A polishing assembly for a CMP process

Abstract

This utility model discloses a grinding assembly for CMP process, including a grinding disk; a polishing head disposed above the grinding disk; and a driving device connected to the grinding disk. The polishing head is used to support and connect a wafer, driving the wafer to grind on the grinding surface of the grinding disk. The driving device drives the grinding disk to rotate around its symmetrical central axis. The grinding disk has internal fluid channels, with a fluid inlet and a fluid outlet connected to these channels. The fluid inlet and outlet are connected to a cooling medium circulation pipe, which, together with the fluid channels within the grinding disk, forms a cooling medium circulation loop. The cooling medium in this application flows inside the grinding disk, improving the cooling effect on the wafer and thus ensuring the planarization grinding effect.

Description

Technical Field

[0001] This utility model relates to the field of wafer processing equipment technology, and in particular to a grinding component for CMP process. Background Technology

[0002] Chemical mechanical polishing (CMP) is a key technology for achieving wafer surface planarization in integrated circuit manufacturing. For example... Figure 1 As shown, during the CMP process, as the polishing pad rotates relative to wafer 3, the polishing slurry dripping onto the polishing pad reacts chemically with the surface of wafer 3, releasing heat. To prevent wafer 3 from overheating, cooling control of wafer 3 is necessary.

[0003] Currently, a common method for cooling wafers is to spray low-temperature nitrogen gas onto the surface of the polishing pad, thereby indirectly cooling the wafer by cooling the polishing pad. However, in practical applications, this cooling method has limited effectiveness in cooling the wafer, which may affect the wafer planarization polishing process. Utility Model Content

[0004] The purpose of this invention is to provide a grinding component for CMP process that can improve the cooling effect during wafer grinding to a certain extent, thereby ensuring the wafer planarization grinding effect.

[0005] To solve the above-mentioned technical problems, this utility model provides a grinding assembly for CMP process, including a grinding disc; a polishing head disposed above the grinding disc; and a driving device connected to the grinding disc;

[0006] The polishing head is used to support and connect the wafer, so as to drive the wafer to be polished on the polishing surface of the polishing disk; the driving device is used to drive the polishing disk to rotate around the symmetrical central axis of the polishing disk.

[0007] The grinding disc has a fluid channel inside, and a fluid inlet and a fluid outlet connected to the fluid channel are provided on the grinding disc. The fluid inlet and the fluid outlet are connected to a cooling medium circulation pipe. The cooling medium circulation pipe and the fluid channel in the grinding disc together form a cooling medium circulation loop.

[0008] In one optional embodiment of this application, the polishing head includes a retaining ring that surrounds the side of the wafer and a temperature sensor that is attached to the surface of the retaining ring near the polishing disk, wherein the temperature sensing surface of the temperature sensor is flush with the surface of the wafer to be polished.

[0009] In one alternative embodiment of this application, a plurality of temperature sensors are uniformly arranged around the wafer.

[0010] In one optional embodiment of this application, the polishing head can drive the wafer to translate radially above the grinding disk;

[0011] The fluid channel includes at least a first fluid channel and a second fluid channel;

[0012] Wherein, the first fluid channel is an annular channel with a width in the radial direction greater than the diameter of the wafer;

[0013] The second fluid channel is a channel located within the ring of the annular channel;

[0014] The first fluid channel is connected to the cooling working fluid circulation pipeline through a first fluid inlet and a first fluid outlet;

[0015] The second fluid channel is connected to the cooling working fluid circulation pipeline through a second fluid inlet and a second fluid outlet;

[0016] It also includes a control structure for controlling the opening or closing of the second fluid inlet and the second fluid outlet independently of the first fluid inlet and the first fluid outlet.

[0017] In one optional embodiment of this application, the grinding disc includes an annular grinding disc and a circular grinding disc disposed within the annular grinding disc, and the annular grinding disc and the circular grinding disc are rotatable relative to each other;

[0018] The first fluid channel is disposed in the annular grinding disk; the second fluid channel is disposed inside the annular grinding disk.

[0019] The control structure includes a first through hole and a second through hole disposed on the inner ring wall of the annular grinding disc and connected to the first fluid channel;

[0020] Both the second fluid inlet and the second fluid outlet are located on the outer wall of the central grinding disc;

[0021] When the annular grinding disc and the circular grinding disc rotate relative to each other to a first predetermined relative position, the first through hole and the second through hole are respectively connected to the second fluid inlet and the second fluid outlet;

[0022] When the annular grinding disc and the circular grinding disc rotate relative to each other to a second predetermined relative position, the first through hole and the second through hole are not connected to the second fluid inlet and the second fluid outlet, respectively.

