CN117412836A - Method for detecting orientation of chemical mechanical polishing adjustment disc - Google Patents
Method for detecting orientation of chemical mechanical polishing adjustment disc Download PDFInfo
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- CN117412836A CN117412836A CN202280039787.5A CN202280039787A CN117412836A CN 117412836 A CN117412836 A CN 117412836A CN 202280039787 A CN202280039787 A CN 202280039787A CN 117412836 A CN117412836 A CN 117412836A
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- 238000005498 polishing Methods 0.000 title claims abstract description 185
- 238000000034 method Methods 0.000 title claims abstract description 28
- 239000000126 substance Substances 0.000 title claims description 12
- 238000006073 displacement reaction Methods 0.000 claims abstract description 143
- 230000003750 conditioning effect Effects 0.000 claims abstract description 126
- 239000000758 substrate Substances 0.000 claims abstract description 54
- 230000001939 inductive effect Effects 0.000 claims abstract description 9
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- 238000005859 coupling reaction Methods 0.000 claims description 5
- 238000003672 processing method Methods 0.000 claims description 4
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- 238000005259 measurement Methods 0.000 description 20
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- 239000002002 slurry Substances 0.000 description 4
- 239000004696 Poly ether ether ketone Substances 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000011229 interlayer Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229920002530 polyetherether ketone Polymers 0.000 description 3
- 238000005389 semiconductor device fabrication Methods 0.000 description 3
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- 229920002313 fluoropolymer Polymers 0.000 description 2
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- 239000004033 plastic Substances 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910001094 6061 aluminium alloy Inorganic materials 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- -1 Polytetrafluoroethylene Polymers 0.000 description 1
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- JUPQTSLXMOCDHR-UHFFFAOYSA-N benzene-1,4-diol;bis(4-fluorophenyl)methanone Chemical compound OC1=CC=C(O)C=C1.C1=CC(F)=CC=C1C(=O)C1=CC=C(F)C=C1 JUPQTSLXMOCDHR-UHFFFAOYSA-N 0.000 description 1
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- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B53/00—Devices or means for dressing or conditioning abrasive surfaces
- B24B53/017—Devices or means for dressing, cleaning or otherwise conditioning lapping tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/005—Control means for lapping machines or devices
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
Abstract
Methods and apparatus for determining a polishing pad thickness profile are described herein. The orientation of the conditioning disk and the thickness of the polishing pad are determined using a set of displacement sensors including an arm displacement sensor and one or more conditioning disk displacement sensors. The displacement sensor is a non-contact sensor such as a laser sensor, a capacitive sensor, or an inductive sensor. Once the thickness profile of the polishing pad is determined, one or more process conditions are changed to improve substrate polishing.
Description
Background
Technical Field
Embodiments of the present disclosure relate generally to semiconductor device fabrication, and more particularly, to a chemical mechanical polishing (chemical mechanical polishing, CMP) system used in semiconductor device fabrication and related substrate processing methods.
Description of related Art
Chemical Mechanical Polishing (CMP) is commonly used to fabricate high density integrated circuits to planarize or polish a layer of material deposited on a substrate. One common application of CMP processes in semiconductor device fabrication is planarization of bulk films, such as pre-metal dielectric (PMD) or inter-layer dielectric (interlayer dielectric, ILD) polishing, where underlying two-or three-dimensional features create recesses and protrusions in the surface of the material surface to be planarized. Other common applications include shallow trench isolation (shallow trench isolation, STI) and inter-layer metal interconnect formation, where a CMP process is used to remove vias, contacts, or trench fill material (overburden) from exposed surfaces (fields) of material layers in which STI or metal interconnect features are disposed.
In a typical CMP process, a polishing pad is mounted to a rotatable polishing platen. The material surface of the substrate is forced against the polishing pad in the presence of the polishing liquid. Typically, the polishing liquid is an aqueous solution of one or more chemically active components and abrasive particles suspended in the aqueous solution, such as a CMP slurry. The substrate carrier is used to force the material surface of the substrate against the polishing pad. A typical substrate carrier includes a membrane, bladder, or backing plate disposed against a backside surface of the substrate, and an annular retaining ring surrounding the substrate. The membrane, bladder or backplate is used to apply a downward force against the substrate as the substrate carrier rotates about the carrier axis. The retaining ring surrounds the substrate as it is forced against the polishing pad and serves to prevent the substrate from slipping off the substrate carrier. Material on the surface of the substrate in contact with the polishing pad is removed by a combination of chemical and mechanical activity provided by the relative motion of the polishing liquid, the substrate, and the polishing pad, and the downward force applied to the substrate against the polishing pad.
In general, CMP process performance is characterized with reference to the rate of material removal from the surface of the substrate and the uniformity of the rate of material removal across the substrate surface (removal rate uniformity). In a dielectric bulk film planarization process, uneven material removal rates across the substrate surface can result in poor planarity and/or undesirable thickness variations of the dielectric material remaining after CMP. In metal interconnect CMP applications, metal loss caused by poor local planarization and/or uneven material removal rates can result in undesirable changes in the effective resistance of the metal features, thereby affecting device performance and reliability. As a result, uneven material removal rates across the substrate surface may adversely affect device performance and/or cause device failure, which results in suppressed yields of usable devices formed on the substrate.
