Wafer polishing apparatus and wafer polishing device

Abstract

The embodiment of the present application provides a wafer grinding device and a wafer grinding equipment, the wameer grinding device comprises a grinding disc, a grinding fence and a cleaning assembly; the grinding disc is used for placing a wafer to be ground; the grinding fence is surrounded outside the grinding disc; in the perspective angle, the projection of the grinding disc is located in the projection surrounding area of the grinding fence; wherein, the projection area of the grinding disc is used as the grinding area, and the projection surrounding area of the grinding fence is used for limiting the grinding liquid of the wafer to be ground in the grinding area; the cleaning assembly is fixed to the side of the grinding fence facing the grinding disc, and the distance of the cleaning assembly along the normal direction of the grinding fence facing the grinding disc is less than or equal to the distance between the grinding fence and the grinding disc, so as to clean the overflowed grinding liquid around the grinding disc, thereby the cleaning difficulty of the grinding disc is reduced, and the product yield is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, specifically to a wafer grinding apparatus and wafer grinding equipment. Background Technology

[0002] Chemical mechanical polishing (CMP) plays a crucial role in semiconductor manufacturing processes, achieving wafer surface planarization through the relative movement between the wafer and polishing pads. During polishing, the wafer to be polished is typically attached face down to the polishing pad of a wafer polishing apparatus. A single wafer polishing apparatus may contain one or more polishing pads. The rotation of the polishing pad causes the wafer's polished surface to rotate relative to it, and the polishing head corresponding to the polishing pad applies downward pressure, pressing the wafer firmly onto the polishing pad. Simultaneously, the polishing head also rotates relative to the polishing pad, polishing the wafer's surface. A slurry dispensing arm is also provided for each polishing pad, delivering slurry to the pad and distributing it evenly through centrifugal force. The chemical components in the slurry react chemically with the wafer's polished surface, and the mechanical friction of the polishing head achieves the wafer surface planarization effect.

[0003] However, as the polishing pad rotates at high speed, polishing fluid will overflow around the polishing pad and leave residue. If it is not removed in time, it will form crystals around the polishing pad, increasing the difficulty of cleaning the polishing pad. Furthermore, these crystals can also scratch the wafer products and reduce the product yield. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a wafer grinding apparatus and a wafer grinding equipment that can clean up the grinding fluid overflowing around the grinding pad in a timely manner, reducing the difficulty of cleaning the grinding pad and thus improving product yield.

[0005] The first aspect of this invention provides a wafer polishing apparatus, applied to wafer polishing equipment, comprising: a polishing disc, a polishing guard plate, and a cleaning component;

[0006] The grinding disc is used to place the wafer to be ground;

[0007] The grinding enclosure surrounds the grinding disk. From a top-down perspective, the projection of the grinding disk is located within the area surrounded by the projection of the grinding enclosure. The projection area of ​​the grinding disk is used as the grinding area, and the projection area of ​​the grinding enclosure is used to confine the grinding fluid of the wafer to be ground within the grinding area.

[0008] The cleaning component is fixed to the grinding plate on the side facing the grinding disk, and the distance of the cleaning component along the normal direction of the grinding plate towards the grinding disk is less than or equal to the distance between the grinding plate and the grinding disk, and is used to clean the grinding liquid overflowing around the grinding disk.

[0009] Optionally, the cleaning assembly includes a cleaning component and an engaging component;

[0010] The cleaning component engages with the engaging component and is used to clean the polishing fluid that has overflowed around the polishing disc;

[0011] The engaging component includes a slot facing the grinding disc for engaging the cleaning component to a target position.

[0012] Optionally, with the direction perpendicular to the surface of the grinding disc as the thickness direction, the thickness of the cleaning component is greater than or equal to the thickness of the grinding disc; with the direction of the grinding plate toward the normal of the grinding disc as the width direction, the width of the cleaning component is greater than the width of the slot.

[0013] Optionally, the wafer grinding apparatus further includes a snap-fit ​​connector for snapping the engagement component.

[0014] Optionally, corresponding to the snap-fit ​​plug, the grinding plate is provided with a first snap-fit ​​hole, and the engaging component is provided with a second snap-fit ​​hole on the side facing the grinding plate, so that the snap-fit ​​plug can penetrate the grinding plate and engage with the engaging component based on the first snap-fit ​​hole and the second snap-fit ​​hole.

[0015] Optionally, with the normal direction of the grinding plate toward the grinding disk as the length direction, the length of the snap-fit ​​plug is less than or equal to the sum of the length of the grinding plate and the length of the second snap-fit ​​hole;

[0016] Wherein, the length of the second snap-fit ​​hole is less than the thickness of the snap-fit ​​component on one side of the second snap-fit ​​hole.

