Abstract: A CMP conditioner having excellent corrosion resistance around abrasive grains includes a grindstone base having, formed on one side, an abrasive grain layer including abrasive grains fixed in a metallic bonding phase treated to form a first protective layer comprising an oxide on the surface of the metallic bonding phase of the abrasive grain layer by the sol-gel method. Subsequently, an aerosol obtained by dispersing fine particles of a brittle material in a gas is jetted and caused to strike on the surface of the first protective layer to form a second protective layer comprising a thick oxide film.

Abstract: A pedestal pad (workpiece supporting table pad) is arranged on the top of a pedestal (workpiece supporting table) for temporarily placing and holding a pre-polished or post-polished wafer (workpiece). This pedestal pad is formed of resin, and at least a surface of the pedestal pad which comes into contact with the wafer is non-absorbable to a fluid. The tissue of the pedestal pad is dense and smooth, and does not have any cavity, such as fine holes, which holds the fluid.

Abstract: An apparatus for conditioning a polishing pad, or conditioner, includes a supporting substrate and abrasive elements. The abrasive elements of the conditioner are used to condition a polishing pad to be used in abrasive, or at least partially mechanical, semiconductor substrate treatment processes, such as chemical-mechanical polishing or chemical-mechanical planarization processes. The abrasive elements are formed from a material that may be degraded or dissolved by at least one chemical that will not substantially degrade or dissolve a material of the polishing pad. Any residue or particles of, or from, the abrasive elements that stick to or become embedded in the polishing pad are removed therefrom by exposing the polishing pad to the at least one chemical so as to degrade or dissolve the residue or particles without substantially degrading or dissolving a material of the polishing pad.

Abstract: A non-glazing dressing wheel (10) suitable for dressing a grinding wheel surface to be used for maintaining a certain tolerance to assure reliability and quality control of ground parts during the grinding operation. The dressing wheel includes at least a first dressing wheel component (12) including at least one interrupted cutting outer surface, wherein the interrupted cutting surface is embodied in a cutting wheel (10) with a plurality of tips (12) extending outwardly from the outer surface. The plurality of tips (12) contact the grinding wheel during the grinding operation, thereby alleviating glazing and heat expansion of the grinding wheel while being dressed. Other preferred embodiments include sandwiching the interrupted cutting surface between two flat grinding surfaces, preferably being made of diamond or Borazon.

Abstract: A CMP pad conditioner comprises a plurality of abrasive segments. Each abrasive segment includes a segment blank and an abrasive layer attached to the segment blank, the abrasive layer including a superhard abrasive material. A pad conditioner substrate is also provided. Each of the plurality of abrasive segments is permanently affixed to the pad conditioner substrate in an orientation that enables removal of material from a CMP pad by the abrasive layer as the pad conditioner and the CMP pad are moved relative to one another.

Abstract: A cleaning device for chemical-mechanical equipment, which includes: an irrotatable center shaft irrotatably coupled with a spindle which is rotated, the irrotatable center shaft including a first channel and a second channel formed in an interior of the irrotatable center shaft, cleaning liquid flowing into the first channel and compressed gas flowing into the second channel; and a nozzle block coupled with the spindle so as to revolve about the irrotatable center shaft above a polishing pad, the nozzle block mixing cleaning liquid supplied through the first channel with compressed gas supplied through the second channel so as to generate twin-fluid, and pressure-injecting the mixed twin-fluid on the polishing pad. Accordingly, cleaning liquid is pressurized so as to be rapidly injected on a polishing pad so that slurry particles and alien substances on the polishing pad are completely removed. Furthermore, wafer scratch can be prevented and the life of the polishing pad can also be increased.

Abstract: A CMP pad conditioner comprises a plurality of abrasive segments. Each abrasive segment includes a segment blank and an abrasive layer attached to the segment blank, the abrasive layer including a superhard abrasive material. A pad conditioner substrate is also provided. Each of the plurality of abrasive segments is permanently affixed to the pad conditioner substrate in an orientation that enables removal of material from a CMP pad by the abrasive layer as the pad conditioner and the CMP pad are moved relative to one another.

