阅读说明：本技术 一种超高纯铜锰合金的制备方法 (Preparation method of ultra-pure copper-manganese alloy ) 是由 姚力军 潘杰 边逸军 王学泽 慕二龙 汪焱斌 于 2021-09-08 设计创作，主要内容包括：本发明提供了一种超高纯铜锰合金的制备方法,采用电子束熔炼制备超高纯铜锰合金,包括如下步骤：超高纯铜原料和锰原料经酸洗并混合后进行热等静压得到超高纯铜锰合金坯料,坯料经电子束熔炼并引锭得到超高纯铜锰合金。本发明所述制备方法采用热等静压促进原料均匀混合,并减少电子束熔炼过程中金属的损失；利用双电子枪进行熔炼,可以在超高纯铜锰合金坯料熔炼的同时实现超高纯铜锰合金溶液的精炼,坯料熔化后滴入水冷铜坩埚的过程起到了混合的作用,使超高纯铜锰合金更均匀；与传统的真空感应熔炼相比,电子束熔炼得到的超高纯铜锰合金碳颗粒夹杂减少,可以确保制备所得靶材在溅射过程中溅射性能稳定；且具有工艺操作简单,适用性广的优势。(The invention provides a preparation method of an ultra-high purity copper-manganese alloy, which adopts electron beam melting to prepare the ultra-high purity copper-manganese alloy and comprises the following steps: and carrying out acid washing and mixing on the ultrahigh-purity copper raw material and the manganese raw material, then carrying out hot isostatic pressing to obtain an ultrahigh-purity copper-manganese alloy blank, and carrying out electron beam melting and ingot casting on the blank to obtain the ultrahigh-purity copper-manganese alloy. The preparation method of the invention adopts hot isostatic pressing to promote the uniform mixing of the raw materials and reduces the loss of metal in the electron beam smelting process; the ultrahigh-purity copper-manganese alloy is smelted by using the double electron guns, so that the ultrahigh-purity copper-manganese alloy solution can be refined while the ultrahigh-purity copper-manganese alloy blank is smelted, and the process of dripping the molten blank into a water-cooled copper crucible plays a role in mixing, so that the ultrahigh-purity copper-manganese alloy is more uniform; compared with the traditional vacuum induction melting, the ultra-pure copper-manganese alloy obtained by electron beam melting has less carbon particle inclusions, and can ensure that the sputtering performance of the prepared target material is stable in the sputtering process; and has the advantages of simple process operation and wide applicability.)

1. The preparation method of the ultra-high purity copper-manganese alloy is characterized in that the ultra-high purity copper-manganese alloy is prepared by adopting electron beam melting.

2. The method of claim 1, comprising the steps of:

(1) mixing an ultra-high pure copper raw material and a manganese raw material, and then carrying out static pressure to obtain an ultra-high pure copper-manganese alloy blank;

(2) and (2) smelting the ultrahigh-purity copper-manganese alloy blank in the step (1) by using an electron beam and carrying out ingot casting to obtain the ultrahigh-purity copper-manganese alloy.

3. The method according to claim 2, wherein the ultra-high purity copper raw material in the step (1) is an ultra-high purity copper electrolytic sheet;

preferably, the purity of the ultra-high purity copper raw material in the step (1) is more than or equal to 99.9999 wt%;

preferably, the manganese raw material in the step (1) is a manganese electrolytic sheet;

preferably, the purity of the manganese raw material in the step (1) is more than or equal to 99.999 wt%;

preferably, the content of Mn in the ultra-high purity copper-manganese alloy blank in the step (1) is 0.1-1.0 wt%.

4. The method of claim 2 or 3, wherein the ultra-high purity copper raw material and manganese raw material are acid-washed before the mixing in step (1);

preferably, the pickling solution used for pickling is a nitric acid aqueous solution;

preferably, the concentration of the aqueous nitric acid solution is 28 to 32 wt%.

5. The production method according to any one of claims 2 to 4, wherein the hydrostatic pressing in step (1) is hot isostatic pressing;

preferably, the temperature of the hot isostatic pressing is 850-950 ℃;

preferably, the pressure of the hot isostatic pressing is 180-;

preferably, the dwell time of the hot isostatic pressing is 5-6 h;

preferably, the ultra-high purity copper-manganese alloy blank in the step (1) is cylindrical, the diameter is 190-210mm, and the height is 900-1100 mm.

6. The production method according to any one of claims 2 to 5, wherein the electron beam melting of step (2) is performed in an electron beam melting furnace;

preferably, before the electron beam melting in the step (2), fixing the ultra-high purity copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace;

preferably, after the ultra-high purity copper-manganese alloy blank is fixed in the step (1) and before the electron beam melting in the step (2), the electron beam melting furnace is vacuumized.

7. The method according to claim 6, wherein the electron beam melting of step (2) uses a double electron gun for melting;

preferably, a first electron gun in the double electron guns is used for melting the ultrahigh-purity copper-manganese alloy blank, and a second electron gun is used for refining the melted ultrahigh-purity copper-manganese alloy solution;

preferably, the electron beam melting in the step (2) comprises the following operations: starting a first electron gun for smelting, and starting a second electron gun for refining when the ultra-pure copper-manganese alloy blank starts to be melted and is dripped into the water-cooled copper crucible;

preferably, the speed of vertically pulling the ingot downwards from the water-cooled copper crucible is 15-20 mm/min;

preferably, the power of the first electron gun is 80-120 kW;

preferably, the power of the second electron gun is 80-120 kW.

