MULTIPLE DISK PAD CONDITIONER

Embodiments of the present disclosure provide a multiple disk pad conditioner and methods of using the multiple disk pad conditioner during a chemical mechanical polishing (CMP) process. The multiple disk pad conditioner has a plurality of conditioning heads having conditioning disks affixed thereto. The multiple disk pad conditioner can include a conditioning arm, and a plurality of conditioning heads attached to the conditioning arm. Each of the plurality of conditioning heads has a conditioning disk affixed thereto. In some embodiments, each of the conditioning heads include a rotational axis, wherein each of the rotational axes is disposed a distance apart in a first direction that extends along the length of the conditioning arm.

FIELD OF DISCLOSURE

The present disclosure relates to chemical mechanical polishing (CMP), and more specifically to a multiple disk pad conditioner for use in chemical mechanical polishing.

BACKGROUND OF DISCLOSURE

Integrated circuits are typically formed on substrates, particularly silicon wafers, by the sequential deposition of conductive, semiconductive or insulative layers. After each layer is deposited, the layer is etched to create circuitry features. As a series of layers are sequentially deposited and etched, the outer or uppermost surface of the substrate, i.e., the exposed surface of the substrate, becomes successively less planar. This non-planar outer surface presents a problem for the integrated circuit manufacturer as a non-planar surface can prevent proper focusing of the photolithography apparatus. Therefore, there is a need to periodically planarize the substrate surface to provide a planar surface.

CMP is one accepted method of planarization. This planarization method typically requires that the substrate be mounted on a carrier or polishing head, with the surface of the substrate to be polished exposed. The substrate is then placed against a rotating polishing pad. The carrier head may also rotate and/or oscillate to provide additional motion between the substrate and polishing surface. Further, a polishing liquid, typically including an abrasive and at least one chemically reactive agent, may be spread on the polishing pad.

When the polisher is in operation, the pad is subject to compression, shear and friction producing heat and wear. Slurry and abraded material from the wafer and pad are pressed into the pores of the pad material and the material itself becomes matted and even partially fused. These effects, sometimes referred to as “glazing,” reduce the pad's roughness and ability to apply and retain fresh slurry on the pad surface. It is, therefore, desirable to condition the pad by removing trapped slurry, and unmatting, re-expanding or re-roughening the pad material. The pad can be conditioned after each substrate is polished, or after a number of substrates are polished, which is often referred to as ex-situ pad conditioning. The pad can also be conditioned at the same time substrate are polished, which is often referred to as in-situ pad conditioning.

Therefore, there is a need for a method and device that can reliably and uniformly condition a polishing pad. There is also a need for a method and device that solves the problems described above.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

An aspect of the present disclosure provides a multiple disk pad conditioner for conditioning a polishing pad, comprising a conditioning arm; and a plurality of conditioning heads attached to the conditioning arm, wherein each of the plurality of conditioning heads has a conditioning disk affixed thereto, each of the plurality of conditioning heads comprise a rotational axis, and each of the rotational axes are is disposed a distance apart in a first direction that extends along the length of the conditioning arm.

Another aspect of the present disclosure provides a method of conditioning a polishing pad, conditioning the polishing pad using a multiple disk pad conditioner, wherein the multiple disk pad conditioner comprises: a conditioning arm for carrying a plurality of pad conditioning heads; each of the plurality of conditioning heads has a conditioning disk affixed thereto; each of the plurality of conditioning heads comprise a rotational axis; and each of the rotational axes are is disposed a distance apart in a first direction that extends along the length of the conditioning arm, and conditioning the polishing pad comprises urging the plurality of pad conditioning heads against a surface of a polishing pad.

Yet another aspect of the present disclosure provides a polishing system, comprising: a plurality of polishing modules, each comprising: a carrier support module comprising a carrier platform, and one or more carrier assemblies comprising one or more corresponding carrier heads which are suspended from the carrier platform; a carrier loading station for transferring substrates to and from the one or more carrier heads; a polishing station comprising a polishing platen, wherein the carrier support module is positioned to move the one or more carrier assemblies between a substrate polishing position disposed above the polishing platen and a substrate transfer position disposed above the carrier loading station; and a multiple disk pad conditioner having a plurality of conditioning heads attached to the conditioning assembly and disposed linearly along the conditioning assembly; and wherein each of the plurality of conditioning heads has a conditioning disk affixed thereto.

One or more of the following possible advantages may be realized. The multiple disk pad conditioner can reduce time for pad conditioning. The multiple disk pad conditioner provides additional and/or more efficient conditioning to occur as multiple conditioning surfaces may concurrently contact the polishing pad surface. Thus, conditioning process time may be reduced, and the useful life of the conditioning elements may be extended in comparison to conventional pad conditioners.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments are possible. This description is not to be taken in a limiting sense, but rather made merely for the purpose of describing general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.

As used herein, the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element”. Further, the terms “couple”, “coupling”, “coupled”, “coupled together”, and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements”. As used herein, the terms “up” and “down”; “upper” and “lower”; “top” and “bottom”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements.

Embodiments of the present disclosure provide CMP processes that include an in-situ pad conditioning step in which a conditioning disk, e.g., a disk coated with abrasive diamond particles, is pressed against the rotating polishing pad to condition and texture the polishing pad surface concurrent with substrate polishing. It should be understood, however, that embodiments of the present disclosure also allow for ex-situ conditioning of the polishing pad.

