CMP polishing pad and CMP equipment
By setting a monitoring window and groove pattern on the CMP polishing pad, the problem of uneven polishing rate was solved, the uniformity of polishing rate was improved, and the uniformity between wafers and within wafers was improved.
Patent Information
- Application Number
- CN202410979567.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2026-01-20
AI Technical Summary
Existing CMP polishing pads cause uneven polishing rates at the monitoring window, especially with jumps within +/-30mm, which are difficult to improve by adjusting the pressure adjustment zone.
Multiple monitoring windows are set on the CMP polishing pad, and a groove pattern structure, including concentric circular grooves, is designed on the first surface. The isolation structure is used to adjust the polishing fluid washing rate, reduce the polishing fluid washing rate in the area affected by the monitoring window, and compensate for the increased impact of the monitoring window on the polishing fluid washing rate.
By designing the monitoring window and groove pattern structure, the uniformity of the grinding rate was improved, the uniformity between wafers and within wafers was enhanced, and the grinding uniformity was improved.
Smart Images
Figure CN121361028A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a semiconductor integrated circuit manufacturing equipment, in particular to a chemical mechanical polishing (CMP) pad. The present application also relates to a CMP equipment. BACKGROUND
[0002] The continuous shrinkage of advanced process nodes in semiconductor manufacturing leads to increasingly narrow process windows. The introduction and exploitation of "advanced weapons" for process window expansion play an important role in improving device performance. The next generation full vision (FVXE) assembly achieves the effect of in-situ adjustment of wafer topography by real-time optical monitoring of wafer topography and the use of multiple pressure controllers (MPC). The FVXE assembly is considered a non-metal layer real-time process controller (RTPC). The FVXE assembly needs to be matched with a triple-window (3-window) pad to ensure that the light path passes through the corresponding platen of the pad to the wafer to achieve the purpose of real-time improvement of uniformity (NU).
[0003] However, it is found during testing that the polishing rate of the wafer has a "jumping height" within + / - 30 mm, and this "jumping height" only occupies a part of the pressure adjustment zone that can be adjusted by one polishing head, so it is difficult to improve by pressure adjustment. SUMMARY
[0004] The technical problem to be solved by the present application is to provide a CMP pad that can prevent the adverse effects of monitoring windows on polishing rate under the condition of setting monitoring windows, thereby improving polishing uniformity. To this end, the present application also provides a CMP equipment.
[0005] To solve the above technical problems, the CMP pad provided by the present application comprises:
[0006] A first surface and a second surface opposite to each other, the first surface being a polishing surface and being circular.
[0007] A plurality of monitoring windows, each of the monitoring windows penetrating the first surface and the second surface, each of the monitoring windows being uniformly distributed on a first circular surface, a first annular region centered on the first circular surface being a monitoring window influence zone; the monitoring windows increase the polishing liquid scrubbing rate of the monitoring window influence zone.
[0008] The first surface is provided with a groove pattern structure for adjusting the polishing liquid brushing speed on the first surface, and the groove pattern structure reduces the polishing liquid brushing speed of the monitoring window influence area to compensate for the influence of the monitoring window on the increase of the polishing liquid brushing speed of the monitoring window influence area.
[0009] Further improvement is that the groove pattern structure comprises a plurality of concentric circular grooves.
[0010] In the radial direction of the first surface, each of the circular grooves is in a non-penetrating isolation structure, and the isolation structure serves as a structure for reducing the polishing liquid brushing speed of the monitoring window influence area.
[0011] Further improvement is that the width of the monitoring window influence area is less than the diameter of the center pressure adjustment area of the polishing head.
[0012] Further improvement is that the width of the monitoring window influence area is less than or equal to 60mm.
[0013] Further improvement is that the monitoring window is connected to the light emitting device and the spectrometer of the FVXE assembly through an optical fiber.
[0014] Further improvement is that the number of monitoring windows is three.
