Machining method of molybdenum-niobium target material

Abstract

The invention provides a machining method of a molybdenum-niobium target material. The machining method comprises the steps of finish-milling a welding surface, finish-milling a sputtering surface, finish-milling an appearance and finish-milling an R angle in sequence. The machining method is reasonably arranged, a self-made cutter is selected, and reasonable machining parameters are set, so that the planeness, the parallelism and the size specification of the molybdenum-niobium target obtained through machining all meet the requirements of semiconductor products; the phenomenon of abnormal discharge caused by residual stress is effectively solved, the thickness of a stress layer on the surface of the target material after machining is effectively controlled, and normal use of the target material in the sputtering process is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of target processing, and relates to a mechanical processing method for a target, in particular to a mechanical processing method for a molybdenum-niobium target. Background Art

[0002] At present, sputtering targets are mainly used in industries such as information storage, integrated circuits, displays, and automotive rearview mirrors, and are mainly used for magnetron sputtering of various thin film materials. Magnetron sputtering is a method for preparing thin film materials. Ions generated by an ion source are accelerated and aggregated into a high-speed ion flow in a vacuum. The accelerated particle flow bombards the surface of the object to be deposited with a thin film. Kinetic energy exchange occurs between the ions and the atoms on the surface of the object to be deposited with a thin film, and a nano or micron thin film is deposited on the surface of the object to be deposited with a thin film. The solid being bombarded is the raw material for depositing a thin film by sputtering, and is called a sputtering target.

[0003] In the production of large-scale integrated circuits, a target assembly is composed of a target meeting sputtering performance and a backplane combined with the target and having a certain strength. The backplane can play a supporting role when the target assembly is assembled into a sputtering base, and has the effect of conducting heat, and can effectively ensure sputtering control of the target under the action of a magnetic field and an electric field. In the prior art, it is necessary to first mechanically process the molybdenum-niobium target to meet the quality requirements of size and flatness before welding it to the backplane.

[0004] When the target is subjected to the force of tool cutting during processing, in order to prevent it from deforming, internal forces that oppose it are generated within the material. These two forces are equal in magnitude and opposite in direction, so a balance is achieved during the processing. When the tool cutting force on the target disappears after processing, the internal balance is broken, and the internal stress that counteracts it within the product changes irregularly, resulting in irregular deformation of the product.

[0005] CN 102059582A discloses a processing method for a molybdenum target, including: providing a molybdenum target; providing a cooling medium, the cooling medium including an emulsion and water; during the cutting process, uniformly spraying the cooling medium on the surface of the molybdenum target to be processed and the surface of the processing tool; the rotational speed of the processing tool is 2500 - 3000 revolutions per minute, the feed per tooth is less than or equal to 0.2 mm / tooth, and the feed rate is 300 - 350 mm / minute. The molybdenum target processing method provided by this patent can improve the processing effect and avoid problems such as cracks or chipping of the molybdenum target during processing. The molybdenum-niobium target has different target requirements for the welding surface and the sputtering surface, and the mechanical processing method does not distinguish between the processing methods for the welding surface and the sputtering surface.

[0006] In summary, there is an urgent need to develop a mechanical processing method for molybdenum-niobium targets. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a mechanical processing method for a molybdenum-niobium target. By reasonably arranging the processing technology, selecting self-made tools and setting reasonable processing parameters, the flatness, parallelism and dimensional specifications of the processed molybdenum-niobium target all meet the requirements of semiconductor products; effectively solving the abnormal discharge phenomenon caused by stress residue, effectively controlling the stress layer thickness on the surface of the target after mechanical processing, and ensuring the normal use of the target during the sputtering process.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] The present invention provides a mechanical processing method for a molybdenum-niobium target, and the mechanical processing method includes milling the welding surface, milling the sputtering surface, milling the outer shape and milling the R corner in sequence.

[0010] In the present invention, the molybdenum-niobium target is an LCD planar target. Using the mechanical processing method provided by the present invention can effectively solve the abnormal discharge phenomenon of the LCD planar target caused by stress residue, effectively control the stress layer thickness on the surface of the target after mechanical processing, and ensure the normal use of the target during the sputtering process. In addition, by reasonably arranging the processing technology, selecting self-made tools and setting reasonable processing parameters, the flatness, parallelism and surface roughness of the processed molybdenum-niobium target meet the requirements of semiconductor products.

[0011] As a preferred technical solution of the present invention, the tool used in the milling of the welding surface includes a first non-standard R245 disc cutter.

