Method and apparatus for monitoring impurity content to improve material production efficiency

Abstract

The present invention provides a method and apparatus for monitoring impurity content, which can effectively measure the impurity content of a metal material and improve the efficiency of material production. [Solution] The present invention provides a method for monitoring impurity content to improve material production efficiency. The method for measuring impurity content includes: peeling off adsorbent impurities and oxides from the surface of a metal lump; dissolving the metal lump in a mixed solution of nitric acid and hydrochloric acid, but without dissolving the impurities in the metal lump, thereby generating a solution to be measured; passing the solution to be measured through a transparent channel; recording particle images of impurities in the solution to be measured in the transparent channel using an optical system; and analyzing the particle images using image recognition to obtain statistics on the concentration of impurities contained in a unit mass of the metal lump.

Description

Technical Field

[0001] The present invention relates to a measurement method and apparatus, and particularly to an impurity content monitoring method and an impurity content monitoring apparatus for improving material production efficiency.

Background Art

[0002] In semiconductor processes, chemical vapor deposition (CVD) and physical vapor deposition (PVD) are two common processes. In physical vapor deposition, a metal ingot is a common raw material in the physical vapor deposition process. When the metal ingot contains impurities, they will mix into the semiconductor device during the physical vapor deposition process, reducing the yield of the semiconductor device.

[0003] Currently, there is no effective detection method for the purity of metal ingot raw materials, and it is impossible to complete the establishment of control lines before manufacturing.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides an impurity content monitoring method for improving material production efficiency that can effectively measure the impurity content of metal materials.

[0005] The present invention provides an impurity content monitoring apparatus for improving material production efficiency that can effectively measure the impurity content of metal materials.

Means for Solving the Problems

[0006] One embodiment of the present invention provides a method for monitoring impurity content to improve material production efficiency. The method for measuring impurity content includes: peeling off adsorbent impurities and oxides from the surface of a metal lump; dissolving the metal lump in a mixed solution of nitric acid and hydrochloric acid, but without dissolving the impurities in the metal lump, thereby generating a solution to be measured; passing the solution to be measured through a transparent channel; recording particle images of the impurities in the solution to be measured in the transparent channel using an optical system; and analyzing the particle images using image recognition to obtain statistics on the concentration of impurities contained in a unit mass of the metal lump.

[0007] One embodiment of the present invention provides an impurity content monitoring device that improves material production efficiency. The impurity content measuring device includes a transparent channel, an optical system, and a processor. The transparent channel is used to pass a liquid to be measured through, which is a mixed solution of nitric acid and hydrochloric acid, in which the metal mass dissolves but the impurities in the metal mass do not. The optical system is used to record particle images of the impurities in the liquid to be measured in the transparent channel. The processor is used to analyze the particle images using image recognition and thereby compile statistics on the concentration of impurities contained in a unit mass of the metal mass. [Effects of the Invention]

[0008] In the impurity content monitoring method and apparatus for improving material production efficiency according to embodiments of the present invention, a mixed solution of nitric acid and hydrochloric acid is used to dissolve the metal mass, but the impurities in the metal mass do not dissolve, generating a solution to be measured. Furthermore, particle images are analyzed using image recognition, thereby obtaining statistics on the concentration of impurities contained in a unit mass of the metal mass. For this reason, the impurity content measurement method and apparatus for improving material production efficiency according to embodiments of the present invention can effectively measure the impurity content of metal materials. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional diagram illustrating one step of the flow of a method for monitoring impurity content to improve material production efficiency according to one embodiment of the present invention. [Figure 2]This is a schematic cross-sectional view illustrating another step in the flow of a method for monitoring impurity content to improve material production efficiency according to one embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view illustrating yet another step in the flow of a method for monitoring impurity content to improve material production efficiency according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Figures 1 to 3 are schematic cross-sectional diagrams illustrating the flow of an impurity content monitoring method for improving material production efficiency according to one embodiment of the present invention, and Figure 3 is also a schematic cross-sectional diagram of an impurity content monitoring device for improving material production efficiency according to one embodiment of the present invention. Referring to Figures 1 to 3, the impurity content monitoring method for improving material production efficiency according to this embodiment includes the following steps. First, as shown in Figure 1, the adsorbent impurities 110 and oxides 120 on the surface of the metal ingot 100 are removed to prevent the adsorbent impurities 110 and oxides 120 from affecting subsequent metal ingot 100 dissolution experiments. In this embodiment, the method for removing the adsorbent impurities 110 and oxides 120 on the surface of the metal ingot 100 includes physical or chemical methods. In this embodiment, the surface of the metal ingot 100 may be removed by dissolution and dried, without additional cleaning with chemicals. In this way, impurities generated on the surface due to contact with the outside environment (e.g., oxidation of air and water, or surface aggregation of organic substances) can be removed. Furthermore, this method can simplify the flow by reducing the number of experimental steps, thereby decreasing the possibility of introducing contaminants.