8. The production method according to any one of claims 2 to 7, wherein the electron beam spot of the electron beam melting of step (2) is circular;

preferably, the electron beam melting in the step (2) is vertical melting.

9. The production method according to any one of claims 2 to 8, wherein the degree of vacuum of the electron beam melting in the step (2) is 1 x 10^-4-1×10^-3Pa；

Preferably, the voltage of the electron beam melting in the step (2) is 25-45 kV;

preferably, the current of the electron beam melting in the step (2) is 6-10A.

10. The method of any one of claims 2 to 9, comprising the steps of:

(1) respectively carrying out acid pickling on an ultra-high pure copper electrolytic sheet with the purity of more than or equal to 99.9999 wt% and a manganese electrolytic sheet with the purity of more than or equal to 99.999 wt% by using a nitric acid aqueous solution with the concentration of 28-32 wt% as a pickling solution, then mixing the two raw materials for hot isostatic pressing, controlling the temperature of the hot isostatic pressing to be 850-;

(2) fixing the ultra-pure copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace, and vacuumizing the electron beam melting furnace to the vacuum degree of 1 multiplied by 10^-4-1×10^-3Pa, performing electron beam melting under the conditions of voltage of 25-45kV and current of 6-10A, controlling electron beam spots of the electron beam melting to be circular, performing vertical melting in the electron beam melting mode, and then performing ingot guiding at the speed of 15-20mm/min to obtain the ultra-pure copper-manganese alloy;

the method comprises the following steps of smelting by using two electron guns, wherein a first electron gun in the two electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, a second electron gun is used for heating and melting the ultra-high-purity copper-manganese alloy solution, when the electron guns are used for smelting, the first electron gun is started, the power is gradually increased to 80-120kW for smelting, and when the ultra-high-purity copper-manganese alloy blank is melted and dropped into a water-cooled copper crucible, the second electron gun is started, the power is adjusted to 80-120kW for refining.

Technical Field

The invention belongs to the field of manufacturing of ultra-high-purity copper-manganese alloy targets, and particularly relates to a preparation method of an ultra-high-purity copper-manganese alloy.

Background

With the rapid development of very large scale integrated circuits, the size of chips for semiconductors has been reduced to nanometer level, RC delay and electromigration of metal interconnects have become major factors affecting the performance of chips, and conventional aluminum and aluminum alloy interconnects have not been able to meet the requirements of process of very large scale integrated circuits. Compared with aluminum, Copper has higher electromigration resistance and higher conductivity, wherein the Copper with the Purity of more than or equal to 6N is called Ultra High Purity Copper (UHPC), the impurity content of the Copper is less than or equal to 1ppm, so the Copper has the minimum crystal interface area, and the internal crystal lattice defects are few, thereby the Ultra High Purity Copper has excellent electromigration resistance, conductivity, ductility, thermal conductivity and corrosion resistance, and in addition, the recrystallization temperature of the Copper is lower. At present, ultra-high purity copper is widely applied to interconnection materials in ultra-large integrated circuits below 45nm technical nodes, and the ultra-high purity copper has important significance for reducing the resistance of chip interconnection wires and improving the operation speed of the chip interconnection wires.

However, below 14nm process node, the electromigration problem of ultra-high purity copper is serious, and at present, the ultra-high purity copper-manganese alloy target material with 0.1 wt% -1 wt% of manganese content is adopted as a seed layer during wiring, wherein Mn element can spontaneously move to substrate SiO₂The diffusion forms a barrier layer, thereby reducing the Cu atoms in the copper of the wire to SiO of the substrate₂Diffusion is performed, so that electromigration can be effectively reduced and semi-conduction can be ensuredPerformance and life of the bulk chip.

CN103667783A discloses a copper-manganese alloy and a preparation method thereof, wherein the copper-manganese alloy comprises the following components in parts by weight: 11.2 to 12.4 weight percent of Mn, 0.2 to 0.3 weight percent of Sc, 0.1 to 0.2 weight percent of Nb, 0.05 to 0.10 weight percent of Zr, 0.05 to 0.10 weight percent of Cs and the balance of copper. The copper-manganese alloy is obtained through the steps of high-temperature secondary smelting, cooling and the like according to the components, and the prepared copper-manganese alloy has a low friction coefficient and a high heat conductivity coefficient.

CN108411151A discloses a vacuum induction melting method of a high-manganese-content copper-manganese intermediate alloy, which comprises the following steps: firstly, placing copper and manganese into a crucible of a vacuum induction melting furnace, then carrying out primary vacuum pumping, and then carrying out preheating treatment; secondly, refining the preheated raw materials to obtain a copper-manganese alloy melt, and then filling argon as a protective gas for heating; thirdly, casting the heated copper-manganese alloy melt to form a copper-manganese intermediate alloy cast ingot; and step four, placing the copper-manganese intermediate alloy cast ingot on an alumina brick or alumina sand, and air-cooling to room temperature to obtain the copper-manganese intermediate alloy with high manganese content. The method is characterized in that high-purity argon is filled into the vacuum induction melting furnace in the preheating process of the copper-manganese raw material, so that gas adsorbed on the surfaces of the copper and manganese raw materials is discharged and then is mixed with the argon, thereby reducing the oxygen partial pressure in the furnace, avoiding the oxidation and slagging phenomena of manganese in the melting process, and ensuring that the content of the manganese in the copper-manganese intermediate alloy is more than 30% and not more than 50%.

At present, the conventional preparation process of the ultra-high-purity copper-manganese alloy refers to the preparation method of ultra-high-purity copper, and the ultra-high-purity copper-manganese alloy is prepared by adopting vacuum induction melting, but the preparation method has some problems. On one hand, Mn element can volatilize, thereby causing the uneven composition of the alloy; on the other hand, a high-purity graphite crucible is used in the vacuum induction melting process, and the graphite crucible is washed by the alloy solution, so that carbon particles are mixed in the alloy.

