrom Mo-99 is sorbed into at least one nuclear-safe reservoir for fuel solution conditioning. Fuel solution is conditioned, if necessary. Repeatedly emptied reactor is filled with fuel solution from the nuclear-safe reservoir for fuel solution conditioning.

EFFECT: raised efficiency of solution reactor producing Mo-99 under discrete mode due to reduced idle time.

9 cl, 1 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in extracting uranium by means of liquid extraction of organic phase of synergy mixture on base of di(2-ethylhexyl)phosphorous acid containing tributylphosphate (TBP) or tributylphosphate together with trialkylamine (TAA) or heteroradical phosphynoxide of composition of oxide of isoamyldioktylphosphyne in organic thinner. Also, while mixing, there is performed simultaneous gradual neutralisation of mixture of phases with mineral acid till there are established balanced values of pH of water phase in interval 5.6-6.6.

EFFECT: increased efficiency of extraction of uranium and molybdenum from carbonate solutions.

3 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: procedure for hydro-metallurgical treatment of rhenium containing molybdenite concentrate consists in rhenium and molybdenum autoclave leaching with solution of nitric acid and in producing solution containing nitric and sulphuric acids. Further, residue in form of molybdenum acid is filtered and washed; molybdenum acid is dissolved in ammonia water and molybdenum and rhenium are extracted. Upon autoclave leaching rhenium is extracted from solution by sorption in two stages. At each stage duration of phase contact is 22-24 hours. Summary concentration of sulphuric and nitric acids at the first stage is maintained at ≤120 g/l and pH value at the second stage is maintained at 2-4. Molybdenum is extracted from a merged solution produced from the solution after sorption extraction of rhenium and from ammonia solution of dissolved molybdenum acid. Molybdenum is extracted by sorption in two stages at duration of phase contact 22-24 hours and maintaining pH value=1.5-2.0 at the first stage and pH=2.5-4.0 at the second stage.

EFFECT: increased output of molybdenum and rhenium into finish products, their high quality, simplification of process and its raised efficiency.

1 ex

FIELD: chemistry.

SUBSTANCE: method involves mixing concentrates with additives selected from MgO, MgCO3, CaO, CaO2, CaCO3, BaO, BaO2, BaCO3 in amount of 100-120 % of the stoichimetrically required for bonding sulphur. The concentrates then undergo oxidising roasting at 450-650°C for 30-90 minutes and the obtained ash is leached with a solution of an alkali metal carbonate with concentration of 150-250 g/dm3. The alkali metal carbonate used is sodium carbonate or potassium carbonate. After leaching, molybdenum and rhenium are extracted from the solution.

EFFECT: higher extraction ratio of molybdenum with concomitant extraction of rhenium.

4 cl, 1 tbl, 1 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to hydrometallurgy, particularly to extraction of uranium and molybdenum from carbonate ores. Method includes crushing, grinding and high-volume sorptive leaching at presence of oxidants. Additionally after 2-4 stage of sorptive leaching of uranium and molybdenum into pulp there are introduced KMnO4 at its consumption 0.15-0.25% of ore mass and it is implemented after-oxidation of uranium and molybdenum during 40-60 minutes at absence of sorbent. After after-oxidation it is finished sorptive leaching.

EFFECT: reduction of oxidant consumption and total process duration.

2 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: group of inventions relates to extraction of molybdenum from acid liquors, containing mixture of nitric and sulfur acid and molybdenum in wide range of concentration and also other admixtures and can be used at regeneration of molybdenum from waste colution for etching of molybdenum cores in manufacturing of electric bulbs and electronic devices and solutions of hydrometallurgy manufacturing. Extraction of molybdenum is implemented from solutions with diferent content in it of molybdenum. Acid solution is treated by electromagnetic field with frequency selected in the area of mid-range radio waves, formed water is driven off, laid-down sediment is filtered. Extracted acid is returned into etching process. Installation includes reactor block, filtration unit, tanks for solutions, pipelines, stop and variable valves. Reactor block includes reactor, electromagnetic field generator, inductor and matching device. Inductor is located inside or outside thru reactor. Installation additionally contains rectifying still for distillation of water, direct connected to reactor.

EFFECT: increasing of extraction ratio subject to circulation of colutions, process is ecologically safe, industrial sewages are not formed.

7 cl, 1 dwg, 2 tbl, 2 ex

FIELD: technological processes.

SUBSTANCE: invention is related to production of highly pure molybdenum for spattering targets. Method includes cleaning of ammonium paramolybdate in the form of solution from admixtures with ion exchange in neutral and alkalescent mediums on hydrated tin oxide and on weakly-basic anion-exchange resin AN-106. Then thermal decomposition of ammonium paramolybdate is executed at the temperature of 600-800°C to produce molybdenum oxide, as well as cleaning of molybdenum oxide by zone sublimation at the temperature of 750-800°C in continuous flow of oxygen. After cleaning, heterogeneous recovery of molybdenum oxide is carried out by hydrogen at the temperature of 700-750°C to produce molybdenum powder, as well as its pressing to produce bar. Then electronic vacuum zone recrystallisation of pressed bars is carried out to produce crystals of highly pure molybdenum, as well as electronic vacuum melting in flat crystalliser with melting of flat bars of highly pure molybdenum from each side to the whole depth at least twice. Device is also suggested for cleaning of molybdenum oxide by zonal sublimation.

EFFECT: sharp increase in purity of molybdenum intended for thin-film metallisation by magnetron spattering of targets, since purity of molybdenum to a large degree defines electrophysical parametres of applied thin layers.

2 cl, 2 dwg, 1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to application of mono-disperse macro-porous chelate ion-exchange resins for sorption of metals from pulp in hydro-metallurgical processes, particularly, in so called processes "resin-in-pulp". Mono-disperse macro-porous chelate ion-exchanging resin has average diametre of granules within the range from 0.35 to 1.5 mm. Sorbed metals correspond to mercury, iron, titanium, chromium, tin, cobalt, nickel, copper, zinc, lead, cadmium, manganese, uranium, bismuth, vanadium, such elements of platinum group as ruthenium, osmium, iridium, rhodium, palladium, platinum and also such valuable metals, as gold and silver. Here is also disclosed the procedure for production of mono-disperse macro-porous chelate resin containing picoline-amine groups.

EFFECT: increased output of extracted metals and more efficient sorption of metals.

9 cl, 1 tbl, 5 ex

Up!