CN113106362B - Manufacturing method of target material back plate with concave surface - Google Patents

Abstract

The invention discloses a method for manufacturing a target back plate with a concave surface. 0.4h to 4.1h, form the annealed flat blank; forging forming: under the same conditions as the annealing temperature in the above step, use the forging die with protrusions to forge the annealed flat blank for several times until the annealed flat blank has the same thickness as the forging die. After the concave surface that fits, stop forging to form a concave billet; annealing the concave billet: anneal the concave billet in a vacuum environment or an inert gas environment, the annealing temperature is not higher than the annealing temperature in the annealing step of the flat billet, and the annealing time is not less than The annealing time in the annealing step of the flat blank forms a target backing plate with a concave surface. The method for manufacturing a target backplane with a concave surface can manufacture a target backplane with good performance in a relatively simple and economical process.

Description

A kind of manufacturing method of target material back plate with concave surface

technical field

The invention relates to the technical field of semiconductors, and in particular, to a method for manufacturing a target backplane with a concave surface.

Background technique

Various types of sputtering thin film materials have been widely used in semiconductor integrated circuits (VLSI), optical discs, flat-panel displays, and surface coatings of workpieces. Since the 1990s, the development of sputtering targets and sputtering technology has The simultaneous development has greatly satisfied the needs of the development of various new electronic components.

Sputtering is one of the main technologies for preparing thin film materials. The sputtering technology uses ions generated by an ion source to form a high-speed energy ion beam through accelerated aggregation in a vacuum. The ion beam bombards the surface of the target material. Due to the principle of momentum conversion. , the atoms on the target are sputtered from the target surface with high kinetic energy and fly to the substrate, thereby depositing a film on the substrate.

The target material is welded by a target blank and a backing plate, wherein the target blank is the target material bombarded by high-speed ion beams, and is mainly made of high-purity rare metals; and the backing plate mainly plays the role of fixing the target blank. Due to the low strength of high-purity rare metals, and the sputtering process needs to be completed in a dedicated machine, and the inside of the machine is a high-voltage and high-vacuum environment, the backplane needs to have good performance.

In terms of electrical conductivity, the better the electrical conductivity, the better the sputtering stability, and the less abnormal circuit phenomena such as short circuits. Once the short circuit occurs in the target, it will instantly generate huge heat. Under the action of short-circuit heat, local melting is prone to occur, forming molten holes and deformation. For the existing backplane, the conductivity of oxygen-free copper material is generally about 51ms/m-55ms/m, and the conductivity of aluminum alloy material is generally about 20ms/m. material damage.

In addition, in terms of manufacturing process, when manufacturing concave backplanes, machining is generally used to excavate material from solid blanks to form grooves. The removed materials can account for 70% of the blank mass, and the material utilization rate is low. This method has serious waste, high cost, long processing time and large tool loss for the expensive backing material. In other manufacturing processes, such as casting, the process conditions are complex, and it is difficult to manufacture a backplane with higher conductivity at a lower cost.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the prior art and solve the above-mentioned technical problems, the purpose of the present invention is to provide a manufacturing method of a target backplane with a concave surface, which can manufacture a target backplane with good performance in a relatively simple and economical process.

The purpose of the present invention adopts following technical scheme to realize:

A method for manufacturing a target backplane with a concave surface, comprising the following steps:

Flat blank annealing: The flat blank is a metal flat blank. The flat blank is annealed in a vacuum environment or an inert gas environment. flat blank;

Forging and forming: under the same conditions as the annealing temperature in the above step, the annealed flat blank is forged several times using a forging die with protrusions until the annealed flat blank has a concave surface that fits with the forging die. Forging to form a concave blank;

Concave billet annealing: anneal the concave billet in a vacuum environment or an inert gas environment, the annealing temperature is not higher than the annealing temperature in the annealing step of the flat billet, and the annealing time is not less than Annealing time to form a target backplate with a concave surface.

