Ruthenium-cobalt target material for forming component gradient film

Abstract

The invention provides a ruthenium-cobalt target material for forming a component gradient thin film, which comprises a target material unit and a back plate, the target material unit has different ruthenium-cobalt proportions, and the target material unit is prepared by uniformly mixing ruthenium powder and cobalt powder according to different atomic ratios, carrying out die forming and then carrying out hot isostatic pressing sintering, the target material units with two different component proportions are sequentially and alternately spliced and fixed on the back plate to form the ruthenium-cobalt target material. The ruthenium-cobalt target material is composed of two ruthenium-cobalt alloy target materials with different ruthenium-cobalt proportions, the ruthenium-cobalt target materials are fixed to the same back plate, and the gradient film with the ruthenium-cobalt components continuously changing in the film thickness direction can be formed by adjusting sputtering parameters under the condition that the target material is not replaced.

Description

Technical Field

[0001] The present invention relates to the technical field of ruthenium-cobalt target materials, in particular to a ruthenium-cobalt target material for forming a composition gradient film. Background Art

[0002] The traditional gradient thin film production process typically requires constant replacement of target materials with different compositions, which not only increases the complexity of the production process but also reduces production efficiency. Furthermore, traditional targets typically require replacement based on specific composition ratios, making it impossible to flexibly adjust the composition ratio of the film, thus affecting the film quality and production stability.

[0003] To solve this problem, the present invention proposes a new ruthenium-cobalt target design, which can form a gradient film on a single target without the need to replace the target, thereby improving production efficiency and ensuring film quality. Summary of the Invention

[0004] The object of the present invention is to provide a ruthenium-cobalt target for forming a composition gradient thin film. The ruthenium-cobalt target comprises a ruthenium-cobalt alloy with different composition ratios. The target can be formed without replacing the target during the sputtering process by controlling the magnetic field position, thereby reducing the process of frequent target replacement, improving production efficiency, and ensuring that the composition gradient change of the film is more stable.

[0005] According to one object of the present invention, the present invention provides a ruthenium-cobalt target for forming a composition gradient thin film, comprising a target unit and a backing plate, wherein the target unit has different ruthenium-cobalt ratios, and the target unit is prepared by uniformly mixing ruthenium powder and cobalt powder according to different atomic ratios, molding them, and then hot isostatic pressing and sintering. The target units with two different composition ratios are alternately spliced and fixed on the backing plate to form the ruthenium-cobalt target.

[0006] Furthermore, the purity of the ruthenium powder and the cobalt powder is both above 99.99%.

[0007] Furthermore, the content of ruthenium or cobalt in the target material unit is not less than 20%.

[0008] Furthermore, the atomic ratios of ruthenium powder and cobalt powder used to prepare the ruthenium-cobalt target are 60-70:40-30 and 30-40:70-60.

[0009] Furthermore, the atomic ratios of ruthenium to cobalt in the two target material units are 70:30 and 30:70 respectively.

[0010] Furthermore, the target unit is in the shape of a long strip.

[0011] Furthermore, the widths of the two long strip-shaped target units with different ruthenium and cobalt composition ratios are equal.

[0012] Furthermore, the two target material units are spliced alternately in sequence along the width direction, and the splicing gap is less than 1 mm.

[0013] Furthermore, the target unit is fixed to the upper surface of the backing plate by brazing.

[0014] Furthermore, the back plate is made of non-magnetic material.

[0015] The ruthenium-cobalt target provided by the technical solution of the present invention is composed of target units with two different ruthenium-cobalt ratios. The target units are alternately spliced and fixed on a back plate. Without changing the target material, by adjusting the sputtering parameters, a gradient film in which the ruthenium-cobalt composition continuously changes along the film thickness direction can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the welding structure of the actual ruthenium-cobalt target brazing material and the target backing plate according to an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the structure of a ruthenium-cobalt target, a target backing plate, and a magnet assembly according to an embodiment of the present invention;

[0019] In the figure: 1. Target backing plate; 2. Splicing gap; 3. Welding layer; 4. Component A target; 5. Component B target. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0023] Example 1

[0024] A ruthenium-cobalt target for forming a composition-gradient thin film comprises a target unit and a backing plate. The ruthenium-cobalt target is composed of target units with different ruthenium-cobalt ratios. The target units are prepared by uniformly mixing ruthenium powder and cobalt powder according to different atomic ratios, molding them, and then hot isostatic pressing and sintering. The two target units with different composition ratios are alternately spliced and fixed on the backing plate to form the ruthenium-cobalt target.

[0025] Specifically, the steps include:

[0026] Ruthenium powder and cobalt powder with a purity of 99.99% are selected and dry-milled in an atomic ratio of 60-70:40-30 and 30-40:70-60, respectively, to ensure uniform powder. (The composition ratio can be freely matched, but the content of ruthenium or cobalt must be greater than or equal to 20%: taking pure metal targets as an example, the sputtering temperature parameters of ruthenium targets and cobalt targets differ greatly. When the composition ratio of ruthenium to cobalt materials in the alloy target is too large, the sputtering process becomes abnormal and the film parameters become unstable.) In this embodiment, ruthenium powder and cobalt powder are specifically dry-milled in an atomic ratio of 70:30 and 30:70, respectively.

[0027] The uniformly mixed powders are placed into regular-shaped elongated molds for molding to obtain two regular-shaped ruthenium-cobalt alloy billets.

[0028] The molded blank is placed in a hot isostatic pressing furnace for sintering, and a high-density, high-purity target unit is obtained after sintering. The widths of the two long strip target units are equal.

