Apparatus and method for processing polishing slurry
The polishing slurry processing apparatus and method address the non-homogeneous particle size distribution in existing slurries by filtering out large and small particles, achieving improved polishing quality and slurry recycling.
Patent Information
- Application Number
- JP2024135534
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2026-02-27
AI Technical Summary
The existing polishing slurry compositions have non-homogeneous particle size distributions due to the presence of abrasive particles that are too large or too small, affecting the quality of chemical mechanical polishing processes.
A polishing slurry processing apparatus and method using a filtration unit to remove particles larger than a first dimension and a permeation unit to eliminate particles smaller than a second dimension, resulting in a homogenized particle size distribution.
The apparatus and method improve the quality of chemical mechanical polishing by homogenizing the particle size distribution, enhancing the polishing process efficiency and enabling the recycling of abrasive slurry.
Smart Images
Figure 2026032711000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a polishing slurry used in the field of chemical mechanical polishing, and more particularly to an apparatus and method for processing a polishing slurry. [Background technology]
[0002] Chemical mechanical polishing technology is widely used in polishing wafer thin plates, and is mainly performed by appropriately selecting and applying a polishing pad in accordance with a polishing slurry. In this process, a polishing plate equipped with the polishing pad is held facing the wafer thin plate, and the polishing pad is in contact with the surface of the wafer thin plate. The polishing pad and the wafer thin plate are moved relative to each other, and at the same time, the polishing process of the wafer thin plate is completed with the polishing slurry supplied between the polishing pad and the wafer thin plate. Summary of the Invention [Problem to be solved by the invention]
[0003] The polishing slurry is mainly composed of a stock solution containing an appropriate proportion of abrasive particles, of which the stock solution is prepared by mixing a concentrated solution composed of chemical components with a diluent. During polishing, the wafer thin plate is removed by the abrasive particles to form a polishing action, and the particle size of the abrasive particles directly affects the amount of the wafer thin plate removed by the abrasive particles, which controls the particle size range of each abrasive particle constituting the polishing slurry and helps to control the surface flatness of the wafer thin plate after polishing. However, among the many abrasive particles added to the stock solution, there is no lack of abrasive particles with particle sizes that are too large or too small, which may tend to homogenize the particle size distribution span of each abrasive particle in the polishing slurry, and help improve the quality of the polishing process.
[0004] SUMMARY OF THE INVENTION It is a primary object of the present invention to provide an apparatus and method for processing abrasive slurries. [Means for solving the problem]
[0005] To achieve the above objectives, the present invention adopts the following technical solutions:
[0006] A polishing slurry treatment device comprising a filtration unit, a permeation unit, a transport pipeline, and a control unit,
[0007] the transport pipeline connects the filtration unit and the permeation unit; the control unit is mainly composed of an electronic circuit, and the control unit electrically connects the filtration unit and the permeation unit, thereby controlling the filtration unit and the permeation unit;
[0008] The filtration unit is used to filter the polishing slurry derived from an external polishing slurry source, and removes a plurality of first particles having a particle size larger than a first dimension contained in the polishing slurry, and transports the filtered polishing slurry through the transport pipeline to the permeation unit;
[0009] the permeation unit includes a permeator, and an osmosis membrane is provided inside the permeator; one end of a first passage located on one side of the osmosis membrane is connected to a first pipeline, and the first pipeline is connected to the transport pipeline; the other end of the first passage is connected to a second pipeline, and the second pipeline is used to communicate with an external storage tank; one end of a second passage located on the other side of the osmosis membrane is connected to a third pipeline, and the third pipeline is used to communicate with an external raw liquid supply source; the other end of the second passage is connected to a fourth pipeline, and the fourth pipeline is used to communicate with an external storage tank;
[0010] As a result, the abrasive slurry passes from the first pipeline through the first passage and enters the second pipeline, and a large number of second particles contained in the abrasive slurry, whose particle size is smaller than the second dimension, permeate through the permeation membrane and enter the second passage, so that the raw liquid supplied from the raw liquid supply source passes from the third pipeline through the second passage and enters the fourth pipeline, and each of the second particles guided into the second passage passes through the fourth pipeline and enters the storage tank, characterized in that this is an abrasive slurry processing device.