[0015] Further improvement is that the first circle is located in one of the circular grooves.
[0016] Further improvement is that the polishing object of the polishing pad is a non-metallic layer, and the FVXE assembly is used to monitor the topography of the non-metallic layer in real time.
[0017] To solve the above technical problems, the CMP device provided by the present application comprises a polishing pad.
[0018] Opposite first surface and second surface, the first surface is a polishing surface and is circular.
[0019] A plurality of monitoring windows, each of the monitoring windows penetrates the first surface and the second surface, each of the monitoring windows is uniformly distributed on a first circle, and a first annular area centered on the first circle is a monitoring window influence area; the monitoring window increases the polishing liquid brushing speed of the monitoring window influence area.
[0020] The first surface is provided with a groove pattern structure for adjusting the polishing liquid brushing speed on the first surface, and the groove pattern structure reduces the polishing liquid brushing speed of the monitoring window influence area to compensate for the influence of the monitoring window on the increase of the polishing liquid brushing speed of the monitoring window influence area.
[0021] The second surface of the polishing pad is arranged on a polishing table.
[0022] A polishing head is arranged above the first surface of the polishing pad, and is used to fix the polished piece and make the polished surface of the polished piece press against the first surface.
[0023] Further improvement is that the groove pattern structure comprises a plurality of concentric circular grooves.
[0024] In the radial direction of the first surface, each of the circular grooves is in an isolated structure which is not connected to each other, and the isolated structure is used as a structure for reducing the polishing liquid brushing rate of the monitoring window influence area.
[0025] Further improvement is that the polishing head is divided into a plurality of pressure adjustment areas, and the pressure of each of the pressure adjustment areas is adjusted by a multi-pressure controller.
[0026] The width of the monitoring window influence area is less than the diameter of the central pressure adjustment area of the polishing head.
[0027] Further improvement is that the width of the monitoring window influence area is less than or equal to 60mm.
[0028] Further improvement is that the CMP polishing equipment further comprises an FVXE assembly; and the monitoring window is connected to the light emitting device and the spectrometer of the FVXE assembly through an optical fiber.
[0029] Further improvement is that the number of the monitoring windows is 3.
[0030] Further improvement is that the first circle is located in one of the circular grooves.
[0031] Further improvement is that the polishing object of the polishing pad is a non-metallic layer formed on the polished piece, and the FVXE assembly is used to monitor the topography of the non-metallic layer in real time.
[0032] The CMP polishing pad of the present application is provided with a monitoring window, which changes the roughness of the area affected by the monitoring window and thus makes the roughness different from the area not affected by the monitoring window, thereby affecting the uniformity of the polishing rate. Therefore, the present application specially provides the groove pattern structure on the first surface of the polishing pad, and particularly, the groove pattern structure is set according to the requirement of adjusting the polishing liquid brushing rate on the first surface, so that the polishing liquid brushing rate of the area affected by the monitoring window is reduced to compensate the increase of the polishing liquid brushing rate of the area affected by the monitoring window, thus the polishing rate of the area affected by the monitoring window is well controlled, the polishing rate of the area affected by the monitoring window is prevented from jumping up, and finally the polishing uniformity, the wafer-to-wafer (WTW) uniformity and the wafer-to-wafer (WIW) uniformity are all improved.