FIG.1illustrates a known pad conditioning assembly10in accordance with the prior art. Pad conditioning assembly10may include a base12, an arm14, a conditioning head16, and a pad conditioner18mounted to conditioning head16. Pad conditioner18may have a conditioning surface20with abrasive particles thereon. Conditioning surface20may be configured to rub against and abrade a surface of a polishing pad. Conditioning head16may be configured to vertically move pad conditioner18(as indicated by arrow21) from an elevated retracted position (as shown inFIG.1) to a lowered extended position such that conditioning surface20of pad conditioner18may engage a polishing surface of a polishing pad (not shown). Conditioning head16may further be configured to rotate pad conditioner18about longitudinal axis15. Arm14may be configured to rotate about longitudinal axis15such that conditioning head16may sweep across a polishing pad surface (not shown) with a reciprocal motion. The rotating motion of pad conditioner18and the reciprocating motion of conditioning head16may cause conditioning surface20of pad conditioner18to condition the polishing surface of the polishing pad by abrading the polishing surface to remove contaminants and to retexture the surface.

In embodiments of the present disclosure, a multiple disk pad conditioner is provided that can reduce time for pad conditioning. The multiple disk pad conditioner provides additional pad coverage and/or more efficient conditioning to occur as multiple conditioning surfaces may concurrently contact and abrade the polishing pad surface during a pad conditioning process. Thus, conditioning process times may be reduced, and the useful life of the conditioning elements may be extended in comparison to conventional pad conditioners utilizing a single conditioning surface.

An embodiment of the multiple disk pad condition of the present disclosure is illustrated inFIGS.2A and2B. Specifically,FIG.2Aprovides a side view schematic cross-sectional side view of a the multiple disk pad conditioner50within a polishing station30, andFIG.2Bprovides a schematic perspective view of the multiple disk pad conditioner50of the present disclosure placed on a polishing pad40for conditioning the polishing pad.

As shown inFIGS.2A and2B, the polishing station30of a CMP apparatus includes a rotatable disk-shaped platen34, which supports a polishing pad40, and a carrier head70to hold a substrate71against the polishing pad40. As discussed herein, the CMP apparatus can include multiple polishing stations.

In embodiments of the present disclosure, the polishing pad40can be a two-layer polishing pad with an outer layer44and a softer backing layer42. In some cases, the polishing pad40can be a soft polishing pad or a 3D printed polishing pad. That is, the construction materials of the polishing pad40can include soft materials or 3D printing materials, which can include polymeric materials. The polishing pad can have a hardness of 40 to 80 Shore D scale.

The platen34is operable to rotate about an axis35. For example, a motor32can turn a drive shaft38to rotate the platen34and polishing pad40.

The carrier head70is suspended from a support structure72, e.g., a carousel or a track, and is connected by a drive shaft74to a carrier head rotation motor76so that the carrier head can rotate about an axis77. Optionally, the carrier head70can oscillate laterally, e.g., on sliders on the carousel or track72; or by rotational oscillation of the carousel itself. In operation, the platen is rotated about its central axis35, and the carrier head is rotated about its central axis77and translated laterally across the top surface of the polishing pad40. Where there are multiple carrier heads, each carrier head70can have independent control of its polishing parameters, for example each carrier head70can independently control the pressure applied to each respective substrate71.

The carrier head70can include a flexible membrane80having a substrate mounting surface to contact the back side of the substrate71, and a plurality of pressurizable chambers82to apply different pressures to different zones, e.g., different radial zones, on the substrate71. The carrier head70can also include a retaining ring to hold the substrate.

The polishing station30can include a supply port or a combined supply-rinse arm39to dispense a polishing liquid38, such as slurry, onto the polishing pad40

The polishing station30also includes an embodiment of the multiple disk pad conditioner50of the present disclosure. In one embodiment, the multiple disk pad conditioner50of the present disclosure comprises a plurality of conditioning heads linearly arranged. In the example illustrated inFIGS.2A and2B, the multiple disk pad conditioner50includes three conditioning heads54a,54b, and54c, but it should be understood that any number of conditioning heads may be utilized dependent on the specifications for a particular conditioning application. It should also be understood that although the conditioning heads54a,54b, and54care shown having substantially equal spacing along the conditioning arm52of the multiple disk pad conditioner50, the spacing of the conditioning heads54a,54b,54ccan be set at any spacing useful for the particular conditioning process. As shown, in addition to the conditioning heads54a,54b, and54c, the multiple pad conditioner50of the present disclosure comprises base53(FIGS.4A-7B) and a conditioning arm52connecting the conditioning heads54a,54b, and54cto the base. The base53can include an actuator59that is configured to rotate a portion of the arm52about an arm axis52A (FIG.7A). The base53is thus configured to cause the arm52and the conditioning heads54a,54b, and54cto sweep across a surface of the polishing pad40.

The polishing station30can also include a cleaning station90(shown inFIGS.4A and4B), which contains a one or more nozzles that configured to deliver a cleaning and/or rinsing liquid to the conditioning heads54a,54b, and54c. The cleaning station90may also include one or more brushes of abrasive disks that are configured to engage with the conditioning surface of each of the conditioning heads54a,54b, and54c. The conditioning arm52and base53can move the conditioning heads54a,54b, and54cout of the cleaning station90and place the conditioning heads54a,54b, and54catop the polishing pad40. In some embodiments, the cleaning station90is configured to simultaneously process the conditioning heads54a,54b, and54c, and thus is shaped to match the configuration of the conditioning heads54a,54b, and54c, such as the configurations illustrated inFIGS.4A-4B and6A-6B.

