A method for measuring the etching of a runway on a sputtering target.

Abstract

This invention discloses a method for measuring the etching runway of a sputtered target, comprising: capturing a radial image of the sputtered surface of the target after sputtering using a confocal microscope with a three-dimensional imaging mode; processing the captured three-dimensional image using image processing software, performing steps such as leveling, filling, and extracting profiles to obtain the contour curve of the etched runway; and performing geometric measurements such as distance, height, and area on the contour curve to obtain geometric dimensional parameters such as the maximum width of the runway, the circumference diameter at the center of the runway, the sputtering cross-sectional area, the deepest point of the runway, and the sputtered etching volume of the target. Because the measurement is performed using a confocal microscope, it has advantages such as convenient operation and clear image details, enabling the acquisition of a three-dimensional true-color image of the sputtered etched surface of the target. The measurement does not cause any damage to the sputtered surface of the target, making it particularly suitable for micron-level measurements of the sputtered etched runway and geometric parameters of small-sized targets of 4 inches and below.

Description

Technical Field

[0001] This invention relates to the field of sputtering target size measurement technology, and in particular to a method for measuring the etched runway of a sputtering target. Background Technology

[0002] Magnetron sputtering is a key process commonly used in semiconductors, magnetic recording storage, optics, solar energy, and information display. Especially in high-end advanced manufacturing, sputtering targets are typically high-purity rare and precious metals, requiring strict control over target breakdown life. Due to the structure of the magnetron sputtering source, the surface morphology of the etched target is non-uniform. The depth of the deepest part of the sputtering runway determines the target's lifespan, and the sputtering etching volume determines its utilization efficiency. Therefore, accurate measurement and effective monitoring of the etched surface of the sputtering target are crucial aspects of sputtering target dimensional measurement technology.

[0003] CN102521445A discloses a simulation calculation method for the etching morphology of a copper target in a magnetron sputtering device. The method includes: obtaining the horizontal component of the magnetic field strength of the magnetron on the target surface through ANSYS simulation or measurement using a three-dimensional gaussmeter; establishing an effective magnetic field data matrix after polynomial fitting; and obtaining the etching track matrix. Based on the actual structure and motion principle of the magnetron, the method calculates the trajectory equation of the center point of the magnet assembly. It establishes the target etching matrix and obtains the target etching matrix at the specified step length. The target etching time t is discretized to obtain the target etching matrix after etching time t. Through matrix operations, the required parameters or graphics are obtained, such as the three-dimensional morphology of the target etching, the target etching curve, the etching track graphic, the motion trajectory graphic, and the target utilization rate. This simulation method can be used to verify the quality of the designed parameters or to further optimize the magnetron parameters during magnetron design. However, this invention is a theoretical simulation calculation method, and the calculation process is complex, requiring the measurement of the magnetic field strength on the target surface and the magnetron structure as prerequisites for calculation.

[0004] CN103322900A discloses an etching measurement device and method for a target material. The measurement device includes a guide rail, a positioning component, and an etching depth measuring component. The etching depth measuring component is mounted on the guide rail in a manner that allows relative movement with respect to the guide rail. The positioning component is located on both sides of the guide rail to support it. Thus, the guide rail is fixed above the surface of the target material by the positioning component, and the etching depth measuring component is moved to measure the etching depth at any point on the surface of the target material. This invention directly measures the etching depth measurement data from the etching depth measuring component; however, the testing device requires a combination of multiple components, and the components directly contact the target material surface during measurement, which can affect the target material surface.

[0005] CN108180814A discloses an apparatus for measuring the etching depth of an etched surface of a target material. The apparatus includes a collection unit that replicates at least a portion of the etched surface of a planar target material to form a simulated surface. The unevenness of the simulated surface is identical to that of the etched surface contacted by the measuring needle in the collection unit. Therefore, the maximum depth of the indentation on the etched surface contacted by the measuring needle can be measured by contacting the measuring unit with the measuring end of the measuring needle at the point of maximum protrusion on the simulated surface. This invention can accurately measure the etching depth at different locations on the target material; however, the direct contact of the measuring needle with the target surface can affect the surface, and the testing range is limited by the requirement that the length of the measuring needle must be greater than or equal to the thickness of the target material.

[0006] CN215572621U discloses a measuring device for sputtering channels of a target material, comprising: a base with a detection plane for placing the target material to be tested on its upper surface; a vertical support connected to the base and erected on the detection plane; a horizontal support connected to the top of the vertical support and mounted above the detection plane, the horizontal support having a horizontally extending guide rail; a depth measuring device with its upper end slidably connected to the guide rail and its lower end being an elastically retractable measuring head; the depth measuring device further includes a signal transmitter electrically connected to the measuring head for transmitting the data measured by the measuring head to a back-end system. This measuring device has a simple structure and low cost, but its testing accuracy is not high enough, only obtaining the depth data of the sputtering channel.