[0012] Preferably, the blade material of the first non-standard R245 disc cutter includes cemented carbide, and a coating is applied on the cemented carbide.

[0013] In the present invention, the coating applied on the cemented carbide includes any one of titanium nitride coating, titanium aluminum nitride coating or chromium nitride coating.

[0014] Preferably, 8 to 12 blades are installed on the first non-standard R245 disc cutter, for example, it can be 8, 9, 10, 11 or 12.

[0015] In the present invention, the first non-standard R245 disc cutter is obtained by optimizing and adjusting a 12T3K-MM2030 tool and a Sandvik tool. Combining with an appropriate amount of blades can better achieve precise processing of the welding surface.

[0016] As a preferred technical solution of the present invention, the spindle speed in the finish milling welding surface is 220 - 260 m / s. For example, it can be 220 m / s, 230 m / s, 240 m / s, 250 m / s or 260 m / s, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0017] Preferably, the feed rate in the finish milling welding surface is 500 - 700 mm / min. For example, it can be 500 mm / min, 540 mm / min, 580 mm / min, 620 mm / min, 660 mm / min or 700 mm / min, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0018] Preferably, the depth of cut in the finish milling welding surface is 0.15 - 0.25 mm. For example, it can be 0.15 mm, 0.17 mm, 0.19 mm, 0.21 mm, 0.23 mm or 0.25 mm, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0019] As a preferred technical solution of the present invention, the tool used in the finish milling sputtering surface includes a second non-standard R245 disc cutter.

[0020] Preferably, the blade material of the second non-standard R245 disc cutter includes cemented carbide, and a coating is applied on the cemented carbide.

[0021] In the present invention, the coating applied on the blade of the second non-standard R245 disc cutter includes a titanium carbonitride coating.

[0022] Preferably, 2 - 4 blades are installed on the second non-standard R245 disc cutter. For example, it can be 2, 3 or 4.

[0023] In the present invention, the second non-standard R245 disc cutter is obtained by optimizing and adjusting a 12T3K-MM2030 tool and a Sandvik tool. Combined with an appropriate amount of blades, it can better achieve precise machining of the sputtering surface.

[0024] As a preferred technical solution of the present invention, the spindle speed in the finish milling sputtering surface is 220 - 260 m / s. For example, it can be 220 m / s, 230 m / s, 240 m / s, 250 m / s or 260 m / s, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0025] Preferably, the feed rate in the finish milling of the sputtering surface is 180 - 220 mm / min. For example, it can be 180 mm / min, 190 mm / min, 200 mm / min, 210 mm / min, or 220 mm / min. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0026] Preferably, the depth of cut in the finish milling of the sputtering surface is 0.04 - 0.06 mm. For example, it can be 0.04 mm, 0.044 mm, 0.048 mm, 0.052 mm, 0.056 mm, or 0.06 mm. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0027] As a preferred technical solution of the present invention, the tool used in the finish milling of the outer shape includes a non-standard D20 milling cutter;

[0028] Preferably, the blade material of the non-standard D20 milling cutter includes tungsten steel.

[0029] As a preferred technical solution of the present invention, the spindle speed in the finish milling of the outer shape is 1600 - 2000 m / s. For example, it can be 1600 m / s, 1700 m / s, 1800 m / s, 1900 m / s, or 2000 m / s. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0030] Preferably, the feed rate in the finish milling of the outer shape is 800 - 1200 mm / min. For example, it can be 800 mm / min, 900 mm / min, 1000 mm / min, 1100 mm / min, or 1200 mm / min. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] Preferably, the depth of cut in the finish milling of the outer shape is 0.25 - 0.35 mm. For example, it can be 0.25 mm, 0.27 mm, 0.29 mm, 0.31 mm, 0.33 mm, or 0.35 mm. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0032] As a preferred technical solution of the present invention, the tool used in the finish milling of the R corner includes a non-standard R3.5 external round cutter.

[0033] Preferably, the blade material of the non-standard R3.5 external round cutter includes tungsten steel.

[0034] As a preferred technical solution of the present invention, the spindle speed for precision milling the R corner is 2800 - 3200 m / s. For example, it can be 2800 m / s, 2900 m / s, 3000 m / s, 3100 m / s or 3200 m / s, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0035] Preferably, the feed rate for precision milling the R corner is 800 - 1200 mm / min. For example, it can be 800 mm / min, 900 mm / min, 1000 mm / min, 1100 mm / min or 1200 mm / min, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0036] Preferably, during the machining process of the machining method, a cutting fluid is used for cooling.