[0029] The above examples demonstrate the fabrication of two ruthenium-cobalt alloy targets with different composition ratios. These targets are then welded to a single backing plate, ensuring the required splicing precision. The resulting targets can stably form gradient thin films during sputtering, with smooth and uniform composition transitions, thus avoiding the inefficiencies associated with frequent target replacement.

[0030] Example 2

[0031] like Figure 1 As shown, the ruthenium-cobalt target prepared in Example 1 is used, and two ruthenium-cobalt alloy targets having different ruthenium-cobalt content ratios are welded to the target backing plate 1, forming a welding layer 3 between the component A target 4 and the component B target 5 and the target backing plate 1. The atomic ratio of ruthenium to cobalt in the component A target 4 is 70:30, while the atomic ratio of ruthenium to cobalt in the component B target 5 is 30:70.

[0032] It is understandable that the ruthenium powder and the cobalt powder can also be mixed in other atomic ratios such as 65:35 and 35:65.

[0033] like Figure 1 As shown, two long strips of ruthenium-cobalt alloy targets—component A target 4 and component B target 5—are bonded to a target backing plate 1 along its width, forming a large rectangular target. After bonding, a gap exists between the two targets. This gap 2 must be less than 1 mm. The smaller the gap, the less abnormal discharge occurs during sputtering, and the more stable the sputtering process.

[0034] The ruthenium-cobalt target prepared in this embodiment can effectively form gradient thin films during sputtering. The target has high density and uniformity, and can operate stably during the sputtering process, avoiding the inefficiency and increased costs caused by frequent target replacement in traditional methods.

[0035] The above embodiments demonstrate how to prepare ruthenium-cobalt alloy targets with different composition ratios by using methods such as powder mixing, molding, and hot isostatic pressing, and fix them on a backing plate by welding to form a composition gradient film during the sputtering process.

[0036] Example 3

[0037] like Figure 2As shown, during the actual sputtering process, several magnet groups are set below the target back plate. The magnet group includes multiple groups of magnets arranged along the width direction of the target, and the polarities of the magnets are arranged alternately.

[0038] In this embodiment, the magnet group is periodically moved along the width direction of the target material to adjust the position of the magnetic field. The effect of the magnetic field on the target material etching rate is utilized to mark the two ruthenium-cobalt alloy targets as component A target 4 and component B target 5, respectively. The target material composition ratio in Example 1 is used as an example for illustration. The ruthenium:cobalt atomic ratio of the component A target material is 70:30, and the ruthenium:cobalt atomic ratio of the component B target material is 70:30. Due to the effect of the magnetic field, the etching rate at position ① is the highest. At this time, the etching rate of the component A target material is relatively high, and the etching rate of the component B target material 5 is relatively low. As a result, the ruthenium content of the sputtered film is higher than the cobalt content. When the magnet group is moved to the moved position, such as the position of the magnet represented by the gray rectangular block and the dotted rectangular block, the etching rate at position ② is the highest due to the effect of the magnetic field. At this time, the etching rate of the component B target material is relatively high, and the etching rate of the component A target material 5 is relatively low. As a result, the ruthenium content of the sputtered film is lower than the cobalt content. Thus, by periodically adjusting the position of the magnet group, the composition ratio of the formed film can be controlled, for example, the content of ruthenium and cobalt can be gradually changed from 40%:60% to 60%:40%.

[0039] The ruthenium-cobalt target provided by the present invention can form thin films with compositional gradients by directly adjusting the magnetic field position during the sputtering process, eliminating the need for target replacement, reducing production costs, and improving production efficiency. Furthermore, the ruthenium-cobalt target enables a more stable sputtering process, contributing to improved film uniformity and performance.

[0040] The present invention demonstrates how to form compositionally gradient thin films using two ruthenium-cobalt alloy targets with different composition ratios and periodically adjusting the position of a magnet assembly. In practical applications, this method can effectively improve the reliability and stability of the film and reduce the target replacement issues associated with traditional methods, thereby significantly improving production efficiency and reducing costs. These embodiments provide an effective and feasible technical solution suitable for thin film fabrication for various microelectronic devices.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ruthenium-cobalt target for forming a composition gradient thin film, characterized in that: The target material unit comprises a target material unit and a back plate. The target material unit has different ruthenium-cobalt ratios. The target material unit is prepared by uniformly mixing ruthenium powder and cobalt powder according to different atomic ratios, molding them, and then hot isostatic pressing and sintering. The target material units with two different composition ratios are alternately spliced and fixed on the back plate to form the ruthenium-cobalt target material.

2. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 1, characterized in that: The purity of the ruthenium powder and the cobalt powder is both above 99.99%.

3. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 1, characterized in that: The content of ruthenium or cobalt in the target material unit is not less than 20%.

4. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 1, characterized in that: The atomic ratios of ruthenium powder and cobalt powder used to prepare the target unit are 60-70:40-30 and 30-40:70-60.

5. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 4, characterized in that: The atomic ratios of ruthenium to cobalt in the two target units are 70:30 and 30:70, respectively.

6. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 1, characterized in that: The target unit is in the shape of a long strip.

7. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 6, characterized in that: The widths of the two long strip target units with different ruthenium and cobalt composition ratios are equal.

8. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 1, characterized in that: The two target unit materials are alternately spliced in sequence along the width direction, and the splicing gap is less than 1 mm.

9. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 8, characterized in that: The target unit is fixed to the upper surface of the backing plate by brazing.

10. The ruthenium-cobalt target for forming a composition gradient thin film according to claim 9, characterized in that: The back plate is made of non-magnetic material.

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