A trimming head

Abstract

The application discloses a dressing head, which comprises a dressing assembly and a base assembly for bearing the dressing assembly, the dressing assembly can be rotated and vertically moved relative to the base assembly to dress a polishing pad, and a sensor is arranged in the dressing head to monitor the vertical position of the dressing assembly relative to the base assembly. The dressing head is used for dressing and activating the polishing pad in a chemical mechanical polishing device, has a reasonable structure, and is internally provided with the sensor to monitor the vertical position of the dressing assembly relative to the base assembly in real time, and the distance between the bottom surface of the dressing assembly and the polishing pad is acquired in real time, so that a good dressing effect is ensured.

Description

[0001] This application is a divisional application of the invention patent application filed on June 28, 2019, with application number 201910576078.0. Technical Field

[0002] This invention belongs to the field of chemical mechanical polishing technology, and more specifically, relates to a dressing head. Background Technology

[0003] Chemical mechanical polishing (CMP) is an acceptable method for global substrate polishing. This method typically involves holding the substrate to the underside of a support head, with the side of the substrate having the deposited layer pressed against a rotating polishing pad. The support head, driven by a drive unit, rotates in the same direction as the polishing pad and applies a downward load to the substrate. Simultaneously, polishing slurry is supplied to the upper surface of the polishing pad and distributed between the substrate and the pad. The combined chemical and mechanical action of these processes completes the global polishing of the substrate.

[0004] To achieve the desired polishing results, the surface of the polishing pad must be regularly trimmed to remove polishing byproducts accumulated on the pad and ensure that it has good polishing properties.

[0005] The dressing disc is positioned below the dressing head. The dressing head descends and contacts the rotating polishing surface. Driven by a driving device, the dressing head rotates relative to the polishing pad. Simultaneously, the dressing head moves radially across the surface of the polishing pad to complete the dressing operation. During the movement of the dressing disc, the distance between the dressing disc and the polishing pad, as well as the load exerted by the dressing disc on the polishing pad, all affect the dressing effect.

[0006] Therefore, there is an urgent need to design a trimming head to periodically trim the polishing pad in order to ensure the polishing effect of the substrate. Summary of the Invention

[0007] The present invention aims to at least partially solve one of the technical problems existing in the prior art. To this end, the present invention discloses a dressing head, including a dressing component and a base assembly for supporting the dressing component, wherein the dressing component is rotatable and vertically movable relative to the base assembly to dress a polishing pad; and the dressing head is provided with a sensor to monitor the vertical position of the dressing component relative to the base assembly.

[0008] Preferably, the sensor is a non-contact position sensor.

[0009] Preferably, the upper part 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, the magnetic switch being located outside the circumference of the positioning ring to measure its vertical movement.

[0010] Preferably, the number of sensors is at least two, which are disposed at different positions in the vertical direction of the base assembly.

[0011] Preferably, the base assembly includes a support plate concentrically fitted onto the outside of the connecting shaft, the support plate having at least two grooves for mounting the sensor.

[0012] Preferably, the grooves are evenly and symmetrically distributed along the central axis of the bearing disk.

[0013] Preferably, the base assembly includes a base, an upper rotating sleeve and a lower rotating sleeve, the upper rotating sleeve and the lower rotating sleeve are connected as one unit and concentrically arranged in the base, and the sensor is arranged in the vertical space between the upper rotating sleeve and the lower rotating sleeve.

[0014] Preferably, the upper rotating sleeve and the lower rotating sleeve are made of a metal material with low magnetic permeability.

[0015] Preferably, the upper rotating sleeve and the lower rotating sleeve are made of composite materials.

[0016] Preferably, the upper rotating sleeve and the lower rotating sleeve are glass-filled polyphenylene sulfide (PPS) or glass-filled polyether ether ketone (PEEK).