Abstract: A CMP pad dresser for dressing a polishing pad of a CMP apparatus is provided with a dressing pad having abrasive grains, a purified water supply unit provided to an external periphery of the dressing pad, and a drive mechanism for sliding the dressing pad in a radial direction of the polishing pad. The dressing pad is slidable to the outer side of the polishing pad. The purified water supply unit supply purified water at a prescribed pressure so that particles of abrasive grains that are dislodged from the dresser accumulate in the dressing pad.

Abstract: A system for cleaning a conditioning device to improve the efficiency of the conditioning of a polishing pad using the conditioning device as part of a chemical-mechanical polishing process, the system comprising a conditioning device; a fluid dispenser arranged to dispense a fluid on the conditioning device; and an acoustic nozzle arranged to emit a megasonic or ultrasonic signal at the conditioning device while the fluid dispenser is dispensing the fluid on the conditioning device.

Abstract: In a first aspect, a first apparatus is provided for a chemical mechanical polishing (CMP) process. The first apparatus includes (1) a rotatable member; (2) an end effector adapted to receive and retain a conditioning disk; and (3) an elastic device disposed between the rotatable member and the end effector. The elastic device is (a) adapted to rotate the end effector via a torque from the rotatable member, and (b) flexibly extensible so as to impart a force to the end effector while permitting the end effector to deviate from a perpendicular alignment with the rotatable member in order for a conditioning surface of the conditioning disk to conform to an irregular polishing surface of a pad being conditioned. Numerous other aspects are provided, including methods and apparatus for using liquid or gas to deter polishing slurry or debris from entering the conditioning head.

Abstract: A polishing pad cleaner of a chemical mechanical polishing apparatus throughly and efficiently cleans the polishing pad of the apparatus. The head of the polishing pad cleaner includes a nozzle support plate, a plurality of nozzles mounted to the nozzle support plate, and extending from the bottom of the nozzle support plate, and partitions interposed between the nozzles. The head is placed over the polishing pad. Subsequently, the polishing pad is roated relative to the nozzles, and cleaning agent is ejected from the nozzles. The partitions help maintain the pressure of the cleaning agent as the agent flows from the nozzles to the polishing pad. Also, different types of cleaning agents can be simultaneously ejected from the nozzles, respectively, onto the polishing pad. Specifically, a high pressure gas and a cleaning solution can be directed onto the same region of the pad one after the other.

Abstract: A sweetening and cleaning system that is used with one or more lapping machines to sweeten a lapping compound in a sweetening mode, and to clean parts of the system itself and parts of the one or more lapping machines with a cleaning compound in a cleaning mode. The system includes a virgin receptacle for holding the lapping compound, a cleaning receptacle for holding the cleaning compound, a waste receptacle for holding waste, and at least one pump.

Abstract: A method and apparatus for cleaning a web-based chemical-mechanical planarization (CMP) system. Specifically, a fluid spray bar is coupled to a frame assembly which may be mounted on a CMP system. The fluid spray bar will move along the frame assembly. As the fluid spray bar traverses the length of the frame assembly, a cleaning fluid is sprayed onto the web in order to clean the web between planarization cycles.

Abstract: A pad conditioner is provided for conditioning a polishing pad in chemical mechanical planarization (CMP). The pad conditioner comprises a plastic abrasive portion having a first hardness and optionally a brush portion having a second hardness less than the first hardness. The plastic abrasive portion comprises a base plate and a plurality of plastic nodules formed on a surface of the base plate, each of the plastic nodules having a planar top surface, wherein the planar top surface is positioned to substantially contact a polishing pad. The brush portion may be positioned adjacent to the plastic abrasive portion, the brush portion having a plurality of brush elements positioned to substantially contact the pad.

Abstract: A dresser adapted to a chemical mechanical polishing apparatus is used to perform dressing on a polishing pad for polishing a semiconductor wafer such that a circular-shaped support surface thereof is positioned opposite to and in contact with the polishing surface of the polishing pad. In the dresser, at least three polish retainers having band-like shapes are formed and elongated in radial directions from substantially the center of the support surface so as to form a plurality of sectorial regions. A plurality of parallel portions are formed in parallel with the polish retainer in each sectorial region. A plurality of band-shaped non-polish retainers are formed between the polish retainer and its parallel portion in each sectorial region. The dresser ensures adequate fuzziness of the polishing pad by way of dressing; hence, it is possible to maintain desired polishing performance of the polishing pad for a long time.

Abstract: The present invention is related to an improved cleaning cup arrangement for CMP systems that efficiently and effectively removes most, if not all, of any slurry material present on the abrasive conditioning disk and conditioner head as they are resting in the cup between conditioning cycles. The cleaning cup of the present invention includes an underside water knife for directing a high velocity stream of cleaning fluid against the rotating abrasive disk (or conditioning brush, which may be used instead of a disk) surface, and at least a pair of spray stems for directing columns of cleaning fluid with sufficient cleaning force against all exposed portions of the conditioner head.

Abstract: A method of performing mechano-chemical polishing serving as a primary polishing operation for a GaAs wafer, by using a mechano-chemical polishing solution containing dichloroisocyanuric acid, sodium tripolyphosphate, sodium sulfate, sodium carbonate, and colloidal silica as components except for water, includes the steps of: mounting the wafer on a mechano-chemical polishing apparatus; performing first-stage polishing by supplying the polishing apparatus with the polishing solution having a first composition in which 20-31 mass % of sodium tripolyphosphate is contained in the components except for water; and subsequently performing second-stage polishing by supplying the polishing apparatus with the polishing solution having a second composition in which 13-19 mass % of sodium tripolyphosphate is contained in the components except for water.

Abstract: A method and system for pad conditioning in an electrochemical mechanical planarization (eCMP) tool is disclosed. A polishing pad having a pad electrode is placed onto a platen of the eCMP tool. A conditioning disk, having a second electrode is placed on the polishing pad, such that the pad electrode and conditioning disk form an electrode pair. An electric potential is established between the conditioning disk and the pad electrode. This causes debris from the polishing pad to become ionized, and attracted to the conditioning disk. The conditioning disk is then removed from the eCMP tool, allowing the eCMP tool to resume operation on normal semiconductor wafers.

Abstract: A substrate processing apparatus has a polishing tape and a polishing head for pressing the polishing tape against a peripheral portion of a semiconductor wafer. The substrate processing apparatus polishes the wafer due to sliding contact of the polishing tape and the wafer. The polishing head has an elastic body for supporting the polishing tape. The substrate processing apparatus has an air cylinder for pressing the polishing head so that the elastic body of the polishing head presses the polishing tape against the predetermined portion of the wafer under a constant force.

Abstract: A method and apparatus for conditioning is provided. In one embodiment, a conditioning disk includes a plurality of conditioning elements each having an abrasive working surface, and a flexible foundation having the conditioning elements coupled thereto. The flexible foundation has physical properties that retain the working surfaces in a substantially coplanar orientation with respect to the pad surface.

Abstract: An object of the present invention is to provide a polishing method and a polishing apparatus that can secure an even polished shape and can remove slurry that has contributed to polishing and contains polishing by-product to the outside of a pad efficiently to reduce scratches due to the polishing by-product, and can suppress consumption of slurry to the minimum to realize cost reduction during running for mass production.

Abstract: In a first aspect, a first apparatus is provided for a chemical mechanical polishing (CMP) process. The first apparatus includes (1) a rotatable member; (2) an end effector adapted to receive and retain a conditioning disk; and (3) an elastic device disposed between the rotatable member and the end effector. The elastic device is (a) adapted to rotate the end effector via a torque from the rotatable member, and (b) flexibly extensible so as to impart a force to the end effector while permitting the end effector to deviate from a perpendicular alignment with the rotatable member in order for a conditioning surface of the conditioning disk to conform to an irregular polishing surface of a pad being conditioned. Numerous other aspects are provided, including methods and apparatus for using liquid or gas to deter polishing slurry or debris from entering the conditioning head.

Abstract: A polishing method can prevent scratches in a polished surface of a polishing object, caused by foreign matter adhering to a surface of a polishing member, thus preventing the attendant lowering of the yield even when the polishing object is large-sized. The polishing method includes: specifying a foreign matter adhesion position or a foreign matter adhesion area in a surface of the polishing member; and intensively cleaning the foreign matter adhesion position or the foreign matter adhesion area in the surface of the polishing member.

Abstract: In one embodiment, a method for cleaning a chemical mechanical polishing (CMP) pad is provided. The CMP pad surface has a residue thereon. Chemicals are applied onto the surface of the CMP pad and the pad surface is rinsed so as to substantially remove by-product produced by the chemicals. A mechanical conditioning operation is performed on the surface of the pad. The wafer surface includes copper and oxide during the CMP operation.

Abstract: A conditioner including abrasive elements for conditioning a polishing pad to be used in abrasive semiconductor substrate treatment processes, such as chemical-mechanical polishing or chemical-mechanical planarization processes. The abrasive elements are formed from a material that may be degraded or dissolved by at least one chemical that will not substantially degrade or dissolve a material of the polishing pad. The abrasive elements of the conditioner may be degraded or dissolved in at least one chemical that will not substantially degrade or dissolve a material of the polishing pad. Any residue or particles of, or from, the abrasive elements that stick to or become embedded in the polishing pad are removed therefrom by exposing the polishing pad to the at least one chemical so as to degrade or dissolve the residue or particles without substantially degrading or dissolving a material of the polishing pad.

Abstract: CMP pad dressers and their methods of manufacture are disclosed. One aspect of the present invention provides a CMP pad dresser having improved superabrasive grit retention in a resin layer. The CMP pad includes a resin layer, superabrasive grit held in the resin layer such that an exposed portion of each superabrasive grit protrudes from the resin layer, and a metal coating layer disposed between each superabrasive grit and the resin layer, where the exposed portions are substantially free of the metal coating layer. The metal coating layer acts to increase the retention of the superabrasive grit in the resin layer as compared to superabrasive grit absent the metal coating layer.

Abstract: A method and apparatus for conditioning polishing pads that utilize an apertured conditioning disk for introducing operation-specific slurries, without the need for additional tooling, platens, and materials handling. The method and apparatus utilize a vacuum capability to pull waste material out of the conditioning pad and through the apertured conditioning disk to evacuate the apparatus through an outlet port, the apparatus may also include self-contained flushing means and a piezo-electric device for vibrating the pad conditioning apparatus.

Abstract: A cylindrical valve guide having a roughened external surface texture from about 50 to about 100 microinches permits effective amounts of lubricating oil to become trapped or contained by such roughened external surface and thereby facilitates subsequent press fitting of the valve guide into an internal combustion engine. Centerless grinding constitutes a preferred method of achieving the surface texture of the invention.

Abstract: A polishing apparatus can detect completion of initialization of a polishing pad quantitatively. The polishing apparatus has a polishing table having a polishing pad attached thereto and a substrate holder configured to bring a surface of a substrate into contact with the polishing pad and press the substrate against the polishing pad. The polishing apparatus also has a drive mechanism operable to drive at least one of the polishing table and the substrate holder so as to provide a relative movement between the polishing pad and the substrate. The polishing apparatus includes a current sensor operable to detect a drive current supplied to the driving mechanism. The polishing apparatus also includes a polishing pad condition detector operable to detect a condition of the polishing pad based on the drive current detected by the current sensor when the dummy substrate is polished by a relative movement between the polishing pad and a dummy substrate held by the substrate holder.

Abstract: A Belt Sander Eraser Attachment is disclosed. The attachment is configured to be attached to a conventional belt sander such that it provides the operator with the ability to remove built up sawdust and the like from the sanding belt. The device removably replaces the conventional front handle on a sander and the new handle has functionality as both a handle and an actuator for the belt sander eraser. The eraser actuation is convenient and ergonomically comfortable for the user while the sander is in use.

Abstract: Truing of a grinder is performed by irradiating a laser beam onto abrasive grains on the outermost periphery of the grinder from the tangential direction of the grinder. Truing of the grinder for adjusting the number of working abrasive grains and the shape of the abrasive grains involved in the actual machining is performed under a non-contact condition and at highly accurately, thereby enabling highly accurate and highly efficient machining.

Abstract: A chemical mechanical polishing apparatus includes a polishing pad. A pad conditioner includes a static conditioner head having a surface area configured to contact and condition the pad. The surface area has a first end proximate to an axis of rotation of the pad and a second end remote from the axis of rotation of the pad. The first end defines a first arc length, and the second end defines a second arc length, where the first arc length and the second arc length are substantially identical.

Abstract: An apparatus for use in a chemical mechanical planarization system is provided. The apparatus includes a fluid displacing device and a fluid delivery device. The fluid displacing device is capable of being positioned at a proximate location over a polishing pad, the fluid displacing device configured to displace at least part of a first fluid from a region of the polishing pad. The fluid delivery device is capable of replacing the displaced first fluid with a second fluid at the region of the polishing pad, the second fluid being different than the first fluid. A method of controlling properties of a film present over a polishing pad surface is also provided.