[0017] Optionally, the wafer polishing apparatus further includes a cleaning brush for cleaning impurities on the wafer surface;

[0018] The cleaning component is made of the same material as the cleaning brush.

[0019] Optionally, corresponding to the cleaning component, the wafer polishing apparatus further includes a spray component for cleaning the cleaning component;

[0020] The spray assembly includes a nozzle and a liquid transfer pipe; the nozzle is located on the cleaning assembly and is used to spray the cleaning assembly; the liquid transfer pipe is located on the side of the abrasive enclosure away from the cleaning assembly and is used to supply spray liquid to the nozzle.

[0021] Optionally, the liquid transfer pipe is provided with a bend, and the liquid transfer pipe is connected to the nozzle based on the bend.

[0022] A second aspect of the present invention provides a wafer polishing apparatus, including the wafer polishing device as described above.

[0023] In this embodiment of the invention, a cleaning component is fixed to the side of the grinding plate facing the grinding disk. The distance of the cleaning component along the normal direction of the grinding plate towards the grinding disk is less than or equal to the distance between the grinding plate and the grinding disk. This allows the cleaning component to contact the edge of the grinding disk. During the rotation of the grinding disk, the cleaning component promptly cleans the grinding fluid overflowing around the grinding disk, thereby reducing the accumulation of grinding fluid around the grinding disk, reducing the difficulty of cleaning the grinding disk, and thus improving the yield of the produced wafer products. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 A top view schematic diagram of a wafer grinding device;

[0026] Figure 2 This is a top view schematic diagram of the wafer grinding apparatus provided in an embodiment of the present invention;

[0027] Figure 3 For the corresponding Figure 2 A cross-sectional view of the wafer grinding apparatus along line Aa. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0029] Figure 1 This is a top view schematic diagram of a wafer grinding apparatus. Figure 1 As shown, the wafer polishing apparatus may include a polishing disc 10 and a polishing guard plate 11.

[0030] The grinding disc 10 is used to place the wafer to be ground during the chemical mechanical polishing (CMP) process. By contacting the wafer surface and applying pressure, it removes the inhomogeneity and roughness of the wafer surface, so as to achieve the required flatness and smoothness.

[0031] The polishing pad 10 can also be attached to a polishing pad (not shown in the figure), and the wafer surface is planarized through the relative movement between the wafer and the polishing pad. Furthermore, a polishing head 12 can be provided on the polishing pad to provide downward pressure and press the wafer firmly onto the polishing pad. When the polishing pad attached to the polishing pad 10 rotates under the drive of a motor, the polishing head 12 can also rotate relative to it. A polishing pad trimming disc 13 can also be provided on the polishing pad to trim and polish the polishing pad, maintaining its flatness and uniformity to ensure consistent polishing of the wafer surface during CMP. Simultaneously, a polishing slurry distribution arm 14 can be provided on the polishing pad to distribute polishing slurry onto the polishing pad. Specifically, the polishing slurry can be delivered to the polishing pad through the polishing slurry distribution arm and evenly distributed on the polishing pad based on the centrifugal force of the rotating polishing pad. The polishing slurry is typically composed of an abrasive and a chemical solution, and removes surface unevenness and impurities through friction with the wafer surface.

[0032] After the polishing slurry is dispensed onto the polishing pad by the polishing slurry dispensing arm, the flowing slurry will overflow around the polishing pad due to the rotation of the pad, leaving residue. Furthermore, the overflowing slurry will splash as the pad rotates, contaminating the surrounding environment and devices. To prevent slurry splashing, a polishing guard 11 can be provided outside the polishing pad to confine the slurry within the polishing area. The polishing guard 11 also prevents impurities from entering and damage to the wafer substrate.

[0033] However, if the polishing slurry remaining around the polishing pad is not removed in time, it will gradually crystallize. These crystals are difficult to remove, increasing the difficulty of cleaning the polishing pad. Furthermore, the presence of these crystals can also scratch the wafer products, reducing product yield.

[0034] In view of this, embodiments of the present invention provide an improved wafer polishing apparatus and wafer polishing equipment. By fixing a cleaning component on the side of the polishing shroud facing the polishing disk, and the distance of the cleaning component along the normal direction of the polishing shroud towards the polishing disk is less than or equal to the distance between the polishing shroud and the polishing disk, the cleaning component can contact the edge of the polishing disk. During the rotation of the polishing disk, the cleaning fluid overflowing around the polishing disk is cleaned in a timely manner, thereby reducing the accumulation of polishing fluid around the polishing disk, reducing the difficulty of cleaning the polishing disk, and thus improving the yield of the produced wafer products.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Figure 2 This is a top view schematic diagram of a wafer grinding apparatus provided in an embodiment of the present invention. Figure 2 As shown, the wafer polishing apparatus may include: polishing disc 100, polishing guard plate 110 and cleaning assembly 120.

[0037] The grinding disc 100 is used to place the wafer to be ground. In an optional implementation, a grinding pad may also be attached to the grinding disc. Moreover, to avoid damaging the wafer and to provide a stable grinding effect and a long service life, the grinding disc may be made of polyurethane with good wear resistance and chemical corrosion resistance, or a polyurethane substrate coated with a polyurethane elastic layer.

[0038] The grinding baffle 110 surrounds the grinding disk 100, and from a top-view perspective, the projection of the grinding disk 100 can be located within the area surrounded by the projection of the grinding baffle 110. Since the wafer to be ground is placed on the grinding disk, the projected area of ​​the grinding disk 100 can be used as the grinding area. The area surrounding the projection of the grinding baffle 110 can be used to confine the polishing slurry of the wafer to be ground within the grinding area, thereby preventing splashing of the polishing slurry from contaminating or damaging the surrounding environment and devices. In an optional implementation, the grinding baffle can be made of the same material as the grinding disk, such as polyurethane with good elasticity.

[0039] The cleaning component 120 is fixed to the side of the grinding plate 110 facing the grinding disk 100, and the cleaning component 120 extends along the normal direction of the grinding plate 110 towards the grinding disk 100. Figure 2 The distance (in the direction indicated by the dashed arrow) can be less than or equal to the distance between the grinding plate 110 and the grinding disk 100, used to clean the grinding fluid that overflows around the grinding disk.

[0040] It is understandable that when the distance of the cleaning component along the normal direction of the grinding plate towards the grinding disc is less than or equal to...， When the distance between the grinding bezel and the grinding disc is set, the cleaning component can contact the edge of the grinding disc, thereby enabling timely cleaning of the grinding fluid overflowing around the grinding disc during its rotation and reducing its accumulation. In an optional example, when the distance of the cleaning component along the grinding bezel towards the normal direction of the grinding disc is less than the distance between the grinding bezel and the grinding disc (the difference can be slight), this still achieves the goal of timely cleaning of the grinding fluid overflowing around the grinding disc during its rotation and reducing its accumulation. The distance of the cleaning component along the grinding bezel towards the normal direction of the grinding disc can also be set according to actual needs in this embodiment of the invention, and the invention does not impose limitations in this regard.

[0041] As can be seen, in this embodiment of the invention, a cleaning component is fixed to the side of the grinding plate facing the grinding disk, and the distance of the cleaning component along the normal direction of the grinding plate towards the grinding disk is less than or equal to the distance between the grinding plate and the grinding disk, so that the cleaning component can contact the edge of the grinding disk. During the rotation of the grinding disk, the grinding fluid overflowing around the grinding disk is cleaned in time, thereby reducing the accumulation of grinding fluid around the grinding disk, reducing the difficulty of cleaning the grinding disk, and thus improving the yield of the produced wafer products.

[0042] In some embodiments, to secure the cleaning component to the abrasive plate, refer to Figure 2 As shown, the cleaning assembly 120 may include a cleaning component 121 and a locking component 122. To facilitate understanding of the structure of the cleaning component in the wafer polishing apparatus of this embodiment, the corresponding... Figure 2 Line Aa is shown. Figure 3 An exemplary cross-sectional view of a wafer grinding apparatus according to an embodiment of the present invention is shown along line Aa.

[0043] Combination Figure 2 and Figure 3 As shown, the cleaning component 121 can be engaged with the engaging component 122 to clean the polishing fluid that has overflowed around the polishing disc.

[0044] The engaging component 122 may include a slot 1221, which may be positioned facing the cleaning component 121 to engage the cleaning component 121 to a target position.

[0045] The target position can be a position corresponding to the side of the grinding pad away from the wafer to be ground (i.e., the bottom position of the grinding pad). In an optional example, the target position can be a position below the bottom of the grinding pad, for example... Figure 3 The position corresponding to the height z; it can also be the position equal to the bottom of the grinding disc.

[0046] It should be noted that, in order to ensure the cleaning effect of the cleaning components in the cleaning assembly in this embodiment of the invention, in an optional example, the cleaning components may be positioned perpendicular to the surface of the grinding disc. Figure 3 The direction indicated by the dashed arrow B is the thickness direction. The thickness of the cleaning component can be greater than or equal to the thickness of the grinding disc. Figure 3 The example is illustrated with the cleaning component having a thickness z greater than the grinding disc thickness r. Furthermore, since the distance m from the grinding enclosure to the grinding disc is small, the grinding enclosure can be positioned in the direction normal to the cleaning component (…). Figure 3 The direction indicated by the dashed arrow b) is the width direction. In this embodiment of the invention, the width of the cleaning component can be greater than the thickness of the slot, such as... Figure 3 As shown, the width n of the cleaning component is greater than the width x of the slot, so that the cleaning component protrudes from the slot and contacts the grinding disc.

[0047] In some embodiments, the wafer grinding apparatus may further include a snap-fit ​​connector 130 for snapping into the engagement component 122.

[0048] As an optional implementation, corresponding to the snap-fit ​​connector 130, the grinding plate may be provided with a first snap-fit ​​hole. Figure 3 The first snap-fit ​​hole indicates the position of the snap-fit ​​connector inserted into the grinding plate, and the snap-fit ​​component has a second snap-fit ​​hole on the side facing the grinding plate. Figure 3 The position of the snap-fit ​​plug inserted into the snap-fit ​​component indicates the second snap-fit ​​hole, so that the snap-fit ​​plug 130, based on the first snap-fit ​​hole and the second snap-fit ​​hole, passes through the grinding plate 110 and snaps into the snap-fit ​​component 122.

[0049] Wherein, the length direction is defined as the normal direction of the card connector toward the engaging component. Figure 3 (in the direction indicated by the dashed arrow C), the length of the snap-fit ​​connector 130 can be less than or equal to the length of the grinding plate. Figure 3 (shown as b1) and the second snap-fit ​​hole ( Figure 3 The sum of the lengths of the holes, shown as b2).

[0050] In an optional example, to ensure that the insertion of the snap-fit ​​connector into the engaging component does not affect the engagement of the cleaning component, the length of the snap-fit ​​connector inserted into the engaging component, i.e., the length of the second snap-fit ​​hole, can be less than the length of the side of the engaging component where the second snap-fit ​​hole is located. Figure 3 The b2 shown is less than y.

[0051] In some embodiments, based on the grinding operation on the wafer surface, the wafer grinding apparatus may further include a cleaning brush (not shown) for cleaning impurities on the wafer surface, the impurities being substances ground off the wafer surface.

[0052] In this embodiment of the invention, corresponding to the cleaning function of the cleaning component, the material of the cleaning component can be the same as the material of the cleaning brush. In one example, both the material of the cleaning component and the material of the cleaning brush can be elastic polyurethane material.

[0053] In some embodiments, based on the cleaning effect of the cleaning component on the polishing fluid overflowing around the polishing pad, the wafer polishing apparatus may further include a spray component 140 for cleaning the cleaning component.

[0054] The spray assembly 140 may include a nozzle 1401 and a liquid transfer pipe 1402.

[0055] The nozzle 1401 can be located on the cleaning assembly 120 and is used to spray the cleaning assembly.

[0056] The liquid transfer pipe 1402 is located on the side of the abrasive enclosure 110 away from the cleaning assembly 120 and is used to provide spray liquid to the nozzle.

[0057] In an alternative example, the liquid transfer pipe may be provided with a bend ( Figure 3 (The position is circled in the middle), the liquid transfer pipe 1402 can be connected to the nozzle 1401 based on the bend.

[0058] As can be seen, in this embodiment of the invention, a cleaning component is fixed on the side of the grinding plate facing the grinding disk, and the thickness of the cleaning component is equal to the distance between the grinding plate and the grinding disk, so that the cleaning component contacts the edge of the grinding disk. This allows the cleaning component to clean the grinding fluid overflowing around the grinding disk in a timely manner during the rotation of the grinding disk, reducing the accumulation of grinding fluid around the grinding disk, reducing the difficulty of cleaning the grinding disk, and thus improving the yield of the produced wafer products.

[0059] As another optional implementation of the disclosed content of the embodiments of the present invention, the embodiments of the present invention also provide a wafer grinding apparatus, which includes the wafer grinding device provided in any of the above embodiments.

[0060] In an optional implementation, the wafer polishing apparatus of the present invention may specifically include a reaction chamber, which may include one or more of the wafer polishing devices. When the reaction chamber has multiple wafer polishing devices, the number of the wafer polishing devices may be, for example, three. These three wafer polishing devices may be isolated and distinguished based on separators. The reaction chamber may also include a wafer transfer device (load cup) for transferring the wafer to the polishing head of the wafer polishing apparatus and unloading the polished wafer from the polishing head.

[0061] As can be seen, in the wafer grinding apparatus of the present invention, a cleaning component is fixed on the side of the grinding plate facing the grinding disk, and the thickness of the cleaning component is equal to the distance between the grinding plate and the grinding disk, so that the cleaning component contacts the edge of the grinding disk. This allows the cleaning component to clean the grinding fluid overflowing around the grinding disk in a timely manner during the rotation of the grinding disk, reducing the accumulation of grinding fluid around the grinding disk, reducing the difficulty of cleaning the grinding disk, and thus improving the yield of the produced wafer products. Correspondingly, when the wafer grinding equipment including the above-mentioned wafer grinding apparatus is in operation, it can avoid the impact of untimely cleaning of the grinding fluid overflowing around the grinding disk, thereby improving the working efficiency of the wafer grinding equipment.

[0062] The foregoing describes multiple embodiments of the present invention. The optional methods described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as embodiments disclosed or made public by the present invention.

[0063] While the embodiments of the present invention have been disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A wafer grinding apparatus, characterized in that, Used in wafer grinding equipment, including: grinding discs, grinding guards, and cleaning components; The grinding disc is used to place the wafer to be ground; The grinding enclosure surrounds the grinding disk. From a top-down perspective, the projection of the grinding disk is located within the area surrounded by the projection of the grinding enclosure. The projection area of ​​the grinding disk is used as the grinding area, and the projection area of ​​the grinding enclosure is used to confine the grinding fluid of the wafer to be ground within the grinding area. The cleaning component is fixed to the grinding plate on the side facing the grinding disk, and the distance of the cleaning component along the normal direction of the grinding plate towards the grinding disk is less than or equal to the distance between the grinding plate and the grinding disk, which is used to clean the grinding liquid overflowing around the grinding disk; The cleaning component includes a cleaning part and a locking part. The cleaning part is locked in place by the locking part, which includes a slot. The cleaning part protrudes from the slot and contacts the grinding disc.

2. The wafer grinding apparatus as described in claim 1, characterized in that, The cleaning component is used to clean the polishing fluid that has overflowed around the polishing disc; The slot faces the grinding disc and is used to engage the cleaning component to the target position.

3. The wafer grinding apparatus as described in claim 2, characterized in that, With the direction perpendicular to the surface of the grinding disc as the thickness direction, the thickness of the cleaning component is greater than or equal to the thickness of the grinding disc; with the direction normal to the cleaning component from the grinding plate as the width direction, the width of the cleaning component is greater than the width of the slot.

4. The wafer grinding apparatus as described in claim 2, characterized in that, The wafer grinding apparatus also includes a snap-fit ​​connector for snapping the engagement component.

5. The wafer grinding apparatus as described in claim 4, characterized in that, Corresponding to the snap-fit ​​plug, the grinding plate is provided with a first snap-fit ​​hole, and the engaging component is provided with a second snap-fit ​​hole on the side facing the grinding plate, so that the snap-fit ​​plug can penetrate the grinding plate and engage with the engaging component based on the first snap-fit ​​hole and the second snap-fit ​​hole.

6. The wafer grinding apparatus as described in claim 5, characterized in that, With the normal direction of the snap-fit ​​plug toward the engaging component as the length direction, the length of the snap-fit ​​plug is less than or equal to the sum of the length of the grinding plate and the length of the second snap-fit ​​hole; Wherein, the length of the second snap-fit ​​hole is less than the thickness of the snap-fit ​​component on one side of the second snap-fit ​​hole.

7. The wafer grinding apparatus as described in claim 2, characterized in that, The wafer grinding apparatus also includes a cleaning brush for cleaning impurities on the wafer surface; The cleaning component is made of the same material as the cleaning brush.

8. The wafer grinding apparatus as described in claim 1, characterized in that, Corresponding to the cleaning component, the wafer polishing apparatus further includes a spray component for cleaning the cleaning component; The spray assembly includes a nozzle and a liquid transfer pipe; the nozzle is located on the cleaning assembly and is used to spray the cleaning assembly; the liquid transfer pipe is located on the side of the abrasive enclosure away from the cleaning assembly and is used to supply spray liquid to the nozzle.

9. The wafer grinding apparatus as described in claim 8, characterized in that, The liquid transfer pipe is provided with a bend, and the liquid transfer pipe is connected to the nozzle based on the bend.

10. A wafer grinding apparatus, characterized in that, Includes the wafer polishing apparatus as described in any one of claims 1-9.

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