Therefore, it is necessary to find a preparation method of the ultra-pure copper-manganese alloy which is simple to operate, can reduce the volatilization of the manganese element and does not introduce impurities.

Disclosure of Invention

The invention aims to provide a preparation method of an ultra-high-purity copper-manganese alloy, which is used for preparing the ultra-high-purity copper-manganese alloy by adopting electron beam melting. Compared with the traditional vacuum induction melting, the electron beam melting disclosed by the invention can ensure that the inclusion of the obtained ultra-pure copper-manganese alloy carbon particles is reduced, so that the sputtering performance of the prepared target material in the sputtering process is stable, the uniform mixing of raw materials can be promoted, the metal loss in the electron beam melting process is reduced, and the method has the advantages of simple process operation and wide applicability.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention aims to provide a preparation method of an ultra-high-purity copper-manganese alloy, which is used for preparing the ultra-high-purity copper-manganese alloy by adopting electron beam melting.

Electron Beam Melting (EBM) refers to a vacuum Melting method for Melting metals by converting kinetic energy of high-speed Electron beams into heat energy under high vacuum as a heat source, and bombards the surface of materials by using high-energy Electron beams in Electron Beam Melting, has the characteristics of high Melting temperature, adjustable furnace power and heating speed and good product quality, is not only used for Melting and refining steel and rare metals, but also widely used for welding, ceramic material casting and the like.

The traditional preparation method of the ultra-high purity copper-manganese alloy is vacuum induction melting, Mn element volatilizes in the vacuum induction melting process, so that the alloy components are not uniform, and carbon particle impurities exist in the ultra-high purity copper-manganese alloy due to the fact that the ultra-high purity copper-manganese alloy is used in a high-purity graphite crucible. The invention adopts electron beam melting to well solve the problems of Mn element volatilization and uneven alloy components, and avoids the pollution of the crucible to the alloy because the water-cooled copper crucible is used during the electron beam melting.

As a preferred technical scheme of the invention, the preparation method comprises the following steps:

(1) mixing an ultra-high pure copper raw material and a manganese raw material, and then carrying out static pressure to obtain an ultra-high pure copper-manganese alloy blank;

(2) and (2) smelting the ultrahigh-purity copper-manganese alloy blank in the step (1) by using an electron beam and carrying out ingot casting to obtain the ultrahigh-purity copper-manganese alloy.

As a preferable technical scheme of the invention, the raw material of the ultra-high pure copper in the step (1) is an ultra-high pure copper electrolytic sheet.

Preferably, the purity of the ultra-high purity copper raw material in step (1) is 99.9999 wt%, such as 99.9999 wt%, 99.99991 wt%, 99.99992 wt%, 99.99993 wt%, 99.99994 wt%, 99.99995 wt%, 99.99996 wt%, 99.99997 wt%, 99.99998 wt%, 99.99999 wt%, etc., but not limited to the recited values, and other values not recited in the above-mentioned range of values are also applicable.

Preferably, the manganese raw material in the step (1) is a manganese electrolytic sheet.

Preferably, the manganese raw material of step (1) has a purity of 99.999 wt% or more, such as 99.999 wt%, 99.9992 wt%, 99.9994 wt%, 99.9995 wt%, 99.9996 wt%, 99.9998 wt%, 99.9999 wt%, 99.99992 wt%, 99.99995 wt%, 99.99999 wt%, etc., but not limited to the recited values, and other values not recited in the above-mentioned range of values are also applicable.

Preferably, the content of Mn in the ultra-high purity copper-manganese alloy billet in the step (1) is 0.1 to 1.0 wt%, and may be, for example, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, and the like, but is not limited to the enumerated values, and other unrecited values within the above-mentioned range of values are also applicable.

In the hot isostatic pressing process, only the mixing and compression of the raw materials occur, and the condition of raw material loss does not occur, namely, the ultra-high pure copper content in the ultra-high pure copper-manganese alloy billet is the proportion of the ultra-high pure copper raw material to the total raw material adding amount when the raw materials are added, and the Mn content in the ultra-high pure copper-manganese alloy billet is the proportion of the manganese raw material to the total raw material adding amount when the raw materials are added.

As a preferable technical scheme of the invention, before the mixing in the step (1), the ultra-high pure copper raw material and the manganese raw material are subjected to acid washing, and the acid washing can remove impurities on the surfaces of the raw materials and ensure the purity of the ultra-high pure copper-manganese alloy obtained by subsequent preparation.

Preferably, the pickling solution used for pickling is an aqueous nitric acid solution.

Preferably, the concentration of the aqueous nitric acid solution is 28 to 32 wt%, and may be, for example, 28 wt%, 28.5 wt%, 29 wt%, 29.5 wt%, 30 wt%, 30.5 wt%, 31 wt%, 31.5 wt%, 32 wt%, but is not limited to the recited values, and other values not recited within the above range are also applicable.

In a preferred embodiment of the present invention, the static pressing in step (1) is hot isostatic pressing.

According to the invention, the ultra-high pure copper raw material and the manganese raw material are mixed through the hot isostatic pressing, so that the mixing effect can be promoted, the uniform degree of mixing is increased, and in addition, the hot isostatic pressing can enable the raw materials to be combined together more tightly, thereby reducing the loss of metal in the subsequent electron beam melting process.

Preferably, the hot isostatic pressing temperature is 850-.