Abstract: Conditioning devices, systems and methods for conditioning a contact surface of a processing pad used in processing microelectronic workpieces. One embodiment of a conditioning device comprises an end-effector having a conditioning surface configured to engage the contact surface of the processing pad and a plurality of microstructures on the conditioning surface. The microstructures can be arranged in a pattern corresponding to a desired pattern of microfeatures on the contact surface of the processing pad. In several embodiments, the microstructures are raised elements projecting from the conditioning surface and/or depressions in the conditioning surface. The condition surface can also be smooth. The conditioning device can also include a heater coupled to the end-effector for heating the processing pad.

Abstract: A CMP conditioner is provided in which diamond grit that is adhered to a conditioning surface so as to face and be in contact with a polishing pad of a CMP apparatus is adhered such that 111 surfaces of crystal surfaces of the diamond grit are substantially parallel with the conditioning surface and face in a direction faced by the conditioning surface.

Abstract: Conditioning devices, systems and methods for conditioning a contact surface of a processing pad used in processing microelectronic workpieces. One embodiment of a conditioning device comprises an end-effector having a conditioning surface configured to engage the contact surface of the processing pad and a plurality of microstructures on the conditioning surface. The microstructures can be arranged in a pattern corresponding to a desired pattern of microfeatures on the contact surface of the processing pad. In several embodiments, the microstructures are raised elements projecting from the conditioning surface and/or depressions in the conditioning surface. The condition surface can also be smooth. The conditioning device can also include a heater coupled to the end-effector for heating the processing pad.

Abstract: A wafer planarization process with a conditioning tool having an electrical insulator that electrically insulates the abrasive surface of the conditioning tool. The electrical insulator extends the useful life of the abrasive surface of the conditioning tool by reducing the level of electrochemically driven corrosion.

Abstract: The present invention relates to a polishing method for polishing a workpiece by pressing the workpiece, to be polished, against a fixed abrasive and bringing the workpiece into sliding contact with the fixed abrasive. The polishing method includes a first step of polishing the workpiece while supplying a polishing liquid which contains an anionic surface-active agent and does not contain abrasive particles, and a second step of polishing the workpiece while supplying a polishing liquid which contains a cationic surface-active agent and does not contain abrasive particles.

Abstract: A system includes a measuring station for positioning an eddy current probe proximate to a substrate in a substrate holder. The probe can produce a time-varying magnetic field, in order to induce eddy currents in one or more conductive regions of a substrate either prior to or subsequent to polishing. The eddy current signals are detected, and may be used to update one or more polishing parameters for a chemical mechanical polishing system. The substrate holder may be located in a number places; for example, in a substrate transfer system, a factory interface module, a cleaner, or in a portion of the chemical mechanical polishing system away from the polishing stations. Additional probes may be used.

Abstract: A method and apparatus for polishing a thin film on a semiconductor substrate is described. A polishing pad is rotated and a wafer to be polished is placed on the rotating polishing pad. The polishing pad has grooves that channels slurry between the wafer and polishing pad and rids excess material from the wafer, allowing an efficient polishing of the surface of the wafer. The polishing pad smoothes out due to the polishing of the wafer and must be conditioned to restore effectiveness. A conditioning assembly with a plurality of diamonds is provided. The diamonds have predetermined angles that provide strength to the diamond. This allows for an optimal rotation speed and downward force in effective conditioning of the polishing pad, while reducing diamond fracture rate.

Abstract: A grindstone of a diamond wheel is cleaned by a rotating brush additionally provided in close proximity of the diamond wheel during a grinding operation in which a magnetic layer of a magnetic tape material being transferred is ground continuously by the diamond wheel.

Abstract: A polishing apparatus comprises a polishing table having a polishing surface thereon, a top ring for pressing a workpiece to be polished against the polishing surface, and a dresser for dressing the polishing surface on the polishing table. The dresser comprises a dressing element provided on a surface of the dresser for dressing the polishing surface by sliding contact with the polishing surface, and an ejection nozzle provided on the surface of the dresser for ejecting a fluid supplied from a fluid source toward the polishing surface.