The conditioning heads54a,54b, and54ccomprise conditioning disks56a,56b, and56cthat can be simultaneously brought into contact with the polishing pad40. In some embodiments, as discussed below, it is desirable to simultaneously bring less than the complete number of conditioning disks into contact with the polishing pad40during at least a portion of a pad conditioning recipe. The conditioning disks56a,56b, and56care generally positioned at a bottom of the conditioning heads54a,54b, and54cand can rotate around a respective axis51a,51b, and51c. In some embodiments, as shown inFIGS.2A and2B, each of the rotational axes axis51a,51b, and51care disposed a distance apart in a first direction that extends along the length of the conditioning arm52, wherein the length is generally defined by the distance between the arm axis52A (FIG.7A) and the opposing distal end of the conditioning arm52. A bottom surface of the conditioning disks56a,56b, and56c, include abrasive regions that contact the surface of the polishing pad40during the conditioning process. During conditioning, both the polishing pad40and the conditioning disks56a,56b, and56cmay rotate, so that these abrasive regions move relative to the surface of the polishing pad40, thereby abrading and retexturizing the surface of the polishing pad40.

The conditioning heads54a,54b, and54cinclude mechanisms to attach the conditioning disks56a,56b, and56cto the conditioning heads54a,54b, and54c(such as mechanical attachment systems, e.g., bolts or screws, or magnetic attachment systems) and mechanisms to rotate the conditioning disks56a,56b, and56caround the respective rotating axis51a,51b, and51c(such as drive belts through the arm or rotors inside the conditioner head). In embodiments of the present disclosure the conditioning heads54a,54b, and54cand the conditioning disks56a,56b, and56care driven by a single motor to cause each conditioning head54a,54b, and54crotate at the same revolutions-per-minute (RPM). In one example, the each conditioning head54a,54b, and54cis rotate at substantially the same RPM, or similar RPM (+/−20%), as the RPM of the polishing platen. In alternate embodiments, the conditioning disks56a,56b, and56cmay be rotated at different RPMs through use of differing motors, different gearing, or other rotational control mechanisms known in the art.

In some embodiments, due to the variation in linear speed of a rotating polishing pad40with the radius of the rotating pad (i.e., velocity (v)=ω·r, where w is the angular speed (rad/s) and r is the radius (mm) of the platen), it is desirable to adjust the rotational speed of each of the conditioning disks56a,56b, and56crelative to their radial position on the polishing pad as the arm52is swept across the polishing pad. In one example, when the arm52is aligned with the radius of the platen34(e.g., solid lined multiple disk pad conditioner50inFIG.5) the conditioning head54cis rotated at angular speed that is greater than the angular speed of the conditioning head54b, which has an angular speed that is greater than the angular speed of the conditioning head54a. In another example, when the arm52is aligned in a tangential relationship to a radius of the platen34(e.g., dashed multiple disk pad conditioner50inFIG.5), the conditioning head54ccan be rotated at an angular speed that is similar to the angular speeds of the conditioning head54band the conditioning head54a, since the linear speeds of the pad experienced by each of conditioning heads will be similar. In embodiments of the present disclosure the conditioning heads54a,54b, and54cand polishing pad40(i.e., platen) are both driven at a varying RPM during a pad conditioning process. In one processing configuration, the conditioning heads54a,54b, and54cand polishing pad40are driven at substantially the same RPM, or similar RPM (+/−20%), at each instant in time during the pad conditioning process.

In addition, the multiple disk pad conditioner50can also include mechanisms to regulate the pressure (i.e., down force) between the conditioning disks56a,56b, and56cand the polishing pad40(such as pneumatic or mechanical actuators inside the conditioning heads or the base). For example, the conditioning disks54a,54b, and54ccan each include a down-force actuator to adjust the pressure of the conditioning disks56a,56b, and56con the polishing pad50. In embodiments of the present disclosure, the down-force actuator may include a single electronic pressure regulator (EPR) that is disposed within the base53and used to uniformly control the pressure of all of the conditioning disks56a,56b, and56c. In alternate embodiments of the present disclosure, the pressure of the conditioning disks56a,56b, and56cmay be regulated independently by use of a down-force actuator that includes a force generating device for better control. Such pressure control mechanisms are known and can have many possible implementations in embodiments of the present disclosure, and can include, for example, air cylinders, bladders, solenoids or other similar devices. In one embodiment, the pressure applied to each of the conditioning disks54a,54b, and54cis adjusted such that one or more of the conditioning disks54a,54b, and54cis placed in contact with the polishing pad40. The down-force actuator, or down-force actuators, used to regulate the pressure between the conditioning disks56a,56b, and56cand the polishing pad40is thus also configured to retract one or more of the conditioning disks56a,56b, and56cfrom the surface of polishing pad and/or simultaneously generate a positive pressure between one or more other of the conditioning disks56a,56b, and56cand the polishing pad40during processing.

In embodiments of the present disclosure, the conditioning disks56a,56b, and56cof the multiple disk pad conditioner50include abrasive elements, such as abrasive diamond particles secured to the conditioning disks56a,56b, and56c. It is understood that in some embodiments other compositions such as silicon carbide can be used instead of or in addition to the abrasive diamond particles. The abrasive diamond particles provide a structure capable of removing (e.g., cutting, polishing, scraping) material from the polishing pad40. Each individual abrasive diamond particle can have one or more cutting points, ridges or mesas. In some implementations, the abrasive diamond particles are substantially rectangular solid in shape. Such “blocky” abrasive particles can provide superior conditioning of the material used in 3D printed polishing pads, e.g., a low wear rate while maintaining uniform surface roughness across the pad, as compared to other shapes such as jagged, octahedral, etc. In some implementations, the abrasive diamond particles are 125-250 μm in size. In some implementations, the diamond abrasive particles have a mean diameter of 140-200 μm, e.g., 150-180 μm, and a standard deviation less than 40 μm, e.g., less than 30 μm, e.g., less than 20 μm, e.g., less than 10 μm. This size range can provide superior conditioning of the material used in 3D printed polishing pads, e.g., a low wear rate while maintaining uniform surface roughness across the pad.