The hot isostatic pressing temperature is controlled to be 850-950 ℃, the melting point of copper is 1083.4 ℃, when the hot isostatic pressing temperature exceeds 950 ℃, the hot isostatic pressing temperature is very close to the melting point of copper, and errors often exist due to the fact that the temperature cannot be controlled accurately in actual operation, so that the state of ultra-high-purity copper is changed, the strength is reduced, and the compactness of ultra-high-purity copper-manganese alloy blanks is influenced; if the hot isostatic pressing temperature is lower than 850 ℃, the tightness of the ultra-high-purity copper-manganese alloy blank can be affected, and if the tightness is insufficient, part of metal is volatilized in the subsequent electron beam melting process, so that the uniformity of the ultra-high-purity copper-manganese alloy is affected.

Preferably, the hot isostatic pressing pressure is 180-200MPa, and may be, for example, 180MPa, 182MPa, 184MPa, 186MPa, 188MPa, 190MPa, 192MPa, 194MPa, 196MPa, 198MPa, 200MPa, etc., but is not limited to the values listed, and other values not listed in the above range are also applicable.

The pressure of the hot isostatic pressing is 180-200MPa, if the pressure is less than 180MPa, the compactness of the ultra-high purity copper-manganese alloy blank is insufficient, partial metal is volatilized in the electron beam smelting process, and the uniformity of the ultra-high purity copper-manganese alloy is poor; and the pressure of more than 200MPa can not be realized by the current instrument.

Preferably, the dwell time for hot isostatic pressing is 5-6h, and may be, for example, 5h, 5.1h, 5.2h, 5.3h, 5.4h, 5.5h, 5.6h, 5.7h, 5.8h, 5.9h, 6h, etc., but is not limited to the recited values, and other values not recited in the above range of values are equally applicable.

The pressure maintaining time of the hot isostatic pressing is 5-6h, and if the pressure maintaining time is less than 5h, the tightness degree of the ultra-high purity copper-manganese alloy blank is deteriorated, and finally the uniformity of the ultra-high purity copper-manganese alloy is deteriorated; the pressure maintaining time does not need to exceed 6 hours, the pressure maintaining time can meet the production requirement after 5-6 hours, and if the pressure maintaining time exceeds 6 hours, the energy consumption can be increased, which is not beneficial to industrial production.

Preferably, the ultra-pure copper-manganese alloy ingot in step (1) is cylindrical, and has a diameter of 190-210mm and a height of 900-1100mm, for example, the diameter may be 190mm, 192mm, 194mm, 196mm, 198mm, 200mm, 202mm, 204mm, 206mm, 208mm, 210mm, etc., and the height may be 900mm, 920mm, 940mm, 960mm, 980mm, 1000mm, 1020mm, 1040mm, 1060mm, 1080mm, 1100mm, etc., but not limited to the above-mentioned values, and other values in the above-mentioned value range are also applicable.

In a preferred embodiment of the present invention, the electron beam melting in step (2) is performed in an electron beam melting furnace.

Preferably, before the electron beam melting in the step (2), the ultra-high purity copper-manganese alloy blank in the step (1) is fixed in the electron beam melting furnace directly above a water-cooled copper crucible.

Preferably, after the ultra-high purity copper-manganese alloy blank is fixed in the step (1) and before the electron beam melting in the step (2), the electron beam melting furnace is vacuumized.

In a preferred embodiment of the present invention, the electron beam melting in step (2) is performed using a double electron gun.

Preferably, a first electron gun of the double electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, and a second electron gun is used for refining the melted ultra-high-purity copper-manganese alloy solution.

Preferably, the electron beam melting in the step (2) comprises the following operations: and starting a first electron gun for smelting, and starting a second electron gun for refining when the ultra-pure copper-manganese alloy blank starts to be molten and is dripped into the water-cooled copper crucible.

The invention utilizes double electron guns to complete two processes of smelting and refining in the same equipment, greatly simplifies the operation process, saves the operation time and simultaneously can reduce the energy consumption in the whole process compared with the prior vacuum induction smelting process.

Preferably, the rate of ingot pulling vertically downward from the water-cooled copper crucible is 15-20mm/min, and may be, for example, 15mm/min, 15.5mm/min, 16mm/min, 16.5mm/min, 17mm/min, 17.5mm/min, 18mm/min, 18.5mm/min, 19mm/min, 19.5mm/min, 20mm/min, etc., but is not limited to the values recited, and other values not recited within the above range of values are equally applicable.

The forming of the ultra-high purity copper-manganese alloy cast ingot is controlled by controlling the speed of the dummy ingot, the speed of the preferred dummy ingot is 15-20mm/min, if the speed of the dummy ingot is more than 20mm/min, the speed of the dummy ingot is too high, the ultra-high purity copper-manganese alloy solution is pulled out without being completely solidified, and liquid leakage is caused; if the speed of the dummy ingot is less than 15mm/min, namely the speed of the dummy ingot is too low, the ultra-high purity copper-manganese alloy solution is cooled in the traction process, and the traction difficulty is increased.

Preferably, the power of the first electron gun is 80-120kW, and may be, for example, 80kW, 85kW, 90kW, 95kW, 100kW, 105kW, 110kW, 115kW, 120kW, etc., but is not limited to the values listed, and other values not listed in the above range of values are also applicable.

Preferably, the power of the second electron gun is 80-120kW, and may be, for example, 80kW, 85kW, 90kW, 95kW, 100kW, 105kW, 110kW, 115kW, 120kW, etc., but is not limited to the values listed, and other values not listed in the above-mentioned range of values are also applicable.