[0011] 1. A processing method carried out using an abrasive slurry processing apparatus as described, comprising:
[0012] A processing method characterized by including, in sequence, an introduction step of abrasive slurry for guiding the abrasive slurry from the abrasive slurry source to enter the filtration unit; a sieving and filtering step for sieving and filtering the abrasive slurry using the filtration unit to eliminate a large number of first particles contained in the abrasive slurry whose particle size is larger than the first dimension; and a permeation and exclusion step for drawing the abrasive slurry that has passed through the sieving and filtering step into the permeation unit to eliminate at least a portion of the second particles contained in the abrasive slurry, thereby making the abrasive slurry mainly contain third particles whose particle size is between the first dimension and the second dimension, thereby obtaining the abrasive slurry with a homogenized particle size span. [Effects of the Invention]
[0013] The present invention can eliminate the first particles having a particle size larger than the first dimension from the abrasive slurry, and can also eliminate most or all of the second particles from the abrasive slurry, which tends to homogenize the particle size distribution span of the abrasive particles in the abrasive slurry, thereby improving the quality of the polishing process when the abrasive slurry is applied to perform a chemical mechanical polishing process, and the present invention can be used to process the prepared abrasive slurry, and can also be used to process the abrasive slurry containing chips recovered during the polishing process. [Brief explanation of the drawings]
[0014] [Figure 1] 1 is a system configuration diagram of a polishing slurry processing apparatus according to a preferred embodiment of the present invention; [Figure 2] 1 is an axial cross-sectional view of a penetrator according to a preferred embodiment of the present invention; [Figure 3] 1 is a diagram showing the state in which the infiltrator of the preferred embodiment of the present invention is used; [Figure 4] 10A and 10B are diagrams showing different usage states of the infiltrator of the preferred embodiment of the present invention. [Figure 5] 1 is a flowchart illustrating a processing method for abrasive slurry using a processing apparatus according to a preferred embodiment of the present invention. [Figure 6] FIG. 2 is a particle size distribution curve diagram of abrasive particles contained in the polishing slurry. DETAILED DESCRIPTION OF THE INVENTION
[0015] As shown in Figures 1 to 3, the polishing slurry processing device of the present invention comprises a filtration unit 10, a permeation unit 20, a transport pipeline 30, and a control unit 40, of which the transport pipeline 30 connects the filtration unit 10 and the permeation unit 20, and the control unit 40 is mainly composed of an electronic circuit, and the control unit 40 electrically connects the filtration unit 10 and the permeation unit 20, thereby controlling the filtration unit 10 and the permeation unit 20.
[0016] The filtration unit 10 is used to filter the polishing slurry 90 coming from an external polishing slurry source (not shown in the figure), removes a large number of first particles (not shown in the figure) whose particle size is larger than a first dimension contained in the polishing slurry 90, and transports the filtered polishing slurry 90 through the transport pipeline 30 to the penetration unit 20. The filtration unit 10 can be directly and uniquely derived from conventional technology applied by those skilled in the art in the field to which the present invention belongs, and since the filtration unit 10 is not necessarily related to the technical features of the present invention, a detailed description of the specific configuration of the filtration unit 10 will be omitted.
[0017] The permeation unit 20 includes a permeator 21, in which a permeation membrane 22 is provided inside the permeator 21, a first passage 23 is located on one side of the permeation membrane 22, and a second passage 24 is located on the other side of the permeation membrane 22. In this example, the permeation membrane 22 has a tubular structure, and is arranged to annularly surround the radial outer periphery of the first passage 23, and the second passage 24 is arranged to surround the radial outer side of the permeation membrane 22.
[0018] One end of the first passage 23 is connected to a first pipeline 25, the first pipeline 25 is connected to the transport pipeline 30, the other end of the first passage 23 is connected to a second pipeline 26, the second pipeline 26 is used to connect to an external storage tank (not shown in the figure), one end of the second passage 24 is connected to a third pipeline 27, the third pipeline 27 is used to connect to an external concentrate supply source (not shown in the figure), and the other end of the second passage 24 is connected to a fourth pipeline 28, the fourth pipeline 28 is used to connect to an external storage tank (not shown in the figure).