Further, the forging die includes an upper die and a lower die, the lower surface of the upper die has grooves, the upper surface of the lower die has protrusions, and the protrusions are matched with the grooves;

In the forging forming step, forging the annealed flat blank for multiple times by using a forging die with protrusions specifically includes the following steps:

The lower mold is placed on the platform with the protrusion facing upward, the annealed flat blank is placed on the upper surface of the protrusion, the upper mold is located above the annealed flat blank, and the annealed flat blank is beaten several times with an air hammer. the upper die so that the upper die forges the annealed flat blank.

Further, after the step of annealing the concave billet, it also includes the steps of roughness processing as follows:

Roughness processing is performed on the surface of the target backing plate having the concave surface, so that the surface roughness is Ra0.32 μm to Ra0.61 μm.

Further, in the forging and forming step, the forging force of each forging is 3 kN to 15 kN, and the speed of the forging die falling during each forging is 1 mm/s to 15 mm/s.

Further, the flat blank is an oxygen-free copper blank or a copper alloy blank.

Further, the annealing temperature in the flat blank annealing step is 640°C to 690°C, and the annealing time is 1.8 to 3.2 hours; in the forging and forming step, the forging force of each forging is 5kN to 8kN, and each forging is 5kN to 8kN. The descending speed of the forging die during the first forging is 3mm/s to 15mm/s; the annealing temperature in the step of annealing the concave billet is 640°C to 690°C, and the annealing time is 1.8h to 3.2h.

Further, the flat blank is an aluminum alloy blank.

Further, the annealing temperature in the flat blank annealing step is 380°C to 450°C, and the annealing time is 0.4 to 0.6 h; in the forging and forming step, the forging force of each forging is 3 kN to 4 kN, and each forging is 3 kN to 4 kN. The descending speed of the forging die during the first forging is 1mm/s to 8mm/s; the annealing temperature in the step of annealing the concave billet is 340°C to 370°C, and the annealing time is 1.5h to 2.5h.

Further, the flat blank is a titanium alloy blank or a molybdenum blank.

One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

(1) The ductility of the flat blank is increased through the annealing step of the flat blank, and the abnormal growth of grains is avoided by appropriate annealing temperature and annealing time, and the obtained annealed flat blank has good microstructure uniformity. More importantly, combined with the effect of avoiding oxidation in a vacuum environment or an inert gas environment, the electrical conductivity of the annealed slab can reach a higher level than that in the prior art, with an average increase of about 7% to 20%. Thereby greatly reducing the probability of short-circuit phenomenon during sputtering;

(2) Since the plasticity of the material is improved in the annealing step of the flat blank, it is convenient to use the method of forging to obtain the shape of the concave surface in the back plate of the target material. Under the same conditions as the annealing temperature in the annealing step of the flat blank, the formed concave blank The high conductivity and other properties obtained in the previous step can be basically maintained; in addition, this method wastes less material and greatly reduces the manufacturing cost.

(3) The annealing of the concave billet is the secondary annealing of the entire material, which makes the high temperature performance of the overall material stronger and the comprehensive mechanical properties stronger. When applied to sputtering, its stability is better, and the sputtered film material formed Higher quality.

Therefore, the present invention provides a relatively simple and feasible method for manufacturing a target backplane with a concave surface, which can not only reduce the manufacturing cost, but also obtain a target backplane with better performance than the prior art, which is beneficial to It has a strong practical value to reduce the high price of backplanes on the market.

Description of drawings

1 is a flow chart of a method for manufacturing a target backplane with a concave surface according to the present invention;

2 is a schematic diagram of the use of a forging die in a method for manufacturing a target backing plate with a concave surface of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, on the premise of no conflict, the embodiments or technical features described below can be combined arbitrarily to form new embodiments. .

In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

The terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of this application, unless stated otherwise, "plurality" means two or more.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used herein in the description of the invention are for the purpose of describing specific embodiments only and are not intended to limit the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The invention provides a relatively simple and feasible method for manufacturing a target backplane with a concave surface, which can not only reduce the manufacturing cost, but also obtain a target backplane with better performance than the prior art, which is beneficial to reducing the current The high price of the backplane in the market has a strong practical value.

1 shows a method for manufacturing a target backing plate with a concave surface according to the present invention, which includes the steps of annealing flat blanks, forging and forming and annealing concave blanks:

The flat blank annealing step includes: annealing the flat blank in a vacuum environment or an inert gas environment, the annealing temperature is 380°C to 860°C, and the annealing time is 0.4h to 4.1h to form an annealed flat blank 3; The annealing step increases the plasticity of the slab, the annealing temperature of 380°C to 860°C, and the annealing time of 0.4h to 4.1h avoids abnormal grain growth, and the obtained annealed slab 3 has good microstructure uniformity. More importantly, combined with the effect of avoiding oxidation in a vacuum environment or an inert gas environment, the electrical conductivity of the flat blank obtained by annealing can reach a higher level than that in the prior art, with an average increase of about 5% to 20%. Thereby greatly reducing the probability of short circuit during sputtering;

The forging forming step includes: under the same conditions as the annealing temperature in the above steps, using a forging die with protrusions 12 to forge the annealed flat blank 3 multiple times until the annealed flat blank 3 has the same size as the forging die. After the concave surface is matched, the forging is stopped to form a concave billet; since the plasticity of the material is improved in the annealing step of the flat billet, it is convenient to use the method of forging to obtain the shape of the concave surface in the back plate of the target material, and annealing in the annealing step with the flat billet Under the conditions of the same temperature, the formed concave billet can basically maintain the properties such as high electrical conductivity obtained in the previous step; wherein, the forging force of each forging is preferably 3kN to 15kN, and the forging die is lowered during each forging. When the speed is 1 mm/s to 15 mm/s, the annealed flat blank 3 can be deformed stably during the forging process, and the uniformity and balance in the microstructure are less affected. In addition, there is less waste of material in this way, and the manufacturing cost can be greatly reduced. Among them, the size of the forging force is selected according to the hardness of the metal plate itself, and the metal plate with higher hardness itself adopts a larger forging force within this range.

The step of annealing the concave billet includes: annealing the concave billet in a vacuum environment or an inert gas environment, the annealing temperature is not higher than the annealing temperature in the annealing step of the flat billet, and the annealing time is not lower than the annealing step of the flat billet annealing time in , a target backplate with a concave surface is formed. The concave billet annealing is the re-annealing of the entire billet, and the metastable phase is retained during the air cooling of the flat billet annealing (first annealing), while the concave billet annealing (second annealing) during the holding time, compared to the flat billet. The annealing temperature of annealing (the first annealing) will not be higher, or even lower, and the annealing time will not be lower, or even increase, which can further improve the degree of spheroidization of the internal grains of the metal, and the secondary α sheet The layer is also thicker, which makes the high temperature performance of the overall material stronger and the comprehensive mechanical properties stronger. When applied to sputtering, its stability is better, and the quality of the sputtered film material formed is higher.

As shown in FIG. 2 , as a preferred solution of the forging die in this embodiment, the forging die includes an upper die 1 and a lower die 2 , the lower surface of the upper die 1 has a groove 11 , and the upper die of the lower die 2 has a groove 11 The surface has projections 12 which match the grooves 11 . The groove 11 of the upper die 1 and the protrusion 12 of the lower die 2 of such a die just define a concave shape space, when used for forging and annealing the flat blank 3, the flat blank can be made to present the same shape as the shape space. same shape. Specifically, the longitudinal sections of the grooves 11 and the protrusions 12 in this embodiment are both trapezoidal, which facilitates demolding and reduces stress concentration.

In the forging forming step using the above-mentioned forging die, using the forging die with the protrusions 12 to forge the annealed flat blank 3 multiple times preferably specifically includes the following steps:

The lower mold 2 is placed on the platform with the protrusion 12 facing upward, the annealed flat blank 3 is placed on the upper surface of the protrusion 12, and the upper mold 1 is located above the annealed flat blank 3, using The air hammer beats the upper die 1 for many times, so that the upper die 1 forges the annealed flat blank 3 . The air hammer is powered by compressed air, which is convenient to adjust the beating strength and frequency according to the air pressure.

In order to better meet the roughness requirements of the target backing plate and remove the uneven protrusions 12 that may appear on the surface after forging, this embodiment preferably includes the following roughness processing steps after the step of annealing the concave blank:

Roughness processing is performed on the surface of the target backing plate having the concave surface, so that the surface roughness is Ra0.32 μm to Ra0.61 μm. The roughness in this parameter range can not only meet the roughness requirements of the backing plate, but also make the surface of the backing plate close to the mirror surface, and the debris generated after processing can quickly separate from the surface of the target backing plate to avoid scratches and damage.

There are many ways to process the roughness. In this embodiment, the turning process is preferably used, which specifically includes the following steps:

Using a numerically controlled machine tool, the surface of the target backing plate is turned, the turning speed is 300RPM to 600RPM, the feed amount is less than 0.1mm, and the cutting speed is 0.08mm/min to 0.12mm/min. According to this parameter, the required roughness can be processed in a short time, and the production efficiency can be improved.

In the flat slab annealing step and the concave slab annealing step, the preferred cooling method for annealing in this embodiment is cooling with the furnace. Although the speed of this method is reduced, it can not only ensure that the furnace is not in contact with the air during the annealing process to prevent oxidation, but also avoid the possible reaction between the metal surface and the elements in the water during the water cooling process.

The flat blank in this embodiment can be made of various materials, and the first flat blank provided in this embodiment is an oxygen-free copper blank or a copper alloy blank.

Combined with the physical properties of copper, its hardness and melting point are relatively high. In order to have the above-mentioned properties and advantages of the target backplane made of oxygen-free copper blanks or copper alloy blanks, it is preferred that the oxygen-free copper blanks or copper alloy blanks are described in the The annealing temperature in the annealing step of the flat blank is 640° C. to 690° C., and the annealing time is 1.8 to 3.2 hours. After this step, the electrical conductivity is 8% to 16% higher than that of the existing target backing plate of the same material; In the forming step, the forging force of each forging is 5kN to 8kN, and the speed of the falling of the forging die is 3mm/s to 15mm/s during each forging; the annealing temperature in the step of annealing the concave billet is 640 ℃ to 690 ℃, the annealing time is 1.8h to 3.2h, after this step, compared with the previous step, the hardness decreases by 33% to 50%, and the elongation increases by about 50%.

The following table illustrates the above manufacturing method by taking oxygen-free copper blanks with a diameter of 400mm and a thickness of 15mm and C18000 chrome-nickel-silicon copper blanks as examples:

Oxygen-free copper blanks and C18000 chrome-nickel-silicon-copper blanks of the above dimensions can be produced by the method in this embodiment to produce a finished target backplane with a total thickness of 40mm and a diameter of 368mm. A flat blank with a thickness of 42 mm and a diameter of 375 mm weighs about 42 kg; however, the flat blank in this embodiment is only about 17 kg, which can save more than half of the material. In terms of electrical conductivity, the electrical conductivity of the existing oxygen-free copper backplane is about 51ms/m to 55ms/m, while the electrical conductivity of the present invention can reach more than 59ms/m, and the improvement rate is 7% to 16%; The conductivity of some C18000 chrome-nickel-silicon-copper backplanes is about 31ms/m to 32ms/m, while the conductivity of the present invention can reach more than 34ms/m, and the improvement rate is 5% to 10%.

The second type of flat blank provided in this embodiment is an aluminum alloy blank.