[0023] In one optional embodiment of this application, the second fluid channel is a circular cavity within the circular grinding disc;

[0024] The second fluid inlet and the second fluid outlet are respectively located at both ends of the same diameter of the circular cavity;

[0025] The central region of the circular cavity is provided with multiple flow dividers, and the length direction of each flow divider extends along the straight line where the second fluid inlet and the second fluid outlet are located.

[0026] In an optional embodiment of this application, the first fluid inlet, the first fluid outlet, the first through hole, the second through hole, the second fluid inlet, and the second fluid outlet are all located on the same straight line; and the first fluid inlet and the first fluid outlet, the first through hole and the second through hole are respectively located on both sides of the circular grinding disc.

[0027] In an optional embodiment of this application, the first fluid inlet, the first fluid outlet, the second fluid inlet, and the second fluid outlet are all respectively disposed on the lower bottom surface of the grinding disc;

[0028] The cooling working fluid circulation pipeline includes a first output pipe connected to the first fluid inlet, a second output pipe connected to the second fluid inlet, a first input pipe connected to the first fluid outlet, and a second input pipe connected to the second fluid outlet.

[0029] The control structure includes control valves respectively installed on the first input pipe, the second input pipe, the first output pipe, and the second output pipe, and the opening and closing of each control valve can be controlled independently.

[0030] In an optional embodiment of this application, a heating plate is further embedded in the grinding disc, located between the grinding surface of the grinding disc and the fluid channel.

[0031] In one optional embodiment of this application, the heating plate is a conductive metal resistor sheet.

[0032] This utility model provides a grinding assembly for CMP process, including a grinding disc; a polishing head disposed above the grinding disc; and a driving device connected to the grinding disc. The polishing head is used to support and connect a wafer, thereby driving the wafer to grind on the grinding surface of the grinding disc. The driving device is used to drive the grinding disc to rotate around its symmetrical central axis. The grinding disc has a fluid channel inside, and a fluid inlet and a fluid outlet connected to the fluid channel are provided on the grinding disc. The fluid inlet and fluid outlet are connected to a cooling medium circulation pipe, and the cooling medium circulation pipe and the fluid channel inside the grinding disc together form a cooling medium circulation loop.

[0033] In this application, to improve the cooling effect of wafers in the CMP process, a fluid channel is provided inside the grinding pad for grinding the wafer, and this fluid channel is connected to the cooling medium circulation pipeline. This allows the low-temperature fluid to flow within the fluid channel, thereby keeping the grinding surface of the grinding pad at a relatively low temperature, thus indirectly cooling the wafer through the grinding pad. Compared to cooling by directly spraying low-temperature nitrogen gas onto the surface of the grinding pad, the cooling medium in this application flows inside the grinding pad, eliminating the problem of nitrogen gas overflowing into the surrounding space. The cooling effect on the grinding pad is obviously better, thereby improving the cooling effect on the wafer to a certain extent and ensuring the planarization grinding effect of the wafer. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a wafer during conventional CMP (Chemical Metallurgical Processing).

[0036] Figure 2 This is a schematic diagram of the structure of the grinding assembly for the CMP process provided in the embodiments of this application;

[0037] Figure 3 This is a bottom view of the polishing head provided in an embodiment of this application;

[0038] Figure 4 This is a schematic diagram showing the relative positions between the grinding disk and the wafer provided in an embodiment of this application.

[0039] Figure 5 This is a schematic diagram of the internal structure of a grinding disc provided in an embodiment of this application;

[0040] Figure 6 This is a cross-sectional structural diagram of the grinding assembly for the CMP process provided in an embodiment of this application. Detailed Implementation

[0041] The core of this invention is to provide a grinding component for CMP process, which can ensure the cooling effect during wafer grinding to a certain extent, thereby ensuring the grinding effect.

[0042] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] like Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of the grinding assembly for the CMP process provided in an embodiment of this application.

[0044] In one specific embodiment of this application, the polishing assembly of the CMP process may include:

[0045] Grinding disc 1; polishing head 2 disposed above grinding disc 1; drive device connected to grinding disc 1;

[0046] Among them, the polishing head 2 is used to support the connected wafer 3 so as to drive the wafer 3 to be polished on the polishing surface of the polishing disk 1; the driving device is used to drive the polishing disk 1 to rotate around the symmetrical central axis of the polishing disk 1.

[0047] The grinding disc 1 has a fluid channel 10 inside. The grinding disc 1 has a fluid inlet 101 and a fluid outlet 102 connected to the fluid channel 10. The fluid inlet 101 and the fluid outlet 102 are connected to a cooling medium circulation pipe. The cooling medium circulation pipe and the fluid channel 10 in the grinding disc 1 together form a cooling medium circulation loop.

[0048] like Figure 2 As shown, in this embodiment, the grinding disk 1 is in the shape of a disc. At the same time, the driving device can drive the grinding disk 1 to rotate around its own symmetrical central axis. Thus, when the wafer 3 carried by the polishing head 2 is attached to the grinding surface (i.e. the upper surface) of the grinding disk 1, the surface of the wafer 3 facing the grinding disk 1 can be ground.

[0049] Based on this, the grinding disc 1 in this application is also provided with a fluid channel 10 inside, and the fluid channel 10 forms a cooling working medium circulation loop with the cooling working medium circulation pipeline through the fluid inlet 101 and the fluid outlet 102 respectively.

[0050] It should be noted that the cooling medium circulation pipeline referred to in this application, in addition to the pipes that accommodate the flow of the cooling medium, should also include a cooling device to cool the cooling medium and maintain it at a low temperature, as well as a drive pump installed on the pipeline to drive the fluid to circulate throughout the entire circulation loop. Specific references can be made to conventional circulating fluid circulation loop equipment, and this application does not impose specific limitations on this. Furthermore, the cooling medium in this application can be low-temperature nitrogen, liquid water, or other fluids, and this application does not impose specific limitations on this either.

[0051] In this application, a fluid channel 10 is formed directly within the grinding disk 1. A low-temperature cooling medium can flow within this channel 10, directly cooling the grinding disk 1 and ensuring the grinding surface remains at a low temperature. This better cools the wafer 3 during the grinding process. Compared to directly spraying low-temperature nitrogen onto the surface of the grinding disk 1, the cooling medium in this application is confined within the grinding disk 1, eliminating the problem of cooling medium overflowing into the surrounding environment. Furthermore, the cooling medium absorbs heat from the grinding disk 1 to the maximum extent possible, rather than absorbing heat from the surrounding environment. This also improves the heat absorption efficiency of the cooling medium on the grinding disc 1. Because the cooling medium in this application has a better cooling and heat absorption effect on the grinding disc 1, it has a better absorption effect on the heat generated by the chemical reaction during the grinding of the wafer 3, and thus can better cool down the wafer 3, so that the temperature of the wafer 3 is maintained within a suitable temperature range. On the other hand, because the cooling medium circulates in a closed loop without any overflow, it can not only reduce the amount of cooling medium used, but also the cooling medium is not limited to nitrogen. Low-temperature water or other lower-cost liquid or gaseous substances can also be considered, thereby reducing the cost of cooling the grinding disc 1.

[0052] like Figure 2 As shown, the grinding disc 1 in this application can specifically be a cavity disc with an internal cavity, which can also form a fluid channel 10. Furthermore, a fluid inlet 101 and a fluid outlet 102 can be respectively provided on opposite sides of the grinding disc 1, so that the flow path of the cooling medium through the internal cavity of the grinding disc 1 covers as much as possible all areas within the grinding disc 1. Of course, to ensure that the cooling medium can cool the grinding disc 1 more comprehensively, multiple baffles can also be provided inside the grinding disc 1, so that the cooling medium is more comprehensively distributed in different areas within the grinding disc 1, thereby avoiding the problem of uneven cooling of the grinding disc 1 due to an overly concentrated flow path of the cooling medium within the cavity.

[0053] Based on this, refer to Figure 3In order to more accurately control the temperature of the wafer 3, in an optional embodiment of this application, the polishing head 2 may include a retaining ring 21 that is attached to the side of the wafer 3 and surrounds it, and a temperature sensor 22 that is attached to the surface of the retaining ring 21 near the polishing disk 1. The temperature sensing surface of the temperature sensor 22 is flush with the surface of the wafer 3 to be polished, that is, the surface of the temperature sensor 22 near the polishing disk 1 and the surface of the wafer 3 near the polishing disk 1 are located in the same horizontal plane.

[0054] In this embodiment, the temperature sensor 22 is positioned on the same surface as the wafer 3, thereby enabling more accurate detection of temperature data in the area between the wafer 3 and the polishing pad 1. Compared to the current practice of placing the temperature sensor 22 below the polishing pad 1 to collect its temperature, the temperature data measured by the temperature sensor 22 in this embodiment more accurately reflects the temperature of the wafer 3. In practical applications, the flow rate of the cooling medium in the fluid channel 10 can be reasonably adjusted based on the temperature data measured by the temperature sensor 22, thereby controlling the temperature of the wafer 3 within a reasonable range and ensuring the polishing effect of the wafer 3.

[0055] Furthermore, to ensure the accuracy of temperature acquisition of wafer 3, multiple temperature sensors 22 can be evenly arranged around wafer 3. Alternatively, in this embodiment, temperature sensors 22 can also be placed on the surface of the polishing head 2 that is not the surface to be polished (i.e., the surface facing away from the polishing disk 1), which can also measure the temperature data of wafer 3.

[0056] Based on any of the above embodiments, refer to Figure 4 and Figure 5 , Figure 5 The dashed line with an arrow indicates the approximate flow direction of the cooling medium.

[0057] In another optional embodiment of this application, the polishing assembly of the CMP process may further include:

[0058] The polishing head 2 can drive the wafer 3 to move radially above the polishing disk 1;

[0059] The fluid channel 10 includes at least a first fluid channel 11 and a second fluid channel 12;

[0060] The first fluid channel 11 is an annular channel with a width in the radial direction greater than the diameter of the wafer 3;

[0061] The second fluid channel 12 is a channel located within the ring of the annular channel;

[0062] The first fluid passage 11 is connected to the cooling working fluid circulation pipeline through the first fluid inlet 111 and the first fluid outlet 112;

[0063] The second fluid channel 12 is connected to the cooling working fluid circulation pipeline through the second fluid inlet 121 and the second fluid outlet 122.

[0064] It also includes a control structure for controlling the opening or closing of the second fluid inlet 121 and the second fluid outlet 122 independently of the first fluid inlet 111 and the first fluid outlet 112.

[0065] Reference Figure 4 ,according to Figure 4 The circular dashed lines shown divide the grinding disk 1 into an annular region outside the dashed lines and a circular region inside the dashed lines. The polishing head 2 can move the wafer 3 along the radial direction of the grinding disk 1, thus allowing the wafer 3 to be ground within either the circular or annular region. Obviously, when the polishing head 2 moves the wafer 3 into the annular region for grinding, the relative speed between the opposing surfaces of the grinding disk 1 and the wafer 3 is greater, while when the polishing head 2 moves the wafer 3 into the circular region for grinding, the relative speed between the opposing surfaces of the grinding disk 1 and the wafer 3 is smaller.

[0066] Therefore, in the actual grinding process of wafer 3, based on the different grinding requirements of wafer 3, the polishing head 2 adjusts the position of wafer 3 relative to the grinding disk 1 along the radial direction of the grinding disk 1, so that wafer 3 is ground in one area of ​​the annular area or the circular area. Based on this, in order to achieve targeted cooling of the grinding disk 1 during the grinding of the wafer 3 based on different regions on the grinding disk 1, the fluid channel 10 is further divided into two parts, namely the first fluid channel 11 and the second fluid channel 12. The first fluid channel 11 is located in the annular region within the grinding disk 1, while the second fluid channel 12 is located in the circular region within the grinding disk 1. The first fluid channel 11 is provided with a first fluid inlet 111 and a first fluid outlet 112, while the second fluid channel 12 is connected to a second fluid inlet 121 and a second fluid outlet 122. The connection between the first fluid inlet 111 and the first fluid outlet 112 and the cooling medium circulation pipeline, as well as the connection between the second fluid inlet 121 and the second fluid outlet 122 and the cooling medium circulation pipeline, can be independently controlled by a control structure.

[0067] When the polishing head 2 drives the wafer 3 to be ground in the annular area, it can be controlled that only the first fluid channel 11 and the cooling working fluid circulation pipeline are connected, that is, only the annular area on the polishing disk 1 that is polishing the wafer 3 is cooled down, thereby ensuring the cooling effect of the wafer 3.

[0068] When the polishing head 2 drives the wafer 3 to be ground in the circular area, it can be controlled that only the second fluid channel 12 and the cooling working fluid circulation pipeline are connected, that is, only the circular area on the polishing disk 1 is cooled down.

[0069] Furthermore, when the polishing head 2 drives the wafer 3 to move back and forth along the radial direction of the polishing disk 1 for polishing, the first fluid channel 11 and the second fluid channel 12 can be simultaneously connected to the cooling working fluid circulation pipeline to achieve cooling of the entire polishing disk 1, thereby ensuring the cooling effect on the wafer 3.

[0070] Therefore, the fluid channel 10 in the grinding disk 1 of this application can switch the cooling area on the grinding disk 1 according to different actual grinding needs, and thus specifically cool only the grinding area on the grinding disk 1. When grinding the wafer 3 in only a local area on the grinding disk 1, the flow path of the cooling medium in the grinding disk 1 can be shortened, thereby improving the cooling speed while ensuring the cooling effect.

[0071] In an optional implementation of this embodiment, the first fluid inlet 111, the first fluid outlet 112, the second fluid inlet 121, and the second fluid outlet 122 are all respectively disposed on the lower bottom surface of the grinding disc 1;

[0072] The cooling working fluid circulation pipeline includes a first output pipe connected to the first fluid inlet 111, a second output pipe connected to the second fluid inlet 121, a first input pipe connected to the first fluid outlet 112, and a second input pipe connected to the second fluid outlet 122.

[0073] The control structure includes control valves respectively installed on the first input pipe, the second input pipe, the first output pipe, and the second output pipe, and the opening and closing of each control valve can be controlled independently.

[0074] In this embodiment, four fluid inlets and outlets are respectively provided on the bottom surface of the grinding disc 1: a first fluid inlet 111, a first fluid outlet 112, a second fluid inlet 121, and a second fluid outlet 122. Correspondingly, the cooling working fluid circulation pipeline is also configured with a first output pipe and a second output pipe, as well as a first input pipe and a second input pipe. The first output pipe and the second output pipe are the two pipes from which the cooling working fluid flows out of the cooling working fluid circulation pipeline, while the first input pipe and the second input pipe are the two pipes from which the cooling working fluid flows back to the cooling working fluid circulation pipeline.

[0075] Therefore, when the two control valves on the first output pipe and the first input pipe are opened simultaneously, the cooling medium in the cooling medium circulation pipeline can flow from the first fluid inlet 111 into the first fluid channel 11, and finally flow back into the cooling medium circulation pipeline through the first fluid outlet 112 and the first input channel. Conversely, when the control valves on the first output pipe and the first input pipe are closed simultaneously, the passage between the first fluid channel 11 and the cooling medium circulation pipeline is broken, that is, the cooling medium no longer flows into the first fluid channel 11. Thus, it can be seen that whether the cooling medium flows through the first fluid channel 11 can be controlled by whether the two control valves on the first output pipe and the first input pipe are opened and closed synchronously.

[0076] Similarly, when the two control valves on the first output pipe and the second input pipe are opened simultaneously, the cooling medium in the cooling medium circulation pipeline can flow from the second fluid inlet 121 into the second fluid channel 12, and finally return to the cooling medium circulation pipeline through the second fluid outlet 122 and the second input channel. Conversely, when the control valves on the second output pipe and the second input pipe are closed simultaneously, the passage between the second fluid channel 12 and the cooling medium circulation pipeline is broken, that is, the cooling medium no longer flows into the second fluid channel 12. In other words, by controlling whether the two control valves on the second output pipe and the second input pipe are opened and closed synchronously, the flow of the cooling medium through the second fluid channel 12 can be controlled.

[0077] Based on this, in practical applications, by independently controlling the opening and closing of the control valves on the first output pipe and the first input pipe, as well as on the second output pipe and the second input pipe, it is possible to independently control whether there is a flowing cooling medium in the first fluid channel 11 and the second fluid channel 12.

[0078] Based on the above embodiments, the connection methods between the first fluid channel 11 and the second fluid channel 12 and the cooling working fluid circulation pipeline in this application are not limited to the above-described implementation method.

[0079] In another optional embodiment of this application, the grinding disk 1 in the grinding assembly of the AMP process may further include:

[0080] The annular grinding disc 110 and the circular grinding disc 120 disposed within the annular grinding disc 110 are rotatable relative to each other.

[0081] The first fluid channel 11 is disposed in the annular grinding disk 110; the second fluid channel 12 is disposed inside the annular grinding disk 110.

[0082] The control structure includes a first through hole 113 and a second through hole 114 disposed on the inner ring wall of the annular grinding disk 110 and connected to the first fluid channel 11;

[0083] The second fluid inlet 121 and the second fluid outlet 122 are both located on the outer wall of the central grinding disc 1;

[0084] When the annular grinding disc 110 and the circular grinding disc 120 rotate relative to each other to the first set relative position, the first through hole 113 and the second through hole 114 are respectively connected to the second fluid inlet 121 and the second fluid outlet 122.

[0085] When the annular grinding disc 110 and the circular grinding disc 120 rotate relative to each other to the second set relative position, the first through hole 113 and the second through hole 114 are not connected to the second fluid inlet 121 and the second fluid outlet 122, respectively.

[0086] In this embodiment, it is further considered that during the grinding process of the grinding disk 1 on the wafer 3, two grinding methods are often used. One method is that the polishing head 2 drives the wafer 3 to remain stationary in the annular region on the grinding disk 1, and the other method is that the polishing head 2 drives the wafer 3 to swing back and forth in the annular and circular regions along the radial direction of the grinding disk 1. Therefore, in this embodiment, the grinding disk 1 is divided into two parts that can rotate relative to each other: an annular grinding disk 110 and a circular grinding disk 120. The internal cavity of the annular grinding disk 110 forms the first fluid channel 11, while the internal cavity of the circular grinding disk 120 forms the second fluid channel 12.

[0087] like Figure 5 As shown, in Figure 5 In the illustrated embodiment, the first fluid inlet 111 and the first fluid outlet 112 are located on the outer walls of opposite sides of the annular grinding disc 110, thereby causing the cooling medium flowing into the first fluid channel 11 to flow in two parallel semi-circular channels to the first fluid outlet 112 and then out. In this embodiment, the first fluid channel 11 is directly connected to the cooling medium circulation pipeline through the first fluid inlet 111 and the first fluid outlet 112, respectively; while the second fluid channel 12 in this embodiment is indirectly connected to the cooling medium circulation pipeline through the first fluid channel 11.

[0088] like Figure 5As shown, in this embodiment, a first through hole 113 and a second through hole 114 are respectively provided on the inner ring sidewall of the annular grinding disk 110 (that is, the sidewall that is in contact with the outer sidewall of the circular grinding disk 120). The second fluid inlet 121 and the second fluid outlet 122, which are connected to the second fluid channel 12, are located on the outer sidewall of the circular grinding disk 120. The relative position between the second fluid inlet 121 and the second fluid outlet 122 is the same as the relative position between the first through hole 113 and the second through hole 114, so that when the second fluid inlet 121 is directly opposite the first through hole 113 and they are connected to each other, the second through hole 114 is also directly opposite the second fluid outlet 122 and thus they are connected to each other. Therefore, as the circular grinding disc 120 and the annular grinding disc 110 rotate relative to each other, the relative positions between the grinding disc and the annular grinding disc 110 can change, thereby adjusting whether the first through hole 113 and the second fluid inlet 121 are interconnected, and whether the second through hole 114 and the second fluid outlet 122 are interconnected. That is, adjusting whether the second fluid channel 12 and the first fluid channel 11 in the circular grinding disc 120 are interconnected, and finally realizing the control and adjustment of whether the second fluid channel 12 is connected to the cooling working fluid circulation pipeline.

[0089] Combination Figure 5 In an optional embodiment of this example, the first fluid inlet 111, the first fluid outlet 112, the first through hole 113, the second through hole 114, the second fluid inlet 121, and the second fluid outlet 122 are all located on the same straight line; and the first fluid inlet 111 and the first fluid outlet 112, the first through hole 113, and the second through hole 114 are all located on both sides of the circular grinding disc 120.

[0090] Therefore, when the annular grinding disc 110 and the circular grinding disc 120 rotate relative to each other to a first predetermined relative position, such that the first through hole 113 and the second through hole 114 are connected to the second fluid inlet 121 and the second fluid outlet 122 respectively, as the cooling medium is introduced into the first fluid inlet 111, the cooling medium can be divided into three flows. Two of these flows parallel to each other along the two semi-circular arc-shaped channels on both sides of the first fluid channel 11 towards the first fluid outlet 112. The third flow enters the second fluid channel 12 within the circular grinding disc 120 through the interconnected first through hole 113 and the second fluid inlet 121, then flows through the second fluid channel 12 to the interconnected second through hole 114 and the second fluid outlet 122, and then flows back into the first fluid channel 11 from the second fluid outlet 122, finally flowing to the first fluid outlet 112. This allows the cooling medium to circulate throughout the entire inner wall of the grinding disc 1, thereby cooling the entire grinding disc 1.

[0091] When the annular grinding disk 110 and the circular grinding disk 120 rotate relative to each other to the second predetermined relative position, the first through hole 113 and the second through hole 114 are not connected to the second fluid inlet 121 and the second fluid outlet 122, respectively. This means that the first fluid channel 11 and the second fluid channel 12 are not connected to each other. This means that after the cooling medium flows into the first fluid channel 11 through the first fluid inlet 111, it only flows out of the first fluid channel 11 and out of the first fluid outlet 112. No cooling medium flows into the circular grinding disk 120. As a result, the cooling medium only cools the annular area on the grinding disk 1, thereby improving the cooling effect on the area of ​​the wafer 3 being ground.

[0092] It is understood that this application is not limited to the one implementation described above. For example, without dividing the grinding disc 1 into two relatively movable parts, the interior of the grinding disc 1 can be divided into... Figure 5 The first fluid channel 11 and the second fluid channel 12 are similar to those in the previous one; however, the difference is that two movable baffles are respectively provided at the first through hole 113 and the second through hole 114. By adjusting the extension and retraction of the two baffles, the connection and disconnection between the first fluid channel 11 and the second fluid channel 12 can be realized, and the flow of the cooling working fluid to the second fluid channel 12 can also be realized.

[0093] In addition, Figure 5 In the illustrated embodiment, the second fluid channel 12 is a circular cavity within the circular grinding disc 120. Although the second fluid inlet 121 and the second fluid outlet 122 are far apart and located at opposite ends of the same diameter of the circular cavity, when the cooling medium flows within the second fluid channel 12, it may only concentrate on the straight line where the second fluid inlet 121 and the second fluid outlet 122 are located. Therefore, in this embodiment, multiple diversion strips 123 can be further provided in the middle region of the circular cavity of the circular grinding disc 1, with the length direction of each diversion strip 123 extending along the straight line where the second fluid inlet 121 and the second fluid outlet 122 are located.

[0094] like Figure 4 As shown, in this embodiment, three diversion bars 123 are provided between the first fluid inlet 111 and the second fluid outlet 122. Thus, when the cooling medium flows in from the second fluid inlet 121, it can be diverted by each diversion bar 123 to form multiple parallel fluid branch channels, ultimately ensuring that the cooling medium can be dispersed as much as possible and flow through the entire circular cavity, ensuring more complete and comprehensive cooling of the entire circular grinding disc 120.

[0095] It should be noted that, in practical applications, the extension methods of the first fluid channel 11 and the second fluid channel 12 are not limited to... Figure 4In the embodiments shown, for example, multiple baffles can be provided in the first fluid channel 11 and the second fluid channel 12 respectively, so that the cooling medium can flow in the first fluid channel 11 and the second fluid channel 12 along any one of the following paths: a zigzag path, a serpentine path, a U-shaped path, or a sawtooth path. This application does not impose any specific limitations on this.

[0096] Furthermore, as the flow paths of the cooling medium within the first fluid channel 11 and the second fluid channel 12 differ, the arrangement of the first fluid inlet 111 and the second fluid outlet 122, the second fluid inlet 121 and the second fluid outlet 122, and the first through hole 113 and the second through hole 114 is not necessarily the same. Figure 4 In the illustrated configuration, for example, a circular baffle extending along the centerline of the first fluid channel 11 is provided in the first fluid channel 11, thereby allowing the cooling medium to flow along a U-shaped path in the first fluid channel 11. In this case, the first fluid inlet 111 and the second fluid outlet 122 can be located in the same area on the side wall of the grinding disc 1. Correspondingly, the first through hole 113 and the second through hole 114, as well as the second fluid inlet 121 and the second fluid outlet 122, can be located in close proximity, as long as the cooling medium in the first fluid channel 11 and the second fluid channel 12 can flow through each area in the fluid channel 10, flowing in from the inlet and out from the outlet. This application does not specifically limit this.

[0097] Based on any of the above embodiments, during the CMP process, although the chemical reaction of wafer 3 generates heat, if the temperature between wafer 3 and polishing pad 1 is too low, it may affect the chemical reaction of wafer 3 and affect the polishing effect of wafer 3.

[0098] Therefore, in another optional embodiment of this application, the polishing assembly of the CMP process may further include:

[0099] A heating plate 4 is also embedded inside the grinding disc 1, located between the grinding surface of the grinding disc 1 and the fluid channel 10.

[0100] like Figure 5 As shown, in this application, a heating plate 4 is further embedded in the grinding disc 1. Thus, when the temperature data of the wafer 3 measured by the temperature sensor 22 is too low, while controlling the cessation of the cooling medium into the grinding disc 1, the heating plate 4 can be used to further heat it, thereby allowing the temperature between the wafer 3 and the grinding disc 1 to be adjusted to a suitable temperature range more quickly.

[0101] In practical applications, the entire grinding disc 1 should include, from top to bottom, a grinding layer 100, a heating plate 4, and a fluid channel 10. Furthermore, the heating plate 4 in this application can be a conductive metal resistance sheet, which has good thermal conductivity, allowing the cooling medium to absorb heat from the grinding layer 100 more quickly through the heating sheet. It can also generate heat after the current is turned on, thereby heating the grinding layer 100. This allows for more flexible control of the temperature of the uppermost grinding layer 100 on the grinding disc 1, thus ensuring the grinding effect on the wafer 3.

[0102] In summary, to improve the cooling effect of wafers in the CMP process, this application incorporates a fluid channel within the grinding pad used for wafer grinding, and this fluid channel is connected to the cooling medium circulation pipeline. This allows the low-temperature fluid to flow within the fluid channel, thereby keeping the grinding surface of the grinding pad at a relatively low temperature, thus indirectly cooling the wafer. Compared to methods such as directly spraying low-temperature nitrogen onto the surface of the grinding pad for cooling, the cooling medium in this application flows inside the grinding pad, eliminating the problem of nitrogen overflowing into the surrounding space. The cooling effect on the grinding pad is obviously better, thereby improving the cooling effect on the wafer to a certain extent and ensuring the planarization grinding effect of the wafer.

[0103] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0104] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A grinding assembly for CMP process, characterized in that, Includes a grinding disc; a polishing head disposed above the grinding disc; and a drive device connected to the grinding disc; The polishing head is used to support and connect the wafer, so as to drive the wafer to be polished on the polishing surface of the polishing disk; the driving device is used to drive the polishing disk to rotate around the symmetrical central axis of the polishing disk. The grinding disc has a fluid channel inside, and a fluid inlet and a fluid outlet connected to the fluid channel are provided on the grinding disc. The fluid inlet and the fluid outlet are connected to a cooling medium circulation pipe. The cooling medium circulation pipe and the fluid channel in the grinding disc together form a cooling medium circulation loop.

2. The grinding assembly for the CMP process as described in claim 1, characterized in that, The polishing head includes a retaining ring that surrounds the side of the wafer and a temperature sensor that is attached to the surface of the retaining ring near the polishing disk, wherein the temperature sensing surface of the temperature sensor is flush with the surface of the wafer to be polished.

3. The grinding assembly for the CMP process as described in claim 2, characterized in that, Multiple temperature sensors are evenly arranged around the wafer.

4. The grinding assembly for the CMP process as described in any one of claims 1 to 3, characterized in that, The polishing head can drive the wafer to move radially above the grinding disk; The fluid channel includes at least a first fluid channel and a second fluid channel; Wherein, the first fluid channel is an annular channel with a width in the radial direction greater than the diameter of the wafer; The second fluid channel is a channel located within the ring of the annular channel; The first fluid channel is connected to the cooling working fluid circulation pipeline through a first fluid inlet and a first fluid outlet; The second fluid channel is connected to the cooling working fluid circulation pipeline through a second fluid inlet and a second fluid outlet; It also includes a control structure for controlling the opening or closing of the second fluid inlet and the second fluid outlet independently of the first fluid inlet and the first fluid outlet.

5. The grinding assembly for the CMP process as described in claim 4, characterized in that, The grinding disc includes an annular grinding disc and a circular grinding disc disposed within the annular grinding disc, and the annular grinding disc and the circular grinding disc are rotatable relative to each other; The first fluid channel is disposed in the annular grinding disk; the second fluid channel is disposed inside the annular grinding disk. The control structure includes a first through hole and a second through hole disposed on the inner ring wall of the annular grinding disc and connected to the first fluid channel; Both the second fluid inlet and the second fluid outlet are located on the outer wall of the circular grinding disc; When the annular grinding disc and the circular grinding disc rotate relative to each other to a first predetermined relative position, the first through hole and the second through hole are respectively connected to the second fluid inlet and the second fluid outlet; When the annular grinding disc and the circular grinding disc rotate relative to each other to a second predetermined relative position, the first through hole and the second through hole are not connected to the second fluid inlet and the second fluid outlet, respectively.

6. The grinding assembly for the CMP process as described in claim 5, characterized in that, The second fluid channel is a circular cavity inside the circular grinding disc; The second fluid inlet and the second fluid outlet are respectively located at both ends of the same diameter of the circular cavity; The central region of the circular cavity is provided with multiple flow dividers, and the length direction of each flow divider extends along the straight line where the second fluid inlet and the second fluid outlet are located.

7. The grinding assembly for the CMP process as described in claim 5, characterized in that, The first fluid inlet, the first fluid outlet, the first through hole, the second through hole, the second fluid inlet, and the second fluid outlet are all located on the same straight line; and the first fluid inlet, the first fluid outlet, the first through hole, and the second through hole are all located on both sides of the circular grinding disc.

8. The grinding assembly for the CMP process as described in claim 4, characterized in that, The first fluid inlet, the first fluid outlet, the second fluid inlet, and the second fluid outlet are all respectively disposed on the bottom surface of the grinding disc; The cooling working fluid circulation pipeline includes a first output pipe connected to the first fluid inlet, a second output pipe connected to the second fluid inlet, a first input pipe connected to the first fluid outlet, and a second input pipe connected to the second fluid outlet. The control structure includes control valves respectively installed on the first input pipe, the second input pipe, the first output pipe, and the second output pipe, and the opening and closing of each control valve can be controlled independently.

9. The grinding assembly for the CMP process as described in any one of claims 1 to 3, characterized in that, A heating plate is also embedded in the grinding disc, located between the grinding surface of the grinding disc and the fluid channel.

10. The grinding assembly for the CMP process as described in claim 9, characterized in that, The heating plate is a conductive metal resistor.

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