[0011] Next, as shown in Figure 2, the metal lump 100 is dissolved in the mixed solution 200 of nitric acid and hydrochloric acid, but the impurities in the metal lump 100 do not dissolve, generating the solution to be measured 60 (for example, as shown in Figure 3). In this embodiment, the molar ratio of nitric acid to hydrochloric acid in the mixed solution 200 is within the range of 1 to 4. In this embodiment, the method for monitoring impurity content to improve material production efficiency may optionally include diluting the aqueous solution obtained after dissolving the metal lump 100 in the mixed solution 200 with water to obtain the solution to be measured 60 with N times the volume, where N is greater than 1 and 4 or less. Alternatively, in yet another embodiment, the aqueous solution obtained after dissolving the metal lump 100 in the mixed solution 200 may be used directly as the solution to be measured 60 without dilution. In this embodiment, the mixed solution 200 is sufficient to dissolve most of the metal lump 100 and retains the particulate impurity form, which is useful for detecting and observing fine contaminants in particulate form using image-based methods. Furthermore, compared to aqua regia preparations, reverse aqua regia (i.e., where the number of moles of nitric acid is greater than the number of moles of hydrochloric acid) is milder, less corrosive to equipment, and reduces potential contamination caused by equipment erosion. In addition, the aforementioned dilution of the aqueous solution with water effectively avoids the precipitation of large amounts of salts that would render liquid detection impossible.

[0012] Subsequently, as shown in Figure 3, the liquid to be measured 60 is passed through the transparent channel 52. In this embodiment, the generation of bubbles can be prevented by filling the sample container 330 with the liquid to be measured 60 and filling it quickly at a flow rate of 1 ml / min to 10 ml / min (i.e., filling the transparent channel 52). Next, the flow rate of the liquid to be measured 60 passing through the transparent channel 52 is maintained within the range of 0.1 ml / min to 5 ml / min to ensure that impurities flow within a stable flow field. In this embodiment, the width W1 of the transparent channel 52 is in the range of 10 micrometers to 200 micrometers, or in the range of 200 micrometers to 800 micrometers.

[0013] Then, the optical system 400 records an image of the impurity particles in the liquid 60 to be measured in the transparent channel 52. In this embodiment, the optical system 400 may be instructed to search for the optimal focal position within a distance of 9 to 180 micrometers or 180 to 720 micrometers within the width W1 range of the transparent channel 52. That is, if the width W1 is 10 to 200 micrometers or 200 to 800 micrometers, the optimal focal position is searched within a distance range of 90% of the width W1 in both cases.

[0014] Subsequently, the particle image is analyzed using image recognition to obtain statistics on the concentration of impurities contained in a unit mass of the metal block 100. In this embodiment, this step may be completed by the processor 510. Furthermore, in this embodiment, the step of analyzing the particle image using image recognition achieves feature classification by analyzing the contours of the impurity particles using an image recognition algorithm, thereby avoiding duplicate counting of particles attached to the transparent channel.

[0015] In this embodiment, the impurity content monitoring method for improving material production efficiency may further include preparing for the next measurement by replacing the transparent channel 52 with a new one.

