Cleaning device for chemical mechanical polishing

Abstract

The embodiment of the invention relates to a cleaning device for chemical mechanical polishing. The invention provides a cleaning device for chemical mechanical polishing, comprising: a base in which a chamber for accommodating cleaning fluid is formed; the first end of the piston assembly is arranged in the cavity, so that the piston assembly can move under the action of the cleaning fluid; the cleaning brush is arranged at the second end of the piston assembly; the piston assembly comprises a liquid channel penetrating through the piston assembly, so that the cleaning liquid can reach the second end of the piston assembly through the liquid channel, and the cleaning liquid and the cleaning brush together clean a cleaning object. According to the invention, the diamond disc for chemical mechanical polishing can be properly cleaned, so that the adjusting efficiency of the polishing pad is improved, the service life of the polishing pad is prolonged, and the stability of a chemical mechanical polishing process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer manufacturing, and in particular to a cleaning device for chemical mechanical polishing (CMP). Background Art

[0002] Wafer manufacturing includes several process flows, such as photolithography, etching, thin film growth, diffusion, ion implantation, chemical mechanical polishing / polishing, metallization, etc. As one of the key processes in wafer manufacturing, chemical mechanical polishing (CMP) is a process used to flatten and grind the surface of semiconductor materials. In the wafer manufacturing process, CMP is often used to remove surface unevenness to make it flatter.

[0003] CMP combines the friction between the material surface and a chemical solution (e.g., slurry) and abrasive particles. The chemicals in the slurry react with the surface material to help remove uneven parts. At the same time, the abrasive particles exert force on the surface during the friction process, further promoting the flattening of the material. CMP plays a key role in semiconductor manufacturing because it ensures good contact between different layers and provides more reliable electronic component performance.

[0004] For wafer manufacturing, a grinding pad is usually used in the CMP process in combination with a grinding liquid to grind the wafer. During operation, the grinding pad can rotate around its central axis under the drive of a driving device. In addition, a conditioner including a disk is also used in the CMP process to condition, clean or restore the grinding pad. In other words, the conditioner is used to restore the surface of the grinding pad to its properties after grinding, thereby maintaining a stable removal rate throughout the service life of the grinding pad and the disk. Usually, the disk is embedded with diamonds and installed on the conditioner as a consumable.

[0005] During the conditioning process, the diamonds cut the surface of the pad and clean the grooves of the pad, which is a key factor in the stable removal rate of the pad. However, the surface of the repairer is easily clogged by the sticky abrasive fluid, which reduces the cleaning performance and thus affects the handling performance of the pad.

[0006] In the prior art, deionized water is usually used to rinse the repairer, but this cannot effectively remove all blockages because some residual polishing fluid is viscous and has an electric charge. In a worse case, in order to solve the problem of reduced polishing pad removal rate, the repairer has to be replaced more frequently.

[0007] Due to the above reasons, the consumables used in the CMP process, including polishing pads and repairers, cannot be fully utilized, thereby increasing costs and affecting the time for consumable replacement.

[0008] Therefore, how to overcome the poor cleaning effect of the repairer in the CMP process and improve the stability of the CMP process has become an urgent problem to be solved in this field.

[0009] The information disclosed in the Background Art section is only for enhancing the understanding of the general background of the invention and should not be regarded as an acknowledgement or default that such information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0010] In view of the above situation in the art, the purpose of the present invention is to propose a technology that can improve the cleaning effect of the repairer in the CMP process and enhance the stability of the CMP process.

[0011] According to one aspect of the present invention, a cleaning device for chemical mechanical polishing is provided, characterized in that the cleaning device comprises: a base, a chamber for containing a cleaning liquid is formed in the base; a piston assembly, a first end of the piston assembly is arranged in the chamber, so that the piston assembly can move under the action of the cleaning liquid; and a cleaning brush, the cleaning brush is arranged at the second end of the piston assembly; wherein the piston assembly includes a liquid channel running through it, so that the cleaning liquid can reach the second end of the piston assembly through the liquid channel, and clean the cleaning object together with the cleaning brush.

