Retaining ring

Abstract

Disclosed herein is a retaining ring for use in polishing semiconductor substrates. The retaining ring includes a bottom surface configured to contact a polishing pad and a top surface configured to be attached to a carrier head. The top surface includes a plurality of screw holes and a plurality of alignment slots. The top surface also includes a first insert disposed in a first alignment slot of the plurality of alignment slots, the first insert being flush with or lower than the top surface and configured to prevent insertion of an alignment pin into the first alignment slot.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to apparatuses and methods for polishing and / or planarizing a semiconductor substrate. More particularly, embodiments of the present disclosure relate to a retaining ring for a carrier head utilized in chemical mechanical polishing (CMP).

Background Art

[0002] During the manufacture of semiconductor devices, various layers, such as oxides and copper, require polishing to remove steps or irregularities prior to the formation of the next layer. Polishing is useful for removing unwanted surface topographies and surface defects, such as rough surfaces, material agglomerations, damage to the crystal lattice, scratches, and contamination of the layer or material. Polishing is also useful for forming features on a substrate by removing deposited excess material used to fill the features, and for providing a flat surface for the next level of metallization and processing.

[0003] Polishing is typically performed mechanically, chemically, and / or electrically using processes such as chemical mechanical polishing (CMP) or electrochemical mechanical polishing (ECMP).

[0004] CMP removes material from the surface of a substrate by a combination of mechanical and chemical interactions in the presence of a slurry. During CMP, the slurry is delivered onto a rotating polishing pad, and the substrate is pressed against the polishing pad by a carrier head. The carrier head may also rotate and move the substrate relative to the polishing pad. As a result of the movement between the carrier head, the polishing pad, and the chemicals contained in the slurry, the substrate surface is planarized.

[0005] Retaining rings are fixed to a carrier head to hold semiconductor substrates and improve the finish and flatness of the substrate surface. Each retaining ring has a bottom surface for contact with the polishing pad during polishing and a top surface fixed to the carrier head. While the top surfaces of various retaining rings are identical to each other to facilitate mounting to the same carrier head, the bottom surfaces may differ in terms of material, groove design, and other aspects. The bottom surfaces can wear down due to contact with the polishing pad during operation and therefore require periodic replacement. Because retaining rings have various bottom surfaces, a critical aspect of CMP maintenance is the proper mounting of retaining rings to the carrier head during construction, rebuilding, and / or refurbishment.

[0006] In this regard, there is a quality control issue where improperly fitted retaining rings are installed on carrier heads, which can pose a manufacturing quality risk to thousands of circuit boards and / or result in the discarding of boards. Currently, this issue is addressed using visual checks when building or rebuilding carrier heads and / or before mounting them to the CMP tool. However, the retaining rings look identical, the only difference being the product number stamped on the inside of the retaining ring, which becomes invisible once the retaining ring is installed on the carrier head. Therefore, the proper installation of retaining rings on carrier heads largely depends on the attention and diligence of the maintenance technicians.

[0007] Therefore, there is a need for equipment and methods to avoid the above-mentioned quality control problems. [Overview of the project]

[0008] Embodiments of this disclosure generally relate to retaining rings for carrier heads used in chemical mechanical polishing (CMP).

[0009] In one or more embodiments, the retaining ring includes a bottom surface configured to contact a polishing pad and a top surface configured to be attached to a carrier head. The top surface includes a plurality of screw holes, a plurality of alignment slots, and a first insert disposed within a first alignment slot of the plurality of alignment slots. The first insert is flush with or lower than the top surface and is configured to prevent the insertion of an alignment pin into the first alignment slot.

[0010] In one or more embodiments, the polishing system includes a retaining ring and a carrier head. The carrier head has a bottom surface that contacts the top surface of the retaining ring, and the carrier head includes at least one alignment pin extending from the bottom surface into one of a plurality of alignment slots that are open.