[0016] The impurity content monitoring device 300 for improving the material production efficiency of this embodiment includes a transparent channel 52, an optical system 400, and a processor 510. The transparent channel 52 is used to allow the liquid to be measured 60 to pass through, and the liquid to be measured 60 is a mixed solution 200 of nitric acid and hydrochloric acid in which the metal lump 100 dissolves, but the impurities in the metal lump 100 do not dissolve. The optical system 400 is used to record particle images of the impurities in the liquid to be measured 60 in the transparent channel 52. The processor 510 is used to analyze the particle images using image recognition and thereby obtain statistics on the concentration of impurities contained in a unit mass of the metal lump 100.

[0017] In this embodiment, the optical system 400 includes a light source 410, a spatial light modulator 420, an objective lens 430, a spatial filter 440, and an array-type optical sensor 450. The light source 410 is used to emit a light beam 412. The spatial light modulator 420 is positioned in the path of the light beam 412 and is used to modulate the light beam 412. In this embodiment, the light source 410 is, for example, a superluminescent diode (SLD) which can avoid laser speckle interference. In this embodiment, the spatial light modulator 420 is, for example, a reflective spatial light modulator which controls the phase, polarization, and intensity by forming a 45-degree angle with the incident light beam 412. In this embodiment, the spatial light modulator 420 is, for example, an LCOS panel (liquid-crystal-on-silicon panel) or a digital micro-mirror device (DMD). Furthermore, in this embodiment, at least one achromatic collimator 460 may be provided in the path of the light beam 412 between the light source 410 and the spatial light modulator 420, which is used to ensure the intensity of the light beam 412 and to increase the signal intensity.

[0018] The transparent channel 52 is located on the path of the light beam 412 modulated by the spatial light modulator 420. The transparent channel 52 is used as an observation stage for impurity particles, and the sample is restricted to near the channel surface by sheath flow. In this embodiment, the transparent channel 52 is a replaceable transparent channel, which allows for convenient multiple measurements.

[0019] The objective lens 430 is positioned on the path of the light beam 412 from the transparent channel 52. In this embodiment, the objective lens 430 is, for example, an infinity-corrected objective lens and is used as an imaging lens to modulate the light wavefront of the light beam 412. The spatial filter 440 is positioned on the path of the light beam 412 from the objective lens 430 and is used to filter higher-order diffraction and improve the signal-to-noise ratio. In this embodiment, the spatial filter 440 includes a first lens 442, a pinhole plate 444 (which has one light-transmitting pinhole), and a second lens 446, which are sequentially positioned on the path of the light beam 412. In one embodiment, the focal lengths of the first lens 442 and the second lens 446 are, for example, 25 millimeters and 55 millimeters, respectively. The array-type photosensor 450 is positioned on the path of the light beam 412 from the spatial filter 440 and can significantly increase the sampling rate per step. In this embodiment, the array-type optical sensor 450 is, for example, a complementary metal oxide semiconductor (CMOS) image sensor.

[0020] In the impurity content monitoring method and impurity content monitoring device 300 for improving material production efficiency of this embodiment, the metal ingot 100 is dissolved using a mixed solution 200 of nitric acid and hydrochloric acid, but the impurities in the metal ingot 100 do not dissolve, generating the liquid to be measured 60. Furthermore, particle images are analyzed using image recognition, thereby obtaining statistics on the concentration of impurities contained in the unit mass of the metal ingot 100. For this reason, the impurity content monitoring method and impurity content monitoring device 300 for improving material production efficiency of this embodiment can effectively measure the impurity content of metal materials.

[0021] In this embodiment, the impurity content monitoring device 300 for improving material production efficiency further includes a transparent flow path device 310, a particle size sorting device 320, a sample container 330 with a conical bottom, a three-way pipeline switching valve 340, a pump 350, and an air particle filter 360. The transparent flow path device 310 includes a transparent flow path 52. The particle size sorting device 320 is provided upstream of the transparent flow path device 310. The sample container 330 is provided upstream of the transparent flow path device 310. In this embodiment, the sample container 330 is provided upstream of the particle size sorting device 320. The three-way pipeline switching valve 340 is provided downstream of the transparent flow path device 310. The pump 350 is provided downstream of the three-way pipeline switching valve 340 and is used for liquid delivery of the fluid. The air particle filter 360 is connected to the sample container 330.

