A chemical mechanical polishing system

Abstract

The present invention discloses a chemical mechanical polishing system, which comprises: a front unit; a polishing unit; a cleaning unit, which is arranged between the front unit and the polishing unit; the polishing unit comprises a plurality of polishing modules, the polishing module comprises a polishing disc, a polishing assembly and a loading and unloading platform, the loading and unloading platform is arranged on the outer side of the polishing disc, and the polishing assembly is arranged on the upper side of the polishing disc and the loading and unloading platform; the polishing assembly comprises a support frame and a carrier head suspended below the support frame, and the rotating support frame can drive the wafer loaded by the carrier head to move between the loading and unloading platform and the polishing disc; the polishing module also comprises a moisturizing mechanism arranged above the carrier head, the moisturizing mechanism comprises an infusion piece and a protective piece, and the protective piece cover is arranged on the upper side of the carrier head; when the carrier head rotates to the loading and unloading platform, the infusion piece can be plugged and fixed with the protective piece and convey fluid to form a water curtain on the outer peripheral side of the carrier head.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical mechanical polishing, and in particular relates to a chemical mechanical polishing system. Background Art

[0002] The integrated circuit industry is the core of the information technology industry and plays a key role in promoting the transformation and upgrading of the manufacturing industry towards digitalization and intelligence. Chips are the carriers of integrated circuits. Chip manufacturing involves process flows such as integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, cutting packaging and testing. Among them, chemical mechanical polishing (CMP) is one of the five core processes in the wafer manufacturing process.

[0003] CMP is an ultra-precision surface processing technology for global flattening. Chemical mechanical polishing usually involves sucking the wafer onto the bottom surface of the carrier head, with the side of the wafer with the deposition layer abutting against the upper surface of the polishing pad. The carrier head rotates in the same direction as the polishing pad under the actuation of the drive assembly and applies a downward load to the wafer; the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer completes the chemical mechanical polishing of the wafer under the combined action of chemistry and mechanics.

[0004] During the polishing process, the surface of the device inside the polishing module needs to be moisturized to prevent the polishing liquid and / or particles from adhering to the device surface and crystallizing. These crystals may fall off during the polishing operation and cause scratches or even breakage of the wafer.

[0005] In the prior art, a spray assembly is provided inside the polishing module to achieve device moisturizing, but spray-type moisturizing easily causes fluid splashing, resulting in insufficient controllability of the fluid containing particulate matter and weakening the moisturizing effect; in addition, the existing spray assembly occupies a large space, which will reduce the polishing operation space and affect the convenience of operation. Summary of the invention

[0006] An embodiment of the present invention provides a chemical mechanical polishing system, aiming to solve at least one of the technical problems existing in the prior art.

[0007] An embodiment of the present invention provides a chemical mechanical polishing system, comprising:

[0008] Pre-unit;

[0009] Polishing unit;

[0010] A cleaning unit is arranged between the front unit and the polishing unit;

[0011] The polishing unit includes a plurality of polishing modules, each of which includes a polishing disc, a polishing assembly and a loading and unloading platform, wherein the loading and unloading platform is arranged on the outside of the polishing disc, and the polishing assembly is arranged on the upper side of the polishing disc and the loading and unloading platform; the polishing assembly includes a support frame and a carrier head suspended below the support frame, and the rotating support frame can drive the wafer loaded by the carrier head to move between the loading and unloading platform and the polishing disc;

[0012] The polishing module also includes a moisturizing mechanism arranged above the carrying head, the moisturizing mechanism includes an infusion piece and a protective piece, and the protective piece cover is arranged on the upper side of the carrying head; when the carrying head is rotated to the loading and unloading platform, the infusion piece can be plugged and fixed with the protective piece and transport fluid to form a water curtain on the outer peripheral side of the carrying head.

[0013] In one embodiment, the protective member is an annular structure, and a liquid outlet is disposed at the lower end thereof to form an annular water curtain.

[0014] In one embodiment, the protective member is configured with a concentric annular groove and a horizontal connecting hole, the connecting hole is connected to the annular groove, and the liquid outlet is connected to the annular groove; the infusion member is connected to the connecting hole of the protective member to transport fluid toward the annular groove and discharge it through the liquid outlet to form a water curtain.

[0015] In one embodiment, the carrier head is suspended on the support frame via a fixing member, the fixing member is movable along the length direction of the support frame, and the protective member is disposed at the lower portion of the fixing member.