[0011] To allow for a more detailed understanding of the features of the Disclosure listed above, a more specific description of the Disclosure, which has been briefly summarized above, can be given by reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments and should not be considered limiting in scope, allowing for other equally valid embodiments. [Brief explanation of the drawing]

[0012] [Figure 1] This is a partial lateral cross-sectional view of a polishing system according to one embodiment. [Figure 2A] Figure 1 is a bottom view of one embodiment of a carrier head that may be used in the polishing system. [Figure 2B] Figure 1 is a top view of one embodiment of a carrier head that may be used in the polishing system. [Figure 2C] This is an enlarged view of the carrier head in Figure 2A, which shows one embodiment of the alignment pin. [Figure 2D]This is a cross-sectional view taken along the cutting line 2D-2D in Figure 2C, showing one embodiment of the alignment pin. [Figure 2E] Figure 2A is a perspective view of one embodiment of an alignment pin that may be used in a carrier head. [Figure 3A] Figure 1 is a plan view of one embodiment of a retaining ring that may be used in the polishing system. [Figure 3B] Figure 1 is a bottom view of one embodiment of a retaining ring that may be used in the polishing system. [Figure 3C] This is an enlarged view of the retaining ring in Figure 3A, showing one embodiment of the alignment slot. [Figure 3D] This is a cross-sectional view taken along the cutting line 3D-3D in Figure 3C, showing one embodiment of the alignment slot. [Figure 3E] Figure 3A is a perspective view of one embodiment of an insert that may be used in the retaining ring. [Figure 4A] This is a schematic diagram of various combinations of insert and empty alignment slots that can be used to distinguish between different types of retaining rings. [Figure 4B] This is another schematic diagram of various combinations of insert and empty alignment slots that can be used to distinguish between different types of retaining rings. [Figure 4C] This is yet another schematic diagram of various combinations of insert and empty alignment slots that can be used to distinguish between different types of retaining rings. [Modes for carrying out the invention]

[0013] For ease of understanding, the same reference numerals are used for identical elements common to multiple figures, where possible. It is intended that elements and features of one embodiment can be advantageously incorporated into other embodiments without further detail.

[0014] Before describing some exemplary embodiments of the apparatus and method, it should be understood that this disclosure is not limited to the structural or processing step details specified in the following description. Some embodiments of this disclosure may be combined with other embodiments.

[0015] One or more embodiments of this disclosure are directed to retaining rings configured to be selectively combined with carrier heads for chemical mechanical polishing (CMP). Generally, this disclosure provides techniques for ensuring that only predetermined retaining rings are compatible with carrier heads having complementary combination features. The combination features of a particular combination of retaining ring and carrier head are selected to be used to perform a predetermined CMP process on a polishing system, and retaining rings configured to perform a different CMP process cannot be combined with that carrier head. This selective combination significantly reduces the component of human error, substantially preventing the mounting of an inappropriate retaining ring on a CMP carrier head, thereby eliminating substrate waste caused by the use of inappropriate retaining rings.

[0016] The present disclosure provides a retaining ring for use in polishing a semiconductor substrate. The retaining ring includes a bottom surface configured to contact a polishing pad and a top surface configured to be attached to a carrier head. The top surface of the retaining ring includes a plurality of threaded holes and a plurality of alignment slots. The surface of the carrier head that receives the top surface of the retaining ring includes at least one alignment pin. One or more alignment pins of the carrier head have a size and configuration that define a mating feature that is complementary to (i.e., mates with) an empty one of the plurality of alignment slots. At least one alignment slot has an insert that prevents insertion of an alignment pin, where at least one alignment slot is empty and configured to receive an alignment pin, and thus the empty alignment slot becomes a complementary mating feature for the alignment pin extending from the carrier head. As a result, a unique selection of a predefined combination pattern of complementary empty alignment slots and alignment pins limits the installation of only one particular retaining ring to a particular carrier head, and as a result, an unintentional installation of a retaining ring of a similar size to that carrier head is substantially prevented.

[0017] The present disclosure further provides a polishing system. The polishing system includes a retaining ring and a carrier head as described above.

[0018] FIG. 1 is a partial side cross-sectional view of a polishing system 100 according to one embodiment. Polishing systems that may be adapted to benefit from the present disclosure include, among others, MIRRA™, MIRRA MESA™, REFLEXION™, and REFLEXION™ Planarizing System, all of which are available from Applied Materials, Inc., Santa Clara, Calif.