Abstract: A method and apparatus for polishing a workpiece are set forth which can polish the workpiece at a constant rate at a stable condition even when plural workpieces are continually polished. The method comprises dressing a polishing surface of a polishing table while supplying a dressing solution. After the dressing, the dressing solution remaining on the polishing surface is removed by rotating the polishing table at a dewatering rotation speed while stopping the supply of the dressing solution. Then, the workpiece is polished by making the workpiece slidingly contact with the polishing surface while supplying a polishing solution to the polishing surface.

Abstract: Systems and methods for activating end effectors used to condition microfeature workpiece polishing pads are disclosed. A system in accordance with one embodiment of the invention includes a rotatable end effector having a conditioning surface configured to condition a microfeature workpiece polishing medium, and a driver coupled to the end effector to rotate the end effector. The driver does not include a flexible, continuous belt coupled to the end effector. For example, the driver can include a motor-driven worm meshed with a worm gear. The system can further include a forcing element coupled to the end effector to apply a force to the end effector that is at least approximately normal to a conditioning surface of the end effector. The forcing element can include a first generally rigid member and a second generally rigid member coupled to the end effector and movable relative to the first generally rigid member to apply the force.

Abstract: A polishing pad conditioner comprises a base and a pad conditioning face on the base. The conditioning face comprises central and peripheral regions. Abrasive spokes having a substantially constant width of abrasive particles, extend from the central to the peripheral region. The spokes are symmetric and radially spaced apart from one another, and may have a variety of shapes. The conditioning face can also have a cutout inlet channel to receive polishing slurry when the conditioning face is rubbed against a polishing pad, a conduit to receive the polishing slurry from the cutout inlet channel, and an outlet on the peripheral edge of the base to discharge the received polishing slurry.

Abstract: A method and apparatus for cleaning a web-based chemical-mechanical planarization (CMP) system. Specifically, a fluid spray bar is coupled to a frame assembly which may be mounted on a CMP system. The fluid spray bar will move along the frame assembly. As the fluid spray bar traverses the length of the frame assembly, a cleaning fluid is sprayed onto the web in order to clean the web between planarization cycles.

Abstract: A method and apparatus for conditioning polishing pads that utilize an apertured conditioning disk for introducing operation-specific slurries, without the need for additional tooling, platens, and materials handling. The a method and apparatus utilize a vacuum capability to pull waste material out of the conditioning pad and through the apertured conditioning disk to evacuate the apparatus through an outlet port, the apparatus may also include self-contained flushing means and a piezo-electric device for vibrating the pad conditioning apparatus.

Abstract: A wafer carrier gap washer includes at least one wafer carrier head and at least one nozzle installed on a wafer load/unload mechanism. The wafer carrier head has a flexible membrane and a retaining ring for holding a wafer beneath the wafer carrier head during a CMP process. The nozzle sprays fluid toward a gap between the flexible membrane and the retaining ring so as to wash the gap and remove slurry residues produced in the CMP process.

Abstract: Methods and apparatuses for planarizing a microelectronic substrate. In one embodiment, a planarizing pad for mechanical or chemical-mechanical planarization includes a base section and a plurality of embedded sections. The base section has a planarizing surface, and the base section is composed of a first material. The embedded sections are arranged in a desired pattern of voids, and each embedded section has a top surface below the planarizing surface to define a plurality of voids in the base section. The embedded sections are composed of a second material that is selectively removable from the first material. A planarizing pad in accordance with an embodiment of the invention can be made by constructing the embedded sections in the base section and then removing a portion of the embedded sections from the base section. By removing only a portion of the embedded sections, this procedure creates the plurality of voids in the base section and leaves the remaining portions of the embedded sections.

Abstract: A pad refurbisher that provides in situ, real-time conditioning and/or cleaning of a polishing surface on a polishing pad used in chemical-mechanical polishing of a semiconductor wafer and other microelectronic substrates. The pad refurbisher has a body adapted for attachment to a wafer carrier of a chemical-mechanical polishing machine, and a refurbishing element connected to the body. The body has a distal face positioned proximate to a perimeter portion of the wafer carrier and facing generally toward the polishing surface of the polishing pad. The body travels with the wafer carrier as the wafer carrier moves over the polishing pad. The refurbishing element is connected to the distal face of the body so that the refurbishing element can operatively engage the polishing surface substantially adjacent to the perimeter of the wafer carrier.