A trimming head

Abstract

The present invention discloses a dressing head, comprising a dressing component and a base component for carrying the dressing component, wherein the dressing component can rotate relative to the base component and move vertically to dress the polishing pad; and a sensor is arranged in the dressing head to monitor the vertical position of the dressing component relative to the base component. The dressing head provided by the present application is used for dressing and activating the polishing pad in a chemical mechanical polishing device, and has a reasonable structure. A sensor is arranged inside to monitor the vertical position of the dressing component relative to the base component in real time, and obtain the distance between the bottom surface of the dressing component and the polishing pad in real time to ensure a good dressing effect.

Description

Technical Field

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

[0002] Chemical mechanical polishing is an acceptable method for global polishing of substrates. This polishing method usually involves sucking the substrate under the carrier head, with the side of the substrate with the deposition layer abutting against the rotating polishing pad. The carrier head rotates in the same direction as the polishing pad under the drive of the driving component and applies a downward load to the substrate; at the same time, the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the substrate and the polishing pad, so that the substrate is globally polished under the combined action of chemical and mechanical forces.

[0003] In order to achieve the desired polishing result, the surface of the polishing pad must be regularly conditioned to remove polishing byproducts accumulated on the polishing pad and ensure that the polishing pad has good polishing characteristics.

[0004] The dressing disc is arranged at the bottom of the dressing head. The dressing head descends and contacts the rotating polishing surface. The dressing head rotates under the action of the driving device to rotate relative to the polishing pad. At the same time, the dressing head moves radially on the surface of the polishing pad to complete the dressing operation of the polishing pad. During the movement of the dressing disc, the distance between the dressing disc and the polishing pad and the load of the dressing disc on the polishing pad will affect the dressing effect of the dressing disc.

[0005] Therefore, it is urgent to design a dressing head to regularly dress the polishing pad to ensure the polishing effect of the substrate. Summary of the invention

[0006] The present invention aims to solve one of the technical problems existing in the prior art to at least some extent. To this end, the present invention discloses a dressing head, comprising a dressing assembly and a base assembly for carrying the dressing assembly, wherein the dressing assembly can rotate relative to the base assembly and move vertically to dress the polishing pad; and a sensor is provided in the dressing head to monitor the vertical position of the dressing assembly relative to the base assembly.

[0007] Preferably, the sensor is a non-contact position sensor.

[0008] Preferably, the upper portion of the connecting shaft of the trimming assembly has a positioning ring, and the sensor is a magnetic switch fixedly connected to the base assembly, and the magnetic switch is located outside the circumference of the positioning ring to measure its vertical movement.

[0009] Preferably, there are at least two sensors, which are arranged at different positions in the vertical direction of the base assembly.

[0010] Preferably, the base assembly comprises a carrier plate concentrically sleeved on the outer side of the connecting shaft, and the carrier plate has at least two grooves for arranging the sensor.

[0011] Preferably, the grooves are evenly and symmetrically distributed along the central axis of the carrying plate.

[0012] Preferably, the base assembly comprises a base, an upper rotating sleeve and a lower rotating sleeve, the upper rotating sleeve and the lower rotating sleeve are connected as a whole and are concentrically arranged in the base, and the sensor is arranged in the vertical space between the upper rotating sleeve and the lower rotating sleeve.

[0013] Preferably, the upper rotating sleeve and the lower rotating sleeve are made of metal material with low magnetic permeability.

[0014] Preferably, the upper rotating sleeve and the lower rotating sleeve are made of composite materials.

[0015] Preferably, the upper rotating sleeve and the lower rotating sleeve are glass-filled polyphenylene sulfide (PPS) or glass-filled polyetheretherketone (PEEK).

[0016] The dressing head disclosed in the present application has the beneficial effect that a sensor is arranged inside the dressing head to monitor the vertical position of the dressing component relative to the base component in real time, and the polishing pad is regularly dressed to ensure the polishing effect of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] Figure 1 is a schematic structural diagram of an embodiment of a trimming head according to the present invention;

[0019] Figure 2 is a schematic structural diagram of another embodiment of the trimming head according to the present invention;

[0020] Figure 3 It is a structural schematic diagram of the carrier plate of the present invention;

[0021] Figure 4 It is a top view of the carrier plate for arranging the sensor inside the base assembly of the present invention.