[0007] In summary, the current methods for measuring the etched morphology of sputtered target surfaces in the target manufacturing industry mainly rely on coordinate measuring machines, digital micrometers, or self-made measuring devices. However, these methods lack sufficient measurement accuracy, have high equipment costs, and involve cumbersome procedures. Furthermore, they struggle to accurately obtain the three-dimensional morphology of the etched target surface and calculate the cross-sectional area of ​​the etched area. Using common confocal microscopes for optical measurement can achieve precise three-dimensional measurement of the etched surface and runway of sputtered targets, making it an effective means for micron-level measurement of small-sized targets. Summary of the Invention

[0008] The technical problem this invention aims to solve is to overcome the aforementioned shortcomings and provide a method for measuring the etching runway of sputtered targets. The basic concept of this method is as follows: First, a confocal microscope with a three-dimensional imaging mode is used to capture a radial image of the sputtered surface of the target. Then, image processing software is used to process the captured three-dimensional image, performing steps such as leveling, filling, and profile extraction to obtain the contour curve of the etched runway. Finally, geometric measurements such as distance, height, and area are performed on the contour curve to obtain geometric dimensional parameters such as the maximum runway width, the circumference diameter at the runway center, the sputtering cross-sectional area, the deepest point of the runway, and the sputtered etching volume of the target. Because the measurement is performed using a confocal microscope, it has advantages such as convenient operation and clear image details. It can obtain a three-dimensional true-color image of the sputtered etched surface of the target, and the measurement does not cause any damage to the sputtered surface of the target. It is particularly suitable for the micron-level measurement of the sputtered etched runway and geometric parameters of small-sized targets of 4 inches and below.

[0009] Specifically, the method for measuring the etching runway on a sputtering target according to the present invention includes the following steps:

[0010] (1) A confocal microscope with a three-dimensional imaging mode was used to capture radial images of the sputtered surface of the target material after sputtering;

[0011] (2) Use image processing software to process the captured three-dimensional image, and perform steps such as leveling, filling, and extracting profiles in sequence to obtain the contour curve of the target etching track.

[0012] (3) Perform geometric measurements such as distance, height, and area on the contour curve to obtain geometric dimensional parameters such as the maximum width of the runway, the circumference diameter at the center of the runway, the sputtering cross-sectional area, the deepest point of the runway, and the sputtering and etching volume of the target material.

[0013] As a preferred technical solution of the present invention, in step (2), the leveling method is the least squares plane method, and a subtraction operation is used to make the leveling speed faster.

[0014] As a preferred technical solution of the present invention, in step (2), when filling non-measured points, a smooth shape calculated from the nearest value is used to fill, so as to ensure that the contour curve is continuous and smooth.

[0015] As a preferred technical solution of the present invention, in step (2), a cross-section is extracted from the captured three-dimensional image to obtain a contour curve.

[0016] As a preferred technical solution of the present invention, a metering filter is used to filter and smooth the contour curve. The filter type is a Gaussian filter, and the cutoff point can be arbitrarily set within the range of 0.001 to 10 mm.

[0017] As a preferred technical solution of the present invention, in step (3), the distance of the contour curve is measured to measure the horizontal distance between the inner and outer edges and the center of the target material runway, so as to obtain the maximum width of the runway and the circumference diameter at the center of the runway.

[0018] As a preferred technical solution of the present invention, in step (3), the line connecting the center of the target surface and the two end points is marked as the baseline, and the area and maximum depth of the hole below the baseline are measured to obtain the sputtering cross-sectional area of ​​the target material and the maximum depth of the runway.

[0019] As a preferred technical solution of the present invention, the circumference of the runway center can be calculated based on the circumference diameter at the center of the runway, and the sputtering etching volume of the target surface can be obtained by multiplying it by the average value of the sputtering cross-sectional area.

[0020] As a preferred technical solution of the present invention, in step (1), a confocal microscope is used to determine the Z-axis shooting range in the radial runway area, anti-sputtering area and unsputtered area of ​​the sputtered surface of the target material, and the number of images taken in a single shooting area is not less than 100 and not more than 1000.

[0021] As a preferred technical solution of the present invention, when using a confocal microscope for imaging, the objective lens magnification is selected to be 5 to 50 times, and the eyepiece magnification is 10 times. As a preferred technical solution of the present invention, the above-mentioned etching raceway measurement method is performed by imaging and measurement using a confocal microscope, which has the advantages of convenient operation and clear image morphology details. It can obtain a three-dimensional true-color image of the sputtered etched surface of the target material, and the measurement will not cause any damage to the sputtered surface of the target material. It is especially suitable for the micron-level measurement of sputtered etched raceways and geometric parameters of small-sized targets of 4 inches and below.