[0017] The trimming head disclosed in this application has the following advantages: the trimming head is equipped with a sensor to monitor the vertical position of the trimming component relative to the base component in real time, and to periodically trim the polishing pad to ensure the polishing effect of the substrate. Attached Figure Description

[0018] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0019] Figure 1 This is a schematic diagram of a structure of an embodiment of the trimming head according to the present invention;

[0020] Figure 2 This is a schematic diagram of another embodiment of the trimming head according to the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the carrier disk of the present invention;

[0022] Figure 4 This is a top view of the carrier plate used to mount the sensor in this invention inside the base assembly.

[0023] The meanings of the numerical reference numerals in the attached figures are as follows:

[0024] 100 - Trim the head;

[0025] 10-Trimming assembly; 11-Trimming assembly body; 12-Connecting shaft; 121-Channel; 13-Trimming unit; 131-Trimming disc; 132-Trimming brush; 14-Cavity; 15-Elastic membrane; 16-Base plate; 17-Linear bearing;

[0026] 20-Base assembly; 21-Base; 22-Upper rotating sleeve; 23-Lower rotating sleeve; 24-Key; 25-First through hole; 26-Bearing plate; 261-Groove; 27-Pipe connector;

[0027] 30 - Transmission pulley;

[0028] 40 - Sensor;

[0029] 50 - Positioning ring. Detailed Implementation

[0030] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0031] The accompanying drawings in this specification are schematic diagrams used to illustrate the concept of the invention and to schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly show the structure of the various components of the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0032] A schematic diagram of the trimming head described in this invention is shown below. Figure 1 As shown, the dressing head 100 includes a dressing component 10 and a base component 20. The base component 20 supports the dressing component 10. The dressing component 10 can rotate and move vertically relative to the base component 20 to dress the polishing pad, thereby activating the worn polishing pad and 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, by monitoring the vertical position of the dressing component 10 through the sensor 40, the effectiveness of the dressing head in dressing the polishing pad is ensured.

[0033] exist Figure 1 In the illustrated embodiment, there are two sensors 40, which are set at different positions in the vertical direction to monitor the distance between the trimming assembly 10 and the polishing pad, thereby enabling real-time monitoring of the trimming operation.

[0034] As an embodiment of the present invention, the trimming assembly 10 includes a trimming assembly body 11, a connecting shaft 12, and a trimming unit 13. The connecting shaft 12 extends vertically upward from the center of the trimming assembly body 11. The connecting shaft 12 of the trimming assembly 10 is slidably connected to the base assembly 20. The connecting shaft 12 of the trimming assembly 10 can slide up and down along the base assembly 20. The trimming unit 13 is disposed at the bottom of the trimming assembly body 11, so that the trimming unit 13 contacts the polishing pad to achieve the trimming operation.

[0035] The polishing pad can be a double-layer polishing pad, comprising a backing layer adjacent to the surface of the polishing disk and a cover layer with a polishing surface. The polishing surface is used to polish the substrate. The cover layer is typically harder than the backing layer and can be composed of foam or molded polyurethane. The backing layer can be composed of compressed fibers impregnated with urethane. As one aspect of this embodiment, the dressing unit 13 can be a dressing disk 131. The dressing disk 131 is used to dress polishing pads with higher hardness. The lower part of the dressing disk 131 is inlaid with diamond. Tiny particles generated during the polishing process and tiny particles in the polishing fluid may block the micropores on the polishing pad, thereby affecting the polishing characteristics of the polishing pad. The diamond inlaid in the lower part of the dressing disk 131 can open the blocked micropores, allowing the polishing fluid to fill the micropores, thereby realizing the dressing operation of the polishing pad.

[0036] In another aspect of this embodiment, the trimming unit 13 can be a trimming brush 132, such as... Figure 2 As shown, it is used to trim polishing pads with low hardness. The lower part of the trimming brush 132 is provided with bristles, which contact the polishing pad to trim the tiny particles attached to the polishing pad in time, so as to ensure good polishing conditions.

[0037] In some embodiments, the dressing disc 131 and dressing brush 132 need to be switched periodically. To save space on the upper part of the polishing pad, a dressing arm that rotates around a fixed point is usually provided. A dressing head is installed at the end of the dressing arm. The dressing disc 131 and dressing brush 132 are switched periodically according to process requirements. Generally, the thickness of the dressing disc 131 is less 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 a certain distance vertically. 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 to the dressing brush, the bristles are in direct contact with the polishing pad, thereby timely removing small particles on the polishing pad and ensuring good polishing conditions.