[0019] The storage tank is a type of container used to store the polishing slurry 90 after processing by the polishing slurry processing device of the present invention, and prepares the polishing slurry 90 to be subsequently used in chemical mechanical polishing. The stock solution supply source is a type of container used to store the stock solution 91. The stock solution 91 is a liquid prepared by mixing a concentrated solution composed of chemical components with a dilution liquid, and the stock solution 91 does not undergo the addition of abrasive particles that create a polishing action capable of removing wafer thin plates or substrates. The storage tank is a type of container used to store a slurry-like material formed by mixing the stock solution 91 and fine particles generated after processing by the penetration unit 20, and these particles may be the abrasive particles. The specific configurations of the storage tank, the stock solution supply source, and the storage tank are not particularly limited and are not necessarily related to the technical features of the present invention. Those skilled in the art to which the present invention pertains can directly select and use various existing containers as the storage tank, the stock solution supply source, and the storage tank.
[0020] The polishing slurry 90 used in chemical mechanical polishing is mainly composed of the stock solution 91 and an appropriate proportion of the abrasive particles. The particle size distribution curve of the abrasive particles is roughly as shown in Figure 6, with the horizontal axis representing the particle size of the abrasive particles and the vertical axis representing the number of the abrasive particles.
[0021] As shown in FIGS. 5 and 6, the processing method performed using the polishing slurry processing apparatus of the present invention includes the following steps, which are carried out in sequence.
[0022] In an abrasive slurry introducing step, the abrasive slurry 90 is directed from the abrasive slurry source to enter the filtration unit 10 .
[0023] In the sieving and filtering step, the polishing slurry 90 is sieved and filtered by the filtering unit 10 to remove a large number of the first particles having a particle size larger than the first size contained in the polishing slurry 90.
[0024] In the permeation and exclusion step, the polishing slurry 90 that has passed through the sieving and filtering step is drawn into the permeation unit 20, and some or all of the second particles 92 contained in the polishing slurry 90 are eliminated, so that the polishing slurry 90 mainly contains third particles 94 whose particle size is between the first dimension and the second dimension, thereby obtaining the polishing slurry 90 with a homogenized particle size span.
[0025] The present invention does not limit the specific numerical values of the first dimension and the second dimension, and the specific numerical values of the first dimension and the second dimension can be set in advance as needed, and the filtration unit 10 and the osmosis membrane 22 having corresponding standards can be selected in accordance with the set first dimension and second dimension.
[0026] The polishing slurry 90 passes from the first pipeline 25 through the first passage 23 and enters the second pipeline 26, and a large number of the second particles 92 contained in the polishing slurry 90, whose particle size is smaller than the second dimension, permeate through the permeation membrane 22 and enter the second passage 24, so that the raw liquid 91 supplied from the raw liquid supply source passes from the third pipeline 27 through the second passage 24 and enters the fourth pipeline 28, and each of the second particles 92 guided into the second passage 24 passes through the fourth pipeline 28 and enters the storage tank.
[0027] When the above-mentioned processing method is carried out using the abrasive slurry processing apparatus of the present invention to process the abrasive slurry 90, which is composed of the raw solution 91 to which an appropriate proportion of abrasive grains is added, the first particle, the second particle 92, and the third particle 94 are abrasive grains of different particle sizes.
[0028] The sieving and filtering step can be performed to remove the first particles having a particle size larger than the first dimension from the polishing slurry 90 using the filtering unit 10, and the permeation and exclusion step can be performed to remove most or all of the second particles 92 from the polishing slurry 90 using the permeation unit 20. The polishing slurry 90 is mainly composed of the raw solution 91 and the abrasive particles, and the majority of the particle size of each abrasive particle is the third particles 94 that are between the first dimension and the second dimension, which tends to homogenize the particle size distribution span of the abrasive particles in the polishing slurry 90, and therefore the quality of the polishing process when the polishing slurry 90 is applied to perform a chemical mechanical polishing process can be improved.
[0029] As shown in Figure 3, the flow direction of the polishing slurry 90 in the first passage 23 and the flow direction of the raw liquid 91 in the second passage 24 are opposite to each other, and as shown in Figure 4, the flow direction of the polishing slurry 90 in the first passage 23 and the flow direction of the raw liquid 91 in the second passage 24 may be the same direction, and Figure 3 should be interpreted as being merely illustrative and not limiting of the present invention.
[0030] The raw liquid 91 passes through the second passage 24, and the second particles 92 are guided to enter the storage tank, where the raw liquid 91 and the second particles 92 are mixed to form a different type of polishing slurry having abrasive particles of a different particle size distribution range, which is mainly composed of the raw liquid 91 and abrasive particles whose particle size is smaller than the second dimension.Therefore, the present invention makes it possible to recover the second particles 92 whose particle size is smaller than the second dimension and which are excluded from the polishing slurry 90 in the permeation exclusion step, and to apply it to a chemical mechanical polishing process, and it can be used as such a different type of polishing slurry to be used in a fine polishing process.
[0031] The sieving and filtering step is performed using the filtering unit 10, and the first particles excluded from the polishing slurry 90 can be similarly recovered, and by adding new stock solution 91 and preparing and blending it, it can be applied to a chemical mechanical polishing process and can be used as a polishing slurry for a relatively rough polishing process.
[0032] In the chemical polishing process, the portions of the wafer thin plate that are removed by the abrasive particles are crushed to form fine particle-like chips, which are detached from the surface of the wafer thin plate or the substrate in conjunction with the flow of the abrasive slurry 90 that accompanies the flow. These chips are crushed during the polishing process, and while performing the above-mentioned processing method, the numerical setting of the second dimension can be selected as needed, making it possible to remove at least the majority of the chips from the abrasive slurry 90, and the abrasive slurry 90 can be recycled in the chemical polishing process. In this case, the first particles, the second particles 92, and the third particles 94 are used to represent the abrasive particles or chips of different particle sizes.
[0033] By carrying out the processing method of the present invention, it is possible to remove the chips from the polishing slurry 90, reduce the sedimentation and accumulation of the chips when the polishing slurry 90 is circulated, and provide a conduit through which the polishing slurry 90 flows circulatoryly, thereby reducing the probability of the chips accumulating and forming clumps, which causes blocking, and helps to improve the quality and efficiency of the polishing process.
[0034] As shown in FIG. 1, the first pipeline 25 is provided with a first pump 252, which is used to pump the polishing slurry 90 through the first passage 23 and into the second pipeline 26, and the third pipeline 27 is provided with a third pump 272, which is used to pump the raw solution 91 through the second passage 24 and into the fourth pipeline 28. The control unit 40 electrically connects the first pump 252 and the third pump 272, and controls the operation of the first pump 252 and the third pump 272, thereby making the pressure in the second pipeline 26 greater than or equal to the pressure in the third pipeline 27.
[0035] In the permeation and removal step, the pressure of the polishing slurry 90 passing through the first passage 23 located on one side of the osmosis membrane 22 is made greater than the pressure of the second passage 24 located on the other side of the osmosis membrane 22, so that the second particles 92 permeate through the osmosis membrane 22 and enter the second passage 24, and the second particles 92 that have entered the second passage 24 do not pass through the osmosis membrane 22 and enter the first passage 23, thereby preventing reverse permeation.
[0036] A second pump 262 is provided in the second pipeline 26, and is used to pump the polishing slurry 90 through the first passage 23 and to pump the polishing slurry 90 containing a plurality of third particles 94 whose particle sizes are between the first dimension and the second dimension to the storage tank.A fourth pump 282 is provided in the fourth pipeline 28, and is used to pump the stock solution 91 containing a plurality of second particles 92 through the second passage 24 and to pump the stock solution 91 containing a plurality of second particles 92 to the storage tank.The control unit 40 controls the second pump 262 and the fourth pump 282 to be electrically connected.