[0022] The meanings of the numerical reference symbols are as follows:

[0023] 100-Trimming head;

[0024] 10-dressing assembly; 11-dressing assembly body; 12-connecting shaft; 121-channel; 13-dressing unit; 131-dressing disk; 132-dressing brush; 14-chamber; 15-elastic membrane; 16-bottom plate; 17-linear bearing;

[0025] 20-base assembly; 21-base; 22-upper rotating sleeve; 23-lower rotating sleeve; 24-key; 25-first through hole; 26-carrying plate; 261-groove; 27-pipe joint;

[0026] 30- transmission pulley;

[0027] 40- sensor;

[0028] 50-Locking ring. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] The structural schematic diagram of the trimming head of the present invention is as follows: Figure 1 As shown, the dressing head 100 includes a dressing component 10 and a base component 20. The base component 20 is used to carry the dressing component 10. The dressing component 10 can rotate and move vertically relative to the base component 20 to dress the polishing pad, so that the worn polishing pad is activated, ensuring that the polishing pad has good polishing conditions to obtain a good polishing effect. At the same time, a sensor 40 is provided inside the dressing head 100. The sensor 40 can monitor the vertical position of the dressing component 10 relative to the base component 20. When the dressing component 10 moves downward along the base component 20 and the bottom surface of the dressing component 10 contacts the upper surface of the polishing pad, the sensor 40 is triggered to obtain a signal. In this way, the vertical position of the dressing component 10 is monitored by the sensor 40 to ensure the effect of the dressing operation of the polishing pad by the dressing head.

[0032] exist Figure 1 In the illustrated embodiment, there are two sensors 40 , which are disposed at different positions in the vertical direction to monitor the distance between the dressing assembly 10 and the polishing pad, thereby achieving real-time monitoring of the dressing operation.

[0033] As an embodiment of the present invention, the dressing component 10 includes a dressing component body 11, a connecting shaft 12 and a dressing unit 13. The connecting shaft 12 extends upward from the center position of the dressing component body 11 in a vertical direction. The connecting shaft 12 of the dressing component 10 is slidably connected to the base component 20. The connecting shaft 12 of the dressing component 10 can slide up and down along the base component 20. The dressing unit 13 is arranged at the bottom of the dressing component body 11, so that the dressing unit 13 contacts the polishing pad to realize the dressing operation.

[0034] The polishing pad may be a double-layer polishing pad, which includes a backing layer adjacent to the surface of the polishing disc and a covering layer having a polishing surface, the polishing surface being used for polishing the substrate, the covering layer being generally harder than the backing layer, the covering layer being composed of foam or molded polyurethane; the backing layer being composed of compressed fibers leached with ethyl formate. As one aspect of this embodiment, the dressing unit 13 may be a dressing disk 131 (disk), the dressing disk 131 being used for dressing a polishing pad with a relatively high hardness, the lower portion of the dressing disk 131 being inlaid with diamonds, the tiny particles generated during the polishing process and the tiny particles in the polishing liquid may block the micropores on the polishing pad, thus affecting the polishing characteristics of the polishing pad, the diamonds inlaid in the lower portion of the dressing disk 131 may scratch the blocked micropores, so that the polishing liquid fills the micropores, thereby realizing the dressing operation of the polishing pad.

[0035] As another aspect of this embodiment, the trimming unit 13 may be a trimming brush 132, such as Figure 2 As shown, it is used to trim a polishing pad with a lower hardness. The lower part of the trimming brush 132 is provided with bristles, and the bristles are in contact with the polishing pad, so as to trim the tiny particles attached to the polishing pad in time to ensure good polishing conditions.

[0036] In some embodiments, the dressing disc 131 and the dressing brush 132 need to be switched regularly. In order to save space on the top of the polishing pad, a dressing swing arm rotating around a fixed point is usually provided, and a dressing head is installed at the end of the dressing swing arm. The dressing disc 131 and the dressing brush 132 are switched regularly according to process requirements. Generally, the thickness of the dressing disc 131 is smaller than the thickness of the dressing brush 132. When switching from the dressing disc 131 to the dressing brush 132, in order to achieve surface contact between the dressing brush and the polishing pad, the dressing assembly 10 must be moved up a certain distance in the vertical direction. The sensor 40 inside the dressing head 100 can monitor the vertical position of the dressing assembly 10 relative to the base assembly 20 to ensure that when the dressing disc is converted into the dressing brush, the bristles are in direct contact with the polishing pad, so as to timely brush off the tiny particles on the polishing pad to ensure good polishing conditions.