Non-uniformities in the distribution of the polishing pad may affect the removal rate on the substrate surface as the substrate passes over the non-uniformities. If such non-uniformities are not considered, the polishing of each of the substrates may be non-uniform and adversely affect device performance. Current methods of addressing polishing pad non-uniformities are destructive to the polishing pad or involve modeling of polishing pad wear. The current non-destructive methods and apparatus for measuring polishing pad distribution have poor resolution and accuracy.
Accordingly, there is a need in the art for a solution to the above-described problems.
Disclosure of Invention
Embodiments herein relate generally to chemical mechanical polishing (chemical mechanical polishing, CMP) systems and methods for improving polishing pad conditioning operations.
In one embodiment, a pad conditioning assembly for a Chemical Mechanical Polishing (CMP) apparatus is described. The pad conditioning assembly includes a conditioning disk, a first actuator coupled to the conditioning disk, a second actuator disposed radially outward of the conditioning disk, a conditioning arm coupled to the first actuator and the second actuator, an arm displacement sensor coupled to the conditioning arm, and one or more conditioning disk displacement sensors coupled to the first actuator.
In another embodiment, an apparatus for substrate processing is described. The apparatus for substrate processing includes a polishing platen, a substrate carrier, and a pad conditioner assembly. The pad conditioning assembly includes a conditioning disk, a first actuator coupled to the conditioning disk, a second actuator disposed radially outward of the conditioning disk, a conditioning arm coupling the first actuator and the second actuator, an arm displacement sensor coupled to a bottom conditioning arm surface of the conditioning arm, and one or more conditioning disk displacement sensors disposed on a bottom actuator surface of the first actuator. The arm displacement sensor is configured to measure a first distance between the arm displacement sensor and a top surface of the polishing platen. The one or more conditioner disk displacement sensors are configured to measure a second distance between each of the conditioner disk displacement sensors and a portion of the conditioner disk.
In yet another embodiment, a substrate processing method is described. The substrate processing method includes forcing a conditioning disk against a surface of a polishing pad, and measuring a distance between a conditioning arm and a polishing platen disposed below the polishing pad. The adjustment arm is coupled to the adjustment plate via a first actuator. One or more conditioning disk displacement sensors are used to determine the orientation of the conditioning disk. The thickness profile of the polishing pad is determined by the orientation of the conditioning disk. After determining the thickness profile, one or more adjustment parameters are changed.
Drawings
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
Fig. 1A is a schematic plan view of a polishing system according to embodiments described herein.
FIG. 1B is a schematic cross-sectional view of the polishing system of FIG. 1A, according to an embodiment described herein.
Fig. 2 is a schematic cross-sectional view of a portion of the polishing system of fig. 1A, in accordance with an embodiment described herein.
FIG. 3 is a schematic cross-sectional view of a portion of the polishing system of FIG. 1A having conditioning disks in multiple positions, according to an embodiment described herein.
Fig. 4A-4C are schematic plan views of conditioning discs having differently configured conditioning disc displacement sensors according to embodiments described herein.
Fig. 5 is a flow chart of a method of forming a polishing pad thickness profile according to an embodiment described herein.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Detailed Description
The present disclosure relates generally to apparatus and methods for use within a CMP system. The apparatus and methods described herein are more particularly directed to measurement of polishing pad distribution within a single polishing module. The apparatus comprises: an arm displacement sensor coupled to the adjustment arm of the pad adjustment assembly; and one or more additional conditioner disk displacement sensors positioned to measure displacement of a portion of the conditioner disk of the mat conditioning assembly. The arm displacement sensor is configured to measure a distance between the conditioner arm and an upper surface of the polishing platen. One or more conditioning disk displacement sensors enable measurement of the orientation of the conditioning disk as the conditioning disk is swept across the top surface of the polishing pad.
The combination of the arm displacement sensor and the conditioner disk displacement sensor enables the thickness distribution of the polishing pad to be determined. The thickness profile can be continuously updated as the conditioning disk is swept across the surface of the polishing pad. The thickness profile enables detection of grooves or pits in the top surface of the polishing pad. The use of a single arm displacement sensor may provide a global estimate of the thickness distribution of the polishing pad, but by adding a conditioning disk displacement sensor, the accuracy and resolution of the polishing pad thickness measurement is improved.
FIG. 1A is a schematic plan view of a polishing system configured to practice the methods described herein, according to one embodiment. FIG. 1B is a schematic cross-sectional side view of the polishing system of FIG. 1A. Here, the polishing system 100 includes a polishing platen 102, a substrate carrier 104, a fluid delivery arm 106, a pad conditioner assembly 108, and a system controller 110. Polishing platen 102 features a cylindrical platen body 114 and a layer of low adhesion material 116 disposed on a surface of platen body 114 to provide a polishing pad mounting surface 118. Platen body 114 is typically formed of a suitably rigid, lightweight, and slurry corrosion resistant material, such as aluminum, an aluminum alloy (e.g., 6061 aluminum), or stainless steel. The low adhesion material layer 116 typically comprises a polymeric material formed from one or more fluoropolymer precursors or melt processible fluoropolymers. Once the polishing pad 112 has reached the end of its useful life, the low adhesion material layer 116 desirably reduces the amount of force required to remove the polishing pad 112 from the polishing pad mounting surface 118 and further protects the metal of the platen body 114 from corrosion caused by the undesirable polishing liquid.