[0019] The polishing system 100 generally includes a polishing station 110, a carrier head 120, and a retaining ring 150. In at least one embodiment, the polishing system 100 has a single polishing station 110. In another embodiment, the polishing system 100 includes a plurality of polishing stations 110 and a plurality of carrier heads 120. For example, the polishing station 110 may be disposed on a system base having a plurality of platens, and the carrier head 120 may be supported by a rotatable carousel having a plurality of carrier heads identical or similar to the carrier head 120. In some embodiments, the carrier head 120 may move the substrate 10 from one polishing station 110 to another polishing station configured to perform different polishing steps on the substrate 10. In some embodiments, one or more carrier heads 120 may be configured to perform a single predefined CMP process, in which case only one type of retaining ring 150 can be combined with the carrier head 120 for that process so that an incorrect retaining ring cannot be attached.

[0020] The polishing station 110 generally includes a rotatable platen 112 on which a polishing pad 114 can be placed. The rotatable platen 112 and the polishing pad 114 are generally larger than the semiconductor substrate 10 being processed. In at least one embodiment, the platen 112 is a rotatable aluminum or stainless - steel plate connected to a platen driver motor (not shown) by a stainless - steel driver shaft 116, and this platen driver motor rotates the platen 112 and the polishing pad 114 during processing.

[0021] The polishing pad 114 has a rough polishing surface 118 configured to polish the substrate 10. In at least one embodiment, the polishing pad 114 can be attached to the platen 112 by a pressure - sensitive adhesive layer. The polishing pad 114 is generally a consumable and is replaceable.

[0022] The polishing station 110 may further include a polishing composition supply pipe (not shown) configured to supply a polishing composition (e.g., slurry) to the polishing pad 114. The polishing composition generally contains a reactant, such as deionized water for oxide polishing; polishing particles, such as silicon dioxide for oxide polishing; and a chemical reaction catalyst, such as potassium hydroxide for oxide polishing.

[0023] The polishing station 110 may further include a pad conditioner (not shown) configured to maintain a polishing pad 114 in a state that effectively polishes the substrate 10. In at least one embodiment, the pad conditioner may include a rotatable arm that holds an independently rotating conditioner head.

[0024] The carrier head 120 is generally configured to press the substrate 10 against the polishing pad 114 during polishing. In one example, the carrier head 120 includes a housing 122, a base assembly 124, a gimbal 126, and a loading chamber 128.

[0025] The housing 122 is generally circular in shape and may be connected to a spindle 130 to rotate and / or sweep the carrier head 120 over the polishing pad 114 during polishing. The base assembly 124 is a vertically movable assembly located beneath the housing 122. The gimbal 126 slides vertically to provide vertical movement for the base assembly 124. The gimbal 126 also allows the base assembly 124 to pivot relative to the housing 122 so that the retaining ring 150 can maintain a state substantially parallel to the polishing surface 118 of the polishing pad 114.

[0026] The loading chamber 128 is positioned between the housing 122 and the base assembly 124 to apply a load (i.e., downward pressure) to the base assembly 124. The vertical position of the base assembly 124 relative to the polishing pad 114 is also controlled by the loading chamber 128.

[0027] Figure 2A is a bottom view of one embodiment of a carrier head 120 that may be used in the polishing system 100 of Figure 1. The base assembly 124 of the carrier head 120 includes a bottom surface 132, which has multiple through holes 134 for receiving multiple fasteners (e.g., machine screws) for attaching a retaining ring 150 to the carrier head 120. In Figure 2A, the carrier head 120 has 18 through holes, which are evenly spaced radially at an angle of 20 degrees. In some other embodiments, the carrier head 120 may have fewer or more through holes 134, and the spacing between the through holes 134 may be uniform or uneven.