[0012] According to a specific embodiment of the present invention, the second end of the piston assembly forms a circular upper pressing plate, the cleaning brush is formed in a circular shape, and the upper pressing plate is concentric with the cleaning brush.

[0013] According to a specific embodiment of the present invention, the cleaning brush is eccentrically arranged with respect to the cleaning object, so that when the cleaning object rotates, the cleaning brush can cover the entire surface to be cleaned of the cleaning object.

[0014] According to a specific embodiment of the present invention, the cleaning device further comprises a cup-shaped cleaning cover, which is disposed above the base and surrounds the cleaning brush and the upper pressing plate.

[0015] According to a specific embodiment of the present invention, the liquid channel forms a nozzle at the second end of the piston assembly to spray the cleaning liquid onto the cleaning object.

[0016] According to a specific embodiment of the present invention, the nozzle is located at the center of the cleaning brush.

[0017] According to a specific embodiment of the present invention, the base comprises a water inlet for injecting the cleaning liquid into the chamber.

[0018] According to a specific embodiment of the present invention, the water inlet is connected to a liquid supply source, so that cleaning liquids with different pressures can be injected into the chamber.

[0019] According to a specific embodiment of the present invention, the first end of the piston assembly divides the chamber into an upper chamber and a lower chamber, and the base includes a vent and an overflow port, wherein the upper chamber can be connected to the vent, and the lower chamber can be connected to the overflow port.

[0020] According to a specific embodiment of the present invention, the cleaning object is a diamond disk used for chemical mechanical polishing.

[0021] Furthermore, the specific embodiments of the present invention may also include any optional features that can achieve the purpose of the present invention.

[0022] According to the embodiments of the present invention, the diamond disk used for chemical mechanical polishing can be properly cleaned, thereby improving the polishing pad conditioning efficiency, extending the service life of the polishing pad, and improving the stability of the chemical mechanical polishing process.

[0023] According to a specific embodiment of the present invention, a cup-shaped automatic polishing pad conditioner cleaning device is provided for timely and thorough cleaning of the surface of a repairer (e.g., a diamond disk embedded with diamonds). During the polishing pad conditioning process, a cleaning brush with an automatic height adjustment function is used to physically clean the surface of the diamond disk, and high-pressure deionized water is used to clean it at the same time, thereby greatly improving the cleaning efficiency.

[0024] According to a specific embodiment of the present invention, the height of the diamond protrusions on the surface of the repairer is kept in a good state by physical methods, thereby effectively adjusting the grinding pad. Since the cleaning device removes the residual grinding liquid in time, the stability of the CMP process is greatly improved. With the improvement of the cleanliness of the repairer, the life of CMP consumables, such as the grinding pad and the repairer, is extended by at least 15%, for example, the life of the grinding pad and / or the repairer is extended from 1500 pcs to 1800 pcs, because the process becomes more stable and reliable.

[0025] By reading this specification, those skilled in the art can understand and think of other beneficial technical effects that can be achieved by the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram showing a cleaning device for chemical mechanical polishing according to an embodiment of the present invention.

[0027] Figure 2is a schematic diagram showing an application scenario of a cleaning device for chemical mechanical polishing according to an embodiment of the present invention.

[0028] For the purpose of clear description, parts not closely related to the technical essence of the present invention are omitted; and in the specification and drawings, the same or similar elements are represented by the same reference numerals. It should be understood that in order to illustrate the basic principles and various features of the present invention, the drawings present a certain degree of simplification, and the scope of the present invention is not limited to the forms shown in the drawings.

[0029] Description of reference numerals:

[0030] 10 base;

[0031] 20 piston assembly;

[0032] 30 cleaning brush;

[0033] 40 Cleaning hood;

[0034] 100 Cleaning Objects;

[0035] 12 chambers;

[0036] 14 water inlet;

[0037] 22 upper pressing plate;

[0038] 24 nozzles;

[0039] 122 vent;

[0040] 124 overflow;

[0041] 200 Abrasive Pad Conditioner;

[0042] 300 fixer;

[0043] 400 Cleaning device. DETAILED DESCRIPTION

[0044] Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Although the present invention is described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the present invention to these exemplary embodiments. On the contrary, the present invention is intended to cover not only these exemplary embodiments, but also various alternative forms, modified forms, and equivalent forms contained in the essence and scope of the present invention defined by the appended claims.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "include", "comprise" and "have" in the specification and claims of this application and any variations thereof mean non-exclusive inclusion.