Here, the pad mounting surface 118 includes a plurality of concentric zones 120 a-120 c formed about the platen axis a. The plurality of concentric zones 120 a-120 c include a circular (when viewed from above) or annular first zone 120a, an annular second zone 120b surrounding the first zone 120a, and an annular third zone 120c disposed radially outward from and surrounding the second zone 120b. The pad mounting surface 118 is divided into a plurality of sections, such first, second and third pad mounting surfaces 118a, 118b and 118c corresponding to each of the annular first, second and third regions 120a, 120b and 120c, respectively.
Here, the second pad mounting surface 118b in the second zone 120b is recessed from the plane P by a distance Z 1 . Plane P is defined by pad mounting surfaces 118a, 118c in first zone 120a and third zone 120c, which in some embodiments and as shown in fig. 1B are substantially coplanar with one another. In some embodiments, for example, where pad mounting surfaces 118a, 118c in first and third regions 120a, 120c are not coplanar with one another, plane P may be defined by an object having a planar surface disposed over first and third regions 120a, 120c and with first region 120a and said third region 120c to span the recessed second region 120b.
In fig. 1B, the second pad mounting surface 118B in the second zone 120B is substantially planar and parallel to the plane formed by the surfaces of the first zone 120a and the third zone 120c. Thus, the distance Z 1 Is substantially constant across the width W of the recessed pad mounting surface 118b in the second region 120b. In other embodiments, the surface of the recess in the second region 120b is not parallel to the plane formed by the pad mounting surfaces of the first and third regions 120a, 120c and/or is substantially uneven across its width W.
Typically, the polishing pad 112 is formed from one or more layers of polymeric material and is secured to the pad mounting surfaces 118 a-118 c using a pressure sensitive adhesive. The polymeric material used to form the polishing pad 112 may be relatively compliant or may be rigid and have channels or grooves formed in its polishing surface to allow the polishing pad 112 to conform to the recessed pad mounting surface 118b in the second zone 120b and the pad mounting surfaces 118a, 118c of the first and third zones 120a, 120c adjacent thereto. Thus, the polishing surface of the polishing pad 112 in each of the zones 120 a-120 c has substantially the same shape and relative dimensions as described above for the pad mounting surface 118 of the platen 102.
Here, as the polishing pad 112 rotates about the platen axis a, a downward force is applied against the substrate 113 using the rotating substrate carrier 104 to force the material surface of the substrate 113 against the polishing pad 112. As shown, the substrate carrier 104 features a flexible membrane 124 and an annular retaining ring 126. During substrate polishing, the flexible membrane 124 applies a downward force against the inactive (backside) surface of the substrate 113 disposed thereunder. The retaining ring 126 surrounds the substrate 113 to prevent the substrate 113 from slipping off the substrate carrier 104 as the polishing pad 112 moves under the substrate carrier. Typically, the substrate carrier 104 is configured to apply a downward force against the retaining ring 126 that is independent of the downward force applied against the substrate 113. In some embodiments, the substrate carrier 104 oscillates in a radial direction of the polishing platen to partially reduce uneven wear of a polishing pad 112 disposed beneath the substrate carrier.
Typically, the substrate 113 is forced against the polishing pad 112 in the presence of one or more polishing fluids delivered by the fluid delivery arm 106. Typical polishing solutions include slurries formed from aqueous solutions having abrasive particles suspended therein. Typically, the polishing slurry comprises one or more chemically active components that are used to modify the material surface of the substrate 113, thereby enabling chemical mechanical polishing of the material surface.
The pad conditioner assembly 108 is used to condition the polishing pad 112 by forcing the conditioning disk 128 against the surface of the polishing pad 112 before, after, or during polishing of the substrate 113. As shown in fig. 2, the pad conditioner assembly 108 includes a conditioner disk 128, a first actuator 130 for rotating the conditioner disk 128 about an axis C, a conditioner arm 132 coupling the first actuator 130 to a second actuator 134, a rotational position sensor 135, and a third actuator 136. The second actuator 134 is used to oscillate the conditioning arm 132 about the axis D to thereby sweep the rotating conditioning disk 128 back and forth between the inner and outer radii of the polishing pad 112. A position sensor 135 is coupled to the second actuator 134 and is used to determine the angular position of the conditioning arm 132, which in turn can be used to determine the radial position of the conditioning disk 128 on the polishing pad 112 as the conditioning disk 128 sweeps across the polishing pad 112. The third actuator 136 is used to exert a downward force on the conditioning disk 128 when the conditioning disk 128 is forced against the polishing pad 112. Here, the third actuator 136 is coupled to an end of the arm 132 at a location proximal to the second actuator 134 and distal from the adjustment plate 128.
Operation of the polishing system 100, including operation of the pad conditioning assembly 108, is facilitated by a system controller 110 (fig. 1B). The system controller 110 includes a programmable central processing unit (CPU 140) that is operable with a memory 142 (e.g., non-volatile memory) and support circuitry 144. For example, in some embodiments, the CPU 140 is one of any form of general purpose computer processor used in an industrial environment, such as a programmable logic controller (programmable logic controller, PLC) for controlling various polishing system components and sub-processors. The memory 142 coupled to the CPU 140 is non-transitory and is typically one or more of readily available memory such as random access memory (random access memory, RAM), read Only Memory (ROM), a floppy disk drive, a hard disk, or any other form of local or remote digital storage. Support circuitry 144 is conventionally coupled to CPU 140 and includes a cache, clock circuitry, input/output subsystems, power supplies, and the like, coupled to the various components of polishing system 100, as well as combinations thereof, to facilitate controlling the substrate polishing process.
Here, the memory 142 is in the form of a computer-readable storage medium (e.g., a non-volatile memory) containing instructions that, when executed by the CPU 140, facilitate the operation of the polishing system 100. Illustrative computer-readable storage media include, but are not limited to: (i) A non-writable storage medium (e.g., a read-only memory device within a computer such as a CD-ROM disk readable by a CD-ROM drive, flash memory, ROM chip, or any type of solid state non-volatile semiconductor memory) on which information is permanently stored; and (ii) a writable storage medium (e.g., a floppy disk within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which is stored variable information. The instructions in memory 142 are in the form of a program product, such as a program (e.g., middleware application, device software application, etc.) that implements the methods of the disclosure. In some embodiments, the present disclosure may be implemented as a program product stored on a non-transitory computer readable storage medium for use by and in a computer system. The program of the program product thus defines functions of the embodiments (including the methods described herein).
Fig. 2 is a schematic cross-sectional view of a portion of the polishing system 100 of fig. 1A, in accordance with an embodiment described herein. The polishing system 100 is configured with an arm displacement sensor 238 and one or more conditioner disk displacement sensors 210a, 210b. The arm displacement sensor 238 and conditioner disk displacement sensors 210a, 210b are configured to enable measurement of the thickness profile of the polishing pad 112. The thickness profile measures the variation in the distribution of the polishing pad 112 caused by depressions in the polishing pad mounting surface 118 of the platen body 114, as well as the non-uniformity of the polishing pad 112 caused by uneven wear or particle accumulation.
Typically, the conditioning disk 128 is coupled to the first actuator 130 using a gimbal 208 that allows the conditioning disk 128 to maintain a parallel relationship with the surface of the polishing pad 112 when the conditioning disk 128 is forced against the polishing pad 112. Here, the tuning disk 128 includes a tuning disk holder 202 and a tuning disk pad 204 disposed within the tuning disk holder 202. The conditioning disk holder 202 is a polymeric or plastic material, such as a fluorocarbon-containing material. The plastic material may be Polytetrafluoroethylene (PTFE) or polyetheretherketone (polyether ether ketone, PEEK). The conditioning disk holder 202 has a thickness of less than about 10mm (such as less than about 5 mm) to enable the conditioning disk displacement sensor 210a to measure the position of the conditioning disk pads 204 disposed therein. Conditioning disk pad 204 has a fixed abrasive conditioning surface (e.g., diamond embedded in a metal alloy) and is used to abrade and refurbish the surface of polishing pad 112 and remove polishing by-products or other debris therefrom. Typically, the diameter of the tuning disk 128 is between about 80mm and about 130mm, such as between about 90mm and about 120mm, or, for example, about 108mm (4.25 inches). In some embodiments, the diameter of conditioning disk 128 is less than the width W of second region 120b such that conditioning disk 128 can maintain contact with the surface of polishing pad 112 during conditioning thereof in second region 120b.
The arm displacement sensor 238 is connected to the adjustment arm 132 such that the arm displacement sensor 238 is located on the bottom surface 220 of the adjustment arm 132. The arm displacement sensor 238 is an inductive sensor, a capacitive sensor, or a laser sensor. In embodiments in which the arm displacement sensor 238 is an inductive sensor, the arm displacement sensor 238 is configured to measure eddy currents to determine the distance Z between the end of the arm displacement sensor 238 and the metal surface of the platen body 114 disposed therebelow 2 . The arm displacement sensor 238 and the position sensor 135 are used in combination to determine the recess distance Z of the surface of the polishing pad 112 in the second zone 120b from the surfaces of the polishing pad 112 in the first zone 120a and the third zone 120c adjacent thereto 3 . However, in which the second zone120b are narrower than the diameter of the dial 128, the distance Z by the arm displacement sensor 238 2 The measurement is merely an estimate and may not take into account the overall shape or depth of the second region 120b. The arm displacement sensor 238 may be mechanically or remotely connected to the system controller 110. In embodiments where the arm displacement sensor 238 is remotely connected to the system controller 110, the arm displacement sensor 238 includes a short range wireless linkRadio frequency or wireless fidelity connections.
The conditioner disk displacement sensors 210a, 210b are coupled to the pad conditioner assembly 108, such as at the bottom surface 206 of the first actuator 130. The conditioner disk displacement sensors 210a, 210b as described herein are disposed directly above the conditioner disk 128. The proximity of the conditioner disk 128 improves measurement accuracy and precision when using the same type of conditioner disk displacement sensors 210a, 210b. Coupling the conditioner disk displacement sensors 210a, 210b to a portion of the pad conditioner assembly 108 that moves with the first actuator 130 and the conditioner disk 128 provides a constant frame of reference for the conditioner disk 128 and eliminates the need to consider the position of the first actuator 130 and the conditioner disk 128 on the surface of the polishing pad 112, thereby reducing errors. The conditioner disk displacement sensors 210a, 210b described herein are non-contact displacement sensors. Problems such as mechanical failure and wear that occur when the dial 128 rotates are prevented by the use of a non-contact displacement sensor.
As examples, the conditioner disk displacement sensors 210a, 210b may be inductive sensors, laser sensors, or capacitive sensors. In embodiments where the conditioner disk displacement sensors 210a, 210b are inductive sensors, the conditioner disk displacement sensors 210a, 210b measure eddy currents to determine one or more distances Z between the ends of the conditioner disk displacement sensors 210a, 210b and the metal surface of the conditioner disk mat 204 disposed therebelow 4 Or Z is 5 . First dial distance Z 4 Measured by a first conditioner disk displacement sensor 210 a. Second dial distance Z 5 Measured by a second conditioner disk displacement sensor 210b. First regulating disk displacementThe sensor 210a and the second conditioner disk displacement sensor 210b are configured to measure distances to different portions of the conditioner disk 128. The conditioner disk displacement sensors 210a, 210b are used in combination to determine the orientation of the conditioner disk 128.
The orientation of conditioning disk 128 and the arm displacement measured by arm displacement sensor 238 enable a better polishing pad thickness profile to be created that accurately accounts for dishing or thickness non-uniformities of polishing pad 112. As the number of conditioning disk displacement sensors 210a, 210b increases, the resolution and accuracy of the polishing pad thickness distribution may increase. The conditioner disk displacement sensors 210a, 210b may be mechanically or remotely connected to the system controller 110. In embodiments where the conditioning disk displacement sensors 210a, 210b are remotely connected to the system controller 110, the conditioning disk displacement sensors 210a, 210b comprise short-range wirelessRadio frequency or wireless fidelity connections.
Although the illustrated pad conditioner assembly 108 includes two conditioner disk displacement sensors 210a, 210b, in some embodiments, only one conditioner disk displacement sensor 210a, or three or more conditioner disk displacement sensors 210a, 210b, are present, as shown in fig. 4A-4C. When a single dial displacement sensor 210a is utilized, only one inclination of the dial 128 can be measured. When two conditioner disk displacement sensors 210a, 210b are utilized, two inclinations of conditioner disk 128 can be measured. When three or more conditioner disk displacement sensors 210a, 210b are utilized, all three inclinations of the conditioner disk 128 can be measured. The use of additional conditioner disk displacement sensors 210a, 210b, which are more than three conditioner disk displacement sensors 210a, 210b, helps to improve the resolution and accuracy of conditioner disk tilt measurements and subsequent polishing pad thickness profiles.
In some embodiments, the pad conditioner assembly 108 is configured to maintain a recessed relationship of the surface of the polishing pad 112 in the second zone 120b relative to the surfaces of the polishing pad 112 in the first and third zones 120a, 120c adjacent thereto. In those embodiments, the system controller 110 may be used to vary the dwell time of the conditioning disk 128 in the second zone 120bInter (dwell time) and/or adjusting the downward force on disc 128. As used herein, residence time refers to the average duration that conditioning disk 128 spends in a radial position as conditioning disk 128 sweeps from the inner radius to the outer radius of polishing pad 112 as platen 102 rotates to move polishing pad 112 thereunder. For example, per cm in the second zone 120b 2 The adjusted residence time of the polishing pad surface area relative to per cm in one or both of the first zone 120a and/or the third zone 120c adjacent thereto 2 The conditioning residence time of the polishing pad surface area can be increased or decreased.
Fig. 3 is a schematic cross-sectional view of a portion of the polishing system 100 of fig. 1A having conditioning disk 128 in a plurality of positions over polishing pad 112. The dial 128 is illustrated at different heights and orientations. The conditioning disk 128 is configured to rotate about axis C as it progresses across the surface of the polishing pad 112.
When conditioning disk 128 is positioned over a portion of polishing pad 112 without any imperfections or pits causing conditioning disk 128 to tilt at an angle different from the resting position of polishing pad 112, conditioning disk 128 as described herein is illustrated as being in a first orientation O 1 . First orientation O 1 May be considered as the original orientation (home orientation) or the rest position.
Conditioning disk 128 'is illustrated as conditioning disk 128' being disposed at least partially over the pits or features within polishing pad 112. As shown herein, the depressions or features in the polishing pad 112 are caused by depressions or features in the platen body 114, which are second regions 120b of the pad mounting surface 118b, such as described above. Conditioner disk 128' is configured to be in a second orientation O when positioned over a recess in polishing pad 112 2 . Second orientation O 2 By measuring the first dial distance Z 4 And a second dial distance Z 5 Measured by a computer. As shown herein, a first dial distance Z 4 Less than the second dial distance Z 5 And thus the orientation of the tuning disk 128' is determined. Finer resolution of features within polishing pad 112 may be possible with smaller conditioner disk 128 and/or additional conditioner disk displacement sensors 210a, 210b。
Conditioner disk 128 "is illustrated as conditioner disk 128" disposed at least partially over the same pits or features within polishing pad 112 as conditioner disk 128', but over a different portion of the pits or features. As shown herein, the average heights of the two adjustment discs 128', 128 "and the respective first actuators 130 are the same. However, the orientation O of each conditioning disk 128' and 128″ 2 And O 3 Is different. Without the adjustment disc displacement sensors 210a, 210b, the arm displacement sensor 238 would not be able to measure the orientation of the adjustment disc 128' or 128 ". Thus, the adjustment trays 128' and 128 "appear to have the same height. This is exaggerated as the conditioner disk 128 described herein passes through smaller features and pits. Thus, the size and shape of the feature or groove cannot be accurately measured using only the displacement sensor 238, but the additional use of the tuning disk displacement sensors 210a, 210b enables more accurate measurement of the size and shape.
At another location on the polishing pad 112, the conditioner disk 128' "is disposed partially over the non-uniformity within the polishing pad 112. The non-uniformity may be a narrower or thicker region of the polishing pad 112 such that the polishing pad 112 has been worn a greater amount in one region. In the depicted embodiment, the conditioner disk displacement sensors 210a, 210b measure a first conditioner disk distance Z 4 And a second dial distance Z 5 . Greater than the second adjusting disk distance Z 5 Is set at a first dial distance Z 4 Fourth orientation O of dial 128' "is indicated 4 。
The combination of the conditioning disk displacement sensors 210a, 210b and the arm displacement sensor 238 enables accurate measurement of non-uniformities in the polishing pad 112 caused by the second region 120b of the pad mounting surface 118 b. The combination of conditioning disk displacement sensors 210a, 210b and arm displacement sensor 238 further enables the controller to determine whether the non-uniformity is caused by polishing pad 112 having a non-uniform thickness or the shape of platen body 114 beneath polishing pad 112.
Fig. 4A to 4C are schematic plan views of the dial 128 having differently configured dial displacement sensors 210a to 210d. The differently configured conditioning disk displacement sensors 210 a-210 d include different orientations and numbers of conditioning disk displacement sensors 210 a-210 d. The radial angle α about the axis of rotation C of the dial 128 may vary.
The conditioner disk displacement sensors 210 a-210 d may also be located radially inward or radially outward of the first actuator 130 such that the conditioner disk displacement sensors 210 a-210 d may not be disposed on the bottom surface of the first actuator 130, but are still configured to be oriented to measure the displacement of a portion of the conditioner disk 128. In some embodiments (not shown), the adjustment disk displacement sensors 210 a-210 d are disposed on a side surface of the first actuator 130 and oriented to measure the displacement of the adjustment disk 128.
As shown in the first configuration 400a of fig. 4A, only two conditioner disk displacement sensors 210a, 210b are utilized. The dial displacement sensors 210a, 210b are provided on the bottom surface of the first actuator 130. The conditioner disk displacement sensors 210a, 210b are aligned along plane E. Plane E is aligned with axis C and passes through axis C. In the first configuration 400a, the conditioner disk displacement sensors 210a, 210b are disposed at a radial angle α of about 180 degrees relative to each other. In other embodiments, two conditioner disk displacement sensors 210a, 210b may be used, but the radial angle α is changed to an angle other than 180 degrees, such that the sensors 210a and 210b lie on different planes to enable another degree of freedom of the conditioner disk 128 to be measured.
As shown in the second configuration 400B of fig. 4B, three conditioner disk displacement sensors 210a, 210B, 210c are utilized. The three conditioner disk displacement sensors are centered about axis C and disposed at radial angles a relative to each other such that each of conditioner disk displacement sensors 210a, 210b, 210C is disposed on a separate plane that intersects at axis C but is not identical. The first dial displacement sensor 210a is disposed on the first plane F, the second dial displacement sensor 210b is disposed on the second plane G, and the third dial displacement sensor 210c is disposed on the third plane H. Each of the first plane F, the second plane G, and the third plane H has a radial angle α disposed therebetween. The radial angle α is from about 10 degrees to about 170 degrees, such as from about 10 degrees to about 150 degrees, such as from about 10 degrees to about 120 degrees, such as from about 45 degrees to about 120 degrees, such as from about 90 degrees to about 120 degrees.
As shown in the third configuration 400C of fig. 4C, four conditioner disk displacement sensors 210a, 210b, 210C, 210d are utilized. The four conditioner disk displacement sensors 210a, 210b, 210C, 210d are centered about axis C and are disposed at radial angles α relative to each other such that conditioner disk displacement sensors 210a, 210b, 210C, 210d are disposed on separate planes that intersect at axis C, but are not identical. The first conditioning disk displacement sensor 210a is disposed on the first plane I, the second conditioning disk displacement sensor 210b is disposed on the second plane J, the third conditioning disk displacement sensor 210c is disposed on the third plane K, and the fourth conditioning disk displacement sensor 210d is disposed on the fourth plane L. Each of the first plane I, the second plane J, the third plane K, and the fourth plane L has a radial angle α disposed therebetween. The radial angle α is from about 10 degrees to about 110 degrees, such as from about 10 degrees to about 100 degrees, such as from about 45 degrees to about 100 degrees, such as from about 60 degrees to about 90 degrees. In one embodiment, plane I and plane K are the same plane as shown. In one embodiment, which may be combined with other embodiments, plane J and plane L are the same plane as shown. In other embodiments, all four planes are separate planes.
Fig. 5 is a flow chart of a method 500 of forming a polishing pad thickness profile according to an embodiment described herein. The polishing pad thickness profile is a plot of polishing pad thickness and orientation. Using the sensors and methods described herein, the polishing pad thickness profile can be continuously or periodically updated. Knowing the thickness profile of the polishing pad enables the residence time of the conditioning disk 128 and substrate carrier 104 to be adjusted accordingly.