The invention adjusts the energy of the electron beam facula emitted by the second electron gun by regulating and controlling the power of the second electron gun, the heating temperature of the ultra-high purity copper-manganese alloy solution in the water-cooled copper crucible can be regulated, the power of the second electron gun is 80-120kW, if the power of the second electron gun is higher than 120W, the temperature of the ultra-high purity copper-manganese alloy solution in the water-cooled copper crucible is too high, the ingot guiding must be carried out at a slower speed in the subsequent ingot guiding process, otherwise the ultra-high purity copper-manganese alloy can not be formed, the operation time is increased due to the too-slow ingot guiding speed, the mass industrial production is not facilitated, in addition, after the power of the second electron gun is higher than 120kW, metal materials in the ultra-high purity copper-manganese alloy solution are volatilized and burnt seriously, so that the metal loss in the ultra-high purity copper-manganese alloy is increased, and the yield is reduced; if the power of the second electron gun is lower than 80W, the temperature of the ultra-high purity copper-manganese alloy solution in the water-cooled copper crucible is too low, and premature cooling is easy to occur in the subsequent ingot guiding process.

As the preferable technical scheme of the invention, the electron beam spot smelted by the electron beam in the step (2) is circular, so that the ultrahigh-purity copper-manganese alloy blank and the ultrahigh-purity copper-manganese alloy solution are uniformly and stably heated.

Preferably, the electron beam melting in the step (2) is vertical melting.

As a preferable technical means of the present invention, the degree of vacuum of the electron beam melting in the step (2) is 1X 10^-4-1×10^-3Pa, for example, may be 1X 10^-4Pa，2×10^-4Pa，3×10^-4Pa，4×10^-4Pa，5×10^-4Pa，6×10^-4Pa，7×10^{- 4}Pa，8×10^-4Pa，9×10^-4Pa，1×10^-3Pa, etc., but are not limited to the recited values, and other values not recited within the above numerical range are also applicable.

The inventionThe vacuum degree of the electron beam melting is controlled to be 1 x 10^-4-1×10^-3In the Pa range, if the vacuum degree is insufficient, elements such as sulfur, nitrogen and the like in the atmosphere can pollute the melted ultrahigh-purity copper-manganese alloy solution, so that impurities exist in the obtained ultrahigh-purity copper-manganese alloy cast ingot, and the stability of the sputtering performance of a subsequently prepared target material is influenced; the purity and uniformity of the ultra-high purity copper-manganese alloy cannot be influenced by overhigh vacuum degree, but unnecessary energy consumption waste can be caused, the process production cost is increased, and the industrial application is not facilitated.

Preferably, the voltage for electron beam melting in step (2) is 25-45kV, such as 25kV, 27kV, 30kV, 32kV, 34kV, 36kV, 38kV, 40kV, 43kV, 45kV, but not limited to the recited values, and other values not recited in the above range are also applicable.

Preferably, the electron beam melting current in step (2) is 6-10A, such as 6A, 6.5A, 7A, 7.5A, 8A, 8.5A, 9A, 9.5A, 10A, etc., but not limited to the recited values, and other values not recited in the above range of values are also applicable.

As a preferred technical scheme of the invention, the preparation method comprises the following steps:

(1) respectively carrying out acid pickling on an ultra-high pure copper electrolytic sheet with the purity of more than or equal to 99.9999 wt% and a manganese electrolytic sheet with the purity of more than or equal to 99.999 wt% by using a nitric acid aqueous solution with the concentration of 28-32 wt% as a pickling solution, then mixing the two raw materials for hot isostatic pressing, controlling the temperature of the hot isostatic pressing to be 850-;

(2) fixing the ultra-pure copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace, and vacuumizing the electron beam melting furnace to be trueThe degree of hollowness is 1 x 10^-4-1×10^-3Pa, performing electron beam melting under the conditions of voltage of 25-45kV and current of 6-10A, controlling electron beam spots of the electron beam melting to be circular, performing vertical melting in the electron beam melting mode, and then performing ingot guiding at the speed of 15-20mm/min to obtain the ultra-pure copper-manganese alloy;

the method comprises the following steps of smelting by using two electron guns, wherein a first electron gun in the two electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, a second electron gun is used for heating and melting the ultra-high-purity copper-manganese alloy solution, when the electron guns are used for smelting, the first electron gun is started, the power is gradually increased to 80-120kW for smelting, and when the ultra-high-purity copper-manganese alloy blank is melted and dropped into a water-cooled copper crucible, the second electron gun is started, the power is adjusted to 80-120kW for refining.

The recitation of numerical ranges herein includes not only the above-recited numerical values, but also any numerical values between non-recited numerical ranges, and is not intended to be exhaustive or to limit the invention to the precise numerical values encompassed within the range for brevity and clarity.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the preparation method of the ultra-high purity copper-manganese alloy, the ultra-high purity copper-manganese alloy blank is prepared through hot isostatic pressing, so that on one hand, uniform mixing of raw materials can be promoted, and on the other hand, metal loss in the electron beam smelting process can be reduced;

(2) the preparation method of the ultra-high purity copper-manganese alloy provided by the invention utilizes double electron guns to carry out smelting, wherein the first electron gun is used for melting ultra-high purity copper-manganese alloy blanks, the second electron gun is used for refining ultra-high purity copper-manganese alloy solution melted in a water-cooled copper crucible, and the process that the ultra-high purity copper-manganese alloy blanks are melted and then dropped into the water-cooled copper crucible plays a role in mixing, so that the obtained ultra-high purity copper-manganese alloy is more uniform;

(3) according to the invention, the ultra-high purity copper-manganese alloy is prepared by adopting electron beam melting, compared with the traditional vacuum induction melting, carbon particle inclusions of the ultra-high purity copper-manganese alloy obtained by electron beam melting are greatly reduced, and the stable sputtering performance of the prepared target material in the sputtering process can be ensured;

(4) the ultra-pure copper-manganese alloy prepared by the preparation method meets the requirement below a 14nm process node, and the preparation method is simple in process operation and wide in applicability.