[0028] The carrier head 120 also includes a number of alignment pins 136 extending from the base surface 132. Generally, at least two alignment pins 136 extend from the base surface 132. The alignment pins 136 may have a circular, polygonal, or other profile. The alignment pins 136 may be oriented vertically, that is, parallel to the centerline of the carrier head 120. The centerline of the carrier head 120 is the axis that becomes the axis of rotation of the carrier head 120 during ring processing. In some embodiments, the alignment pins 136 may be oriented non-vertically. In at least one embodiment, each of the alignment pins 136 has a radial orientation with respect to the centerline of the carrier head 120. In some embodiments, each alignment pin 136 may be press-fitted into a corresponding opening 138 formed in the base surface 132. The opening 138 may be a hole, a recess, or other geometric shape that receives the pin. In some embodiments, the alignment pins 136 may be screwed into corresponding openings 138 or attached to the base assembly 124 by another preferred technique. In some embodiments, the alignment pins 136 may be attached to the base assembly 124 without using the openings 138, for example by machining, brazing, welding, or by another preferred technique. In some embodiments, the combination of alignment pins 136 may vary by carrier head 120 such that each carrier head 120 can only be attached to a uniquely configured retaining ring 150 that is keyed to that particular carrier head 120.

[0029] The carrier head 120 may also include a film 140 that contacts the substrate 10. The pressure applied to the chamber bounded by the back surface of the film 140 may be selected to control the center-to-edge force profile applied to the substrate 10 by the film 140, and consequently the center-to-edge force profile applied to the polishing pad 114 by the substrate 10.

[0030] Figure 2B is a top view of one embodiment of a carrier head 120 that may be used in the polishing system 100 of Figure 1. The carrier head 120 includes a plurality of pneumatic ports 142 for supplying pressurized air to the corresponding chamber of the carrier head 120. The pressure in the chamber is used to control the pressure applied to the membrane 140, to move the base assembly 124, and to displace the retaining ring 150.

[0031] Figure 2C is an enlarged view of the carrier head 120 of Figure 2A, showing one embodiment of the alignment pins 136. In Figure 2C, the carrier head 120 has a first empty opening 138a that does not have alignment pins 136 (i.e., no pins are present in the empty openings). In this case, the number of openings 138 is greater than the number of alignment pins 136. In some other embodiments, each opening 138 is filled with a corresponding pin 136.

[0032] The carrier head 120 generally includes at least one alignment pin 136. In the example shown in Figure 2C, the alignment pins 136 of the carrier head 120 are shown as a first alignment pin 136b at least partially located in a second opening 138b, a second alignment pin 136c at least partially located in a third opening 138c, and a third alignment pin 136d at least partially located in a fourth opening 138d. In at least one embodiment, the alignment pins 136 and / or openings 138 may be evenly spaced. In some other embodiments, the carrier head 120 may have fewer or more alignment pins 136 and / or openings 138, and the spacing between the alignment pins 136 and / or openings 138 may be uniform or non-uniform. In some embodiments, the alignment pins 136 and / or openings 138 may be circular, obround, oval, triangular, square, any other preferred shape, or a combination thereof. In some embodiments, the openings 138 may be formed by drilling, machining, or other preferred techniques. In some embodiments, the alignment pins 136 and / or openings 138 may be grouped between adjacent through holes 134. In at least one embodiment, the alignment pins 136 and / or openings 138 may be grouped radially at an angle of about 20 degrees or less, for example, from about 10 degrees to about 20 degrees. In at least one embodiment, the alignment pins 136 and / or openings 138 may be grouped within a straight-line distance of about 50 mm or less, for example, from about 25 mm to about 50 mm. In one example, the openings 138 are arranged on a common radius. In another example, a first group of openings 138 are arranged on a first common radius, and a second group of openings 138 are arranged on a second common radius.

[0033] Figure 2D is a cross-sectional view along line 2D-2D in Figure 2C, showing one embodiment of the alignment pin 136. The alignment pin 136 may extend from the bottom surface 132 by a distance H1 of about 10 mm or less, for example, about 2 mm to about 10 mm, or for example, about 4 mm to about 6 mm. Adjacent alignment pins 136, for example, the first and second alignment pins 136b to c, may be spaced apart by a distance S1 of about 2 mm or more, for example, about 2 mm to about 10 mm, or for example, about 4 mm to about 5 mm. The opening 138 may have a depth D1 of about 4 mm or more, for example, about 4 mm to about 20 mm, or for example, about 8 mm to about 12 mm. The opening 138 may have a diameter configured to enable press fitting of the alignment pin 136 into the opening 138.

