Chemical mechanical polishing system backside rinse assembly

Abstract

Exemplary chemical mechanical polishing systems may include a plurality of substrate supports. The systems may include a rinse assembly mounted above the plurality of substrate supports. The rinse assembly may include a spray nozzle. The spray nozzle may be directed at a downward angle and is configured to deliver a rinse solution to an entire backside of a substrate seated atop the plurality of substrate supports. The systems may include a fluid source. The systems may include a fluid delivery line that fluidly couples the fluid source with the spray nozzle.

Description

PATENT Attorney Docket No. 080042-1475957-44025611WO01CHEMICAL MECHANICAL POLISHING SYSTEM BACKSIDE RINSE ASSEMBLYTECHNICAL FIELD

[0002] The present technology relates to semiconductor systems, processes, and equipment. More specifically, the present technology relates to removing polishing slurry present on a backside of a substrate after chemical mechanical polishing operations.BACKGROUND

[0003] An integrated circuit is typically formed on a substrate by the sequential deposition of conductive, semiconductive, and / or insulative layers on a silicon wafer. A variety of fabrication processes use the planarization of a layer on the substrate between processing steps. For example, for certain applications, e.g., polishing of a metal layer to form vias, plugs, and / or lines in the trenches of a patterned layer, an overlying layer is planarized until the top surface of a patterned layer is exposed. In other applications, e.g., planarization of a dielectric layer for photolithography, an overlying layer is polished until a desired thickness remains over the underlying layer.

[0004] Chemical mechanical polishing (CMP) is one common method of planarization. This planarization method typically requires that the substrate be mounted on a carrier or polishing head. The exposed surface of the substrate is typically placed against a rotating polishing pad. The carrier head provides a controllable load on the substrate to push it against the polishing pad. Abrasive polishing slurry is ty pically supplied to the surface of the polishing pad.

[0005] Once the film has been polished, some amount of polishing slurry may remain on one or more surfaces of the substrate, including the backside (i.e., non-device side) of the substate. The presence of this slurry^ may ultimately7cause defects on the device side of the substrate. Additionally, during transfer of the substrate from a polishing head to a load cup, such as for transfer of the substrate to different processing stations after completion of polishing, static charge may buildup on the substrate, which may cause further defects on the substrate.

[0006] Thus, there is a need for improved systems and methods that can be used minimize defects on the device side of wafers that are attributed to the polishing operations. These and other needs are addressed by the present technology.SUMMARY

[0007] Exemplary chemical mechanical polishing systems may include a plurality of substrate supports. The systems may include a rinse assembly mounted above the plurality of substrate supports. The rinse assembly may include a spray nozzle. The spray nozzle may be directed at a downward angle and is configured to deliver a rinse solution to an entire backside of a substrate seated atop the plurality of substrate supports. The systems may include a fluid source. The systems may include a fluid delivery line that fluidly couples the fluid source with the spray nozzle.

[0008] In some embodiments, the systems may include an electrically conductive member that is positioned to contact a surface of the substrate when the substrate is seated atop the plurality’ of substrate supports. The electrically conductive member may include a sensor that detects a presence of the substrate when the substrate is seated atop the plurality of substrate supports. The spray nozzle may include an actuator that is configured to translate the spray nozzle in one or both of a vertical direction and a horizontal direction while delivering the rinse solution. The downward angle of the spray nozzle may be between 0 degrees and 45 degrees relative to horizontal. An arc of spray produced by the spray nozzle may be between 15 degrees and 115 degrees. A flow rate of the spray nozzle may be between 0.5 L / min and 5 L / min. The rinse solution may include at least one of deionized water, an acidic solution, a basic solution, or a cleaning chemistry. The systems may include a plurality' of alignment pins that are configured to mechanically seat the substrate at a predetermined horizontal and vertical position atop the plurality of substrate supports. At least one of the alignment pins may have a tapered inner surface that tapers dow ward toward the predetermined horizontal and vertical position.

[0009] Some embodiments of the present technology may encompass chemical mechanical polishing systems that may include a load cup. The load cup may include a plurality of substrate supports. The load cup may include a plurality' of substrate alignment pins. The systems may include a rinse assembly mounted above the plurality of substrate supports. The rinse assembly may include a spray nozzle. The spray nozzle may be directed at a downward angle and is configured to deliver a rinse solution to an entire backside of a substrate seatedatop the plurality of substrate supports. The rinse assembly may include a fluid source. The rinse assembly may include a fluid delivery line that fluidly couples the fluid source with the spray nozzle.