[0038] In one embodiment of the present invention, the base assembly 20 includes a base 21, an upper rotating sleeve 22, and a lower rotating sleeve 23. The upper rotating sleeve 22 and the lower rotating sleeve 23 are integrally connected and concentrically disposed within the base 21. Specifically, a transmission pulley 30 is connected to the upper end of the upper rotating sleeve 22. The upper rotating sleeve 22 is connected to the lower rotating sleeve 23 via a key 24. A first through hole 25 is provided inside the lower rotating sleeve 23. The connecting shaft 12 of the trimming assembly 10 is connected to the first through hole 25 via a linear bearing 17. A bearing hole is provided on the base 21. The bearing is disposed 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 trimming assembly 10 rotate together. The trimming unit 13 of the trimming assembly 10 contacts the polishing pad to complete the trimming operation of the polishing pad.

[0039] Figure 1 In the illustrated embodiment, the top of the lower rotating sleeve 23 is airtightly connected to a pipe joint 27. A rotary joint (not shown) is provided 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. Fluid communicates with the chamber 14 inside the dressing assembly 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 base plate 16. The channel 121 communicates with the chamber 14 at the lower part of the connecting shaft 12. Fluid is injected into or extracted from the chamber 14 to change the pressure inside the chamber 14, causing the connecting shaft 12 on the dressing assembly 10 to move up and down in the vertical direction, thereby adjusting the distance between the dressing unit 13 on the dressing assembly 10 and the polishing pad.

[0040] In one 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 to 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 on the outer circumference of the positioning ring 50 to measure the vertical movement of the trimming assembly 10. In one aspect of this embodiment, the positioning ring 50 is a magnetic ring 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 located on the outer circumference of the connecting shaft 12. When the positioning ring 50 on the connecting shaft 12 approaches the magnetic switch, the two reeds of the reed switch inside the magnetic switch are magnetized and attract each other, and the contact closes. When the positioning ring 50 moves away from the magnetic switch, the two reeds of the reed switch are demagnetized and separate from each other, and the contact opens. Thus, the vertical movement of the positioning ring 50 relative to the magnetic switch can be monitored by the opening and closing of the magnetic switch contact.

[0041] In another embodiment of the present invention, the number of sensors is at least two, and they are disposed 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 set 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 the opening and closing of the contact of the sensor 40.

[0042] exist Figure 1 In the embodiment shown, the base assembly 20 includes a bearing disk 26 concentrically sleeved on the outside of the connecting shaft 12. The bearing disk 26 is engaged in the bearing hole on the base 21 and located between the upper rotating sleeve 22 and the lower rotating sleeve 23. That is, the bearing disk 26 is a relatively stationary component and does not rotate as a whole with the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. This is beneficial for fixing the sensor's wiring connection.

[0043] Figure 3 This is a schematic diagram of the structure of the support disk described in this invention. In this embodiment, the support disk 26 is an annular disk structure with a certain thickness. A through hole is provided in the middle of the support disk 26 for the lower rotating sleeve 23 to pass through, so that the support disk 26 can be separated from the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. The support disk 26 has three grooves 261, and the sensor is disposed in the grooves 261. It can be understood that the number of grooves 261 is matched with the number of sensors, that is, the number of grooves 261 should not be less than the number of sensors. The sensors are installed along the thickness direction of the support disk 26 and 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 embodiment shown, three grooves 261 are evenly distributed on the carrier disk 26, and the sensor 40 is a magnetic switch. The magnetic switch is set at different positions in the thickness direction of the carrier disk 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.

[0044] As one aspect of this embodiment, the grooves 261 are uniformly and symmetrically distributed along the central axis of the support disk 26 to reduce mutual interference between sensors installed in the grooves 261 and improve detection accuracy. It is understood that the grooves 261 may not be uniformly and symmetrically distributed along the axis of the support disk 26, as long as they are spaced apart to reduce mutual interference between adjacent sensors.