[0034] Figure 2E is a perspective view of one embodiment of an alignment pin 136 that may be used in the carrier head 120 of Figure 2A. The alignment pin 136 may have a length L1 of about 2 mm to about 30 mm, for example, about 2 mm to about 10 mm, for example, about 4 mm to about 6 mm, or about 6 mm to about 30 mm, for example, about 10 mm to about 22 mm. The alignment pin 136 may have a diameter DIA1 of about 3 mm to about 6 mm.

[0035] Figure 3A is a plan view of one embodiment of a retaining ring 150 that may be used in the polishing system 100 of Figure 1. The retaining ring 150 is a roughly annular ring that is removablely attached and surrounds the base assembly 124. When the fluid is pressurized into the loading chamber 128, the base assembly 124 and the retaining ring 150 are pushed down, applying a load to the polishing pad 114. In at least one embodiment, the retaining ring 150 may be a ring consisting of one part. In some other embodiments, the retaining ring 150 may be a ring consisting of multiple parts, for example, an upper and lower portion, joined together using at least one of adhesive or fasteners.

[0036] The retaining ring 150 has a top surface 152, which has a number of blind holes 154 with internal threads for receiving a number of fasteners (e.g., machine screws) for attaching the retaining ring 150 to the carrier head 120. The top surface 152 contacts the bottom surface 132 of the carrier head 120 when the retaining ring 150 is mounted on the carrier head 120. The top surface 152 may be made of a number of suitable materials, including stainless steel, molybdenum, aluminum, other suitable metals, composite materials, and plastics. In the example shown in Figure 3A, the top surface 152 of the retaining ring 150 has 18 blind holes formed therein, which are spaced evenly apart radially at an angle of 20 degrees. In some other embodiments, the retaining ring 150 may have fewer or more blind holes 154, and the spacing between the blind holes 154 may be uniform or uneven. The retaining ring 150 also includes a plurality of alignment slots 156 formed on its top surface 152 for receiving a plurality of alignment pins 136 for aligning the retaining ring 150 with the carrier head 120. In one example, each alignment slot 156 has a radial orientation with respect to the centerline of the retaining ring 150. The alignment slots 156 may be configured to limit the number of carrier heads 120 that can engage (i.e., be paired with) in order to prevent the retaining ring 150 from being mounted on an incorrect carrier head, i.e., a carrier head having a configuration of alignment pins that are not complementary.

[0037] Figure 3B is a bottom view of one embodiment of a retaining ring 150 that may be used in the polishing system 100 of Figure 1. The retaining ring 150 has a bottom surface 158 for contact with the polishing pad 114. The bottom surface 158 may include polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyethylene terephthalate (PET), or a combination thereof. In embodiments where the retaining ring 150 is a one-piece ring, the entire retaining ring 150 contains the same plastic material, which is exposed on the bottom surface 158 of the retaining ring 150. In some other embodiments, such as those discussed above, the retaining ring 150 may be a two-piece ring having upper and lower portions containing different materials. The retaining ring 150 may also have a plurality of grooves 160 formed in the bottom surface 158, which facilitate the transport of the polishing composition from the outside of the retaining ring 150 to the substrate 10. In at least one embodiment, the plurality of grooves 160 may be distributed around the retaining ring 150 at equal angular intervals. Each of the plurality of grooves 160 may be oriented at an angle α with respect to a radial line segment extending through the center of the retaining ring 150. In some embodiments, the angle α may be about 30° to about 60°, for example, about 45° or about 50°. Thus, the grooves 160 can transport the polishing composition to and from the substrate 10, even when the bottom surface 158 is in contact with the polishing pad 114. In some other embodiments, the bottom surface 158 may not have grooves 160 and may be substantially flat.