In another embodiment of the present disclosure, each of the conditioning disks56a,56b, and56ccomprise a multi-layer diamond disk.FIG.3provides a side view of an embodiment of the multi-layer diamond disk300. As shown, each multi-layer diamond disk300includes a support plate302in the form of a generally planar disk. The support plate302has an upper surface302athat can contact the conditioning disks54a,54b, and54cand a lower surface302b. The support plate302can be a durable rigid material, e.g., a metal, such as stainless steel, or a ceramic.

Affixed to the lower surface302bof the support plate302is a flexible member304comprised of a rubber, elastomer, silicone, or the like. The upper surface304aof the flexible member304is affixed to the lower surface302bof the support plate302. The lower surface304bof the flexible member304is affixed to a flexible backing element306, comprised of flexible material such as an elastomeric material. In one example, the flexible backing element306includes a rubber or silicone material. In one embodiment, the flexible backing element306includes a thin metal plate (e.g., SST or aluminum (Al) foil or plate) or the like. The flexible backing element306is to be deformable under the loads applied by the down-force actuator configured to apply a downforce to the multilayer diamond disk300and pad40during a pad conditioning process.

In this embodiment, the abrasive diamond particles308can be fixed to the flexible backing element306by a variety of techniques. For example, the abrasive diamond particles308can be attached to the flexible backing element306by way of known electroplating and/or electrodeposition processes. As another example, the abrasive diamond particles308can be attached to the flexible backing element306by way of organic binding, brazing or welding processes.

The multi-layer disk300in this embodiment of the present disclosure provides for better contact between the abrasive diamond particles308and the polishing pad306. The flexibility provided by the flexible member304and the flexible backing element306enables the abrasive diamond particles308to remain in substantially constant contact with the polishing pad40even for those abrasive diamond particles308that have ground down through normal wear and tear from the conditioning process. The flexible member304and flexible backing element308flex to maintain constant contact between the individual abrasive diamond particles308as pressure is applied to the support plate302.

FIGS.4A and4Bprovide schematic top views of an embodiment of the multiple disk pad conditioner50of the present disclosure. To prepare for conditioning, and as shown inFIG.4A, the conditioning arm52is rotated about the conditioning base51such that the conditioning heads54a,54b, and54care positioned over the polishing pad40. To perform conditioning, pneumatic or mechanical actuators (not shown) inside the conditioning heads54a,54b, and54cadjust the vertical position of the conditioning disks56a,56b, and56cto engage the polishing pad40. As discussed previously, the pressure applied to the conditioning disks56a,56b, and56cmay be uniformly applied by a single EPR or, in alternate embodiments, the pressure may be independently applied to each of the individual conditioning disks56a,56b, and56c.

During conditioning, the conditioning disks56a,56b, and56choused within the conditioning heads54a,54b, and54care rotated in a predefined direction. The predefined direction may be counter-clockwise or clockwise as viewed from a top side of the polishing station. In the embodiment shown inFIGS.4A and4B, the conditioning disks56a,56b, and56care driven by a single motor58imparting rotational force through one or more belts60to the conditioning heads54a,54b, and54cand/or the conditioning disks56a,56b, and56c. It should be understood that in alternate embodiments, chains, roller chains, sprockets, or other mechanisms known in the art can be used to drive the rotation of the conditioning disks It should also be understood that in alternate embodiments, individual motors (not shown) or gearing mechanisms can be used to drive the conditioning disks56a,56b, and56cindependently.

The polishing station20can also include a cleaning station90, which contains a cleaning liquid for rinsing or cleaning the conditioning disks56a,56b, and56c. As shown inFIG.4B, the conditioning arm52has moved the conditioning heads54a,54b, and54caway from the polishing pad40and into position atop the cleaning station90. The cleaning step can occur while new substrates are being polished or switched out.

In the embodiment shown inFIGS.4A and4B, the conditioning arm52, while the conditioning disks56a,56b, and56care engaged with the polishing pad40, may remain stationary or sweep a small amount such that each conditioning disk56a,56b, and56cworks on a certain radial zone of the polishing pad40. In alternate embodiments, such as shown inFIG.5, the conditioning arm52may sweep to the edge of the polishing pad40such that the conditioning disks56a,56b, and56cmay simultaneously work on either multiple zones or similar zones on the surface of the polishing pad40, depending upon the radial position of the conditioning arm52, upon the polishing pad40.

An alternate embodiment of the multiple disk pad conditioner50of the present disclosure is shown inFIGS.6A and6B.FIG.6Ashows the multiple disk pad conditioner50in a conditioning position andFIG.6Bshows the multiple disk pad conditioner50in a cleaning position. In this embodiment, there are a plurality (two shown) of conditioning head pivot bases120a,120b, each pivot base120a,120b, having a conditioning head pivot arm122a,122bthat is rotationally affixed to the conditioning arm52such that the conditioning head pivot arms122a,122bmay rotate about the pivot bases120a,120bas indicated by the arrows121. It should be understood that the rotation of the pivot arms122a,122bmay be controlled by the actuator58in combination with other actuators, belts, or other known mechanisms. It should also be understood that the rotation of the pivot arms122a,122bmay be uniform at the same RPM or independently controlled for each pivot arm122a,122b.