[0046] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0047] In the description of the embodiments of the present application, when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or one or more intermediate elements may exist. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intermediate elements.

[0048] For ease of explanation and accurate definition in the appended claims, the terms "inner," "outer," "upper," "lower," "front," "rear," etc. are used to describe features of the exemplary embodiments with reference to their positions as shown in the figures.

[0049] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] Figure 1 is a schematic diagram showing a cleaning device for chemical mechanical polishing according to an embodiment of the present invention.

[0051] like Figure 1 As shown, a cleaning device for chemical mechanical polishing according to an embodiment of the present invention includes: a base 10, in which a chamber 12 for accommodating a cleaning liquid is formed; a piston assembly 20, a first end of which is arranged in the chamber 12, so that the piston assembly 20 can move under the action of the cleaning liquid; and a cleaning brush 30, which is arranged at the second end of the piston assembly 20; wherein the piston assembly 20 includes a liquid channel running through it, so that the cleaning liquid can reach the second end of the piston assembly 20 through the liquid channel, and clean the cleaning object 100 together with the cleaning brush 30.

[0052] Preferably, the cleaning liquid can be deionized water. Deionized water is specially treated water, which is purified by removing ions and dissolved solids. In the semiconductor manufacturing process, deionized water can be used to clean and rinse chips, wafers and other electronic components. Its pure performance prevents the surface of the cleaning object from being contaminated by ions and impurities, ensuring the performance and reliability of chips, wafers and other electronic components.

[0053] The cleaning brush 30 contacts the surface of the repairer and is a consumable in the CMP process and needs to be replaced regularly. Preferably, the cleaning brush 30 is formed in a ring shape, and a nozzle 24 capable of spraying a cleaning liquid is arranged in the center.

[0054] Therefore, during the operation of the cleaning device, the height of the cleaning brush can be controlled and adjusted by means of the pressure of the cleaning liquid (e.g., deionized water), thereby effectively physically cleaning the surface of the repairer (e.g., diamond disk), and the cleaning liquid also cleans the repairer at a certain pressure. In this way, the cleaning efficiency is improved and increased. In other words, by properly cleaning the diamond disk used for CMP, the grinding pad adjustment efficiency is improved, the service life of the grinding pad is extended, and the stability of the CMP process is improved.

[0055] According to the cleaning device for chemical mechanical polishing of the embodiment of the present invention, the second end of the piston assembly 20 forms a circular upper pressing plate 22, the cleaning brush 30 is formed in a circular shape, and the upper pressing plate 22 is concentric with the cleaning brush 30. In addition, the cleaning brush 30 is eccentrically arranged with respect to the cleaning object 100, so that when the cleaning object 100 rotates, the cleaning brush 30 can cover the entire surface to be cleaned of the cleaning object 100. In addition, the cleaning device for chemical mechanical polishing of the embodiment of the present invention further includes a cup-shaped cleaning cover 40, which is arranged above the base 10 and surrounds the cleaning brush 30 and the upper pressing plate 22.

[0056] The upper pressing plate 22 and the cleaning brush 30, which are both circular and concentric with each other, form a compact structure, thereby contributing to the overall simple structure of the cleaning device. The cleaning object 100 is, for example, a circular diamond disk, the center of which is eccentrically arranged with the center of the cleaning brush 30; since the diamond disk can rotate under the drive of a driving device (not shown) and can be displaced in the horizontal direction, the cleaning brush 30 can cover the entire surface to be cleaned of the cleaning object 100, for example Figure 1 The cup-shaped cleaning cover 40 is detachably or integrally disposed above the base 10, covering the cleaning area between the cleaning brush 30 and the cleaning object 100 from bottom to top, thereby preventing the cleaning liquid from overflowing or splashing, and avoiding affecting other components or operators of the CMP process.

[0057] According to the cleaning device for chemical mechanical polishing of the embodiment of the present invention, the liquid channel forms a nozzle 24 at the second end of the piston assembly 20 to spray the cleaning liquid to the cleaning object 100. In addition, the nozzle 24 is located at the center of the cleaning brush 30.

[0058] The nozzle 24 forms an outlet for the cleaning liquid. The nozzle 24 is located in the center of the cleaning brush 30, which is the position with the highest cleaning efficiency. In addition, the nozzle 24 can be formed to a size suitable for spraying the cleaning liquid while also being suitable for maintaining the hydraulic pressure of the chamber 12. For example, the nozzle 24 can be formed to be 0.5 mm 2 The spray area is 120 degrees, and the spray angle is 120 degrees, thereby forming a spray flow rate of 3.5L / min. It should be understood by those skilled in the art that the above parameters are only examples and do not constitute a limitation on the scope of the present invention.

[0059] According to the cleaning device for chemical mechanical polishing of the embodiment of the present invention, the base 10 includes a water inlet 14 for injecting cleaning liquid into the chamber 12. In addition, the water inlet 14 is connected to a liquid supply source (not shown) so that cleaning liquid with different pressures can be injected into the chamber 12.

[0060] The water inlet 14 can be located at any position on the base 10 suitable for injecting the cleaning liquid into the chamber 12. The liquid supply source can be a water source capable of increasing the cleaning liquid at different hydraulic pressures. The hydraulic pressure of the liquid supply source can be set according to the total weight of the cleaning device and / or the required injection pressure of the cleaning liquid. In addition, the pressure of the cleaning liquid can be adjusted by a regulator.

[0061] According to the cleaning device for chemical mechanical polishing according to an embodiment of the present invention, the first end of the piston assembly 20 divides the chamber 12 into an upper chamber and a lower chamber, and the base 10 includes a vent 122 and an overflow port 124, wherein the upper chamber can be connected to the vent 122, and the lower chamber can be connected to the overflow port 124.

[0062] The height of the overflow port 124 can be determined according to the position of the cleaning brush 30 in normal operation. Since the cleaning brush 30 is a consumable, the length of its bristles will gradually shorten during operation. In order to maintain the cleaning ability of the cleaning brush 30, the hydraulic pressure of the cleaning fluid can be increased so that the piston assembly 20 moves upward together with the cleaning brush 30. However, if the piston assembly 20 moves too far, the overflow port 124 can be opened so that the cleaning fluid is discharged therefrom. Therefore, by providing the overflow port 124, it is possible to detect whether the cleaning brush 30 has been over-consumed. In addition, the vent 122 connected to the upper chamber can release the gas in the upper chamber when the piston assembly 20 moves upward, thereby preventing the gap between the piston assembly 20 and the base 10 from being too small, causing the pressure to increase and hindering the movement of the piston assembly 20.

[0063] According to the cleaning device for chemical mechanical polishing according to the embodiment of the present invention, the cleaning object 100 is a diamond disk for chemical mechanical polishing.

[0064] Depending on the application scenario of the present invention, the cleaning object 100 may also be other components used in the CMP process.

[0065] Figure 2 is a schematic diagram showing an application scenario of a cleaning device for chemical mechanical polishing according to an embodiment of the present invention.

[0066] like Figure 2 As shown, the repairer 300 is arranged on the right side of the polishing pad conditioner 200, and the cleaning device 400 is arranged below the repairer 300. During the operation of the cleaning device 400, the cleaning brush with adjustable height therein physically cleans the surface of the repairer 300, and at the same time, it is cleaned by deionized water, thereby greatly improving the cleaning efficiency and the stability of the CMP process.