[0038] Figure 3C is an enlarged view of the retaining ring 150 of Figure 3A, showing one embodiment of the alignment slots 156. Each retaining ring 150 is provided with at least two alignment slots 156, but any desired number of alignment slots 156 can be used as space allows. In one or more embodiments, the alignment slots 156 are elongated radially with respect to the centerline of the retaining ring 150. Referring to the example depicted in Figure 3C, the retaining ring 150 comprises four alignment slots 156, for example, a first alignment slot 156a at position 1, a second alignment slot 156b at position 2, a third alignment slot 156c at position 3, and a fourth alignment slot 156d at position 4. The second alignment slot 156b is adjacent to the first alignment slot 156a. The third alignment slot 156c is adjacent to the second alignment slot 156b, which is located between the first alignment slot 156a and the third alignment slot 156c. The fourth alignment slot 156d is adjacent to the third alignment slot 156c, which is located between the second alignment slot 156b and the fourth alignment slot 156d. In some other embodiments, the retaining ring 150 may have fewer or more alignment slots 156, and the spacing between the alignment slots 156 may be uniform or non-uniform. In at least one embodiment, the alignment slots 156 may be closed slots (i.e., may have closed ends). In some other embodiments, the alignment slots 156 may be open slots (i.e., opening to the ID or OD of the retaining ring 150). In some embodiments, the alignment slots 156 may be circular, polygonal, oval, oblong, any other preferred shape, or a combination thereof. In some embodiments, the alignment slots 156 may be formed by molding, pressing, machining, or other preferred methods. In some embodiments, the alignment slots 156 may be grouped between adjacent blind holes 154.In at least one embodiment, the alignment slots 156 may be grouped radially at angles of approximately 20 degrees or less, for example, between approximately 10 and 20 degrees. In at least one embodiment, the alignment slots 156 may be grouped within a straight-line distance of approximately 50 mm or less, for example, between approximately 25 mm and 50 mm. In at least one embodiment, a second group of alignment slots 156 may be located on opposite sides with respect to the circumference of the retaining ring 150. In some other embodiments, the alignment slots 156 may be distributed circumferentially around the retaining ring 150. In some embodiments, each of the alignment slots 156 and the corresponding alignment pins 136 may have a tangential orientation with respect to the centerline of the retaining ring 150, that is, each of the alignment slots 156 and the corresponding alignment pins 136 is aligned perpendicular to a radial axis passing through the centerline of the retaining ring 150. In some other embodiments, the alignment slots 156 and the corresponding alignment pins 136 may be positioned in a grid pattern or another preferred layout.

[0039] Each of the alignment slots 156 is configured to receive an insert 162. A slot 156 is selected and an insert 162 is received to form a combination feature of a particular type of retaining ring 150, which is complementary to the combination feature of the carrier head 120, so that only a specific ring 150 and head 120 can be paired, depending on a predetermined process to be performed on the polishing system 100. In the example shown in Figure 3C, a first insert 162a at position 1 is positioned in the corresponding first alignment slot 156a. The insert 162a prevents the insertion of the alignment pin 136 into the first alignment slot 156a. The insert 162 is formed of a material that is inert to the chemicals used in the CMP process. The insert 162 may also be formed of a heat-resistant material. In at least one embodiment, the insert 162 is made of a metal or polymer. Suitable polymers include, in particular, PPS, PEEK, PET, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), polymethyl methacrylate (PMMA), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), and polyetherimide (PEI). In Figure 3C, the second alignment slot 156b, the third alignment slot 156c, and the fourth alignment slot 156d, located at positions 2, 3, and 4 respectively, are empty, allowing for the insertion of the first alignment pin 136b, the second alignment pin 136c, and the third alignment pin 136d, respectively.

[0040] Figure 3D is a cross-sectional view along line 3D-3D in Figure 3C, showing one embodiment of the alignment slot 156. The alignment slot 156 may be positioned to correspond to each alignment pin 136 extending from the carrier head 120. Similarly, the alignment slot 156 may be sized and shaped to receive the corresponding alignment pin 136. In at least one embodiment, the alignment slot 156 corresponds precisely to the alignment pin 136. In other words, there are an equal number of alignment slots 156 and alignment pins 136, so that when the retaining ring 150 is mounted on the carrier head 120, each alignment slot 156 is filled by the corresponding alignment pin 136. The alignment slot 156 may have a depth D2 suitable for receiving the alignment pin 136. In at least one embodiment, the depth D2 may be about 10 mm or less, for example, about 2 mm to about 10 mm, for example, about 4 mm to about 6 mm. Adjacent alignment slots 156, for example, the first and second alignment slots 156a and 156b, can be spaced apart by a distance S2 of about 2 mm or more, for example, about 2 mm to about 10 mm, or for example, about 4 mm to about 5 mm. The alignment slots 156 may have a length L2 that is greater than or approximately equal to the diameter DIA1 of the alignment pin 136, for example, about 1 to about 3 times the diameter DIA1. In at least one embodiment, the length L2 may be about 3 mm or more, for example, about 3 mm to about 18 mm. The alignment slots 156 may have a width W1 suitable for receiving the alignment pin 136 with a total one-sided tolerance of about +1 mm or less. In at least one embodiment, the width W1 may be about 3 mm to about 7 mm.