In the embodiment shown inFIGS.6A and6B, the pivot arms122a,122bfurther comprise one or more conditioning heads. In the embodiment shown, each pivot arm122a,122bhas two conditioning heads (54a,54b,54c, and54d), but other embodiments may have any number of conditioning heads depending on the specifications and requirements of the particular conditioning application. As discussed with the previous embodiments of the present disclosure, the conditioning heads54a,54b,54c, and54dfurther comprise abrasive disks or abrasive regions for engaging the polishing pad, and the conditioning heads54a,54b,54c, and54dmay rotate, either uniformly at the same RPM or independently.

As illustrated inFIG.6A, in this embodiment, the polishing pad40is engaged by the multiple disk conditioner50such that the conditioning arm52is sweeping while the conditioning heads54a,54b,54c, and54dare independently rotating, and while the pivot arms122a,122bare rotating, resulting in increased efficiency of the conditioning process as the conditioning disks56a,56b,56c, and56dhoused within the conditioning heads54a,54b,54c, and54dare able to address multiple regions of the polishing pad40simultaneously. Once the conditioning process is complete, as shown inFIG.6B, the conditioning heads54a,54b,54c, and54dof this embodiment may be rotated into a linear alignment for access to the cleaning station90.

FIGS.7A and7Bshow Embodiments of the multi disk pad conditioner of the present disclosure used in a high throughput density CMP system.FIG.7Ais a schematic side view of a the high throughput CMP polishing system, according to one embodiment, which may be used as one or more of a plurality of polishing modules as described herein.FIG.7Bis a top down sectional view ofFIG.7Ataken along line A-A.

Here, the polishing module200ais disposed within a modular frame210and includes a carrier support module220comprising a first carrier assembly230aand a second carrier assembly230bwhere each of the carrier assemblies230a,230bincludes a corresponding carrier head231. The polishing module200afurther comprises a station for loading and unloading substrates to and from the carrier heads, herein a carrier loading station240, and a polishing station250. In embodiments herein, the carrier support module220, the carrier loading station240, and the polishing station250are disposed in a one-to-one-to-one relationship within the modular frame210. This one-to-one-to-one relationship and the arrangements described herein facilitate the simultaneous substrate loading/unloading and polishing operations of at least two substrates280to enable the high throughput density substrate handling methods described herein.

Here, the modular frame210features a plurality of vertically disposed supports, herein upright supports211, a horizontally disposed tabletop212, and an overhead support213disposed above the tabletop212and spaced apart therefrom. The upright supports211, the tabletop212, and the overhead support213collectively define a processing region214. Here, the modular frame210has a generally rectangular footprint when viewed from the top down (FIG.7B) where four individual ones of the upright supports211are respectively coupled to the four outward facing corners of both the tabletop212and the overhead support213. In other embodiments, the tabletop212and the overhead support213may be coupled to upright supports211at other suitable locations which have been selected to prevent interference between the upright supports211and substrate handling operations. In other embodiments, the modular frame210may comprise any desired footprint shape when viewed from the top down.

In some embodiments, the polishing module200afurther includes a plurality of panels215each vertically disposed between adjacent corners of the modular frame210to enclose and isolate the processing region214from other portions of a modular polishing system200. In those embodiments, one or more the panels215will typically have a slit shaped opening (not shown) formed therethrough to accommodate substrate transfer into and out of the processing region214.

Here, the carrier support module220is suspended from the overhead support213and includes a support shaft221disposed through an opening in the overhead support213, an actuator222coupled to the support shaft221, and a carrier platform223coupled to, and supported by, the support shaft221. The actuator222is used to rotate or alternately pivot the support shaft221, and thus the carrier platform223, about a support shaft axis A in the clockwise and counterclockwise directions. In other embodiments (not shown), the support shaft221may be mounted on and/or coupled to the base212to extend upwardly therefrom. In those embodiments, the carrier platform221is coupled to, disposed on, and/or otherwise supported by an upper end of the support shaft221. In those embodiments, the support shaft221may be vertically disposed in an area between the carrier loading station240and the polishing station250which are described below.

As shown, the carrier platform223provides support to the carrier assemblies230a,230band is coupled to an end of the support shaft221which is disposed in the processing region214. Here, the carrier platform223comprises an upper surface and a lower tabletop-facing surface which is opposite of the upper surface. The carrier platform223is shown as a cylindrical disk but may comprise any suitable shape sized to support the components of the carrier assemblies230a,230b. The carrier platform223is typically formed of a relatively light weight rigid material, such as aluminum which is resistant to the corrosive effects of commonly used polishing fluids. In some embodiments, the carrier support module220further includes a housing225disposed on the upper surface of the carrier platform223. The housing225desirably prevents polishing fluid overspray from the polishing process from coming into contact with, and causing corrosion to, the components disposed on or above the carrier platform223in a region defined by the housing225. Beneficially, the housing225also prevents contaminants and/or other defect causing particles from transferring from the components contained therein to the substrate processing regions which might otherwise cause damage to the substrate surface, such as scratches and/or other defectivity.