Drawings

Fig. 1 is a schematic view of an electron beam melting furnace.

Wherein, 1-a first electron gun; 2-a second electron gun; 3-ultra-high purity copper-manganese alloy blank; 4-ultra-high purity copper-manganese alloy solution; 5-water cooling the copper crucible; 6-observation window; 7-a first electron beam; 8-a second electron beam; 9-a traction system; 10-vacuum pump system.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

It is to be noted that the embodiments of the present invention all use the electron beam melting furnace shown in fig. 1 to prepare ultra-high purity copper-manganese alloy, and the thick arrows in fig. 1 indicate the flow direction of cooling water.

Example 1

The embodiment provides a preparation method of an ultra-high purity copper-manganese alloy, which comprises the following steps:

(1) respectively carrying out acid pickling on an ultra-high pure copper electrolytic sheet with the purity of 99.9999 wt% and a manganese electrolytic sheet with the purity of 99.999 wt% by using a nitric acid aqueous solution with the purity of 30 wt% as a pickling solution, then mixing the two raw materials for hot isostatic pressing, controlling the temperature of the hot isostatic pressing to be 900 ℃, the pressure to be 200MPa, and the pressure maintaining time to be 5.5h, so as to obtain an ultra-high pure copper-manganese alloy blank with the Mn content of 0.5 wt%, wherein the ultra-high pure copper-manganese alloy blank is cylindrical with the diameter of 200mm and the height of 1000 mm;

(2) fixing the ultra-pure copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace, and vacuumizing the electron beam melting furnace to the vacuum degree of 5 multiplied by 10^-4Pa, under the conditions of voltage 35kV and current 8APerforming electron beam melting, controlling electron beam spots of the electron beam melting to be circular, performing vertical melting in the electron beam melting mode, and then performing ingot guiding at the speed of 18mm/min to obtain the ultra-pure copper-manganese alloy;

the method comprises the following steps of smelting by using two electron guns, wherein a first electron gun in the two electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, a second electron gun is used for heating and melting the ultra-high-purity copper-manganese alloy solution, when the electron guns are used for smelting, the first electron gun is started, the power is gradually increased to 100kW for smelting, and when the ultra-high-purity copper-manganese alloy blank is melted and dropped into a water-cooled copper crucible, the second electron gun is started, the power is adjusted to 100kW for refining.

Example 2

The embodiment provides a preparation method of an ultra-high purity copper-manganese alloy, which comprises the following steps:

(1) respectively carrying out acid pickling on an ultra-high pure copper electrolytic sheet with the purity of 99.99995 wt% and a manganese electrolytic sheet with the purity of 99.9995 wt% by using a nitric acid aqueous solution with the purity of 32 wt% as a pickling solution, then mixing the two raw materials for hot isostatic pressing, controlling the temperature of the hot isostatic pressing to be 850 ℃, the pressure to be 180MPa, and the pressure holding time to be 6h, so as to obtain an ultra-high pure copper-manganese alloy blank with the Mn content of 0.1 wt%, wherein the ultra-high pure copper-manganese alloy blank is cylindrical with the diameter of 190mm and the height of 900 mm;

(2) fixing the ultra-pure copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace, and vacuumizing the electron beam melting furnace to the vacuum degree of 1 multiplied by 10^-4Pa, performing electron beam melting under the conditions of voltage 25kV and current 6A, controlling electron beam spots of the electron beam melting to be circular, performing vertical melting in the electron beam melting mode, and then performing ingot guiding at the speed of 20mm/min to obtain the ultra-pure copper-manganese alloy;

the method comprises the following steps of smelting by using two electron guns, wherein a first electron gun in the two electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, a second electron gun is used for heating and melting the ultra-high-purity copper-manganese alloy solution, when the electron guns are used for smelting, the first electron gun is started, the power is gradually increased to 80kW for smelting, and when the ultra-high-purity copper-manganese alloy blank is melted and dropped into a water-cooled copper crucible, the second electron gun is started, the power is adjusted to 80kW for refining.

Example 3

The embodiment provides a preparation method of an ultra-high purity copper-manganese alloy, which comprises the following steps:

(1) respectively carrying out acid pickling on an ultra-high pure copper electrolytic sheet with the purity of 99.99992 wt% and a manganese electrolytic sheet with the purity of 99.9995 wt% by using a nitric acid aqueous solution with the purity of 28 wt% as a pickling solution, then mixing the two raw materials for hot isostatic pressing, controlling the temperature of the hot isostatic pressing to be 950 ℃, the pressure to be 190MPa, and keeping the pressure for 5 hours to obtain an ultra-high pure copper-manganese alloy blank with the Mn content of 1.0 wt%, wherein the ultra-high pure copper-manganese alloy blank is cylindrical with the diameter of 210mm and the height of 1100 mm;

(2) fixing the ultra-pure copper-manganese alloy blank in the step (1) right above a water-cooled copper crucible in an electron beam melting furnace, and vacuumizing the electron beam melting furnace to the vacuum degree of 1 multiplied by 10^-3Pa, performing electron beam melting under the conditions of voltage 45kV and current 10A, controlling electron beam spots of the electron beam melting to be circular, performing vertical melting in the electron beam melting mode, and then performing ingot guiding at the speed of 15mm/min to obtain the ultra-pure copper-manganese alloy;

the method comprises the following steps of smelting by using two electron guns, wherein a first electron gun in the two electron guns is used for melting the ultra-high-purity copper-manganese alloy blank, a second electron gun is used for heating and melting the ultra-high-purity copper-manganese alloy solution, when the electron guns are used for smelting, the first electron gun is started, the power is gradually increased to 120kW for smelting, and when the ultra-high-purity copper-manganese alloy blank is melted and dropped into a water-cooled copper crucible, the second electron gun is started, the power is adjusted to 120kW for refining.