During method 500, during operation 502, an conditioning disk (such as conditioning disk 128) is forced against a top surface of a polishing pad (such as polishing pad 114). The conditioning disk may sweep across the top surface of the polishing pad as the conditioning disk and polishing pad rotate. The pressure at which the conditioning disk is pressed against the polishing pad and the dwell time may be a predetermined or adjustable value.
After the conditioning disk is initially forced against the polishing pad, the distance between the conditioning arm (such as conditioning arm 132) and the polishing platen (such as platen body 114) is measured during another operation 504. The polishing platen is disposed below the polishing pad. The distance is measured using one or more arm displacement sensors, such as arm displacement sensor 238. The arm displacement sensor is configured to measure a distance to a polishing pad mounting surface, such as polishing pad mounting surface 118.
During another operation 506, one or more conditioning disk displacement sensors (such as conditioning disk displacement sensors 210 a-210 d) are used to determine the orientation of the conditioning disk. The orientation of the conditioner disk may be determined by measuring the tilt in a single direction or in multiple directions, so that a three-dimensional image of the tilt of the conditioner disk may be obtained. Obtaining the orientation of the conditioning disk during operation 506 is performed concurrently with measuring the distance between the conditioning arm and the polishing platen during operation 504. Obtaining two measurements simultaneously enables the two measurements to be correlated and a more accurate thickness measurement of the polishing pad can be obtained at any given time.
The measurement operations 504, 506 can be cycled to measure the thickness of the polishing pad at different locations. After measuring the thickness of the polishing pad using the combined conditioner disk orientation and arm displacement measurements, the thickness profile of the polishing pad is determined during another operation 508. During operation 508, the polishing pad thickness measurement is propagated with the data table. In some embodiments, during operation 508, the previous thickness measurement or thickness estimate is overwritten with the thickness measurement obtained during operations 504, 506 in order to continuously update the thickness profile of the polishing pad. The thickness profile of the polishing pad can be a three-dimensional profile measurement to create a three-dimensional map of the polishing pad.
Once the thickness profile of the polishing pad is determined, one or more conditioning parameters may be changed during another operation 510 based on the determined thickness profile of the polishing pad. The one or more conditioning parameters may be a residence time of the conditioning disk on the polishing pad, a pressure exerted by the conditioning disk on the polishing pad, a rate at which process fluid is injected onto the polishing pad, a substrate carrier residence time and pressure, or another process parameter. In some embodiments, if a portion of the polishing pad is determined to be below a certain thickness, or if the distribution of the polishing pad is outside of an acceptable level of uniformity, the polishing operation may be stopped and the polishing pad may be removed before being replaced with a new polishing pad.
The apparatus and methods described herein enable more accurate measurement of the thickness of a polishing pad during a chemical mechanical polishing operation. The thickness of the polishing pad can be measured using a combination of an arm displacement sensor coupled to the conditioner disk arm and one or more conditioner disk displacement sensors. The thickness measurements can be plotted to determine the thickness profile of the polishing pad and process conditions, such as conditioning disk residence time, can be varied.
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims (20)
1. A pad conditioning assembly for a Chemical Mechanical Polishing (CMP) apparatus, comprising:
an adjusting plate;
a first actuator coupled to the adjustment plate;
a second actuator disposed radially outward of the adjustment disk;
an adjustment arm coupling the first actuator and the second actuator;
an arm displacement sensor coupled to the adjustment arm; and
one or more conditioner disk displacement sensors coupled to the first actuator.
2. The mat adjustment assembly of claim 1, wherein the adjustment disc displacement sensors are configured to measure a distance between each of the adjustment disc displacement sensors and a portion of the adjustment disc.
3. The pad conditioning assembly of claim 2 wherein the conditioning disk displacement sensor is one of an inductive sensor, a capacitive sensor, or a laser sensor.
4. The pad conditioner assembly of claim 2, wherein said one or more conditioner disk displacement sensors include two or more conditioner disk displacement sensors.
5. The pad conditioning assembly of claim 1 wherein the arm displacement sensor is an inductive sensor, a capacitive sensor, or a laser sensor.
6. The pad conditioning assembly of claim 5 wherein said arm displacement sensor is configured to measure a distance between said arm displacement sensor and a top surface of a polishing platen disposed below said conditioning arm.
7. The pad conditioner assembly of claim 1, wherein said conditioner disk further comprises a conditioner disk holder and a conditioner disk pad disposed within said conditioner disk holder, said conditioner disk pad configured to be forced against a polishing pad.
8. The pad conditioning assembly of claim 1 wherein the pad conditioning assembly is configured to move the conditioning disk over a polishing surface of a polishing pad using the second actuator.
9. An apparatus for substrate processing, comprising:
polishing the platen;
a substrate carrier; and
a pad conditioning assembly, the pad conditioning assembly comprising:
an adjusting plate;
a first actuator coupled to the adjustment plate;
a second actuator disposed radially outward of the adjustment disk;
an adjustment arm coupling the first actuator and the second actuator;
an arm displacement sensor coupled to a bottom conditioning arm surface of the conditioning arm and configured to measure a first distance between the arm displacement sensor and a top surface of the polishing platen; and
one or more conditioner disk displacement sensors disposed on a bottom actuator surface of the first actuator and configured to measure a second distance between each of the conditioner disk displacement sensors and a portion of the conditioner disk.