The hardness and melting point of aluminum are lower than those of copper. The annealing temperature of the aluminum alloy billet in the flat billet annealing step is 380°C to 450°C, and the annealing time is 0.4 to 0.6h. After this step, the electrical conductivity is higher than the existing one. The height of the target material of the same material is about 20% higher; in the forging and forming step, the forging force of each forging is 3kN to 4kN, and the speed of the forging die during each forging is 1mm/s to 8mm. /s; the annealing temperature in the annealing step of the concave billet is 340°C to 370°C, and the annealing time is 1.5h to 2.5h. After this step, compared with the previous step, the hardness decreases by 25% to 33% , the elongation increased from 33% to about 100%.

The following table illustrates the above-mentioned manufacturing method by taking 6061 aluminum alloy billet and aluminum silicide billet with a diameter of 400mm and a thickness of 15mm as examples:

In terms of electrical conductivity, the electrical conductivity of the existing 6061 aluminum alloy backplane and 6061 aluminum alloy backplane is about 20ms/m, while the electrical conductivity in the present invention can reach more than 24ms/m, and the improvement rate is about 20%.

The third flat blank provided in this embodiment is a titanium alloy blank (including pure titanium), preferably Ta1 titanium. Titanium alloy has the characteristics of high strength and low density, good mechanical properties, good toughness and corrosion resistance; among them, Ta1 titanium is industrial pure titanium, and its impurity content is more than that of chemical pure titanium, so its strength and hardness are slightly higher. It retains good plasticity and is suitable for used target backplanes.

The annealing temperature of the titanium alloy billet in the annealing step is 780°C to 820°C, preferably 800°C, and the annealing time is 2h to 3h, preferably 2.5h. After this step, the electrical conductivity can reach 2.45, which is higher than the existing The height of the back plate of the target material of the same material is about 5% to 10%; in the forging and forming step, the forging force of each forging is 10kN to 15kN, and the speed of the forging die during each forging is 3mm/ s to 6mm/s, preferably 5mm; the annealing temperature in the step of annealing the concave billet is 780°C to 820°C, preferably 800°C, and the annealing time is 2h to 3h, preferably 2.5h, after this step, compared with In the previous step, the hardness decreased from 380HV to 340HV, a decrease of about 11%, and the elongation increased from 8% to 12%, an increase of about 50%.

The fourth type of flat blank provided in this embodiment is a molybdenum blank. Molybdenum is chemically stable and has a melting point of up to 2620°C. It has excellent high temperature mechanical stability, so it is very suitable for target backplanes.

The annealing temperature of the molybdenum blank in the annealing step is 840°C to 860°C, preferably 850°C, and the annealing time is 3.5h to 4.5h, preferably 4 hours. After this step, the electrical conductivity can reach 18.47, which is higher than the existing The height of the back plate of the target material of the same material is about 5% to 10%; in the forging forming step, the forging force of each forging is 10kN to 15kN, and the speed of the forging die during each forging is 10kN to 15kN. 1mm/s to 3mm/s, preferably 2mm; the annealing temperature in the step of annealing the concave billet is 840°C to 860°C, preferably 850°C, and the annealing time is 3.5h to 4.5h, preferably 4 hours, after this step After that, compared with the previous step, the hardness decreased from 420HV to 400HV, a decrease of about 5%, and the elongation increased from 3% to 8%, an increase of about 167%.

The above-mentioned embodiments are only preferred embodiments of the present invention, and cannot be used to limit the scope of protection of the present invention. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of the present invention. Scope of protection claimed.