[0022] The beneficial effects of this invention include:

[0023] (1) The present invention uses a confocal microscope for imaging and measurement, which has the advantages of convenient operation and clear image morphology details. The three-dimensional true color image of the sputtered and etched surface of the target material can be obtained by image processing software.

[0024] (2) The measurement method of the present invention does not directly contact the sputtering surface of the target material, and will not cause any damage to the sputtering surface of the target material. This measurement method is particularly suitable for the micron-level measurement of sputtering etching runways and geometric parameters of small-sized targets of 4 inches and below. Attached Figure Description

[0025] Figure 1 This is a flowchart of the measurement method for etching a runway on a sputtering target according to the present invention.

[0026] Figure 2 This is a schematic diagram of the etching profile curve of the sputtering target surface measured in Example 1. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] This embodiment provides a method for measuring the etched runway on a sputtering target, the specific steps of which include:

[0030] (1) A confocal microscope with a three-dimensional shooting mode was used to determine the Z-axis shooting range of the radial raceway area, anti-sputtering area and unsputtered area of ​​the sputtered target surface. The number of images taken in the shooting area was 1000, the objective lens magnification was 5x and the eyepiece magnification was 10x. The radial images of the sputtered target surface after sputtering were taken.

[0031] (2) Use image processing software to process the captured three-dimensional image, and perform steps such as leveling, filling and extracting profiles in sequence. The leveling method is the least squares plane method, and subtraction is used to make the leveling speed faster. When filling non-measured points, use smooth shapes calculated from neighboring values ​​to fill them, so as to ensure that the contour curve is continuous and smooth. Extract the profile from the captured three-dimensional image to obtain the contour curve.

[0032] (3) Use a metering filter to filter and smooth the contour curve. The filter type is Gaussian filter and the cutoff point is set to 0.08mm.

[0033] (4) The distance of the contour curve is measured to obtain the horizontal distance between the inner and outer edges and the center of the target track. The maximum width of the track and the circumference diameter at the center of the track can be obtained.

[0034] (5) Mark the line connecting the center of the target surface and the two ends as the baseline. Measure the area and maximum depth of the hole below the baseline to obtain the sputtering cross-sectional area of ​​the target material and the maximum depth of the runway.

[0035] (6) The circumference of the runway center can be calculated from the circumference diameter at the center of the runway. Multiplying it by the average sputtering cross-sectional area gives the sputtering etching volume of the target surface.

[0036] Example 2

[0037] This embodiment provides a method for measuring the etched runway on a sputtering target, the specific steps of which include:

[0038] (1) A confocal microscope with a three-dimensional shooting mode was used to determine the Z-axis shooting range of the radial raceway area, anti-sputtering area and unsputtered area of ​​the sputtered target surface. The number of images taken in the shooting area was 500, the objective lens magnification was 20x and the eyepiece magnification was 10x. The radial images of the sputtered target surface after sputtering were taken.

[0039] (2) Use image processing software to process the captured three-dimensional image, and perform steps such as leveling, filling and extracting profiles in sequence. The leveling method is the least squares plane method, and subtraction is used to make the leveling speed faster. When filling non-measured points, use smooth shapes calculated from neighboring values ​​to fill them, so as to ensure that the contour curve is continuous and smooth. Extract the profile from the captured three-dimensional image to obtain the contour curve.

[0040] (3) Use a metering filter to filter and smooth the contour curve. The filter type is Gaussian filter and the cutoff point is set to 0.8mm.

[0041] (4) The distance of the contour curve is measured to obtain the horizontal distance between the inner and outer edges and the center of the target track. The maximum width of the track and the circumference diameter at the center of the track can be obtained.

[0042] (5) Mark the line connecting the center of the target surface and the two ends as the baseline. Measure the area and maximum depth of the hole below the baseline to obtain the sputtering cross-sectional area of ​​the target material and the maximum depth of the runway.

[0043] (6) The circumference of the runway center can be calculated from the circumference diameter at the center of the runway. Multiplying it by the average sputtering cross-sectional area gives the sputtering etching volume of the target surface.

[0044] Example 3

[0045] This embodiment provides a method for measuring the etched runway on a sputtering target, the specific steps of which include:

[0046] (1) A confocal microscope with a three-dimensional shooting mode was used to determine the Z-axis shooting range of the radial runway area, anti-sputtering area and unsputtered area of ​​the sputtered target surface. 100 images were taken in the shooting area, with an objective lens magnification of 50x and an eyepiece magnification of 10x. The radial images of the sputtered target surface after sputtering were taken.

[0047] (2) Use image processing software to process the captured three-dimensional image, and perform steps such as leveling, filling and extracting profiles in sequence. The leveling method is the least squares plane method, and subtraction is used to make the leveling speed faster. When filling non-measured points, use smooth shapes calculated from neighboring values ​​to fill them, so as to ensure that the contour curve is continuous and smooth. Extract the profile from the captured three-dimensional image to obtain the contour curve.

[0048] (3) Use a metering filter to filter and smooth the contour curve. The filter type is Gaussian filter and the cutoff point is set to 8mm.

[0049] (4) The distance of the contour curve is measured to obtain the horizontal distance between the inner and outer edges and the center of the target track. The maximum width of the track and the circumference diameter at the center of the track can be obtained.

[0050] (5) Mark the line connecting the center of the target surface and the two ends as the baseline. Measure the area and maximum depth of the hole below the baseline to obtain the sputtering cross-sectional area of ​​the target material and the maximum depth of the runway.

[0051] (6) The circumference of the runway center can be calculated from the circumference diameter at the center of the runway. Multiplying it by the average sputtering cross-sectional area gives the sputtering etching volume of the target surface.

[0052] Using the preferred technical solution of this invention and the solutions of embodiments 1 to 3 above, the etching raceway measurement of sputtering targets yields a smooth and clear etching profile curve on the target surface, as shown in the figure. Figure 2 As shown, the method of this invention can directly measure parameters such as the maximum width of the runway, the circumference diameter at the center of the runway, the sputtering cross-sectional area, and the maximum depth of the runway. It can also calculate parameters such as the target sputtering etching volume. The measurement results are accurate, and the calculated results closely approximate the actual situation. The measurement process does not involve contact with the target sputtering surface, enabling rapid, non-destructive, and precise measurements. The accuracy of the obtained etching profile curves and etching geometric parameters is far superior to existing technologies.

[0053] The applicant declares that the detailed process equipment and process flow of this invention are illustrated through the above embodiments, but this invention is not limited to the above detailed process equipment and process flow, that is, it does not mean that this invention must rely on the above detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, additions of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

Claims

1. A method for measuring the etching of a runway on a sputtering target, characterized in that, Includes the following steps: Step (1): Use a confocal microscope with a three-dimensional imaging mode to capture radial images of the sputtered surface of the target material after sputtering; Step (2): Use image processing software to process the captured three-dimensional image, and perform leveling, filling and profile extraction in sequence to obtain the contour curve of the target etching track. The leveling method is the least squares plane method, and the filling is performed by using a smooth shape calculated from the nearest value when filling non-measurement points. Step (3) Perform geometric measurements on the distance, height, and area of ​​the contour curve to obtain the maximum width of the runway, the circumference diameter at the center of the runway, the sputtering cross-sectional area, the maximum depth of the runway, and the sputtering etching volume of the target material. Step (4): Calculate the circumference of the runway center based on the circumference diameter at the center of the runway, and multiply it by the average sputtering cross-sectional area to obtain the sputtering etching volume value of the target surface.

2. The method for measuring the etching runway of a sputtering target according to claim 1, characterized in that: In step (2), the profile is extracted from the captured 3D image to obtain the contour curve.

3. The method for measuring the etching runway on a sputtering target according to claim 2, characterized in that: The contour curve is filtered and smoothed using a metering filter. The filter type is a Gaussian filter, and the cutoff point can be set arbitrarily within the range of 0.001~10mm.

4. The method for measuring the etched runway on a sputtering target according to claim 1, characterized in that: In step (3), the distance of the contour curve is measured to measure the horizontal distance between the inner and outer edges and the center of the target track, so as to obtain the maximum width of the track and the circumference diameter at the center of the track.

5. The method for measuring the etching runway of a sputtering target according to claim 1, characterized in that: In step (3), the line connecting the center of the target surface and the two endpoints is marked as the baseline. The area and maximum depth of the hole below the baseline are measured to obtain the sputtering cross-sectional area of ​​the target material and the maximum depth of the runway.

6. The method for measuring the etched runway of a sputtering target according to any one of claims 1-5, characterized in that: In step (1), a confocal microscope is used to determine the Z-axis imaging range of the radial runway area, anti-sputtering area and unsputtered area of ​​the target sputtering surface, and several images are captured in a single imaging area.

7. The method for measuring the etching runway of a sputtering target according to any one of claims 1-5, characterized in that: When using a confocal microscope, select an objective lens with a magnification of 5 to 50 times and an eyepiece with a magnification of 10 times.

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