10. The device of claim 9, wherein each of the arm displacement sensor and the one or more conditioner disk displacement sensors is an inductive sensor, a capacitive sensor, or a laser sensor.
11. The apparatus of claim 9, wherein the one or more conditioner disk displacement sensors comprise two or more conditioner disk displacement sensors, each conditioner disk displacement sensor oriented at a different angular position relative to an axis of rotation of the conditioner disk.
12. The apparatus of claim 11, wherein the two or more conditioning disk displacement sensors comprise three conditioning disk displacement sensors.
13. The apparatus of claim 11, wherein the two or more conditioning disk displacement sensors comprise four conditioning disk displacement sensors.
14. The apparatus of claim 9, wherein the conditioner disk further comprises a conditioner disk holder and a conditioner disk pad disposed within the conditioner disk holder, the conditioner disk pad configured to be forced against a polishing pad, and the one or more conditioner disk displacement sensors configured to measure the first distance between each of the conditioner disk displacement sensors and a portion of the conditioner disk pad.
15. The apparatus of claim 9, further comprising a controller configured to:
an orientation of the conditioning disk is determined using inputs from each of the one or more conditioning disk displacement sensors and the arm displacement sensor.
16. The apparatus of claim 15, wherein the controller is further configured to:
determining a thickness profile of a polishing pad disposed on the polishing platen; and
after determining the thickness profile, one or more tuning parameters are changed.
17. A substrate processing method comprising the steps of:
forcing the conditioning disk against the surface of the polishing pad;
measuring a distance between an conditioning arm and a polishing platen disposed below the polishing pad, the conditioning arm coupled to the conditioning disk via a first actuator;
determining an orientation of the conditioning disk using one or more conditioning disk displacement sensors;
determining a thickness profile of the polishing pad based on the orientation of the conditioning disk; and
after determining the thickness profile, one or more tuning parameters are changed.
18. The method of claim 17, wherein determining the orientation of the adjustment dial further comprises using an arm displacement sensor disposed on a bottom arm surface of the adjustment arm.
19. The method of claim 18, wherein each of the arm displacement sensor and the one or more conditioner disk displacement sensors is an inductive sensor, a capacitive sensor, or a laser sensor.
20. The method of claim 17, wherein the one or more conditioning parameters are a residence time of the conditioning disk at different radial positions of the polishing pad or a downforce of the conditioning disk against the different radial positions of the polishing pad.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17/339,699 US20220388116A1 (en) | 2021-06-04 | 2021-06-04 | Method of detecting chemical mechanical polishing conditioning disk orientation |
| US17/339,699 | 2021-06-04 | ||
| PCT/US2022/029028 WO2022256157A1 (en) | 2021-06-04 | 2022-05-12 | Method of detecting chemical mechanical polishing conditioning disk orientation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117412836A true CN117412836A (en) | 2024-01-16 |
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ID=84285829
Family Applications (1)
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|---|---|---|---|
| CN202280039787.5A Pending CN117412836A (en) | 2021-06-04 | 2022-05-12 | Method for detecting orientation of chemical mechanical polishing adjustment disc |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20220388116A1 (en) |
| KR (1) | KR20240017909A (en) |
| CN (1) | CN117412836A (en) |
| TW (1) | TW202304645A (en) |
| WO (1) | WO2022256157A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6343974B1 (en) * | 2000-06-26 | 2002-02-05 | International Business Machines Corporation | Real-time method for profiling and conditioning chemical-mechanical polishing pads |
| EP1270148A1 (en) * | 2001-06-22 | 2003-01-02 | Infineon Technologies SC300 GmbH & Co. KG | Arrangement and method for conditioning a polishing pad |
| US20120270477A1 (en) * | 2011-04-22 | 2012-10-25 | Nangoy Roy C | Measurement of pad thickness and control of conditioning |
| KR20170096025A (en) * | 2014-12-22 | 2017-08-23 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Abrasive articles with removable abrasive member and methods of separating and replacing thereof |
| KR20170022583A (en) * | 2015-08-21 | 2017-03-02 | 주식회사 케이씨텍 | Chemical mechanical polishing apparatus |
| US20200130136A1 (en) * | 2018-10-29 | 2020-04-30 | Taiwan Semiconductor Manufacturing Co., Ltd. | Chemical mechanical polishing apparatus and method |
| KR102601619B1 (en) * | 2018-11-12 | 2023-11-13 | 삼성전자주식회사 | Polishing pad monitoring method and polishing pad monitoring apparatus |
| KR20200063491A (en) * | 2018-11-28 | 2020-06-05 | 주식회사 케이씨텍 | Substrate processing apparatus |
-
2021
- 2021-06-04 US US17/339,699 patent/US20220388116A1/en active Pending
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2022
- 2022-05-12 WO PCT/US2022/029028 patent/WO2022256157A1/en active Application Filing
- 2022-05-12 CN CN202280039787.5A patent/CN117412836A/en active Pending
- 2022-05-12 KR KR1020247000212A patent/KR20240017909A/en unknown
- 2022-06-02 TW TW111120570A patent/TW202304645A/en unknown
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| TW202304645A (en) | 2023-02-01 |
| WO2022256157A1 (en) | 2022-12-08 |
| US20220388116A1 (en) | 2022-12-08 |
| KR20240017909A (en) | 2024-02-08 |
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