[0033] In the present application, after the monitoring window is provided on the polishing pad, the polishing pad is connected with the FVXE assembly through the optical fiber, the FVXE assembly can optically and real-timely monitor the topography of the polishing object and realize real-time adjustment of the polishing process, for example, simultaneously using multiple pressure controllers to realize real-time adjustment of the topography of the polishing object, thereby improving the uniformity of the topography of the polishing object. BRIEF DESCRIPTION OF DRAWINGS
[0034] The present application will be further described in detail below in combination with the drawings and specific embodiments:
[0035] Figure 1 is a structural schematic view of the existing CMP equipment;
[0036] Figure 2 is a top view of the existing CMP equipment shown in Figure 1
[0037] Figure 3 is a structural schematic view of the polishing surface of the polishing pad of the existing CMP equipment;
[0038] Figure 4 is a schematic view of the polishing rate jump-up distribution area in a wafer when the polishing pad of the existing CMP equipment shown in Figure 3
[0039] Figure 5A is a structural schematic view of the polishing surface of the CMP polishing pad of the embodiment of the present application;
[0040] Figure 5B is a sectional structural schematic view of the CMP polishing pad of the embodiment of the present application along the AA dashed line in Figure 5A
[0041] Figure 6 is a structural schematic view of the CMP equipment of the embodiment of the present application;
[0042] Figure 7 is Figure 6 is a top view of a CMP device according to an embodiment of the present application;
[0043] Figure 8 is a schematic view of an influence area of a monitoring window in a wafer when polishing is performed using a polishing pad of an existing CMP device. Figure 6 DETAILED DESCRIPTION
[0044] The existing CMP polishing pad is obtained based on a detailed analysis of technical problems of the existing CMP polishing pad. The existing CMP polishing pad is described in detail as follows.
[0045] As Figure 1 is a schematic view of a structure of an existing CMP device. Figure 2 is a top view of the existing CMP device; the existing CMP device comprises a polishing pad 201. Figure 1 As
[0046] Figure 3 The polishing pad 201 comprises:
[0047] a first surface and a second surface opposite to each other, the first surface being a polishing surface and being circular. Figure 3 The surface shown is the first surface.
[0048] a plurality of monitoring windows 202, each of the monitoring windows 202 penetrating the first surface and the second surface, and each of the monitoring windows 202 being uniformly distributed on a first circle 203. In a three-monitoring-window polishing pad, the number of the monitoring windows 202 is three.
[0049] The second surface of the polishing pad 201 is arranged on a polishing table 102.
[0050] A polishing head 108 is arranged above the first surface of the polishing pad 201, and the polishing head 108 is used to fix a polished piece 101 and make a polished surface of the polished piece 101 abut against the first surface. The polished piece 101 is usually a wafer.
[0051] The monitoring windows 202 are connected to a light emitting device 106 and a spectrograph 105 of an FVXE assembly 104 through optical fibers 107.
[0052] The polishing object of the polishing pad 201 is a non-metallic layer on the polished piece 101, and the FVXE assembly 104 is used to monitor the topography of the non-metallic layer in real time.
[0053] As Figure 1 As shown, the bottom of the polishing table 102 is connected with a rotating shaft 103, and during the polishing process, the rotating shaft 103 drives the whole polishing table 102 to rotate. Figure 1 In the middle of the figure, a rotating arrow is used to indicate the rotation. Figure 1 In the middle of the figure, the FVXE assembly 104 is arranged in the space at the bottom of the polishing table 102, and the power supply or signal line of the FVXE assembly 104 is led out along the rotating shaft 103.
[0054] A plurality of circular grooves 204 and a plurality of longitudinal grooves 205 are arranged on the first surface. The longitudinal grooves 205 are used to connect the circular grooves 204 in the radial direction. During the polishing process, the polishing liquid (not shown) will move along the first surface of the polishing pad 201 and form a uniform distribution structure under the action of the centrifugal force generated by the rotation of the polishing table 102, and the longitudinal grooves 205 will increase the flow of the polishing liquid between the circular grooves 204 in the radial direction.
[0055] During the test, it is found that the polishing rate of the wafer has a "jumping" within + / - 30 mm, and this "jumping" only occupies a part of the pressure adjustment zone that can be adjusted by one polishing head, so it is difficult to improve by pressure adjustment. For example, Figure 4 As shown, the existing CMP equipment uses Figure 3 As shown, the existing CMP equipment uses
[0056] In the prior art, the polishing head 108 is usually divided into a plurality of pressure adjustment zones, and the pressure of each pressure adjustment zone is independently adjusted by a plurality of pressure controllers, so as to adjust the polishing rate of each pressure adjustment zone. However, in the prior art, Figure 4 In the middle of the figure, the range of the area corresponding to the central pressure adjustment zone of the polishing head 108 shown by the dashed circle 101a is larger than the range of the area shown by the dashed circle 101b, so the polishing rate of the area shown by the dashed circle 101b is improved by pressure adjustment. Because the pressure of the central pressure adjustment zone is adjusted alone, the polishing rate of the annular area between the dashed circles 101a and 101b is also affected, and finally the consistency of the polishing rate still does not meet the requirements. Figure 4 In the middle of the figure, the range of the area corresponding to the central pressure adjustment zone of the polishing head 108 shown by the dashed circle 101a is larger than the range of the area shown by the dashed circle 101b, so the polishing rate of the area shown by the dashed circle 101b is improved by pressure adjustment. Because the pressure of the central pressure adjustment zone is adjusted alone, the polishing rate of the annular area between the dashed circles 101a and 101b is also affected, and finally the consistency of the polishing rate still does not meet the requirements.
[0057] As shown in the figure, Figure 5AThe diagram shown is a schematic representation of the abrasive surface of the CMP abrasive pad 301 according to an embodiment of the present invention; as shown... Figure 5B As shown, it is along Figure 5A The cross-sectional structure of the CMP polishing pad 301 of this invention, as shown by the dashed line AA in the middle, is schematically illustrated. The CMP polishing pad 301 of this invention includes:
[0058] The first surface and the second surface are opposite, the first surface is a ground surface and is circular. Figure 5A The surface shown is the first surface, corresponding to Figure 5B The front side; the second surface corresponds to Figure 5B The back side of the middle.
[0059] Multiple monitoring windows 302 are provided, each of which penetrates the first surface and the second surface. The monitoring windows 302 are evenly distributed on the first circle 304, and the first annular area centered on the first circle 304 is the monitoring window influence area. The monitoring windows 302 increase the grinding fluid washing rate in the monitoring window influence area.
[0060] In this embodiment of the invention, the first circular 304 is referred to as Figure 7 As shown by the dashed circle, Figure 7 The circular groove 303 is omitted from the text.
[0061] In some embodiments, the number of monitoring windows 302 is three.
[0062] Please also refer to Figure 7 As shown, the workpiece 401 to be polished is typically a wafer. The monitoring window 302 needs to monitor the thickness of the workpiece 401 during the polishing process. Therefore, the workpiece 401 needs to be placed on the first circular surface 304. When the polishing pad 301 rotates, the annular area centered on the first circular surface 304 will polish the workpiece 401, and the workpiece 401 will also rotate with the polishing head 408. The monitoring window's influence area, after being mapped onto the workpiece 401, corresponds to... Figure 8 The region shown by the dashed circle 401b with a radius of r102.
[0063] A groove pattern structure is provided on the first surface. The groove pattern structure is used to adjust the brushing rate of the polishing fluid on the first surface and reduces the brushing rate of the polishing fluid in the area affected by the monitoring window to compensate for the increase in the brushing rate of the polishing fluid in the area affected by the monitoring window 302.
[0064] In embodiments of the present invention, such as Figure 5AAs shown, the groove pattern structure comprises a plurality of concentric circular grooves 303. In the radial direction of the first surface, each of the circular grooves 303 is isolated from each other, and the isolation structure serves as a structure for reducing the polishing solution brushing rate of the monitoring window affected area.
[0065] In the embodiment of the present application, the first circle 304 is located in one of the circular grooves 303.
[0066] The cross-sectional structure of the circular groove 303 and the monitoring window 302 can be referred to Figure 5B As shown, it can be seen that the roughness of the first surface near the monitoring window 302 is different from that of other areas, and thus the brushing frequency of the polishing solution is increased, which in turn increases the polishing rate of the area near the monitoring window 302, i.e. the monitoring window affected area.
[0067] In the embodiment of the present application, each of the circular grooves 303 is isolated from each other, and thus the polishing solution cannot flow between the circular grooves 303 of different radii through the longitudinal groove, so that the refreshing rate of the polishing solution in each area is reduced, and the refreshing rate of the polishing solution in the monitoring window affected area is also reduced, thereby compensating for the increase in the refreshing rate of the polishing solution caused by the monitoring window 302 itself.
[0068] In the embodiment of the present application, the width of the monitoring window affected area is less than the diameter of the central pressure adjustment area of the polishing head 408. The structure of the polishing head 408 can be referred to Figure 6 As shown, the polishing head 408 is usually divided into a plurality of pressure adjustment areas, and the pressure of each pressure adjustment area is independently adjusted by a multi-pressure controller, so as to adjust the polishing rate of each pressure adjustment area. As shown, Figure 8 As shown, the area shown by the dashed circle 401a is one-to-one corresponding to the area on which the central pressure adjustment area of the polishing head 408 acts. It can be seen that the area shown by the dashed circle 401a is not equal to the area shown by the dashed circle 401b, and the area shown by the dashed circle 401a is greater than the area shown by the dashed circle 401b. Thus, if only the polishing rate of the area shown by the dashed circle 401b is increased, the pressure of the central pressure adjustment area cannot be adjusted to reduce the polishing rate of the area shown by the dashed circle 401b, because adjusting the pressure of the central pressure adjustment area alone will also affect the polishing rate of the annular area between the dashed circles 401a and 401b, and finally the consistency of the polishing rate cannot meet the requirements.
[0069] In some embodiments, the width of the monitoring window affected area is less than or equal to 60 mm. Corresponding to Figure 8The center of the r102 is 30 mm; and the radius of the center pressure adjustment area of the polishing head 408, i.e. r101, is 40 mm.
[0070] In the embodiment of the present application, please refer to Figure 6 As shown in the figure, the monitoring window 302 is connected to the light emitting device 406 and the spectrometer 405 of the FVXE assembly 404 through the optical fiber 407.
[0071] The polishing object of the polishing pad 301 is a non-metallic layer, and the FVXE assembly 404 is used to monitor the topography of the non-metallic layer in real time.
[0072] The monitoring window 302 is arranged on the CMP polishing pad 301 in the embodiment of the present application, which will change the roughness of the area of the monitoring window 302 and thus make the roughness of the area of the monitoring window 302 different from the roughness of the area not affected by the monitoring window 302, thereby affecting the uniformity of the polishing rate. Therefore, the groove pattern structure on the first surface of the polishing pad 301 is specially arranged in the embodiment of the present application, in particular, the groove pattern structure is arranged according to the adjustment requirement of the polishing liquid scrubbing rate on the first surface, so as to reduce the polishing liquid scrubbing rate of the monitoring window affected area 401b to compensate the influence of the monitoring window 302 on the increase of the polishing liquid scrubbing rate of the monitoring window affected area 401b. In this way, the polishing rate of the monitoring window affected area 401b can be well controlled, the polishing rate of the monitoring window affected area 401b is prevented from jumping up, and finally the polishing uniformity, the wafer-to-wafer (WTW) uniformity and the wafer-to-wafer (WIW) uniformity are all improved.
[0073] In the embodiment of the present application, after the monitoring window 302 is arranged on the polishing pad 301, the FVXE assembly 404 can be connected through the optical fiber 407, and the FVXE assembly 404 can optically monitor the topography of the polishing object in real time and realize real-time adjustment of the polishing process, for example, a plurality of pressure controllers are simultaneously used to realize real-time adjustment of the topography of the polishing object, thereby improving the uniformity of the topography of the polishing object.
[0074] As shown in the figure, the CMP equipment in the embodiment of the present application comprises: Figure 6 As shown in the figure, the CMP equipment in the embodiment of the present application comprises: Figure 7 As shown in the figure, the CMP equipment in the embodiment of the present application comprises: Figure 6 As shown in the figure, the CMP equipment in the embodiment of the present application comprises:
[0075] As shown in the figure, the CMP equipment in the embodiment of the present application comprises: Figure 5A As shown in the figure, the CMP equipment in the embodiment of the present application comprises:
[0076] The first surface and the second surface are opposite to each other, and the first surface is a polishing surface and is circular. Figure 5A The first surface is shown in the figure, and corresponds toFigure 5B The front side; the second surface corresponds to Figure 5B The back side of the middle.
[0077] Multiple monitoring windows 302 are provided, each of which penetrates the first surface and the second surface. The monitoring windows 302 are evenly distributed on the first circle 304, and the first annular area centered on the first circle 304 is the monitoring window influence area. The monitoring windows 302 increase the grinding fluid washing rate in the monitoring window influence area.
[0078] In this embodiment of the invention, the first circular 304 is referred to as Figure 7 As shown by the dashed circle, Figure 7 The circular groove 303 is omitted from the text.
[0079] In some embodiments, the number of monitoring windows 302 is three.
[0080] Please also refer to Figure 7 As shown, the workpiece 401 to be polished is typically a wafer. The monitoring window 302 needs to monitor the thickness of the workpiece 401 during the polishing process. Therefore, the workpiece 401 needs to be placed on the first circular pad 304. When the polishing pad 301 rotates, the annular area centered on the first circular pad 304 polishes the workpiece 401. The area affected by the monitoring window, after being mapped onto the workpiece 401, corresponds to... Figure 8 The region shown by the dashed circle 401b with a radius of r102.
[0081] A groove pattern structure is provided on the first surface. The groove pattern structure is used to adjust the brushing rate of the polishing fluid on the first surface and reduces the brushing rate of the polishing fluid in the area affected by the monitoring window to compensate for the increase in the brushing rate of the polishing fluid in the area affected by the monitoring window 302.
[0082] The second surface of the abrasive pad 301 is disposed on the abrasive table 402.
[0083] A grinding head 408 is provided above the first surface of the grinding pad 301. The grinding head 408 is used to fix the workpiece 401 to be ground and press the surface of the workpiece 401 to be ground against the first surface.
[0084] In embodiments of the present invention, such as Figure 5A As shown, the groove pattern structure includes a plurality of concentric circular grooves 303. Along the radial direction of the first surface, each of the circular grooves 303 is isolated from the others, serving as a structure to reduce the slurry washing rate of the monitoring window's affected area.
[0085] In the embodiment of the present application, the first circle 304 is located in one of the circular grooves 303.
[0086] The cross-sectional structure of the circular groove 303 and the monitoring window 302 is shown in Figure 5B As can be seen from the figure, the roughness of the first surface near the monitoring window 302 is different from that of other areas, which will increase the brushing frequency of the polishing liquid, and thus increase the polishing rate of the area near the monitoring window 302, i.e. the monitoring window influence area.
[0087] In the embodiment of the present application, the circular grooves 303 are not connected to each other, so the polishing liquid will not flow through the longitudinal grooves between the circular grooves 303 of different radii. Therefore, the refreshing rate of the polishing liquid in each area will be reduced, and the refreshing rate of the polishing liquid in the monitoring window influence area will also be reduced, thereby compensating for the increase in the refreshing rate of the polishing liquid caused by the monitoring window 302 itself.
[0088] In the embodiment of the present application, the width of the monitoring window influence area is less than the diameter of the central pressure adjustment area of the polishing head 408. The structure of the polishing head 408 is shown in Figure 6 The polishing head 408 is usually divided into multiple pressure adjustment areas, and the pressure of each pressure adjustment area is independently adjusted by a multiple pressure controller, so as to adjust the polishing rate of each pressure adjustment area. As shown in Figure 8 The dashed circle 401a shows the area on which the central pressure adjustment area of the polishing head 408 acts on the polished member 401, and they are one-to-one corresponding. As can be seen, the area shown by the dashed circle 401a is not equal to the area shown by the dashed circle 401b, and the area shown by the dashed circle 401a is larger than the area shown by the dashed circle 401b. Therefore, if only the polishing rate of the area shown by the dashed circle 401b is increased, the pressure of the central pressure adjustment area cannot be adjusted to reduce the polishing rate of the area shown by the dashed circle 401b, because adjusting the pressure of the central pressure adjustment area alone will also affect the polishing rate of the annular area between the dashed circles 401a and 401b, and finally the consistency of the polishing rate will still not meet the requirements.
[0089] In some embodiments, the width of the monitoring window influence area is less than or equal to 60 mm. Corresponding to Figure 8 In the embodiment of the present application, the width of the monitoring window influence area is less than or equal to 60 mm. Corresponding to
[0090] In the embodiment of the present application, the width of the monitoring window influence area is less than or equal to 60 mm. Corresponding to Figure 6As shown, the monitoring window 302 connects the light emitting device 406 of the FVXE assembly 404 and the spectrometer 405 through the optical fiber 407.
[0091] The polishing object of the polishing pad 301 is a non-metal layer, and the FVXE assembly 404 is used to monitor the profile of the non-metal layer in real time.
[0092] As shown, the bottom of the polishing table 402 is connected with the rotating shaft 403, and the rotating shaft 403 drives the whole polishing table 402 to rotate during the polishing process. Figure 6 As shown, the bottom of the polishing table 402 is connected with the rotating shaft 403, and the rotating shaft 403 drives the whole polishing table 402 to rotate during the polishing process. Figure 6 In the middle, a rotating arrow line is used to represent the rotation. Figure 6 In the middle, the FVXE assembly 404 is arranged in the space at the bottom of the polishing table 402, and the power supply or signal line of the FVXE assembly 404 is led out along the rotating shaft 403.
[0093] In the prior art, the 3window pad three-hole position roughness (asperity) is different from other places, which leads to a faster polishing liquid brushing rate at this position, and this position corresponds to the wafer center+ / -30mm, which leads to a high wafer center polishing rate. In the embodiment of the present application, the longitudinal groove of the pad (polishing pad) is removed, and the polishing liquid brushing frequency at the 3window position is reduced, so as to reduce the wafer center polishing rate.
[0094] After the longitudinal groove is removed in the embodiment of the present application, the 30mm inside of the wafer changes from a convex shape to a flat shape. The Nu% (uniformity) is reduced from 6.87% to 2.67%, which can solve the profile problem of the wafer center. After the FVXE function is introduced, the Nu% of wafer to wafer (WTW), within wafer (WIW) and marathon data are all improved by more than 60% compared with the open loop. The open loop means that the FVXE is not used for real-time feedback control of polishing.
[0095] In the prior art, the longitudinal grooves can not only increase the flow of slurry to the pad center, but also remove particles or byproducts on the polishing pad and wafer, thereby improving defects. Experiments show that, after the longitudinal grooves are removed in the embodiments of the present application, the defect level can be equivalent to the baseline of the prior art by adjusting the process recipe, such as adjusting the parameters of pad condition, pad clean / wafer rinse, and brush.
[0096] The above describes the present application in detail through specific embodiments, but these do not constitute a limitation on the present application. Those skilled in the art can also make many modifications and improvements without departing from the principles of the present application, and these should also be considered as falling within the protection scope of the present application.
Claims
1. A CMP polishing pad, characterized by, The polishing pad comprises: a first surface and a second surface opposite to each other, the first surface being a polishing surface and being circular; a plurality of monitoring windows, each of the monitoring windows penetrating through the first surface and the second surface, each of the monitoring windows being uniformly distributed on a first circle, and a first annular region centered on the first circle being a monitoring window influence area; the monitoring window increases a polishing liquid scrubbing rate of the monitoring window influence area; a groove pattern structure is arranged on the first surface, the groove pattern structure is used for adjusting the polishing liquid scrubbing rate on the first surface, and the groove pattern structure reduces the polishing liquid scrubbing rate of the monitoring window influence area to compensate for the influence of the monitoring window on the increase of the polishing liquid scrubbing rate of the monitoring window influence area.
2. The CMP polishing pad of claim 1, wherein: The groove pattern structure comprises a plurality of concentric circular grooves; in a radial direction of the first surface, each of the circular grooves is in an isolation structure that does not penetrate each other, and the isolation structure is used as a structure for reducing the polishing liquid scrubbing rate of the monitoring window influence area.
3. The CMP polishing pad of claim 2, wherein: The width of the monitoring window influence area is less than the diameter of a central pressure adjustment area of a polishing head.
4. The CMP polishing pad of claim 3, wherein: The width of the monitoring window influence area is less than or equal to 60 mm.
5. The CMP polishing pad of claim 1, wherein: The monitoring window is connected to a light emitting device and a spectrometer of an FVXE assembly through an optical fiber.
6. The CMP polishing pad of claim 1, wherein: The number of the monitoring windows is three.
7. The CMP polishing pad of claim 2, wherein: The first circle is located in one of the circular grooves.
8. The CMP polishing pad of claim 5, wherein: The polishing object of the polishing pad is a non-metallic layer, and the FVXE assembly is used for monitoring the morphology of the non-metallic layer in real time.
9. A CMP apparatus characterized by comprising: The polishing pad comprises: a first surface and a second surface opposite to each other, the first surface being a polishing surface and being circular; a plurality of monitoring windows, each of the monitoring windows penetrating through the first surface and the second surface, each of the monitoring windows being uniformly distributed on a first circle, and a first annular region centered on the first circle being a monitoring window influence area; the monitoring window increases a polishing liquid scrubbing rate of the monitoring window influence area; a groove pattern structure is arranged on the first surface, the groove pattern structure is used for adjusting the polishing liquid scrubbing rate on the first surface and the groove pattern structure reduces the polishing liquid scrubbing rate of the monitoring window influence area to compensate for the influence of the monitoring window on the increase of the polishing liquid scrubbing rate of the monitoring window influence area; the second surface of the polishing pad is arranged on a polishing table; a polishing head is arranged above the first surface of the polishing pad, and the polishing head is used for fixing a polished piece and pressing a polished surface of the polished piece against the first surface. The groove pattern structure comprises a plurality of concentric circular grooves; in a radial direction of the first surface, each of the circular grooves is in an isolation structure that does not penetrate each other, and the isolation structure is used as a structure for reducing the polishing liquid scrubbing rate of the monitoring window influence area.
10. The CMP polishing apparatus of claim 9, wherein: The polishing head is divided into a plurality of pressure adjustment areas, and the pressure of each of the pressure adjustment areas is adjusted by a multi-pressure controller. The width of the monitoring window influence area is less than the diameter of a central pressure adjustment area of a polishing head.
11. The CMP polishing apparatus of claim 10, wherein: The width of the monitoring window influence area is less than or equal to 60 mm. 12. The CMP polishing apparatus of claim 11, wherein: 13. The CMP polishing apparatus of claim 9, wherein: The CMP polishing apparatus further comprises an FVXE assembly; the monitoring window is connected to a light emitting device and a spectrometer of the FVXE assembly through an optical fiber.
14. The CMP polishing apparatus of claim 9, wherein: The number of the monitoring windows is three.
15. The CMP polishing apparatus of claim 10, wherein: The first circle is located in one of the circular grooves.
16. The CMP polishing pad of claim 13, wherein: The polishing object of the polishing pad is a non-metallic layer formed on the polished object, and the FVXE assembly is used for monitoring the topography of the non-metallic layer in real time.