[0037] Preferably, during the machining process of the machining method, the molybdenum - niobium target is fixed by a vacuum chuck.

[0038] As a preferred technical solution of the present invention, the machining method for the molybdenum - niobium target provided by the present invention includes the following steps:

[0039] (1) Precision milling the welding surface: The tool for precision milling the welding surface includes a first non - standard R245 disc cutter with 8 - 12 carbide inserts installed. The spindle speed is 220 - 260 m / s, the feed rate is 500 - 700 mm / min, and the depth of cut is 0.15 - 0.25 mm;

[0040] (2) Precision milling the sputtering surface: The tool for precision milling the sputtering surface includes a second non - standard R245 disc cutter with 2 - 4 carbide inserts installed. The spindle speed is 220 - 260 m / s, the feed rate is 180 - 220 mm / min, and the depth of cut is 0.04 - 0.06 mm;

[0041] (3) Precision milling the outer shape: The tool for precision milling the outer shape includes a non - standard D20 milling cutter with tungsten steel inserts. The spindle speed is 1600 - 2000 m / s, the feed rate is 800 - 1200 mm / min, and the depth of cut is 0.25 - 0.35 mm;

[0042] (4) Precision milling the R corner: The tool for precision milling the R corner includes a non - standard R3.5 external round cutter with tungsten steel inserts; the spindle speed is 2800 - 3200 m / s, and the feed rate is 800 - 1200 mm / min.

[0043] The following are preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) By reasonably arranging the processing technology, selecting self-made tools and setting reasonable processing parameters, the flatness, parallelism and dimensional specifications of the processed molybdenum-niobium target meet the requirements of semiconductor products;

[0046] (2) The mechanical processing method provided by the present invention can effectively solve the abnormal discharge phenomenon of the LCD planar target caused by stress residue, effectively control the thickness of the stress layer on the surface of the target after mechanical processing, and ensure the normal use of the target during the sputtering process. Specific Embodiments

[0047] To facilitate the understanding of the present invention, the following embodiments are listed. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0048] Embodiment 1

[0049] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The mechanical processing method includes the following steps:

[0050] (1) Precision milling the welding surface: The tool in the precision milling of the welding surface includes a first non-standard R245 disc cutter with 10 cemented carbide inserts installed. The spindle speed is 240 m / s, the feed rate is 600 mm / min, and the depth of cut is 0.2 mm; The cemented carbide inserts are coated with a coating;

[0051] (2) Precision milling the sputtering surface: The tool in the precision milling of the sputtering surface includes a second non-standard R245 disc cutter with 3 cemented carbide inserts installed. The spindle speed is 240 m / s, the feed rate is 200 mm / min, and the depth of cut is 0.05 mm; The cemented carbide inserts are coated with a coating;

[0052] (3) Precision milling the outer shape: The tool in the precision milling of the outer shape includes a non-standard D20 milling cutter with tungsten steel inserts. The spindle speed is 1800 m / s, the feed rate is 1000 mm / min, and the depth of cut is 0.3 mm;

[0053] (4) Precision milling the R corner: The tool in the precision milling of the R corner includes a non-standard R3.5 external round cutter with tungsten steel inserts; The spindle speed is 3000 m / s, and the feed rate is 1000 mm / min.

[0054] Embodiment 2

[0055] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The mechanical processing method includes the following steps:

[0056] (1) Finish milling the welding surface: The tool in the finish milling of the welding surface includes a first non-standard R245 disk cutter with 8 carbide inserts installed, the spindle speed is 220 m / s, the feed rate is 500 mm / min, and the depth of cut is 0.15 mm; The carbide inserts are coated with a coating;

[0057] (2) Finish milling the sputtering surface: The tool in the finish milling of the sputtering surface includes a second non-standard R245 disk cutter with 2 carbide inserts installed, the spindle speed is 220 m / s, the feed rate is 180 mm / min, and the depth of cut is 0.04 mm; The carbide inserts are coated with a coating;

[0058] (3) Finish milling the outer shape: The tool in the finish milling of the outer shape includes a non-standard D20 milling cutter with tungsten steel blades, the spindle speed is 1600 m / s, the feed rate is 800 mm / min, and the depth of cut is 0.25 mm;

[0059] (4) Finish milling the R corner: The tool in the finish milling of the R corner includes a non-standard R3.5 external round cutter with tungsten steel blades; The spindle speed is 2800 m / s, and the feed rate is 800 mm / min.