As shown, the carrier platform223provides support for two carrier assemblies, the first carrier assembly230aand the second carrier assembly230b, so that the carrier support module220and the carrier assemblies230a,230bare arranged in a one-to-two relationship within the modular frame210. Thus, the carrier support module220, the carrier assemblies230a,230b, the carrier loading station240, and the polishing station250are arranged in a one-to-two-to-one-to-one relationship within the modular frame210. In some embodiments, the carrier support module220supports only a single carrier assembly, such as the first carrier assembly230a. In some embodiments, the carrier support module220supports not more than two carrier assemblies, such as the first carrier assembly230aand the second carrier assembly230b. In some embodiments, a carrier support module220is configured to support not more and not less than the two carrier assemblies230a,230b.

Typically, each of the carrier assemblies230a,230bcomprises a carrier head231, a carrier shaft232coupled to the carrier head231, one or a plurality of actuators, such as a first actuator233and a second actuator234, and a pneumatic assembly235. Here, the first actuator233is coupled to the carrier shaft232and is used to rotate the carrier shaft232about a respective carrier axis B or B′. The second actuator234is coupled to the first actuator233and is used to oscillate the carrier shaft232a distance (not shown) between a first position with respect to the carrier platform221and a second position disposed radially outward from the first position or to positions disposed therebetween. Typically, the carrier shaft232is oscillated during substrate polishing to sweep the carrier head231, and thus a substrate280disposed therein, between an inner diameter of a polishing pad40and an outer diameter of the polishing pad40to, at least in part, prevent uneven wear of the polishing pad40. Beneficially, the linear (sweeping) motion imparted to the carrier head231by oscillating the carrier shaft232may also be used to position the carrier head231on the polishing pad40such that the carrier head231does not interfere with the positioning of the polishing fluid dispense arm253and/or multiple disk pad conditioning arm52(FIG.7B).

The carrier shafts232are disposed through openings disposed through the carrier platform223. Typically, the actuators233and234are disposed above the carrier platform223and are enclosed within the region defined by the carrier platform223and the housing225. The respective positions of the openings in the carrier platform223and the position of the carrier shafts232disposed through the openings determines a swing radius of a carrier head231as it is moved from a substrate polishing to a substrate loading or unloading position. The swing radius of a carrier head231can determine minimum spacing between polishing modules200ain the modular polishing systems described herein as well as the ability to perform processes within a processing module that are ex-situ to the polishing process, i.e., not conducted concurrently therewith.

In some embodiments, the swing radius of a carrier head231is not more than about 2.5 times the diameter of a to-be-polished substrate, such as not more than about 2 times the diameter of a to-be-polished substrate, such as not more than about 1.5 times the diameter of a to-be-polished substrate. For example, for a polishing module100aconfigured to polish a 300 mm diameter substrate the swing radius of the carrier head231may be about 750 mm or less, such as about 600 mm or less, or about 450 mm or less. Appropriate scaling may be used for polishing modules configured to polish other sized substrates. The swing radius of a carrier head231may be more, less, or the same as a swing radius of the carrier platform223. For example, in some embodiments the swing radius of the carrier head231is equal to or less than the swing radius of the carrier platform223.

Here, each carrier head231is fluidly coupled to a pneumatic assembly235through one or more conduits (not shown) disposed through the carrier shaft232. The term “fluidly coupled” as used herein refers to two or more elements that are directly or indirectly connected such that the two or more elements are in fluid communication, i.e., such that a fluid may directly or indirectly flow therebetween. Typically, the pneumatic assembly235is fluidly coupled to the carrier shaft232using a rotary union (not shown) which allows the pneumatic assembly235to remain in a stationary position relative to the carrier platform223while the carrier head231rotates therebeneath. The pneumatic assembly235provides pressurized gases and/or vacuum to the carrier head231, e.g., to one or more chambers (not shown) disposed within the carrier head231. In other embodiments, one or more functions performed by components of the pneumatic assembly235as described herein may also be performed by electromechanical components, e.g., electromechanical actuators.

The carrier head231will often feature one or more of flexible components, such as bladders, diaphragms, or membrane layers (not shown) which may, along with other components of the carrier head231, define chambers disposed therein. The flexible components of the carrier head231and the chambers defined therewith are useful for both substrate polishing and substrate loading and unloading operations. For example, a chamber defined by the one or more flexible components may be pressurized to urge a substrate disposed in the carrier head towards the polishing pad by pressing components of the carrier head against the backside of the substrate. When polishing is complete, or during substrate loading operations, a substrate may be vacuum chucked to the carrier head by applying a vacuum to the same or a different chamber to cause an upward deflection of a membrane layer in contact with the backside of the substrate. The upward deflection of the membrane layer will create a low pressure pocket between the membrane and the substrate, thus vacuum chucking the substrate to the carrier head231. During substrate unloading operations, where the substrate is unloaded from the carrier head231into the carrier loading station240, a pressurized gas may be introduced into the chamber. The pressurized gas in the chamber causes a downward deflection of the membrane to release a substrate from the carrier head231a,231binto the carrier loading station240.

Here, the carrier loading station240has a load cup comprising a basin241, a lift member242disposed in the basin241, and an actuator243coupled to the lift member242. In some embodiments, the carrier loading station240is coupled to a fluid source244which provides cleaning fluids, such as deionized water, which may be used to clean residual polishing fluids from a substrate280and/or carrier head231before and/or after substrate polishing. Typically, a substrate280is loaded into the carrier loading station240in a “face down” orientation, i.e., a device side down orientation. Thus, to minimize damage to the device side surface of the substrate through contact with surfaces of the lift member242, the lift member242will often comprise an annular substrate contacting surface which supports the substrate280about the circumference, or about portions of the circumference, thereof. In other embodiments, the lift member242will comprise a plurality of lift pins arranged to contact a substrate280proximate to, or at, the outer circumference thereof. Once a substrate280is loaded into the carrier loading station240the actuator243is used to move the lift member242, and thus the substrate280, towards a carrier head231positioned thereabove for vacuum chucking into the carrier head231. The carrier head231is then moved to the polishing station250so that the substrate180may be polished thereon.