[0067] For example, in the application scenario of the present invention, after the diamond disk completes the adjustment of the grinding pad, it will return to the position of the cleaning device at a certain speed. The deionized water fills the chamber and generates pressure, and then pushes the piston assembly upward. The cleaning brush contacts the diamond disk for physical cleaning, and the deionized water is ejected from the nozzle at a high speed to carry away impurities.

[0068] The flow rate from the nozzle is controlled by the water pressure and the size of the nozzle and should be adjusted via an upstream regulator.

[0069] The flow rate and water pressure relationship can be calculated based on the total weight of the cleaning brush, upper pressure plate, piston assembly, etc. If the total weight is high, a higher water pressure value can be set in the chamber to achieve a high flow rate. For example, for the above total weight of 300g, a flow rate of 3.5-4L / min can be achieved.

[0070] According to an embodiment of the present invention, the life of the repairer can be extended by 20%. Considering CMP practice, considering both the repairer and the polishing pad, the cost benefit per wafer is about $0.12.

[0071] In addition, if the diamond disc is not in the correct position of the cleaning device or the cleaning brush is over-consumed, the piston assembly will move more distance and open the overflow port. Water will escape from the overflow port and the water flow rate will increase more as the pressure drops. The water flow meter can detect this situation.

[0072] In addition, the cleaning brush is a consumable and needs to be replaced regularly, otherwise it will affect the cleanliness.

[0073] In addition, if the cleaning water pressure is too low and the cleaning brush does not touch the diamond disc, the friction will be different from the standard state. This can be detected by rotating the motor of the grinding pad regulator.

[0074] The above text presents specific exemplary embodiments of the present invention for the purpose of illustration. The above description is not intended to be exhaustive of the present invention without omission, nor is it intended to limit the present invention to the disclosed exact form. Obviously, those skilled in the art can make many changes and variations according to the above description. These exemplary embodiments are selected and described to explain the specific principles of the present invention and its practical application, so that those skilled in the art can make and use each exemplary embodiment of the present invention, and various substitutions and modifications thereof. In fact, the scope of the present invention is limited by the appended claims and their equivalents.

Claims

1. A cleaning device for chemical mechanical polishing, characterized in that: The cleaning device comprises: a base, wherein a chamber for containing a cleaning liquid is formed in the base; a piston assembly, a first end of which is disposed in the chamber so that the piston assembly can move under the action of the cleaning fluid; and a cleaning brush, the cleaning brush being disposed at the second end of the piston assembly; The piston assembly includes a liquid channel running through it, so that the cleaning liquid can reach the second end of the piston assembly through the liquid channel and clean the cleaning object together with the cleaning brush.

2. The cleaning device according to claim 1, characterized in that The second end of the piston assembly forms a circular upper pressing plate, the cleaning brush is formed in a circular shape, and the upper pressing plate is concentric with the cleaning brush.

3. The cleaning device according to claim 2, characterized in that: The cleaning brush is eccentrically arranged with respect to the cleaning object, so that when the cleaning object rotates, the cleaning brush can cover the entire surface to be cleaned of the cleaning object.

4. The cleaning device according to claim 2, characterized in that: The cleaning device further comprises a cup-shaped cleaning cover, which is arranged above the base and surrounds the cleaning brush and the upper pressing plate.

5. The cleaning device according to claim 1, characterized in that: The liquid passage forms a nozzle at the second end of the piston assembly to spray the cleaning liquid to the cleaning object.

6. The cleaning device according to claim 5, characterized in that: The nozzle is located at the center of the cleaning brush.

7. The cleaning device according to claim 1, characterized in that: The base includes a water inlet for injecting the cleaning fluid into the chamber.

8. The cleaning device according to claim 7, characterized in that: The water inlet is connected to a liquid supply source so that cleaning liquids with different pressures can be injected into the chamber.

9. The cleaning device according to claim 1, characterized in that: The first end of the piston assembly divides the chamber into an upper chamber and a lower chamber, and the base includes a vent and an overflow port, wherein the upper chamber can communicate with the vent, and the lower chamber can communicate with the overflow port.

10. The cleaning device according to claim 1, characterized in that The cleaning object is a diamond disk used for chemical mechanical polishing.

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