[0037] The first pipeline 25 is provided with a first flow pressure sensor 254 located between the first pump 252 and the permeator 21, and is used to sense and measure the pressure of the polishing slurry 90 passing through the first pipeline 25. The second pipeline 26 is provided with a second flow pressure sensor 264 located between the second pump 262 and the permeator 21, and is used to sense and measure the pressure of the polishing slurry 90 passing through the second pipeline 26. The third pipeline 27 is provided with a third flow pressure sensor 274 located between the third pump 272 and the permeator 21, and is used to sense and measure the pressure of the raw solution 91 passing through the third pipeline 27. The fourth pipeline 28 is provided with a fourth flow pressure sensor 284 located between the fourth pump 282 and the permeator 21, and is used to sense and measure the pressure of the raw solution 91 passing through the fourth pipeline 28. The first flow pressure sensor 254, the second flow pressure sensor 264, the third flow pressure sensor 274 and the fourth flow pressure sensor 284 are used to sense and measure the pressure exceeding the first flow pressure sensor 254, the second flow pressure sensor 264, the third flow pressure sensor 274 and the fourth flow pressure sensor 284, and the first flow pressure sensor 254, the second flow pressure sensor 264, the third flow pressure sensor 274 and the fourth flow pressure sensor 284 are electrically connected to the control unit 40, so that the control unit 40 can control the operation of the first pump 252, the second pump 262, the third pump 272 and the fourth pump 282, respectively, based on the sensing and measuring results of the first flow pressure sensor 254, the second flow pressure sensor 264, the third flow pressure sensor 274 and the fourth flow pressure sensor 284, and therefore the pressure of the polishing slurry 90 passing through the first passage 23 located on one side of the osmotic membrane 22 becomes greater than the pressure of the second passage 24 located on the other side of the osmotic membrane 22.
[0038] The second pipeline 26 is provided with a second flow meter 266 located between the second pump 262 and the second flow pressure sensor 264, and is used to sense and measure the flow rate of the polishing slurry 90 passing through the second pipeline 26. The fourth pipeline 28 is provided with a fourth flow meter 286 located between the fourth pump 282 and the fourth flow pressure sensor 284, and is used to sense and measure the flow rate of the raw solution 91 passing through the fourth pipeline 28. The second flow meter 266 and the fourth flow meter 286 are each electrically connected to the control unit 40, and the control unit 40 adjusts the flow rates of the polishing slurry 90 and the raw solution 91 passing through the infiltrator 21 by controlling the second pump 262 and the fourth pump 282 based on the flow rates detected and measured by the second flow meter 266 and the fourth flow meter 286. [Explanation of symbols]
[0039] 10: Filtration unit 20: Penetration unit 21: Penetrator 22: Permeable membrane 23:1st aisle 24:Second aisle 25: 1st pipeline 252: First pump 254: First flow pressure sensor 26:Second conduit 262: Second pump 264: Second flow pressure sensor 266:Second flow meter 27: 3rd pipeline 272: Third pump 274: Third flow pressure sensor 28: 4th pipeline 282: 4th pump 284: 4th flow pressure sensor 286: 4th flow meter 30: Transport pipeline 40: Control unit 90: Abrasive slurry 91: Undiluted 92:Second particle 94: Third particle
Claims
1. A polishing slurry treatment device comprising a filtration unit, a permeation unit, a transport pipeline, and a control unit, the transport pipeline connects the filtration unit and the permeation unit; the control unit is mainly composed of an electronic circuit, and the control unit electrically connects the filtration unit and the permeation unit, thereby controlling the filtration unit and the permeation unit; The filtration unit is used to filter the polishing slurry derived from an external polishing slurry source, and removes a plurality of first particles having a particle size larger than a first dimension contained in the polishing slurry, and transports the filtered polishing slurry through the transport pipeline to the permeation unit; the permeation unit includes a permeator, and an osmosis membrane is provided inside the permeator; one end of a first passage located on one side of the osmosis membrane is connected to a first pipeline, the first pipeline is connected to the transport pipeline, and the other end of the first passage is connected to a second pipeline, the second pipeline being used to communicate with an external storage tank; one end of a second passage located on the other side of the osmosis membrane is connected to a third pipeline, the third pipeline being used to communicate with an external raw liquid supply source; the other end of the second passage is connected to a fourth pipeline, the fourth pipeline being used to communicate with an external storage tank; As a result, the abrasive slurry passes from the first pipeline through the first passage and enters the second pipeline, and a large number of second particles contained in the abrasive slurry, the particle size of which is smaller than the second dimension, permeate through the permeation membrane and enter the second passage, so that the raw liquid supplied from the raw liquid supply source passes from the third pipeline through the second passage and enters the fourth pipeline, and each of the second particles guided into the second passage passes through the fourth pipeline and enters the storage tank, characterized in that this is an abrasive slurry processing device.