In other embodiments, the carrier loading station240features buff platen that may be used to buff, e.g., soft polish, the substrate surface before and/or after the substrate is processed at the polishing station. In some of those embodiments, the buff platen is movable in a vertical direction to make room for substrate transfer to and from the carrier loading station using a substrate transfer and/or to facilitate substrate transfer to and from the carrier heads231. In some embodiments, the carrier loading station240is further configured as an edge correction station, e.g., to remove material from regions proximate to the circumferential edge of the substrate before and/or after the substrate is processed at the polishing station250. In some embodiment, the carrier loading station240is further configured as a metrology station and/or a defect inspection station, which may be used to measure the thickness of a material layer disposed on the substrate before and/or after polishing, to inspect the substrate after polishing to determine if a material layer has been cleared from the field surface thereof, and/or to inspect the substrate surface for defects before and/or after polishing. In those embodiments, the substrate may be returned to the polishing pad for the further polishing and/or directed to a different substrate processing module or station, such as a different polishing module200or to an LSP module330(shown onFIG.8) based on the measurement or surface inspection results obtained using the metrology and/or defect inspection station.

Here, a vertical line disposed through the center C of the carrier loading station240is co-linear with the center of a circular substrate280(e.g., a silicon wafer when viewed top down). As shown the center C is co-linear with the shaft axis B or B′ when a substrate280is being loaded to or unloaded from a carrier head231disposed thereover. In other embodiments, the center C of the substrate280may be offset from the shaft axis B when the substrate280is disposed in the carrier head231.

The polishing station250features a platen251, a polishing pad40, a polishing fluid dispense arm253, an actuator (not shown) coupled to the fluid dispense arm253, a pad conditioning arm52, a motor, or actuator58coupled to a first end of the pad conditioning arm52, pad conditioning heads54a,54b, and54c, and a cleaning station90. The pad conditioning heads54a,54b, and54care coupled to the pad conditioning arm52. In other embodiments, the fluid dispense arm253may be disposed in a fixed position relative to the rotational center of the polishing platen251. In some embodiments, the fluid dispense arm253may be curved so as to avoid interference with the carrier heads231as the carrier heads231are rotated by the actuator222coupled to the carrier platform223.

Here, the polishing station250further includes a fence258(FIG.7A) which surrounds the polishing platen251and is spaced apart therefrom to define a drainage basin259(FIG.7A). Polishing fluid and polishing fluid byproducts are collected in the drainage basin259and are removed therefrom through a drain260in fluid communication therewith. In other embodiments, the fence258may comprise one or more sections disposed about, or partially disposed above, respective portions of the polishing platen251, and/or may comprises one or more sections disposed between the carrier loading station240and the polishing station250. Here, the platen251is rotatable about a platen axis D which extends vertically through the center of the platen251. Here, the polishing station250features a single platen251so that the carrier support module220, the carrier loading station240, and the platen251are disposed in a one-to-one-to-one relationship.

Here, the fluid dispense arm253(FIG.7B) is configured to dispense polishing fluids at or proximate to the center of the polishing pad, i.e., proximate to platen axis D disposed therethrough. The dispensed polishing fluid is distributed radially outward from the center of the platen251by centrifugal force imparted to the polishing fluid by the rotation of the platen251. For example, here the actuator254is coupled to a first end of the fluid dispense arm253and is used to rotationally move the fluid dispense arm253so that a second end of the fluid dispense arm253may be positioned over or proximate to the center of the platen251and the polishing pad40disposed thereon.

The pad conditioning arm52comprises a first end coupled to the actuator59, which is disposed with the conditioning base53, and a second end coupled to the pad conditioning heads54a,54b, and54c. The actuator59swings the pad conditioning arm52about the arm axis52A of the conditioning base53. As discussed above one or more down-force actuators are configured to simultaneously urge the pad conditioning heads54a,54b, and54ctoward the surface of the polishing pad40disposed therebeneath. As discussed herein, the pad conditioning heads54a,54b, and54ctypically include a brush or a fixed abrasive conditioning, e.g., a diamond embedded condition disk (56a,56b,56cdescribed herein), which is used to abrade and rejuvenate the polishing surface252of the polishing pad40.

Here, the pad conditioning heads54a,54b, and54care urged against the polishing pad40while being swept back and forth from an outer diameter of the polishing pad40to, or proximate to, the center of the polishing pad40while the platen251, and thus the polishing pad40, rotate therebeneath. The multiple disk pad conditioner50of the present disclosure is used for in-situ conditioning, i.e., concurrent with substrate polishing, ex-situ conditioning, i.e., in periods between substrate polishing, or both. Typically, the pad conditioning heads54a,54b, and54care urged against the polishing pad40in the presence of a fluid, such as polishing fluid or deionized water, which provides lubrication therebetween. The fluid is dispensed onto the polishing pad40near the platen axis D by positioning the fluid dispense arm253thereover. Typically, the carrier support module220and the polishing station250are arranged so that the swing radius of a carrier head231is not within a swing path of one or both of the fluid dispense arm253or the multiple disk pad conditioner50. This arrangement beneficially allows for ex-situ conditioning of the polishing pad40while the carrier support module220pivots the carrier heads231between the carrier loading and substrate polishing positions as further described below.