[0022] In this embodiment, the sample container 330 includes a liquid level detector 332. Further, the impurity content monitoring device 300 for improving material production efficiency further includes a liquid filling detector 370 provided downstream of the transparent flow path device 310. The measured liquid 60 may flow through the liquid inlet of the sample container 330, the sample container 330, the particle size sorting device 320, the transparent flow path device 310, and the liquid filling detector 370 in sequence. In this embodiment, the bottom of the sample container 330 is conical to ensure that sediment particles in the sample can also be detected. In one embodiment, the conical bottom has an inclination angle of 10 degrees to 45 degrees with respect to the horizontal plane as shown in FIG. 3, but the present invention is not limited thereto. The liquid filling detector 370 can ensure that the transparent flow path 52 (for example, a micro flow path) is filled with the measured liquid 60 and is not affected by bubbles.

[0023] Furthermore, when the array-type optical sensor 450 detects an image of the transparent flow path 52, the pump 350 extracts the measured liquid 60 from the liquid filling detector 370, and the three-way pipeline switching valve 340 is arranged to prevent the measured liquid 60 from flowing out from the liquid outlet 70. After the array-type optical sensor 450 detects an image of the transparent flow path 52, the pump 350 discharges the measured liquid 60 from the liquid outlet 70, and the three-way pipeline switching valve 340 is arranged to prevent the sample from flowing upstream to the liquid filling detector 370.

[0024] In one embodiment, the processor 510 is, for example, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a programmable controller, a programmable logic device (PLD), or other similar device, or a combination of these devices, and the present invention is not limited thereto. Also, in one embodiment, each function of the processor 510 may be implemented as a plurality of program codes. These program codes are stored in a memory and executed by the processor 510. Alternatively, in one embodiment, each function of the processor 510 may be implemented as one or more circuits. The present invention is not limited to implementing each function of the processor 510 in a software or hardware manner.

[0025] To summarize the above, in the impurity content monitoring method and the impurity content monitoring device for improving the material production efficiency of the embodiments of the present invention, the metal block dissolves in a mixed solution of nitric acid and hydrochloric acid, but the impurities in the metal block do not dissolve to generate a measurement liquid, and particle images are analyzed using image recognition, thereby obtaining a statistic of the concentration of impurities contained in the unit mass of the metal block. Therefore, the method and device for measuring the impurity content for improving the material production efficiency of the embodiments of the present invention can effectively measure the impurity content of metal materials.

Industrial Applicability

[0026] The impurity content monitoring method and the impurity content monitoring device for improving the material production efficiency of the present invention can be used to measure the impurity content of materials.

Explanation of Signs

[0027] 52: Transparent flow path 60: Measurement liquid 70: Liquid outlet 100: Metal lump 110: Adsorbent impurities 120: Oxides 200: Mixed solution 300: Impurity content monitoring device to improve material production efficiency 310: Transparent flow channel device 320: Particle size sorting device 330: Sample container 332: Liquid level detector 340: Three-way pipe switching valve 350: Pump 360: Air Particle Filter 370: Liquid filling detector 400:Optical system 410: Light source 412: Light beam 420: Spatial Light Modulator 430: Objective lens 440: Spatial Filter 442: First lens 444: Pinhole plate 446: Second lens 450: Array-type optical sensor 460: Achromatic collimator 510: Processor W1: Width

Claims

1. To remove adsorbent impurities and oxides from the surface of the metal mass, The metal mass dissolves in a mixed solution of nitric acid and hydrochloric acid, but the impurities in the metal mass do not dissolve, thus forming the solution to be measured. The liquid to be measured is passed through a transparent channel, The optical system records an image of the impurity particles in the liquid to be measured in the transparent channel, The particle image is analyzed using image recognition, and the statistics of the concentration of the impurities contained in a unit mass of the metal mass are obtained from this analysis. including, A method for monitoring impurity content to improve material production efficiency.