[0045] 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 located 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 magnetic properties of the metal material on the sensor detection and improve the accuracy of the detection.

[0046] In another embodiment of the present invention, the upper rotating sleeve 22 and the lower rotating sleeve 23 are made of composite materials. The composite material has a low magnetic permeability or is non-magnetic. The carrier plate 26 for mounting the sensor is located on the outside of the assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23. The composite material causes almost zero interference to sensor detection, effectively improving detection accuracy. In another aspect of this embodiment, the upper rotating sleeve 22 and the lower rotating sleeve 23 are made of glass-filled polyphenylene sulfide (PPS) or glass-filled polyether ether ketone (PEEK), which has a certain rigidity and is non-magnetic. The assembly formed by the upper rotating sleeve 22 and the lower rotating sleeve 23 causes almost zero interference to sensor detection, effectively improving detection accuracy.

[0047] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A trimming head, characterized in that, include: Trimming components and base components for supporting the trimming components; The trimming assembly includes a connecting shaft, the upper part of which has a positioning ring; The base assembly includes a base, a support plate, an upper rotating sleeve, and a lower rotating sleeve. The base includes a bearing hole, and the support plate is engaged in the bearing hole. The support plate includes a support plate through hole, and the lower rotating sleeve passes through the support plate through hole and is connected to the upper rotating sleeve so that the support plate does not rotate as a whole with the assembly formed by the upper rotating sleeve and the lower rotating sleeve. The lower rotating sleeve has a first through hole inside, and the connecting shaft is disposed in the first through hole and can slide up and down along the first through hole. A sensor is provided on the support plate, and the sensor is located in the vertical space between the upper rotating sleeve and the lower rotating sleeve to monitor the vertical position of the trimming component relative to the base component.

2. The trimming head as described in claim 1, characterized in that, The sensor is a non-contact position sensor located outside the circumference of the positioning ring to measure its vertical movement.

3. The trimming head as described in any one of claims 1 or 2, characterized in that, The number of sensors is at least two, which are disposed at different positions in the vertical direction of the base assembly. One of the sensors is disposed in the vertical space between the upper rotating sleeve and the bearing plate, and the other sensor is disposed in the vertical space between the lower rotating sleeve and the bearing plate.

4. The trimming head as described in claim 3, characterized in that, The trimming assembly includes trimming units for contacting a polishing pad, the trimming units being replaceable and having different thicknesses, and the at least two sensors corresponding to causing trimming units of different thicknesses to contact the polishing pad.

5. The trimming head as described in claim 4, characterized in that, The support plate has grooves for mounting the sensors, the number of grooves being the same as the number of sensors, and the grooves being evenly and symmetrically distributed along the central axis of the support plate.

6. The trimming head as described in claim 5, characterized in that, The trimming assembly has a chamber inside, which is surrounded by an annular elastic membrane and a base plate. Changing the pressure inside the chamber causes the connecting shaft to move up and down in the vertical direction, thereby adjusting the distance between the trimming unit and the polishing pad.

7. The trimming head as described in claim 6, characterized in that, The upper and lower rotating sleeves are made of metal materials with low magnetic permeability.

8. The trimming head as described in claim 6, characterized in that, The upper and lower rotating sleeves are made of composite materials.

9. The trimming head as described in claim 8, characterized in that, The upper and lower rotating sleeves are made of glass-filled polyphenylene sulfide (PPS) or glass-filled polyether ether ketone (PEEK).

10. A chemical mechanical polishing apparatus, characterized in that, It includes a polishing pad and a dressing head as described in any one of claims 1-9, the dressing head being used to dress the polishing pad.

11. A chemical mechanical polishing method, characterized in that, Using the chemical mechanical polishing apparatus as described in claim 10, comprising: Replace the trimming head with a trimming unit of different thicknesses; The sensor monitors the vertical position of the trimming assembly relative to the base assembly, causing the trimming unit to contact the polishing pad; The polishing pad is trimmed using a trimming head.

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