[0041] Figure 3E is a perspective view of one embodiment of an insert 162 that may be used in the retaining ring 150 of Figure 3A. The insert 162 may have a length L3, width W2, and height H2 suitable for placement within the alignment slot 156 without protruding above the top surface 152 of the retaining ring 150. In one example, the insert 162 is sized to be press-fitted into the alignment slot 156. In other examples, the insert 162 may be held in place within the alignment slot 156 using adhesive, staking, or another preferred technique. Each alignment slot 156 is the same size and shape, and therefore any one insert 162 can be fitted into any one of the alignment slots 156. In at least one embodiment, the top surface 164 of the insert 162 is substantially flush with the top surface 152. In some embodiments, the top surface 164 may be recessed relative to the top surface 152.

[0042] In some embodiments, each of the various types of retaining rings 150 has a unique combination of inserts 162 and empty alignment slots 156 that differs from other types of retaining rings 150, so as to prevent the retaining ring 150 from being mounted on an incorrect carrier head, i.e., a carrier head that does not have complementary combination features. In some embodiments, the retaining ring 150 has at least one insert 162. In such embodiments, the total number of different combinations is 2 スロットIt is equal to -2. For example, the retaining ring 150 in Figure 3A has four alignment slots 156, so the total number of different combinations of inserts 162 is equal to 14, as shown in Figures 4A to 4C. It will be understood that a larger number of combinations can be generated by introducing one or more additional alignment slots 156, which will be used with a carrier head that has additional pin locations. For example, with five alignment slots 156, the total number of different combinations of inserts 162 is equal to 30. It will be further understood that if fewer combinations are required, the retaining ring 150 may have fewer alignment slots 156. For example, with three alignment slots 156, the total number of different combinations of inserts 162 is equal to 6.

[0043] Figure 4A is a schematic diagram of various combinations of inserts 162 and empty alignment slots 156 that can be used to distinguish between different types of retaining rings 150. In Figure 4A, each row consisting of inserts 162 and empty alignment slots 156 represents a different retaining ring 150. In the first row representing the first retaining ring, only position 1 has an insert, and positions 2, 3, and 4 are empty. In the second row representing the second retaining ring, only position 2 has an insert, and positions 1, 3, and 4 are empty. In the third row representing the third retaining ring, only position 3 has an insert, and positions 1, 2, and 4 are empty. In the fourth row representing the fourth retaining ring, only position 4 has an insert, and positions 1, 2, and 3 are empty.

[0044] Figure 4B is another schematic diagram of various combinations of inserts 162 and empty alignment slots 156 that can be used to distinguish between different types of retaining rings 150. In Figure 4B, each row consisting of inserts 162 and empty alignment slots 156 represents a different retaining ring 150. In the first row representing the first retaining ring, only positions 1 and 2 have inserts, and positions 3 and 4 are empty. In the second row representing the second retaining ring, only positions 1 and 3 have inserts, and positions 2 and 4 are empty. In the third row representing the third retaining ring, only positions 1 and 4 have inserts, and positions 2 and 3 are empty. In the fourth row representing the fourth retaining ring, only positions 2 and 3 have inserts, and positions 1 and 4 are empty. In the fifth row representing the fifth retaining ring, only positions 2 and 4 have inserts, and positions 1 and 3 are empty. In the sixth row representing the sixth retaining ring, only positions 3 and 4 have inserts, while positions 1 and 2 are empty.