Example 4

This example provides a method for preparing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the hot isostatic pressing temperature in step (1) was changed from 900 ℃ to 800 ℃.

Example 5

This example provides a method for preparing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the hot isostatic pressing temperature in step (1) was replaced by 1000 ℃.

Example 6

This example provides a method for preparing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the hot isostatic pressing pressure in step (1) was replaced by 170MPa at 200 MPa.

Example 7

This example provides a method for preparing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the dwell time for hot isostatic pressing in step (1) was changed from 5.5 hours to 4 hours.

Example 8

This example provides a method for preparing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the dwell time for hot isostatic pressing in step (1) was changed from 5.5 hours to 7 hours.

Example 9

This example provides a method for preparing an ultra-pure copper-manganese alloy, except that the vacuum degree of electron beam melting in step (2) is 5 × 10^-4Pa is replaced by 1X 10^-5Pa, other conditions were exactly the same as in example 1.

Example 10

This example provides a method for preparing an ultra-pure copper-manganese alloy, except that the vacuum degree of electron beam melting in step (2) is 5 × 10^-4Pa is replaced by 3X 10^-3Pa, other conditions were exactly the same as in example 1.

Example 11

This example provides a method for producing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the power of the second electron gun in the electron beam melting described in step (2) was replaced by 70kW, except that the conditions were the same.

Example 12

This example provides a method for producing an ultra-high purity copper-manganese alloy, which is identical to example 1 except that the power of the second electron gun in the electron beam melting described in step (2) is replaced by 130kW, which is 100 kW.

Comparative example 1

The comparative example provides a preparation method of an ultra-high purity copper-manganese alloy, which adopts the method described in CN111534708B, namely vacuum induction melting, and prepares the ultra-high purity copper-manganese alloy according to the raw material proportion described in example 1.

The purity of the ultra-high purity copper electrolytic sheet and the manganese electrolytic sheet used in the preparation process of the ultra-high purity copper-manganese alloy cannot reach 100 percent, other metal impurities and carbon impurities inevitably exist, but the influence of a very small amount of carbon on the subsequent application of the ultra-high purity copper-manganese alloy is very small, and in actual use, the number of carbon particles with the particle size of more than or equal to 1.3 mu m is required to be less than or equal to 5000/g. The manganese content, the metal impurity content and the number of carbon particles with the particle size of more than or equal to 1.3 mu m in the ultra-high purity copper-manganese alloy obtained in the above examples and comparative examples are characterized by the following characterization methods:

manganese content: detecting the manganese content in the ultra-high-purity copper-manganese alloy by using an inductively coupled plasma emission spectrometer (ICP-OES); during characterization, sampling from different positions of the ultra-high purity copper-manganese alloy, testing the manganese content of the ultra-high purity copper-manganese alloy, and if the manganese content of each position is consistent, determining that the manganese element in the ultra-high purity copper-manganese alloy is uniformly distributed, and if the manganese content of each position is inconsistent, determining that the manganese element in the ultra-high purity copper-manganese alloy is non-uniformly distributed;

content of metal impurities: detecting the content of metal impurities except manganese in the ultra-pure copper-manganese alloy by using Glow Discharge Mass Spectrometry (GDMS);

the number of carbon particles with the particle diameter of more than or equal to 1.3 mu m is as follows: and detecting the number of carbon particles with the particle size of more than or equal to 1.3 mu m in each gram of the ultra-pure copper-manganese alloy by using an insoluble particle detector (LPC).

The loss of the manganese element can be obtained by calculation in the following way:

the manganese loss amount is (manganese content in the ultra-high purity copper-manganese alloy blank-manganese content in the ultra-high purity copper-manganese alloy)/(manganese content in 1-ultra-high purity copper-manganese alloy);

because the loss of manganese is very small, the influence on the proportion of the whole components is very small, and the difference value between the manganese content in the ultra-high purity copper-manganese alloy blank and the manganese content in the ultra-high purity copper-manganese alloy is used as the loss of manganese, namely, the loss of manganese is equal to the manganese content in the ultra-high purity copper-manganese alloy blank-the manganese content in the ultra-high purity copper-manganese alloy.

The results of the tests on the manganese content, the manganese loss, the metal impurity content and the number of carbon particles with a particle size of not less than 1.3 μm in the ultra-high purity copper-manganese alloy obtained in the above examples and comparative examples are shown in table 1.

TABLE 1

The following points can be derived from table 1:

(1) from the examples 1-3, the preparation method of the ultra-high purity copper-manganese alloy combines the hot isostatic pressing and the electron beam melting, the prepared ultra-high purity copper-manganese alloy ingot has little loss of manganese element, less metal impurity content which is less than or equal to 0.3ppm, and greatly reduced carbon particle inclusion, and the number of carbon particles with the particle size of more than or equal to 1.3 mu m is less than or equal to 4500 carbon particles/g;

(2) comparing example 1 with examples 4 and 5, the hot isostatic pressing temperature of step (1) in example 4 is 800 ℃ which is lower than the preferred 850-950 ℃ of the invention, which results in that the ultra-high purity copper-manganese alloy blank is not compact enough, the manganese loss is increased from 0.001 wt% to 0.179 wt%, the distribution of each element in the ultra-high purity copper-manganese alloy is not uniform, the content of metal impurities is increased from 0.20ppm to 0.81ppm, and the number of carbon particles with the particle diameter of 1.3 μm or more is increased from 3500 carbon particles/g to 4800 carbon particles/g; since the hot isostatic pressing temperature in the step (1) in the example 5 is 1000 ℃, exceeds the preferred 850-950 ℃ of the invention, and the temperature is too high, which is already very close to the melting point of copper 1083.4 ℃, the strength of the ultra-high pure copper is reduced, so that the ultra-high pure copper-manganese alloy blank is not compact enough, the manganese loss is increased to 0.240 wt% from 0.001 wt%, elements in the ultra-high pure copper-manganese alloy are not uniformly distributed, the content of metal impurities is increased to 0.56ppm from 0.20ppm, and the number of carbon particles with the particle size of more than or equal to 1.3 μm is increased to 4650 carbon particles/g from 3500 carbon particles/g;

(3) comparing example 1 with example 6, the hot isostatic pressing pressure of step (1) in example 6 is 170MPa, which is lower than the preferred 180MPa of the present invention, which results in insufficient compactness of the ultra-high purity copper-manganese alloy billet, further results in that the manganese loss during the electron beam melting process is increased from 0.001 wt% to 0.199 wt%, the uniformity of the ultra-high purity copper-manganese alloy is deteriorated, the content of metal impurities is increased from 0.20ppm to 0.82ppm, and the number of carbon particles with the particle diameter of 1.3 μm or more is increased from 3500 carbon particles/g to 4680 carbon particles/g;

(4) comparing example 1 with examples 7 and 8, the packing degree of the ultra-high purity copper-manganese alloy billet is deteriorated due to the dwell time of hot isostatic pressing of 4h in step (1) of example 7, which is lower than the preferred 5-6h of the invention, the manganese loss is increased from 0.001 wt% to 0.140 wt%, the content of metal impurities is increased from 0.20ppm to 0.88ppm, and the number of carbon particles with the particle diameter of more than or equal to 1.3 μm is increased from 3500 to 4710/g; because the dwell time of the hot isostatic pressing in the step (1) in the implementation 8 is 7 hours, although the dwell time exceeds the preferable 5-6 hours of the invention, the compactness of the ultra-high purity copper-manganese alloy blank cannot be influenced, the loss of manganese is still 0.001 wt%, the content of metal impurities is unchanged, and the number of carbon particles with the particle size of more than or equal to 1.3 mu m is slightly increased, so that the property of the ultra-high purity copper-manganese alloy prepared by increasing the dwell time of the hot isostatic pressing is not obviously improved, and the energy consumption is increased;

(5) example 1 was compared with examples 9 and 10, and the degree of vacuum of the electron beam melting in step (2) of example 9 was 1X 10^-5Pa, exceeding 1X 10 preferred according to the invention^-4-1×10^-3The Pa range, namely the vacuum degree is too high, the influence on the ultra-pure copper-manganese alloy is small, the loss of manganese is still 0.001 wt%, the content of metal impurities is not changed, and the number of carbon particles with the particle size of more than or equal to 1.3 mu m is slightly increased; the vacuum degree of the electron beam melting in the step (2) in the step 10 is 3 multiplied by 10^-3Pa, exceeding 1X 10 preferred according to the invention^-4-1×10^-3Pa range, i.e. insufficient vacuum, ofImpurities in the ultra-high pure copper-manganese alloy are increased, the loss of manganese is increased from 0.001 wt% to 0.068 wt%, the content of metal impurities is increased from 0.20ppm to 0.89ppm, and the number of carbon particles with the particle diameter of more than or equal to 1.3 mu m is increased from 3500/g to 4930/g; therefore, the ultrahigh-purity copper-manganese alloy is not more uniform due to the overlarge vacuum degree, and only the energy consumption is increased;

(6) comparing example 1 with examples 11 and 12, the power of the second electron gun in the electron beam melting of step (2) in example 11 is 70kW, which is lower than the preferred range of 80-120kW of the present invention, the loss of manganese is increased from 0.001 wt% to 0.185 wt%, the content of metal impurities is increased from 0.20ppm to 0.68ppm, and the number of carbon particles with the particle diameter of 1.3 μm or more is increased from 3500 to 4580/g; since the power of the second electron gun in the electron beam melting in the step (2) of the implementation 12 is 130kW, which exceeds the preferred range of 80-120kW of the present invention, the loss amount of manganese is increased from 0.001 wt% to 0.288 wt%, the content of metallic impurities is increased from 0.20ppm to 0.89ppm, and the number of carbon particles with the particle diameter of 1.3 μm or more is increased from 3500/g to 4930/g;

(7) comparing example 1 with comparative example 1, in comparative example 1, the ultra-high purity copper-manganese alloy prepared by vacuum induction melting described in CN111534708B has better uniformity, less manganese loss and less metal impurity content, but because a high-purity graphite crucible is used in the preparation process and a high-temperature ultra-high purity copper-manganese alloy solution washes the high-purity graphite crucible, a large amount of carbon particles exist in the ultra-high purity copper-manganese alloy, the number of carbon particles with a particle size of not less than 1.3 μm is 43922/g, which is far beyond the requirement of not more than 5000/g in the actual use process.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.