Claims (9)

1. A manufacturing method of a target backing plate with a concave surface is characterized by comprising the following steps:

annealing the flat blank: the flat plate blank is made of oxygen-free copper blank or copper alloy blank or aluminum alloy blank or titanium alloy blank or molybdenum blank, and is annealed in a vacuum environment or inert gas environment at the annealing temperature of 380-860 ℃ for 0.4-4.1 h to form an annealed flat plate blank;

forging and molding: forging the annealed flat blank for multiple times by using a forging die with a bulge under the condition of the same annealing temperature as that in the previous step until the annealed flat blank has a concave surface matched with the forging die, and stopping forging to form a concave blank; the method specifically comprises the following steps: the forging die comprises an upper die and a lower die, wherein a groove is formed in the lower surface of the upper die, a protrusion is formed on the upper surface of the lower die, and the protrusion is matched with the groove; the lower die is placed on a platform in a mode that the bulge faces upwards, the annealing flat blank is placed on the upper surface of the bulge, the upper die is positioned above the annealing flat blank, and the upper die is beaten by an air hammer for multiple times, so that the annealing flat blank is forged by the upper die;

annealing the concave blank: and annealing the concave blank in a vacuum environment or an inert gas environment, wherein the annealing temperature is not higher than the annealing temperature in the annealing step of the flat blank, and the annealing time is not lower than the annealing time in the annealing step of the flat blank, so that the target backboard with the concave surface is formed.

2. The method of manufacturing a target backing plate having a concave surface according to claim 1, further comprising a roughness machining step after the concave blank annealing step as follows:

and carrying out roughness processing on the surface of the target back plate with the concave surface to ensure that the roughness of the surface is Ra0.32-Ra0.61 μm.

3. The method for manufacturing a target backing plate having a concave surface according to claim 1, wherein in the forging step, a forging force per forging is 3kN to 15kN, and a speed at which the forging die descends per forging is 1mm/s to 15 mm/s.

4. The method of manufacturing a target backing plate having a concavity according to any one of claims 1 to 3, wherein the flat plate blank is an oxygen-free copper blank or a copper alloy blank.

5. The method according to claim 4, wherein the annealing temperature in the step of annealing the plate blank is 640 ℃ to 690 ℃, and the annealing time is 1.8h to 3.2 h; in the forging forming step, the forging force of each forging is 5kN to 8kN, and the descending speed of the forging die is 3mm/s to 15mm/s during each forging; the annealing temperature in the concave blank annealing step is 640-690 ℃, and the annealing time is 1.8-3.2 h.

6. The method of manufacturing a target backing plate having a concave surface according to any one of claims 1 to 3, wherein the flat plate blank is an aluminum alloy blank.

7. The method for manufacturing the target backing plate with the concave surface according to claim 6, wherein the annealing temperature in the step of annealing the plate blank is 380 ℃ to 450 ℃, and the annealing time is 0.4 to 0.6 h; in the forging forming step, the forging force of each forging is 3kN to 4kN, and the descending speed of the forging die is 1mm/s to 8mm/s during each forging; the annealing temperature in the concave blank annealing step is 340-370 ℃, and the annealing time is 1.5-2.5 h.

8. The method of manufacturing a target backing plate having a concave surface according to any one of claims 1 to 3, wherein the flat plate blank is a titanium alloy blank; the annealing temperature in the flat blank annealing step is 780-820 ℃, and the annealing time is 2-3 h; in the forging forming step, the forging force of each forging is 10kN to 15kN, and the descending speed of the forging die is 3mm/s to 6mm/s during each forging; the annealing temperature in the concave blank annealing step is 780-820 ℃, and the annealing time is 2-3 h.

9. The method of manufacturing a target backing plate having a concave surface according to any one of claims 1 to 3, wherein the flat plate blank is a molybdenum blank; the annealing temperature in the flat blank annealing step is 840 ℃ to 860 ℃, and the annealing time is 3.5h to 4.5 h; in the forging forming step, the forging force of each forging is 10kN to 15kN, and the descending speed of the forging die is 1mm/s to 3mm/s during each forging; the annealing temperature in the concave blank annealing step is 840 ℃ to 860 ℃, and the annealing time is 2h to 3 h.

Images