[0037] As an embodiment of the present invention, the base assembly 20 includes a base 21, an upper rotating sleeve 22 and a lower rotating sleeve 23, wherein the upper rotating sleeve 22 and the lower rotating sleeve 23 are connected as a whole and are concentrically arranged in the base 21. Specifically, a transmission pulley 30 is connected to the upper end of the upper rotating sleeve 22, and the upper rotating sleeve 22 is connected to the lower rotating sleeve 23 through a key 24. A first through hole 25 is arranged inside the lower rotating sleeve 23, and the connecting shaft 12 of the dressing assembly 10 is connected to the first through hole 25 through a linear bearing 17. A bearing hole is arranged on the base 21, and the bearing is arranged between the inner wall of the bearing hole and the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. Driven by the transmission pulley 30, the upper rotating sleeve 22, the lower rotating sleeve 23 and the dressing assembly 10 rotate together, and the dressing unit 13 of the dressing assembly 10 contacts the polishing pad to complete the dressing operation of the polishing pad.

[0038] Figure 1 In the illustrated embodiment, the top of the lower rotating sleeve 23 is air-tightly connected with a pipe joint 27, and a rotating joint (not shown) is arranged between the pipe joint 27 and the lower rotating sleeve 23. The pipe joint 27 is connected to an air source not shown through a pipeline, and the fluid is connected to the chamber 14 in the dressing component 10 via the pipe joint 27, the first through hole 25, and the channel 121 inside the connecting shaft 12. The chamber 14 is surrounded by an annular elastic membrane 15 and a bottom plate 16, and the channel 121 is connected to the chamber 14 at the lower part of the connecting shaft 12; the fluid is filled into or drawn out of the chamber 14 to change the pressure in the chamber 14, so that the connecting shaft 12 on the dressing component 10 moves up and down in the vertical direction to adjust the distance between the dressing unit 13 on the dressing component 10 and the polishing pad.

[0039] As an embodiment of the present invention, the sensor is a non-contact position sensor. Specifically, the sensor 40 can be a magnetic switch, which is fixedly connected in the base assembly 20. A positioning ring 50 is provided on the upper part of the connecting shaft 12 of the trimming assembly 10. The magnetic switch is located outside the circumference of the positioning ring 50 to measure the vertical movement of the trimming assembly 10. As an aspect of this embodiment, the positioning ring 50 is a magnetic annular structure, which can be a permanent magnet. Correspondingly, the connecting shaft 12 of the trimming assembly 10 is a non-magnetic body, and the positioning ring 50 is arranged on the circumferential outside of the connecting shaft 12; when the positioning ring 50 on the connecting shaft 12 is close to the magnetic switch, the two reeds of the reed switch in the magnetic switch are magnetized and attracted to each other, and the contacts are closed; when the positioning ring 50 moves away from the magnetic switch, the two reeds of the reed switch lose magnetism and separate from each other, and the contacts are disconnected; thus, the vertical movement of the positioning ring 50 relative to the magnetic switch can be monitored by the disconnection and closing of the magnetic switch contacts.

[0040] As another embodiment of the present invention, the number of the sensors is at least two, which are arranged at different positions in the vertical direction of the base assembly 20, such as Figure 1 and Figure 2 As shown, the sensors 40 are respectively arranged at different positions in the vertical direction of the base assembly 20. When the positioning ring 50 of the trimming assembly 10 approaches a certain sensor 40, the vertical position of the trimming assembly 10 is indirectly monitored by opening and closing the contacts of the sensor 40.

[0041] exist Figure 1 In the illustrated embodiment, the base assembly 20 includes a carrier plate 26 concentrically sleeved on the outer side of the connecting shaft 12, and the carrier plate 26 is clamped in a bearing hole on the base 21 and is located between the upper rotating sleeve 22 and the lower rotating sleeve 23, that is, the carrier plate 26 is a relatively stationary component, which does not rotate integrally with the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23, which is beneficial to the line connection and fixation of the sensor.