2. 2. The polishing slurry processing device of claim 1, characterized in that the first pipeline is provided with a first pump used to pump the polishing slurry through the first passage and into the second pipeline, the third pipeline is provided with a third pump used to pump the raw solution through the second passage and into the fourth pipeline, the control unit electrically connects the first pump and the third pump, and the pressure in the second pipeline is greater than or equal to the pressure in the third pipeline.
3. The second pipeline is provided with a second pump used to pump the polishing slurry through the first passage and to pump the polishing slurry containing a plurality of third particles whose particle sizes are between the first dimension and the second dimension to the storage tank, and the fourth pipeline is provided with a fourth pump used to pump the stock solution containing a plurality of the second particles through the second passage and to pump the stock solution containing a plurality of the second particles to the storage tank, and the control unit is characterized in that the second pump and the fourth pump are electrically connected.
4. 4. The polishing slurry processing apparatus of claim 3, characterized in that the first pipeline is provided with a first flow pressure sensor located between the first pump and the permeator, used to sense and measure the pressure of the polishing slurry passing through the first pipeline; the second pipeline is provided with a second flow pressure sensor located between the second pump and the permeator, used to sense and measure the pressure of the polishing slurry passing through the second pipeline; the third pipeline is provided with a third flow pressure sensor located between the third pump and the permeator, used to sense and measure the pressure of the raw solution passing through the third pipeline; and the fourth pipeline is provided with a fourth flow pressure sensor located between the fourth pump and the permeator, used to sense and measure the pressure of the raw solution passing through the fourth pipeline; and the first flow pressure sensor, the second flow pressure sensor, the third flow pressure sensor and the fourth flow pressure sensor are each electrically connected to the control unit.
5. The polishing slurry processing device of claim 4, characterized in that the second pipeline is provided with a second flow meter located between the second pump and the second flow pressure sensor, and is used to sense and measure the flow rate of the polishing slurry passing through the second pipeline, and the fourth pipeline is provided with a fourth flow meter located between the fourth pump and the fourth flow pressure sensor, and is used to sense and measure the flow rate of the raw solution passing through the fourth pipeline, and the second flow meter and the fourth flow meter are each electrically connected to the control unit.
6. 2. The polishing slurry processing device according to claim 1, wherein the permeation membrane is tubular and arranged to surround the first passage, and the second passage is arranged to surround the radially outer side of the permeation membrane.
7. 10. A processing method carried out using the polishing slurry processing apparatus of claim 1, comprising: A processing method characterized by including, in sequence, an introduction step of abrasive slurry, which guides the abrasive slurry from the abrasive slurry source to enter the filtration unit; a sieving and filtering step, which sieves and filters the abrasive slurry using the filtration unit to eliminate a large number of first particles contained in the abrasive slurry whose particle size is larger than the first dimension; and a permeation and exclusion step, which draws the abrasive slurry that has passed through the sieving and filtering step into the permeation unit, and eliminates at least a portion of the second particles contained in the abrasive slurry, thereby making the abrasive slurry mainly contain third particles whose particle size is between the first dimension and the second dimension, thereby obtaining the abrasive slurry with a homogenized particle size span.
8. 8. The processing method of claim 7, wherein in the permeation and removal step, the pressure of the polishing slurry passing through the first passage located on one side of the permeation membrane is made greater than the pressure of the second passage located on the other side of the permeation membrane, thereby causing the second particles to permeate through the permeation membrane and enter the second passage.
9. 9. The treatment method according to claim 7 or 8, characterized in that in the permeation and removal step, the raw liquid is drawn into the permeator, and each of the second particles inside the second passage is guided to separate from the permeator.