[0010] In some embodiments, the spray nozzle may be configured to vary' a flow rate of the rinse solution while delivering the rinse solution. The rinse assembly may include a flow meter regulator that is configured to set a flow rate of the rinse solution delivered by the spray nozzle. The spray nozzle may be a first spray nozzle. The rinse assembly may include a second spray nozzle. The first spray nozzle and the second spray nozzle my be at different angular positions relative to a central axis of the load cup. The systems may include one or more sensors that are configured to detect a presence of slurry on the backside of the substrate.

[0011] Some embodiments of the present technology may encompass methods of rinsing a backside of a substrate. The methods may include detecting, using one or more sensors, that a substrate is seated atop a plurality of substrate supports of a chemical mechanical polishing system. The substrate may be positioned with a backside of the substrate facing upward. The methods may include spraying a rinse solution onto the backside of the substrate via a spray nozzle for a period of time upon detecting that the substrate is seated atop the plurality of substrate supports.

[0012] In some embodiments, the methods may include moving the spray nozzle in one or both of a vertical direction and a horizontal direction while spraying the rinse solution. The period of time may include a predetermined period of time. The methods may include monitoring a presence of slurry on the backside of the substrate using one or more sensors. The methods may include setting an endpoint for the period of time based on data from the one or more sensors. The methods may include varying a flow rate of the rinse solution while spraying the rinse solution.

[0013] Such technology may provide numerous benefits over conventional systems and techniques. For example, the rinse assemblies described herein may help remove any slurry present on the backside of the substrate and / or may help neutralize electric change on the substrate. This may enable the rinse assemblies to reduce the presence of defects on the device side of the substrate. These and other embodiments, along with many of their advantages and features, are described in more detail in conjunction with the below description and attached figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remaining portions of the specification and the drawings.

[0015] FIG. 1 shows a schematic cross-sectional view of an exemplary polishing system according to some embodiments of the present technology7.

[0016] FIG. 2 shows a schematic partial cross-sectional view of an exemplary7polishing system according to some embodiments of the present technology.

[0017] FIG. 3 shows a schematic partial cross-sectional view of an exemplary7polishing system according to some embodiments of the present technology.

[0018] FIG. 4 shows a schematic partial top plan view of an exemplary polishing system according to some embodiments of the present technology7.

[0019] FIG. 5 is a flowchart of an exemplary7method of rinsing a backside of a substrate according to some embodiments of the present technology.

[0020] Several of the figures are included as schematics. It is to be understood that the figures are for illustrative purposes, and are not to be considered of scale unless specifically stated to be of scale. Additionally, as schematics, the figures are provided to aid comprehension and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustrative purposes.

[0021] In the appended figures, similar components and / or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the letter.DETAILED DESCRIPTION

[0022] Conventional CMP polishing involves a substrate being positioned face down on a polishing pad, with a carrier that holds the substrate against a rotating polishing pad.Abrasive polishing slurry is typically supplied to the surface of the polishing pad, which may facilitate the removal of portions of the film deposited on the substrate during polishingoperations. While the device side (i.e., the face) of the substrate is directly exposed to the slurry, oftentimes slurry reaches the backside of the substrate. Conventionally, CMP systems in the industry historically have focused primarily on rinsing the device side of the substrate to reduce defects or prevent corrosion. However, recent data has surprisingly shown that the presence of slurry' on the backside of the substrate may increase the number of defects on the device side. Additionally, electric charge may build up on the substrate during the polishing operation and / or during transfer of the substrate from the carrier to a load cup. This electric charge may contribute to further defects on the device side of the substrate.

[0023] The present technology7overcomes these issues with conventional polishing systems by including a backside rinse assembly into a CMP system. The backside rinse assembly may deliver a rinse solution that clears slurry’ residue from the non-device side of the wafer to prevent defects associated with the presence of slurry. By incorporating a backside rinse assembly into the CMP system itself, the duration of the slurry being present on the backside of the substrate may be significantly reduced as compared to conventional systems that do not clean the backside until the substrate is transferred to downstream cleaning stations. This reduced time further reduces defects on the device side of the substrate. Additionally, the system may include one or more electrically conductive members that contact the wafer to draw electronic charge from the substrate to help neutralize any electric charge that has built up on the substrate during polishing and / or transfer operations. Thus, the rinse assemblies described herein may produce substrates with fewer defects on the device side.

[0024] Although the remaining disclosure will routinely identify specific slurry rinsing processes utilizing the disclosed technology, it will be readily understood that the systems and methods are equally applicable to a variety of other semiconductor processing operations and systems. Accordingly, the technology should not be considered to be so limited as for use with the described polishing systems or processes alone. The disclosure will discuss one possible system that can be used with the present technology before describing systems and methods or operations of exemplary process sequences according to some embodiments of the present technology. It is to be understood that the technology7is not limited to the equipment described, and processes discussed may be performed in any number of processing chambers and systems, along with any number of modifications, some of which will be noted below.

[0025] FIG. 1 shows a schematic cross-sectional view of an exemplary polishing system 100 according to some embodiments of the present technology. Polishing system 100 includes a platen assembly 102, which includes a lower platen 104 and an upper platen 106. Lower platen 104 may define an interior volume or cavity through which connections can be made, as well as in which may be included end-point detection equipment or other sensors or devices, such as eddy current sensors, optical sensors, or other components for monitoring polishing operations or components. For example, and as described further below, fluid couplings may be formed with lines extending through the lower platen 104, and which may access upper platen 106 through a backside of the upper platen. Platen assembly 102 may include a polishing pad 110 mounted on a first surface of the upper platen. A substrate earner 108. or carrier head, may be disposed above the polishing pad 110 and may face the polishing pad 110. The platen assembly 102 may be rotatable about an axis A, while the substrate carrier 108 may be rotatable about an axis B. The substrate carrier may also be configured to sweep back and forth from an inner radius to an outer radius along the platen assembly, which may, in part, reduce uneven wear of the surface of the polishing pad 110. The polishing system 100 may also include a fluid delivery arm 118 positioned above the polishing pad 110, and which may be used to deliver polishing fluids, such as a polishing slurry', onto the polishing pad 110. Additionally, a pad conditioning assembly 120 may be disposed above the polishing pad 110, and may face the polishing pad 110.

[0026] In some embodiments of performing a chemical-mechanical polishing process, the rotating and / or sweeping substrate carrier 108 may exert a downforce against a substrate 112, which is shown in phantom and may be disposed within or coupled with the substrate carrier. The dow nw ard force applied may depress a material surface of the substrate 112 against the polishing pad 110 as the polishing pad 110 rotates about a central axis of the platen assembly. The interaction of the substrate 112 against the polishing pad 110 may occur in the presence of one or more polishing fluids delivered by the fluid delivery arm 118. A typical polishing fluid may include a slurry formed of an aqueous solution in which abrasive particles may be suspended. Often, the polishing fluid contains a pH adjuster and other chemically active components, such as an oxidizing agent, which may enable chemical mechanical polishing of the material surface of the substrate 112.

[0027] The pad conditioning assembly 120 may be operated to apply a fixed abrasive conditioning disk 122 against the surface of the polishing pad 110, which may be rotated as previously noted. The conditioning disk may be operated against the pad prior to,subsequent, or during polishing of the substrate 112. Conditioning the polishing pad 110 with the conditioning disk 122 may maintain the polishing pad 110 in a desired condition by abrading, rejuvenating, and removing polish byproducts and other debris from the polishing surface of the polishing pad 110. Upper platen 106 may be disposed on a mounting surface of the lower platen 104 and may be coupled with the lower platen 104 using a plurality of fasteners 138, such as extending through an annular flange shaped portion of the lower platen 104.

[0028] The polishing platen assembly 102, and thus the upper platen 106, may be suitably sized for any desired polishing system, and may be sized for a substrate of any diameter, including 200 mm, 300 mm, 450 mm, or greater. For example, a polishing platen assembly configured to polish 300 mm diameter substrates, may be characterized by a diameter of more than about 300 mm, such as between about 500 mm and about 1000 mm, or more than about 500 mm. The platen may be adjusted in diameter to accommodate substrates characterized by a larger or smaller diameter, or for a polishing platen 106 sized for concurrent polishing of multiple substrates. The upper platen 106 may be characterized by a thickness of between about 20 mm and about 150 mm, and may be characterized by a thickness of less than or about 100 mm, such as less than or about 80 mm, less than or about 60 mm, less than or about 40 mm, or less. In some embodiments, a ratio of a diameter to a thickness of the polishing platen 106 may be greater than or about 3:1, greater than or about 5:1. greater than or about 10:1, greater than or about 15:1, greater than or about 20: 1, greater than or about 25:1. greater than or about 30: 1. greater than or about 40: 1. greater than or about 50:1, or more.