[0045] Figure 4C is yet another schematic diagram of various combinations of inserts 162 and empty alignment slots 156 that can be used to distinguish between different types of retaining rings 150. In Figure 4C, each row consisting of inserts 162 and empty alignment slots 156 represents a different retaining ring 150. In the first row representing the first retaining ring, only positions 1, 2, and 3 have inserts, and position 4 is empty. In the second row representing the second retaining ring, only positions 1, 2, and 4 have inserts, and position 3 is empty. In the third row representing the third retaining ring, only positions 1, 3, and 4 have inserts, and position 2 is empty. In the fourth row representing the fourth retaining ring, only positions 2, 3, and 4 have inserts, and position 1 is empty.

[0046] While the foregoing is directed toward embodiments of the present disclosure, other further embodiments of the present disclosure may be devised without departing from its basic scope, the scope of which is determined by the following claims.

Claims

1. The bottom surface is configured to contact the polishing pad, A top surface configured to be attached to the carrier head, The carrier head has a surface that includes at least one alignment pin. The aforementioned top surface is, Multiple screw holes for attaching the retaining ring to the carrier head, Multiple alignment slots, The device includes a first insert disposed in a first alignment slot among the plurality of alignment slots, wherein the first insert is flush with or lower than the top surface, and the first insert is configured to prevent the insertion of the alignment pin into the first alignment slot. The plurality of alignment slots are positioned between adjacent first and second screw holes among the plurality of screw holes. Retaining ring.

2. The retaining ring according to claim 1, wherein the plurality of alignment slots are arranged radially at an angle of approximately 20 degrees or less.

3. The retaining ring according to claim 1, wherein each of the alignment slots is radially aligned with an axis in the direction of the rotation axis passing through the center of the retaining ring.

4. The retaining ring according to claim 1, wherein the top surface comprises metal and the first insert comprises polymer.

5. The retaining ring according to claim 1, wherein each of the plurality of alignment slots has a shape selected from the group consisting of circular, oval, and oval shapes.

6. The retaining ring according to claim 1, wherein at least one alignment slot is vacant to allow insertion of an alignment pin.

7. The retaining ring according to claim 1, wherein the first insert is configured to be disposed in any of the alignment slots.

8. The aforementioned plurality of alignment slots are The second alignment slot, The third alignment slot, The retaining ring according to claim 1, further comprising a fourth alignment slot.

9. The retaining ring according to claim 8, wherein the second, third, and fourth alignment slots are empty and arranged on the same plane as the first alignment slot, and the first, second, third, and fourth alignment slots are arranged between adjacent screw holes.

10. The retaining ring according to claim 8, wherein the first alignment slot is disposed between the second alignment slot and the third alignment slot, the third and fourth alignment slots are empty and disposed on the same plane as the first alignment slot, and the first, second, third and fourth alignment slots are disposed between adjacent screw holes.

11. The second insert is disposed within the second alignment slot. The retaining ring according to claim 8, further comprising the following:

12. The retaining ring according to claim 11, wherein the first and second alignment slots are arranged adjacent to each other, and the third and fourth alignment slots are empty.

13. The retaining ring according to claim 11, wherein the first and second alignment slots are separated by at least one of the third and fourth alignment slots, and the third and fourth alignment slots are empty.

14. The second insert disposed within the second alignment slot, A third insert disposed within the third alignment slot, The retaining ring according to claim 8, further comprising the following:

15. The retaining ring according to claim 14, wherein the first, second, and third alignment slots are arranged adjacent to each other, and the fourth alignment slot is empty.

16. The retaining ring according to claim 14, wherein the fourth alignment slot is empty and is disposed between two of the first, second, and third alignment slots.

17. The second insert disposed within the second alignment slot, A third insert disposed within the third alignment slot, The fourth insert disposed within the fourth alignment slot, The retaining ring according to claim 8, further comprising the following:

18. The retaining ring according to claim 1, A carrier head having a bottom surface that contacts the top surface of the retaining ring, and including at least one alignment pin extending from the bottom surface into one of the empty alignment slots, A polishing system equipped with the following features.

19. The bottom surface has a plurality of openings formed therein, in which at least one alignment pin can be installed. The polishing system according to claim 18, wherein the number of the plurality of openings is greater than the number of at least one alignment pin.

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