[0060] Example 3

[0061] This example provides a mechanical processing method for a molybdenum-niobium target. The mechanical processing method includes the following steps:

[0062] (1) Finish milling the welding surface: The tool in the finish milling of the welding surface includes a first non-standard R245 disk cutter with 12 carbide inserts installed, the spindle speed is 260 m / s, the feed rate is 700 mm / min, and the depth of cut is 0.25 mm; The carbide inserts are coated with a coating;

[0063] (2) Finish milling the sputtering surface: The tool in the finish milling of the sputtering surface includes a second non-standard R245 disk cutter with 2 carbide inserts installed, the spindle speed is 260 m / s, the feed rate is 180 - 220 mm / min, and the depth of cut is 0.06 mm; The carbide inserts are coated with a coating;

[0064] (3) Finish milling the outer shape: The tool in the finish milling of the outer shape includes a non-standard D20 milling cutter with tungsten steel blades, the spindle speed is 2000 m / s, the feed rate is 1200 mm / min, and the depth of cut is 0.35 mm;

[0065] (4) Finish milling the R corner: The tool in the finish milling of the R corner includes a non-standard R3.5 external round cutter with tungsten steel blades; The spindle speed is 3200 m / s, and the feed rate is 1200 mm / min.

[0066] Example 4

[0067] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0068] In this embodiment, the spindle speed in the finish milling of the welding surface in step (1) is adjusted to 300 m / s.

[0069] Embodiment 5

[0070] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0071] In this embodiment, the feed rate in the finish milling of the welding surface in step (1) is adjusted to 1000 mm / min.

[0072] Embodiment 6

[0073] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0074] In this embodiment, the depth of cut in the finish milling of the welding surface in step (1) is adjusted to 0.5 mm.

[0075] Embodiment 7

[0076] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0077] In this embodiment, the spindle speed in the finish milling of the sputtering surface in step (2) is adjusted to 300 m / s.

[0078] Embodiment 8

[0079] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0080] In this embodiment, the feed rate in the finish milling of the sputtering surface in step (2) is adjusted to 300 r / min.

[0081] Embodiment 9

[0082] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0083] In this embodiment, the depth of cut in the finish milling of the sputtering surface in step (2) is adjusted to 0.1 mm.

[0084] Embodiment 10

[0085] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Embodiment 1 is only that:

[0086] In this embodiment, the blades of the cutting tools used in steps (1) and (2) are both adjusted to diamond blades.

[0087] Example 11

[0088] This embodiment provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Example 1 is only that:

[0089] In this embodiment, the cutting tools used in steps (1) and (2) are adjusted to: no coating is provided on the cemented carbide blades.

[0090] Comparative Example 1

[0091] This comparative example provides a mechanical processing method for a molybdenum-niobium target. The difference between this mechanical processing method and that of Example 1 is only that:

[0092] In this comparative example, the finish milling of the outer shape in step (3) is adjusted to before the finish milling of the welding surface in step (1), that is, the mechanical processing method is adjusted to sequentially perform finish milling of the outer shape, finish milling of the welding surface, finish milling of the sputtering surface, and finish milling of the R corner.

[0093] The flatness, parallelism, and error of the targets processed by the mechanical processing methods provided in the above embodiments and comparative examples are tested, and the results are shown in Table 1;

[0094] Among them, the error is: the error size between the size of the processed workpiece and the size of the standard part.

[0095] Table 1

[0096]

[0097] According to the data in Table 1, the following points can be known:

[0098] (1) Through comprehensive analysis of Examples 1-3, it can be seen that in the present invention, by reasonably arranging the processing method, selecting self-made cutting tools, and setting reasonable processing parameters, the flatness, parallelism, and dimensional specifications of the processed molybdenum-niobium target all meet the requirements of semiconductor products;

[0099] (2) Through comprehensive analysis of Example 1 and Examples 4-9, it can be seen that in the present invention, adjusting the process parameters during the processing will affect the processing effect of the sputtering surface and / or the welding surface, making it unable to meet the requirements of semiconductor products. Thus, it shows that the selection of process parameters is one of the important factors affecting the mechanical processing effect;

[0100] (3) Through comprehensive analysis of Example 1 and Examples 10-11, it can be seen that in the present invention, the selection of the blades in the self-made cutting tools will affect the finish milling effect of the molybdenum-niobium target;

[0101] (4) By comprehensively analyzing Example 1 and Comparative Example 1, it can be seen that by reasonably setting the processing sequence of the sputtering surface and the welding surface of the molybdenum-niobium target, the precise control of the flatness and parallelism of the target can be effectively achieved, and the yield of the target can be improved.

[0102] In summary, through reasonable arrangement of the processing method, selection of self-made tools, and setting of reasonable processing parameters, the flatness, parallelism, and dimensional specifications of the processed molybdenum-niobium target all meet the requirements of semiconductor products; effectively solve the abnormal discharge phenomenon caused by stress residue, effectively control the thickness of the stress layer on the surface of the target after machining, and ensure the normal use of the target during the sputtering process.

[0103] The specific embodiments described above have further detailed the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for machining a molybdenum-niobium target, characterized in that: The mechanical processing method comprises sequentially performing precision milling of a welding surface, precision milling of a sputtering surface, precision milling of an outer shape and precision milling of an R angle.

2. The machining method according to claim 1, characterized in that: The tool used in the fine milling of the welding surface includes a first non-standard R245 disc cutter; Preferably, the blade material of the first non-standard R245 disc cutter includes cemented carbide, and the cemented carbide is coated with a coating; Preferably, 8 to 12 blades are installed on the first non-standard R245 disc cutter.

3. The machining method according to claim 1 or 2, characterized in that: The spindle speed in the precision milling welding surface is 220-260 m / s; Preferably, the feed rate in the fine milling of the welding surface is 500-700 mm / min; Preferably, the cutting depth in the fine milling welding surface is 0.15-0.25 mm.

4. The machining method according to any one of claims 1 to 3, characterized in that: The tool used in the fine milling of the sputtering surface includes a second non-standard R245 disc tool; Preferably, the blade material of the second non-standard R245 disc cutter includes cemented carbide, and the cemented carbide is coated with a coating; Preferably, 2 to 4 blades are installed on the second non-standard R245 disc cutter.

5. The machining method according to any one of claims 1 to 4, characterized in that: The spindle speed in the fine milling sputtering surface is 220-260 m / s; Preferably, the feed rate in the fine milling of the sputtering surface is 180-220 mm / min; Preferably, the cutting depth in the fine milling sputtering surface is 0.04-0.06 mm.

6. The machining method according to any one of claims 1 to 5, characterized in that: The tool used in the fine milling of the shape includes a non-standard D20 milling cutter; Preferably, the blade material of the non-standard D20 milling cutter includes tungsten steel.

7. The machining method according to any one of claims 1 to 6, characterized in that: The spindle speed in the fine milling profile is 1600-2000 m / s; Preferably, the feed rate in the fine milling profile is 800-1200 mm / min; Preferably, the cutting depth in the fine milling shape is 0.25 to 0.35 mm.

8. The machining method according to any one of claims 1 to 7, characterized in that: The tool used in the fine milling R angle includes a non-standard R3.5 external circular tool; Preferably, the blade material of the non-standard R3.5 external circular cutter includes tungsten steel.

9. The machining method according to any one of claims 1 to 8, characterized in that: The spindle speed for the precision milling R angle is 2800-3200 m / s; Preferably, the feed rate of the fine milling R angle is 800-1200 mm / min.

10. The machining method according to any one of claims 1 to 9, characterized in that: The machining method comprises the following steps: (1) Fine milling of the welding surface: The tool used for fine milling of the welding surface includes a first non-standard R245 disc cutter equipped with 8 to 12 carbide blades, a spindle speed of 220 to 260 m / s, a feed rate of 500 to 700 mm / min, and a cutting depth of 0.15 to 0.25 mm; (2) Fine milling of the sputtering surface: The tool used for fine milling of the sputtering surface includes a second non-standard R245 disc cutter equipped with 2 to 4 carbide blades, a spindle speed of 220 to 260 m / s, a feed rate of 180 to 220 mm / min, and a cutting depth of 0.04 to 0.06 mm; (3) Fine milling: The tool used in the fine milling includes a non-standard D20 milling cutter with a blade made of tungsten steel, a spindle speed of 1600 to 2000 m / s, a feed rate of 800 to 1200 mm / min, and a cutting depth of 0.25 to 0.35 mm; (4) Fine milling of R angle: The tool used for fine milling of R angle includes a non-standard R3.5 external cylindrical cutter whose blade material is tungsten steel; the spindle speed is 2800-3200 m / s, and the feed rate is 800-1200 mm / min.

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