[0016] In one embodiment, the infusion component is provided with a moving module, and the moving module can drive the infusion component to move toward the protective component.

[0017] In one embodiment, the infusion piece includes an infusion seat and an infusion rod, and the infusion rod is transversely connected to the infusion seat; the setting position of the infusion rod matches the setting position of the connecting hole.

[0018] In one embodiment, the infusion seat is provided with a mounting hole, and the infusion rod is at least partially disposed in the mounting hole; a spring is sleeved on the outer circumference of the infusion rod, and the spring is disposed in the mounting hole.

[0019] In one embodiment, the liquid outlet is arranged along the circumferential direction of the protective element.

[0020] In one embodiment, the width of the liquid outlet is 0.5-3 mm.

[0021] In one embodiment, the vertical distance between the liquid outlet and the carrier head is less than or equal to 200 mm.

[0022] The beneficial effects of the present invention include:

[0023] a. A detachable moisturizing mechanism is configured for the polishing module, wherein the protective member is integrated into the polishing assembly, and the infusion member is detachably connected to the protective member, which effectively simplifies the structure and reduces space occupation;

[0024] b. The configured moisturizing mechanism can form a water curtain from top to bottom. The water curtain covers the bearing head and the parts below it, forming a good moisturizing effect, preventing polishing particles from crystallizing and falling on the surface of the parts, and improving the yield of wafer polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, which are only schematic and do not limit the scope of protection of the present invention, wherein:

[0026] Figure 1 is a schematic diagram of a chemical mechanical polishing system provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of a polishing module provided by an embodiment of the present invention;

[0028] Figure 3 is a longitudinal cross-sectional view of a protective member provided by one embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of the connection between the infusion piece and the protective piece provided by one embodiment of the present invention;

[0030] Figure 5 It is a schematic diagram of a protective element provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0032] The drawings of this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0033] In the present invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)", and the wafer (Wafer, W) is also called substrate (Substrate), and their meanings and actual functions are equivalent.

[0034] The embodiments disclosed in the present invention generally relate to a chemical mechanical polishing (CMP) system used in the semiconductor device manufacturing industry. During chemical mechanical polishing, a polishing liquid composed of submicron or nano abrasive particles and a chemical solution flows between a wafer and a polishing pad. The polishing liquid is evenly distributed under the transmission and rotation centrifugal force of the polishing pad to form a liquid film between the wafer and the polishing pad. The chemical components in the liquid react with the wafer to convert insoluble substances into soluble substances. These chemical reactants are then removed from the wafer surface by micromechanical friction of the abrasive particles and dissolved into the flowing liquid to be taken away. That is, the surface material is removed in the alternating process of chemical film formation and mechanical film removal to achieve surface flattening treatment, thereby achieving the purpose of global flattening.

[0035] Figure 1 Schematic diagram of a chemical mechanical polishing system provided by an embodiment of the present invention, which includes:

[0036] Pre-unit 1, used for storing wafers to be polished and wafers that have been polished;

[0037] Polishing unit 3, used for removing material from the wafer surface;

[0038] The cleaning unit 2 is disposed between the pre-unit 1 and the polishing unit 3 and is used for cleaning the surface of the wafer to remove particles remaining on the surface of the wafer.

[0039] The polishing unit 3 is a core component of the CMP system. The polishing unit 3 includes a plurality of polishing modules 30 and a wafer transfer mechanism 4. The polishing modules 30 of the polishing unit 3 are arranged around the wafer transfer mechanism 4 to facilitate the wafer transfer mechanism 4 to transfer wafers between the polishing modules 30 to meet a variety of polishing process steps.

[0040] Figure 1 In the illustrated embodiment, the polishing unit 3 includes four polishing modules 30 , namely a polishing module 30A, a polishing module 30B, a polishing module 30C and a polishing module 30D. The polishing modules 30 are arranged horizontally along the length direction of the polishing unit 3 .

[0041] Figure 1In the embodiment, the wafer transfer mechanism 4 includes a wafer transfer robot 41, and the number of the wafer transfer robots 41 is a pair. Among them, one wafer transfer robot 41 is responsible for the wafer transfer of the polishing module 30A and the polishing module 30B; the other wafer transfer robot 41 is responsible for the wafer transfer of the polishing module 30C and the polishing module 30D. One wafer transfer robot 41, the polishing module 30A and the polishing module 30B constitute the first polishing unit, and the other wafer transfer robot 41, the polishing module 30C and the polishing module 30D constitute the second polishing unit. The first polishing unit and the second polishing unit are symmetrically arranged along the center line of the polishing unit 3 and are independent of each other, so as to avoid the failure of a certain polishing module 30 causing the entire polishing unit 3 to fail to operate normally, so as to improve the fault tolerance of the polishing unit 3.