[0042] Figure 3 It is a schematic diagram of the structure of the carrier plate of the present invention. In this embodiment, the carrier plate 26 is an annular disc structure with a certain thickness. The through hole arranged in the middle of the carrier plate 26 is used to pass through the lower rotating sleeve 23, so as to separate the carrier plate 26 from the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. The carrier plate 26 has three grooves 261, and the sensors are arranged in the grooves 261. It can be understood that the number of the grooves 261 is matched with the number of sensors, that is, the number of the grooves 261 should not be less than the number of sensors. The sensors are installed along the thickness direction of the carrier plate 26 and are located at different positions in the thickness direction to detect the vertical movement of the positioning ring 11 on the trimming assembly 10. Figure 4In the illustrated embodiment, three grooves 261 are evenly distributed on the carrier plate 26, and the sensor 40 is a magnetic switch, which is arranged at different positions in the thickness direction of the carrier plate 26 to monitor the vertical movement of the positioning ring 50, thereby obtaining the vertical position of the trimming unit 13 on the trimming assembly 10.

[0043] As one aspect of this embodiment, the grooves 261 are evenly and symmetrically distributed along the central axis of the carrier plate 26 to reduce mutual interference between sensors installed in the grooves 261 and improve detection accuracy. It is understandable that the grooves 261 may not be evenly and symmetrically distributed along the axis of the carrier plate 26, as long as they are spaced apart from each other to reduce mutual interference between adjacent sensors.

[0044] As an embodiment of the present invention, the upper rotating sleeve 22 and the lower rotating sleeve 23 are made of metal materials with low magnetic permeability, such as 304 austenitic stainless steel. The carrier plate 26 for mounting the sensor is arranged on the outside of the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. The metal material with low magnetic permeability can reduce the interference of the magnetism of the metal material on the sensor detection and improve the accuracy of the detection.

[0045] As another embodiment of the present invention, the upper rotating sleeve 22 and the lower rotating sleeve 23 are composite materials, the composite materials have a relatively low magnetic permeability or are non-magnetic, and the carrier plate 26 for mounting the sensor is arranged on the outside of the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23, and the interference of the composite materials on the sensor detection is almost zero, which effectively improves the accuracy of the detection. As one aspect of this embodiment, the upper rotating sleeve 22 and the lower rotating sleeve 23 are glass-filled polyphenylene sulfide (PPS) or glass-filled polyetheretherketone (PEEK), which have a certain rigidity and are non-magnetic, and the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23 has almost zero interference on the sensor detection, which effectively improves the accuracy of the detection.

[0046] 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.

[0047] 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 trimming head, characterized in that: include: A dressing assembly, a drive pulley and a base assembly for carrying the dressing assembly, wherein the dressing assembly can rotate relative to the base assembly and move vertically to dress the polishing pad; and a sensor is provided in the dressing head to monitor the vertical position of the dressing assembly relative to the base assembly; The base assembly comprises a base, an upper rotating sleeve and a lower rotating sleeve, wherein the upper rotating sleeve and the lower rotating sleeve are connected as a whole and are concentrically arranged in the base, and the sensor is arranged in the vertical space between the upper rotating sleeve and the lower rotating sleeve; the base assembly also comprises a bearing plate concentrically sleeved on the outer side of the connecting shaft, the bearing plate is clamped with the base, a bearing plate through hole is arranged in the middle of the bearing plate, the lower rotating sleeve passes through the bearing plate through hole, so that the bearing plate is separated from the assembly formed by the upper rotating sleeve and the lower rotating sleeve, and the bearing plate has at least two grooves for arranging the sensor; The trimming assembly comprises a connecting shaft which can slide up and down along the base assembly, the upper part of the connecting shaft is provided with a positioning ring, the driving pulley is connected to the upper rotating sleeve, and the trimming assembly is connected to the lower rotating sleeve.

2. The trimming head according to claim 1, characterized in that The sensor is a non-contact position sensor.

3. The trimming head according to claim 1, characterized in that The sensor is a magnetic switch fixedly connected to the base assembly, and the magnetic switch is located outside the circumference of the positioning ring to measure the vertical movement thereof.

4. The trimming head according to claim 1, characterized in that The number of the sensors is at least two, and the sensors are arranged at different positions in the vertical direction of the base assembly.

5. The trimming head according to claim 1, characterized in that The grooves are evenly and symmetrically distributed along the central axis of the carrying plate.

6. The trimming head according to claim 1, wherein: The upper rotating sleeve and the lower rotating sleeve are made of metal material with low magnetic permeability.

7. The trimming head according to claim 1, wherein: The upper rotating sleeve and the lower rotating sleeve are made of composite materials.

8. The trimming head according to claim 7, characterized in that The upper rotating sleeve and the lower rotating sleeve are made of glass-filled polyphenylene sulfide (PPS) or glass-filled polyetheretherketone (PEEK).

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