2. The method for removing adsorbent impurities and oxides from the surface layer of the metal mass includes physical or chemical methods. A method for monitoring impurity content to improve the material production efficiency described in claim 1.

3. The molar ratio of nitric acid to hydrochloric acid in the aforementioned mixed solution is within the range of 1 to 4. A method for monitoring impurity content to improve the material production efficiency described in claim 1.

4. The aqueous solution obtained after dissolving the metal mass in the aforementioned mixed solution is diluted with water to obtain the measurement solution in N times its original volume. It further includes, Here, N is greater than 1 and less than or equal to 4. A method for monitoring impurity content to improve the material production efficiency described in claim 1.

5. The width of the transparent channel is in the range of 10 micrometers to 200 micrometers, or in the range of 200 micrometers to 800 micrometers. A method for monitoring impurity content to improve the material production efficiency described in claim 1.

6. Maintain the flow rate of the liquid to be measured through the transparent channel within the range of 0.1 ml / min to 5 ml / min. This also includes, A method for monitoring impurity content to improve the material production efficiency described in claim 1.

7. The optical system is made to search for the optimal focal position within a distance of 9 micrometers to 180 micrometers, or 180 micrometers to 720 micrometers, within the width range of the transparent channel. This also includes, A method for monitoring impurity content to improve the material production efficiency described in claim 1.

8. The step of analyzing the particle image using image recognition includes achieving feature classification by analyzing the contours of the impurity particles using an image recognition algorithm and avoiding duplicate counting of the particles adhering to the transparent channel. A method for monitoring impurity content to improve the material production efficiency described in claim 1.

9. By replacing it with a new transparent channel, we prepare for the next measurement. This also includes, A method for monitoring impurity content to improve the material production efficiency described in claim 1.

10. A transparent channel is used to allow the liquid to be measured to pass through a mixed solution of nitric acid and hydrochloric acid, which dissolves the metal mass but does not dissolve the impurities within the metal mass. An optical system used to record a particle image of the impurities in the liquid to be measured in the transparent channel, A processor and including, An impurity content monitoring device that improves material production efficiency.

11. The liquid to be measured is produced by dissolving the metal mass in the mixed solution, then diluting the resulting aqueous solution with water to increase its volume by N times, where N is greater than 1 and less than or equal to 4. An impurity content monitoring device for improving the material production efficiency described in claim 10.

12. The width of the transparent channel is in the range of 10 micrometers to 200 micrometers, or in the range of 200 micrometers to 800 micrometers. An impurity content monitoring device for improving the material production efficiency described in claim 10.

13. Maintain the flow rate of the liquid to be measured through the transparent channel within the range of 0.1 ml / min to 5 ml / min. An impurity content monitoring device for improving the material production efficiency described in claim 10.

14. The optical system is used to search for the optimal focal position within a distance of 9 micrometers to 180 micrometers, or within a distance of 180 micrometers to 720 micrometers, within the width range of the transparent channel. An impurity content monitoring device for improving the material production efficiency described in claim 10.

15. The processor is used to analyze the contours of the impurity particles using an image recognition algorithm in order to achieve feature classification and avoid duplicate counting of the particles adhering to the transparent channel. An impurity content monitoring device for improving the material production efficiency described in claim 10.

16. The transparent channel is a replaceable transparent channel. An impurity content monitoring device for improving the material production efficiency described in claim 10.

17. The optical system described above is A light source used to emit a light beam, A spatial light modulator is positioned on the path of the light beam and used to modulate the light beam, wherein the transparent channel is located on the path of the light beam modulated by the spatial light modulator, An objective lens is positioned on the path of the light beam from the transparent channel, A spatial filter is placed on the path of the light beam from the objective lens, An array of optical sensors is positioned on the path of the light beam from the spatial filter. including, An impurity content monitoring device for improving the material production efficiency described in claim 10.

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