[0042] Furthermore, the wafer transfer mechanism 4 further includes an in-and-out buffer device 42 and an intermediate buffer device 43, which are arranged along the length direction of the polishing unit 3; and the in-and-out buffer device 42 and the intermediate buffer device 43 are respectively located on both sides of the wafer transfer robot 41. Specifically, the in-and-out buffer device 42 is arranged horizontally adjacent to the cleaning unit 2 to cache the wafers to be processed between the polishing unit 3 and the cleaning unit 2.

[0043] Figure 2 Schematic diagram of a polishing module 30 provided in one embodiment of the present invention. The polishing module 30 includes:

[0044] A polishing plate 31, on which a polishing pad is disposed;

[0045] A polishing assembly 32, used for polishing and turnover of wafers;

[0046] And a loading and unloading platform 33 is used for loading and unloading wafers; the loading and unloading platform 33 is arranged on the outer side of the polishing disk 31; the polishing assembly 32 is arranged on the upper side of the polishing disk 31 and the loading and unloading platform 33 to rotate the wafer between the polishing disk 31 and the loading and unloading platform 33, and to abut the wafer against the polishing pad above the polishing disk 31 to implement chemical mechanical polishing.

[0047] Figure 2 In the embodiment, the polishing module 30 further includes a dresser 34 and a liquid supply arm 35. The dresser 34 can swing around a fixed point located outside the polishing disk 31; the dresser disk (disk) configured by the dresser 34 rotates itself and applies a downward load to dress the surface of the polishing pad; the liquid supply arm 35 is arranged above the polishing pad to spread the polishing liquid on the surface of the polishing pad according to the process requirements.

[0048] Figure 2In the illustrated embodiment, the polishing assembly 32 includes a support frame 32a, a rotating device 32b and a carrier head 32c. The carrier head 32c is suspended below the support frame 32a, and the rotating device 32b is connected to the support frame 32a and can rotate to drive the carrier head 32c thereon to move between the loading and unloading platform 33 and the polishing plate 31; the carrier head 32c can move along the length direction of the support frame 32a, so that the carrier head 32c rotates around its axis and moves along the radial direction of the polishing plate 31, realizing the reciprocating motion of the carrier head 32c, so as to reduce the difference in the radial direction of the polishing pad on the polishing plate 31, and complete the global flattening of the wafer.

[0049] Figure 2 In the embodiment, the polishing module 30 further includes a moisturizing mechanism 36, which is disposed above the carrier head 32c to moisturize the carrier head 32c and prevent the polishing particles from forming crystals on the outer peripheral side of the carrier head 32c.

[0050] Furthermore, the moisturizing mechanism 36 includes an infusion member 36a and a protective member 36b, the protective member 36b is covered on the upper side of the carrier head 32c, and the infusion member 36a can be detachably connected to the protective member 36b to deliver fluid toward the protective member 36b. The introduced fluid can form a water curtain on the outer peripheral side of the carrier head 32c to achieve moisturizing of the parts under the protective member 36b, and prevent the particles generated by polishing from adhering to the surface of the parts and crystallizing. Figure 2 In FIG. 1 , a dotted line is used to indicate a water curtain formed below the protective member 36 b.

[0051] Preferably, when the carrying head 32c rotates to the loading and unloading platform 33, the infusion component 36a can be fixed as a whole with the protective component 36b by plugging, so as to transport the fluid through the infusion component 36a to the inside of the protective component 36b, thereby forming a water curtain on the outer peripheral side of the carrying head 32c.

[0052] Figure 3 It is a longitudinal cross-sectional view of a protective member 36b provided in one embodiment of the present invention. The protective member 36b is an annular protective main body, and a liquid outlet 36b-1 is disposed at the lower end of the protective main body to form an annular water curtain below the protective member 36b.

[0053] Figure 3 In the embodiment, the interior of the protective body is provided with a concentric annular groove 36b-2, and the lower part of the annular groove 36b-2 is connected to the liquid outlet 36b-1. Furthermore, the protective member 36b also includes a connecting hole 36b-3, which is arranged horizontally and is connected to the annular groove 36b-2; the end of the infusion member 36a is connected to the connecting hole 36b-3 to transport the fluid to the annular groove 36b-2 through the connecting hole 36b-3, and then discharged from the liquid outlet 36b-1 arranged at the lower part of the protective member 36b to form a moisturizing water curtain.

[0054] Figure 2 In the figure, the carrying head 32c is suspended below the support frame 32a through the fixing member 32d, and the fixing member 32d is connected to the support frame 32a through the linear module 32e, so that the linear module 32e can drive the carrying head 32c to move along the length direction of the support frame 32a through the fixing member 32d, so as to move the protective member 36b arranged above the carrying head 32c toward the infusion member 36a, thereby realizing the connection between the protective member 36b and the infusion member 36a.

[0055] Specifically, the protective member 36b is connected to the fixing member 32d, and can move synchronously with the carrying head 32c, and then approach or move away from the infusion member 36a through the linear module 32e.

[0056] As an embodiment of the present invention, the location of the infusion piece 36a is relatively fixed, so as to unify the locations where the infusion piece 36a and the protective piece 36b are plugged into each other. Figure 2 In the embodiment shown, when the support frame 32a rotates to Figure 1 When the length directions of the polishing units 2 are shown to be parallel, the fixing member 32e moves along the length direction of the support frame 32a, so that the protective member 36b is connected to the infusion member 36a as a whole.

[0057] Figure 2 In the embodiment shown, when the carrier head 32c rotates and swings to the loading and unloading platform 33, the carrier head 32c is approximately located above the loading and unloading platform 33. At this time, it is necessary to moisturize the components below the protective member 36b. It is understandable that the components below are not limited to the carrier head 32c, but also include components such as the loading and unloading platform 33.

[0058] As another embodiment of the present invention, the infusion member 36a is arranged on the mobile module ( Figure 2 The infusion component 36a is moved toward or away from the protective component 36b by the movable module (not shown), so as to realize the connection or separation between the infusion component 36a and the protective component 36b.

[0059] It is understandable that the infusion member 36a and the fixing member 32d connected to the carrier head 32c can also be controlled to move toward each other at the same time to achieve the connection and fixation of the infusion member 36a and the protective member 36b; at this time, the setting displacement of the connection hole 36b-3 of the infusion member 36a and the protective member 36b is matched to facilitate accurate connection between the two. When the infusion member 36a and the protective member 36b need to be separated from each other, the infusion member 36a and the fixing member 32d can be controlled to move in different directions to improve the efficiency of the separation of the two.

[0060] Figure 4Schematic diagram of the infusion piece 36a and the protective piece 36b connected to each other provided by an embodiment of the present invention. The infusion piece 36a includes an infusion seat 36a-1 and an infusion rod 36a-2, and the infusion rod 36a-2 is transversely connected to the infusion seat 36a-1. One end of the infusion rod 36a-2 is located outside the infusion seat 36a-1 and is arranged toward the protective piece 36b, and the other end of the infusion rod 36a-2 is located outside the infusion seat 36a-1 and is connected to an external fluid source to deliver the fluid through the infusion rod 36a-2 to the annular groove 36b-2 of the protective piece 36b.

[0061] Figure 4 In the embodiment, the infusion seat 36a-1 is provided with a mounting hole 36a-1-1, and the infusion rod 36a-2 is at least partially disposed in the mounting hole 36a-1-1. Specifically, the infusion rod 36a-2 is fixed to the infusion seat 36a-1 through a gland 36a-4. A spring 36a-3 is sleeved on the outer peripheral side of the infusion rod 36a-2, and the spring 36a-3 is disposed in the mounting hole 36a-1-1. Specifically, one end of the spring 36a-3 abuts against the bottom of the mounting hole 36a-1-1, and the other end thereof abuts against the infusion rod 36a-2.

[0062] When the infusion piece 36a abuts the protective piece 36b, the spring 36a-3 is in a compressed state, and the spring 36a-3 can give a certain horizontal thrust to the infusion rod 36a-2 to ensure a reliable connection between the infusion rod 36a-2 and the mounting hole 36a-1-1.

[0063] Figure 4 In the embodiment shown, the end of the infusion rod 36a-2 is sleeved with a sealing member 36a-5. When the infusion member 36a is inserted into the connecting hole 36b-3 of the protective member 36b, the sealing member 36a-5 is located at the outer end surface of the infusion rod 36a-2 and the connecting hole 36b-3 to achieve sealing between the infusion rod 36a-2 and the protective member 36b, thereby preventing the liquid delivered to the protective member 36b from leaking between the two and affecting the formation of the annular water curtain.

[0064] Figure 5 36b is a schematic diagram of a protective member 36b provided in an embodiment of the present invention. The liquid outlet 36b-1 opens downward and is arranged along the circumferential direction of the protective member 36b to form an annular water curtain.

[0065] As one aspect of this embodiment, the width of the liquid outlet 36b-1 is 0.5mm. It is understandable that the width of the liquid outlet 36b-1 can be 0.5-3mm. Since the liquid outlet 36b-1 is arranged along the circumferential direction of the protective member 36b and is relatively small in size. In order to realize the annular water curtain and ensure a good moisturizing effect, it is necessary to accurately control the width of the liquid outlet 36b-1, especially to ensure the uniformity of the circumferential width of the liquid outlet 36b-1.

[0066] In order to control the continuity of the formed water curtain, it is necessary to control the flow rate of the infusion member 36a and the distance between the liquid outlet 36b-1 of the protective member 36b and the carrier head 32c. Preferably, the vertical distance between the liquid outlet 36b-1 and the top cover of the carrier head 32c is less than or equal to 200mm. Here, the top cover of the carrier head 32c refers to the protective cover arranged on the upper part of the carrier head 32c.

[0067] As an embodiment of the present invention, the moisturizing mechanism 36 configured in the polishing module 30 can be set at the position of the loading and unloading platform 33. When the bearing head 32c rotates to the loading station, the bearing head 32c and the parts below it need to be moisturized. The protective member 36b set on the fixing member 32d moves toward the infusion member 36a of the moisturizing mechanism 36, and the two are quickly docked to transport fluid through the infusion member 36a toward the protective member 36b, forming an annular water curtain under the protective member 36b, so as to achieve moisturizing of the bearing head 32c and the parts below it, and prevent the particles in the polishing module 30 from adhering to the surface of the parts and crystallizing.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0069] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A chemical mechanical polishing system, characterized in that: include: Pre-unit; Polishing unit; A cleaning unit is arranged between the front unit and the polishing unit; The polishing unit includes a plurality of polishing modules, each of which includes a polishing disc, a polishing assembly and a loading and unloading platform, wherein the loading and unloading platform is arranged on the outside of the polishing disc, and the polishing assembly is arranged on the upper side of the polishing disc and the loading and unloading platform; the polishing assembly includes a support frame and a carrier head suspended below the support frame, and the rotating support frame can drive the wafer loaded by the carrier head to move between the loading and unloading platform and the polishing disc; The polishing module further comprises a moisturizing mechanism disposed above the carrier head, the moisturizing mechanism comprising a movable infusion member and a protective member, the protective member cover being disposed on the upper side of the carrier head; when the carrier head rotates to the loading and unloading platform, the infusion member can be plugged and fixed with the protective member and deliver fluid to form a water curtain on the outer peripheral side of the carrier head; The protective member is an annular structure, and a liquid outlet opening facing downward is arranged at the lower end thereof, and the liquid outlet is arranged along the annular direction of the protective member and has a uniform annular width; the protective member is provided with a concentric annular groove and a horizontal connecting hole connected to the annular groove, and the liquid outlet is connected to the annular groove; the infusion member is connected to the connecting hole of the protective member to transport the fluid toward the annular groove and discharge it through the liquid outlet to form an annular water curtain; The flow rate of the infusion part is controlled and the vertical distance between the liquid outlet and the top cover of the carrier head is ensured to be less than or equal to 200 mm, so as to control the continuity of the water curtain.

2. The chemical mechanical polishing system according to claim 1, wherein: The carrying head is suspended on the support frame through a fixing member, the fixing member can move along the length direction of the support frame, and the protective member is arranged at the lower part of the fixing member.

3. The chemical mechanical polishing system according to claim 1, wherein: The infusion component is provided with a moving module, and the moving module can drive the infusion component to move toward the protective component.

4. The chemical mechanical polishing system according to claim 1, wherein: The infusion piece comprises an infusion seat and an infusion rod, and the infusion rod is transversely connected to the infusion seat; the setting position of the infusion rod matches the setting position of the connecting hole.

5. The chemical mechanical polishing system according to claim 4, characterized in that: The infusion seat is provided with a mounting hole, and the infusion rod is at least partially arranged in the mounting hole; a spring is sleeved on the outer peripheral side of the infusion rod, and the spring is arranged in the mounting hole.

6. The chemical mechanical polishing system according to claim 1, wherein: The width of the liquid outlet is 0.5-3 mm.

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