Typically, the carrier support module220, the carrier assemblies230a,230b, the carrier loading station240, and the polishing station250are disposed in an arrangement that desirably minimizes the cleanroom footprint of the polishing module100a. Herein, a description of the arrangement is made using the relative positions of the carrier heads231, carrier loading station240, and platen251when the carrier support module220is disposed in one of a first or second processing mode.

InFIGS.7A-7B, the carrier support module220is disposed in a first processing mode. In the first processing mode the first carrier assembly230ais disposed above the platen251and the second carrier assembly230bis disposed above the carrier loading station240. In one example, in the first processing mode the carrier head231of the second carrier assembly230bis positioned above the carrier loading station240to allow for substrate loading and unloading thereinto and therefrom. In a second processing mode (not shown) the carrier platform223will be rotated or pivoted an angle θ of 180° about the support shaft axis A and the relative positions of the first carrier assembly230aand the second carrier assembly230bwill be reversed. In this example, in the second processing mode the carrier head231of the second carrier assembly230awill be positioned above the carrier loading station240to allow for substrate loading and unloading thereinto and therefrom.

FIG.8is a schematic top down sectional view of a modular polishing system comprising a plurality of the polishing modules having multiple disk pad conditioners as set forth inFIGS.7A-7B, according to one embodiment. Here, the modular polishing system300afeatures a first portion320and a second portion305coupled to the first portion320. The second portion305includes two polishing modules200a,200bwhich share a frame210including upright supports211, a shared tabletop212, and a shared overhead support213(such as shown in inFIG.7A). In other embodiments, each of the polishing modules200a,200brespectively comprise individual frames210(such as shown inFIGS.7A-7B) which are coupled together to form the second portion305.

Each of the polishing modules200a,200bfeature a carrier support module220, a carrier loading station240, and a polishing station250disposed in a one-to-one-to-one relationship as shown and described inFIGS.7A-7B. Each of the polishing stations250of the respective polishing modules200a,200bfeatures a single platen251so that each of the respective polishing modules200a,200bcomprise a carrier support module220, a carrier loading station240, and a platen251disposed in a one-to-one-to-one relationship as shown and described inFIGS.7A-7B.

Typically, the polishing module200bis substantially similar to an embodiment of the polishing module200adescribed inFIGS.7A-7B, and may include alternate embodiments, or combinations of alternate embodiments, thereof. For example, in some embodiments, one of the two polishing modules, e.g., polishing module200a, is configured to support a longer material removal polishing process while the other polishing module, e.g.,200bis configured to support a shorter post-material removal buffing process. In those embodiments, substrates processed on polishing modules200aare then transferred to polishing module200b. Often, the shorter post-material removal buffing process will be a throughput limiting process which will benefit from the throughput increasing two carrier assembly230a,230barrangement described inFIGS.7A-7B. Thus, in some embodiments, one or more substrate polishing modules within a modular polishing system may comprise a single carrier assembly230aor230bwhile other polishing modules within the modular polishing system comprise two carrier assemblies230aand230b.

Typically, the first portion320comprises one or combination of a plurality of system loading stations222, one or more substrate handlers, e.g., a first robot324and a second robot326, one or more metrology stations328, one or more location specific polishing (LSP) module330, and one or more one or more post-CMP cleaning systems332. An LSP module330is typically configured to polish only a portion of a substrate surface using a polishing member (not shown) that has a surface area that is less than the surface area of a to-be-polished substrate. LSP modules330are often used after a substrate has been polished within a polishing module to touch up, e.g., remove additional material, from a relatively small portion of the substrate. In some embodiments one or more LSP modules330may be included within the second portion305in place of one of the polishing modules200a,200b.

In other embodiments the one or more LSP modules330may be disposed in any other desired arrangement within the modular polishing systems set forth herein. For example, one or more LSP modules330may be disposed between the first portion320and the second portion305, between adjacently disposed polishing modules200a-iin any of the arrangements described herein, and/or proximate to an end of any of the second portions described herein, the end of the respective second portion being distal from the first portion. In some embodiments, the modular polishing systems may include one or more buffing modules (not shown) which may be disposed in any of the arrangements described above for the LSP module330. In some embodiments, the first portion320features at least two post-CMP cleaning systems332which may be disposed on opposite sides of the second robot326.

A post-CMP cleaning system facilitates removal of residual polishing fluids and polishing byproducts from the substrate280and may include any one or combination of brush or spray boxes334and a drying unit336. The first and second robots324,326are used in combination to transfer substrates280between the second portion305and the first portion320including between the various modules, stations, and systems thereof. For example, here, the second robot326is at least used to transfer substrates to and from the carrier loading stations240of the respective polishing modules200a,200band/or therebetween.

In embodiments herein, operation of the modular polishing system300is directed by a system controller (not shown) that includes a programmable central processing unit (CPU) which is operable with a memory (e.g., non-volatile memory) and support circuits. The support circuits are conventionally coupled to the CPU and comprise cache, clock circuits, input/output subsystems, power supplies, and the like, and combinations thereof coupled to the various components of the modular polishing system300, to facilitate control thereof. The CPU is one of any form of general purpose computer processor used in an industrial setting, such as a programmable logic controller (PLC), for controlling various components and sub-processors of the processing system. The memory, coupled to the CPU, is non-transitory and is typically one or more of readily available memories such as random access memory (RAM), read only memory (ROM), floppy disk drive, hard disk, or any other form of digital storage, local or remote.

Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. The scope of the disclosure should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded.