Wafer carrying component and wafer interaction method

Abstract

The present invention discloses a wafer bearing assembly and a wafer interaction method, wherein the wafer bearing assembly comprises a fixed plate; an annular bracket which is concentrically arranged on the outer peripheral side of the fixed plate; a reset assembly which comprises a pneumatic seat and a support rod, wherein the pneumatic seat is connected to the fixed plate; one end of the support rod is slidably connected to the pneumatic seat, and the other end of the support rod is connected to the support; the chamber of the pneumatic seat is inflated and deflated, and the support rod can lift or lower the support, so that the vertical position of the support matches the wafer interaction position.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical mechanical polishing, and in particular, relates to a wafer carrying component and a wafer interaction method. 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 chip design, wafer manufacturing, wafer processing, electrical measurement, cutting packaging and testing. Among them, chemical mechanical polishing belongs to the wafer manufacturing process.

[0003] Chemical Mechanical Polishing (CMP) is an ultra-precision surface processing technology for global flattening. Chemical mechanical polishing usually involves sucking the wafer onto the bottom surface of a carrier head, with the side of the wafer with the deposition layer pressed 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; at the same time, 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 wafer needs to be operated interactively at different positions. The robot transfers the wafer from other stations (such as buffer) to the wafer carrier component (Load cup), and the polishing head takes the wafer from the Load cup for the next step of polishing. Therefore, the Load cup needs to meet the requirements of accurate loading and unloading of wafers with the robot and the polishing head at the same time.

[0005] According to their respective operating requirements, the trajectory taught by the robot is relatively fixed, which requires the wafer to have a unique and precise repeatable position and a stable relative level requirement; the polishing head interacts with the load cup, mainly relying on the air film for suction and placement. In order to protect the wafer and the corresponding mechanism and ensure the success rate of wafer placement, the load cup is required to have a certain elasticity to cooperate with the downward pressure of the air film. The requirements of these two structures for the load cup are different.

[0006] In the prior art, there are usually two mechanisms that meet the above application requirements, namely springs and diaphragms. The elastic deformation of the spring and diaphragm is used to make the load cup have a certain elasticity to meet the interaction requirements of the polishing head; when the loading force is unloaded, the spring or diaphragm returns to its original state, so that it has a consistent position to meet the interaction requirements of the robot. However, the spring or diaphragm is a passive elastic system. Although it is elastically deformed within the allowable displacement, it may be difficult to ensure continuous and accurate recovery to the initial state with repeated compression or stretching of tens of thousands, hundreds of thousands or even millions of times. For the interaction of the robot, there may be a risk of failure in picking up the film. Summary of the invention

[0007] The present invention aims to solve one of the technical problems existing in the prior art to at least some extent.

[0008] To this end, an embodiment of the present invention provides a wafer supporting assembly, which includes:

[0009] Fixed plate;

[0010] an annular bracket, which is concentrically arranged on the outer peripheral side of the fixing plate;

[0011] A reset assembly, comprising a pneumatic seat and a support rod, wherein the pneumatic seat is connected to the fixing plate; one end of the support rod is slidably connected to the pneumatic seat, and the other end of the support rod is connected to the bracket;

[0012] The chamber of the pneumatic seat is inflated and deflated, and the support rod can lift or lower the bracket so that the vertical position of the bracket matches the interactive position of the wafer.

[0013] As a preferred embodiment, the fixing plate is a hollow disc-shaped structure, which is fixed to the pneumatic seat via a connecting plate.

[0014] As a preferred embodiment, the support rod is connected to the bottom of the bracket through a universal ball bearing.

[0015] As a preferred embodiment, a spring is disposed on the outer peripheral side of the support rod, and the spring abuts between the universal ball bearing and the pneumatic seat.

[0016] As a preferred embodiment, there are multiple reset components, which are evenly distributed along the center of the bracket.

[0017] As a preferred embodiment, the wafer supporting assembly further comprises a detection sensor, and the detection sensor is arranged at the bottom of the bracket, so that after the bracket is pressed and moved downward, the top end of the detection sensor abuts against the bottom surface of the bracket.

[0018] As a preferred embodiment, the detection sensor is an analog sensor, there are multiple sensors and they are fixed to the pneumatic seat through an adapter plate.

[0019] As a preferred embodiment, a limiting column is disposed on the upper surface of the bracket, the top of the limiting column is a frustum structure, and the contour size of the top end of the frustum structure is smaller than the contour size of the bottom end thereof.

[0020] Furthermore, the present invention also discloses a wafer interaction device, which includes a turntable, a lifting assembly and the wafer supporting assembly mentioned above, wherein the wafer supporting assembly is multiple and evenly distributed around the turntable; the lifting assembly is arranged on the lower side of the turntable through a connecting assembly, and the turntable rotates to drive the wafer exchange device thereon to stop at the wafer interaction position.

[0021] In addition, the present invention also provides a wafer interaction method, using the wafer interaction device described above, which includes the following steps:

[0022] S1, the turntable drives the wafer bearing assembly on it to rotate to the circumferential interactive position of the robot, the lifting assembly rises and connects to the lower side of the fixed plate, and the reset assembly lifts the bracket to the high position;

[0023] S2, the lifting assembly drives the wafer carrying assembly to move up to the vertical interaction position of the robot, and the robot places the wafer on the upper surface of the bracket;

[0024] S3, the lifting assembly moves downward, and the wafer carrying assembly is separated from the lifting assembly;

[0025] S4, the turntable drives the wafer exchange device with the wafers placed thereon to rotate to the circumferential interaction position of the carrier head, and the lifting assembly rises and is connected to the lower side of the fixed plate;

[0026] S5, the lifting assembly drives the wafer carrying assembly to move upward to the vertical interaction position of the carrying head, and the carrying head absorbs the wafer on the upper surface of the bracket; repeat step S3.

[0027] The beneficial effects of the present invention include:

[0028] (1) A reset assembly is configured for the wafer support assembly, which effectively ensures the accuracy of the wafer interaction position by inflating the pneumatic seat so that it is usually in a high position; especially when interacting with a robot, the accurate maintenance of the wafer interaction position can avoid interference between the robot and the wafer, thereby ensuring the smoothness of the wafer interaction;

[0029] (2) The wafer interaction device adopts a disc-type rotating structure, which can realize the interaction between the robot and the wafer carrying assembly in advance, place the wafer in place, effectively avoid the waiting time for subsequent interaction with the carrier head, and improve the efficiency of wafer interaction;

[0030] (3) A detection sensor is configured for the wafer carrier assembly. By setting analog quantities, the wear condition of the retaining ring at the bottom of the carrier head is detected and acquired, thereby realizing wear monitoring of the retaining ring and effectively mastering the usage condition of the retaining ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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:

[0032] Figure 1 is a schematic structural diagram of the wafer carrying assembly of the present invention;

[0033] Figure 2 is a three-dimensional diagram of the wafer carrying assembly of the present invention;

[0034] Figure 3 It is a schematic diagram of the fixed connection of the detection sensor of the present invention;

[0035] Figure 4 is a schematic structural diagram of the wafer interaction device of the present invention;

[0036] Figure 5 is a component disassembly diagram of the wafer interaction device of the present invention;

[0037] Figure 6 yes Figure 4 A front view of the wafer interaction device shown;

[0038] Figure 7 It is a flow chart of the wafer interaction method described in the present invention. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Figure 1 and Figure 2 1 is a schematic structural diagram of a wafer carrier assembly according to the present invention. The wafer carrier assembly 100 includes:

[0043] Fixed plate 10;

[0044] An annular bracket 20 is concentrically disposed on the outer peripheral side of the fixing plate 10;

[0045] The reset assembly 30 includes a pneumatic seat 31 and a support rod 32. The pneumatic seat 31 is connected to the fixed plate 10. One end of the support rod 32 is slidably connected to the pneumatic seat 31, and the other end of the support rod 32 is connected to the bracket 20.

[0046] The chamber of the pneumatic seat 31 is inflated and deflated, and the support rods 32 can lift or lower the bracket 20 so that the vertical position of the bracket 20 matches the interactive position of the wafer.

[0047] In the present invention, the so-called wafer interaction refers to the interaction between the wafer carrier assembly 100 and the robot or the carrier head, that is, the robot places the wafer on the wafer carrier assembly 100, or the carrier head places the wafer on the wafer carrier assembly 100. Alternatively, the robot transfers the wafer of the wafer carrier assembly 100 to another location, or the carrier head absorbs the wafer of the wafer carrier assembly 100 and transfers it to the polishing pad for chemical mechanical polishing.

[0048] Figure 1 In the embodiment shown, the support rod 32 moves along the chamber of the pneumatic seat 31 to adjust the relative distance between the fixed plate 10 and the bracket 20. Usually, the relative position of the fixed plate 10 is fixed, and the pneumatic seat 31 is inflated and deflated to adjust the vertical position of the bracket 20.

[0049] As an embodiment of the present invention, the fixing plate 10 is a hollow disc-shaped structure, which is fixed to the pneumatic seat 31 through the connecting plate 40. A wafer cleaning module or an in-situ detection module can be set in the middle position of the fixing plate 10 to save the space occupied by the wafer bearing assembly and improve the compactness of the structural setting.

[0050] During the vertical movement of the bracket 20, the bracket 20 may be laterally offset, resulting in inaccurate wafer interaction positions. In order to solve the above problem, the support rod 32 is connected to the bottom of the bracket 20 through a universal ball bearing 33, such as Figure 1 shown.

[0051] In order to prevent the bracket 20 from moving too fast and to prevent the bottom surface of the bracket 20 from colliding with the upper surface of the pneumatic seat 31, a spring is provided on the outer peripheral side of the support rod 32 arranged between the bracket 20 and the pneumatic seat 31 to prevent the bracket 20 from hard contact with the pneumatic seat 31, thereby preventing the wafers being transferred from being damaged. Figure 2 In the embodiment, a spring is disposed on the outer peripheral side of the support rod 32, which abuts between the universal ball bearing 33 and the pneumatic seat 31 to prevent the air pressure inside the pneumatic seat 31 from being unstable, causing the bracket 20 to move downward quickly and cause the wafer to break.

[0052] Figure 2 In the illustrated embodiment, there are three reset assemblies 30, which are evenly distributed along the center of the bracket 20. It is understandable that the reset assemblies 30 may also be other numbers, such as four or five, to keep the support force on the bracket 20 relatively uniform and ensure that the upper surface of the bracket 20 is in a horizontal state.

[0053] Typically, Figure 1 The bracket 20 of the wafer support assembly 100 is shown to be in a high position, that is, the pneumatic seat 31 is inflated, so that the support rod 32 moves to the upper limit position. The bracket 20 always maintains a relatively stable high position, which is conducive to the robot to accurately place the wafer on the upper part of the bracket 20. Such a setting can avoid the problem of inaccurate passive reset of the spring in the traditional technology, and avoid the wafer clamped by the robot from interfering with the bracket 20 and other components to cause wafer fragments.

[0054] In the present invention, the accuracy of the vertical position of the bracket 20 is ensured by the active inflation of the reset assembly 30, so as to ensure the accurate interaction between the wafer bearing assembly 100 and the robot.

[0055] When the wafer carrier assembly 100 interacts with the carrier head, the pneumatic seat 31 of the reset assembly 30 is still in an inflated state to act as a gas spring and maintain a stable state, and at the same time cooperates with the mechanical spring configured on the circumference of the support rod 32 to form a combined elastic mechanism. Generally, during the process of loading and unloading wafers by the carrier head, the retaining ring of the carrier head is first pressed down to the upper surface of the bracket 20, and then the air film configured at the bottom of the carrier head is used to take and place the wafers.

[0056] Since the retaining ring will be constantly worn and the retaining ring stroke is not particularly precise, a pre-pressing stroke is usually set for the retaining ring to ensure that the retaining ring can be close to the bracket 20 each time, thereby ensuring a stable wafer placement spacing between the carrier head air film and the wafer, thereby improving the success rate of wafer placement. Therefore, during the interaction with the carrier head, the combined elastic mechanism composed of the pneumatic seat 31 and the mechanical spring can provide relatively stable elastic force feedback and carrier head stroke compensation, further ensuring smooth interaction of the wafer.

[0057] Figure 2 In the embodiment, the upper surface of the bracket 20 is provided with a limiting post 70, the top of which is a frustum structure, the top of which is smaller than the bottom. The outer peripheral surface of the limiting post 70 can reliably abut against the outer edge of the wafer to ensure the accuracy of the wafer placement position. In some embodiments, the limiting post 70 is made of PPS or PEEK to be suitable for the chemical mechanical polishing environment.

[0058] During the chemical mechanical polishing process, the consumables such as the retaining ring configured on the carrier head will be worn to varying degrees. Usually, on-site process personnel indirectly determine the wear of the retaining ring by the number of polished wafers. This judgment method has a certain error. If the retaining ring is severely worn and the wafer is still polished, it may result in a poor wafer yield; if the retaining ring is maintained and replaced before the service life, there will be a waste of materials, which will invisibly increase the wafer manufacturing cost.

[0059] In order to accurately determine the wear of the retaining ring and solve the above-mentioned technical problems, the wafer support assembly 100 also includes a detection sensor 50, such as Figure 3 As shown, the detection sensor 50 is disposed at the bottom of the bracket 20 , so that after the bracket 20 is pressed and moved downward, the top end of the detection sensor 50 abuts against the bottom surface of the bracket 20 .

[0060] As an embodiment of the present invention, the detection sensor 50 is an analog sensor, which is multiple and fixed to the pneumatic seat 31 through the adapter plate 60. The end of the detection sensor 50 is a ceramic or hard plastic contact head, such as the contact head can be made of PEEK material.

[0061] When the bracket 20 is pressed down by the carrier head, the bracket 20 moves downward. In the first half of the carrier head pressing stroke, the bracket 20 is set not to contact the contact head of the detection sensor 50. In the second half of the carrier head pressing stroke, the bracket 20 is set to contact the contact head of the detection sensor 50 and cause the contact head to be displaced. The sensor reads the size of the displacement. Specifically, the size of the second half of the carrier head pressing stroke is related to the allowable wear of the retaining ring and can be flexibly set according to the situation, such as 1-2 mm or other values.

[0062] When the carrier head is replaced with a new retaining ring, the detection sensor 50 reads and stores the displacement of the contact head of the carrier head when the contact head is pressed down for the first time. The software is set to use the displacement value read this time as the reference value. When the retaining ring wear exceeds the set value X0, the system is set to indicate that the retaining ring wear has reached a critical value, and it is prompted that the retaining ring needs to be replaced to avoid affecting the wafer polishing effect or index.

[0063] As polishing progresses, when the retaining ring is worn to a certain amount, the downward stroke of the bearing head decreases. When the reduction reaches the X0 value set by the system, it indicates that the life of the retaining ring has reached the critical line and the retaining ring needs to be replaced.

[0064] As Figure 3 In a variation of the embodiment shown, a detection ring is disposed on the outer peripheral side of the pneumatic seat 31 to detect the vertical position of the bottom end of the support rod 32 when the carrier head unloads the wafer onto the bracket 20, so as to indirectly measure the wear of the retaining ring at the bottom of the carrier head. Specifically, the detection ring is a magnetic sensor, and a magnet is disposed at the bottom end of the support rod 32. The detection ring detects the position of the support rod 32 by magnetic induction.

[0065] In addition, the present invention also discloses a wafer interaction device, such as Figures 4 to 6 As shown, the wafer interaction device includes a turntable 200, a lifting assembly 300 and the wafer supporting assembly 100 described above.

[0066] Specifically, there are multiple wafer carrying assemblies 100, which are evenly distributed around the turntable 200; the lifting assembly 300 is disposed on the lower side of the turntable 200 through the connecting assembly 400. When the turntable 200 rotates, the turntable 200 can drive the wafer exchange device 100 thereon to rotate and stop at the wafer interaction position, so as to complete the wafer interaction.

[0067] Figure 5 In the embodiment shown, the turntable 200 is equipped with a rotation drive device (not shown). When the lifting assembly 300 is separated from the turntable 200, the turntable 200 drives the wafer exchange device 100 thereon to rotate. When wafer exchange operation is required, the lifting assembly 300 needs to be moved upward so as to pass through the connection assembly 400 detachably connected to the lower part of the wafer carrier assembly 100. Figure 5 and 6 In the illustrated embodiment, the lifting assembly 300 is a cylinder assembly or an electric cylinder assembly, which is disposed on a disc-shaped fixing seat, and the setting position of the lifting assembly 300 matches the interaction position of the wafer.

[0068] In order to ensure that the bracket 20 and its connecting components on the wafer carrier assembly 100 can move smoothly without interfering with the turntable 200, the turntable 200 is provided with a plurality of through process holes. In order to achieve the rapid connection and disconnection of the lifting assembly 300 and the wafer carrier assembly 100, the opposite surfaces of the lifting assembly 300 and the connecting assembly 400 are provided with a magnetic attraction structure.

[0069] In addition, the present invention also provides a wafer interaction method, using the wafer interaction device described above, and its flow chart is as follows: Figure 7 As shown, it includes the following steps:

[0070] S1, the turntable drives the wafer bearing assembly on it to rotate to the circumferential interactive position of the robot, the lifting assembly rises and connects to the lower side of the fixed plate, and the reset assembly lifts the bracket to the high position;

[0071] S2, the lifting assembly drives the wafer carrying assembly to move up to the vertical interaction position of the robot, and the robot places the wafer on the upper surface of the bracket;

[0072] S3, the lifting assembly moves downward, and the wafer carrying assembly is separated from the lifting assembly;

[0073] S4, the turntable drives the wafer exchange device with the wafers placed thereon to rotate to the circumferential interaction position of the carrier head, and the lifting assembly rises and is connected to the lower side of the fixed plate;

[0074] S5, the lifting assembly drives the wafer carrying assembly to move upward to the vertical interaction position of the carrying head, and the carrying head absorbs the wafer on the upper surface of the bracket; repeat step S3.

[0075] Through the wafer interaction method described above, efficient and accurate wafer interaction can be achieved. Multiple wafer carrying assemblies 100 are configured on the upper part of the turntable 200, which can pre-store wafers, avoid the waiting time of the traditional wafer interaction process, and improve the wafer interaction efficiency.

[0076] 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.

[0077] 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 wafer carrier assembly, characterized in that: include: Fixed plate; an annular bracket, which is concentrically arranged on the outer peripheral side of the fixing plate; A reset assembly, comprising a pneumatic seat and a support rod, wherein the pneumatic seat is connected to the fixing plate; one end of the support rod is slidably connected to the pneumatic seat, and the other end of the support rod is connected to the bracket; The chamber of the pneumatic seat is inflated and deflated, and the support rod can lift or lower the bracket so that the vertical position of the bracket matches the interactive position of the wafer; the support rod is connected to the bottom of the bracket through a universal ball bearing; a spring is arranged on the outer peripheral side of the support rod, which abuts between the universal ball bearing and the pneumatic seat; when the pneumatic seat is in an inflated state, it acts as a gas spring and forms a combined elastic mechanism with the mechanical spring on the outer peripheral side of the support rod; It also includes a detection sensor, which is arranged at the bottom of the bracket, so that after the bracket is pressed and moved downward, the top of the detection sensor abuts against the bottom surface of the bracket.

2. The wafer carrier assembly according to claim 1, characterized in that: The fixing plate is a hollow disc-shaped structure, which is fixed to the pneumatic seat via a connecting plate.

3. The wafer carrier assembly according to claim 1, characterized in that: There are multiple reset components, which are evenly distributed along the center of the bracket.

4. The wafer carrier assembly according to claim 1, characterized in that: The detection sensor is an analog sensor, which is in multiple numbers and is fixed to the pneumatic seat via an adapter plate.

5. The wafer carrier assembly according to claim 1, characterized in that: The upper surface of the bracket is provided with a limiting column, the top of the limiting column is a frustum structure, and the contour size of the top end of the frustum structure is smaller than the contour size of the bottom end thereof.

6. A wafer interaction device, characterized in that: It comprises a turntable, a lifting assembly and the wafer carrying assembly as described in any one of claims 1 to 5, wherein there are multiple wafer carrying assemblies which are evenly distributed around the turntable; the lifting assembly is arranged on the lower side of the turntable through a connecting assembly, and the turntable rotates to drive the wafer exchange device thereon to stop at the interactive position of the wafer.

7. A wafer interaction method, using the wafer interaction device according to claim 6, characterized in that: The following steps are involved: S1, the turntable drives the wafer bearing assembly on it to rotate to the circumferential interactive position of the robot, the lifting assembly rises and connects to the lower side of the fixed plate, and the reset assembly lifts the bracket to the high position; S2, the lifting assembly drives the wafer carrying assembly to move up to the vertical interaction position of the robot, and the robot places the wafer on the upper surface of the bracket; S3, the lifting assembly moves downward, and the wafer carrying assembly is separated from the lifting assembly; S4, the turntable drives the wafer exchange device with the wafers placed thereon to rotate to the circumferential interaction position of the carrier head, and the lifting assembly rises and is connected to the lower side of the fixed plate; S5, the lifting assembly drives the wafer carrying assembly to move upward to the vertical interaction position of the carrying head, and the carrying head absorbs the wafer on the upper surface of the bracket; repeat step S3.

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