[0029] The upper platen and / or the lower platen may be formed of a suitably rigid, lightweight, and polishing fluid corrosion-resistant material, such as aluminum, an aluminum alloy, or stainless steel, although any number of materials may be used. Polishing pad 110 may be formed of any number of matenals, including polymeric materials, such as polyurethane, a polycarbonate, fluoropolymers, polytetrafluoroethylene polyphenylene sulfide, or combinations of any of these or other materials. Additional materials may be or include open or closed cell foamed polymers, elastomers, felt, impregnated felt, plastics, or any other materials that may be compatible with the processing chemistries. It is to be understood that polishing system 100 is included to provide suitable reference to components discussed below, which may be incorporated in system 100, although the description of polishing system 100 is not intended to limit the present technology in any way, asembodiments of the present technology' may be incorporated in any number of polishing systems that may benefit from the components and / or capabilities as described further below.

[0030] The system 100 may include a rinse station 150. The rinse station 150 may include a load cup 155 that may receive a substrate from the substrate earner 108 after polishing, such as for transfer to another processing station. In some embodiments, the rinse station 150 may include a head cleaning assembly 160 for washing the substrate carrier 108 and / or a rinse assembly 165 for rinsing slurry off a backside of the substrate.

[0031] FIG. 2 illustrates a schematic partial cross-sectional side elevation view of an exemplary CMP polishing 200 according to some embodiments of the present technology. The system 200 may show a partial view of the components being discussed and may include any of the features described in relation to polishing system 100. The system 200 may include a load cup 205. which may be similar to load cup 155. The load cup 205 may include a number of substrate supports 210. Each substrate support 210 may be, for example, a pin or other member that may contact a face (e.g., device side) of a substrate 290 that is placed within the load cup 205. The system 200 may include various numbers of substrate supports 210. For example, the system may include three or more substrate supports, four or more substrate supports, five or more substrates, six or more substrate supports, eight or more substrate supports, ten or more substrate supports, or more. The substrate supports 210 may be disposed at regular or irregular angular intervals about a central axis of the load cup 205.

[0032] The load cup 205 may include a number of substrate alignment pins 215. The substrate alignment pins 215 may be configured to mechanically seat the substrate 290 at a predetermined horizontal and vertical position (which may be centered within the load cup in some embodiments) atop the plurality of substrate supports 210 in various embodiments. For example, each of the substrate alignment pins 215 may be positioned radially outward of the substrate supports 210 such that when the substrate 290 is seated atop the substate supports 210, the substrate alignment pins 215 contact peripheral edges of the substrate 290 to force the substrate 290 to the predetermined horizontal and vertical position. In some embodiments, a top end of one or more of the substrate alignment pins 215 may include a tapered inner surface to help properly align the substrate 290 in the predetermined horizontal and vertical position. For example, the inner surface may taper downward and radially inward toward the predetermined horizontal and vertical position such that the slope of the inner surface forces the peripheral edge of the substrate 290 inward until the substrate 290 isin the predetermined horizontal and vertical position. In some embodiments, the top end of one or more of the substrate alignment pins 215 may have a conical or frustoconical shape that helps align the substrate 290 atop the substrate supports 210. In some embodiments, top ends of all of the substate alignment pins 215 may have tapered inner surfaces and / or conical / frustoconical shapes. The system 200 may include three or more substrate alignment pins, four or more substrate alignment pins, five or more substrate alignment pins, six or more substrate alignment pins, eight or more substrate alignment pins, ten or more substrate alignment pins, or more.

[0033] In some embodiments, the load cup 205 may include one or more electrically conductive members 220 that are positioned to contact a surface of the substrate 290 when the substrate 290 is seated atop the plurality of substrate supports 210. The electrically conductive members 220 may be positioned to contact a device side, peripheral edge, and / or backside of the substrate 290 when the substrate 290 is seated atop the plurality of substrate supports 210. In some embodiments, the electrically conductive members 220 may be or form part of the substrate supports 210 and / or the substrate alignment pins 215. In some embodiments, the electrically conductive members 220 may be separate components. Each of the electrically conductive members 220 may for formed from or otherwise include an electrically conductive material, such as aluminum, stainless steel, and / or other metal. The presence of the electrically conductive members 220 may help neutralize any electric charge on the substrate 290. For example, during polishing operations, sliding contact between the substrate 290 and the polishing pad may generate electric charge on the substrate 290.Additionally, during transfer of the substrate 290 from the carrier to the load cup 205 may generate some electric charge. Contact between the electrically conductive members 220 and the substrate 290 may help pull electric charge from the substrate 290 to the electrically conductive members 220 to neutralize the substrate 290, which may help reduce defects on the device side of the substrate.

[0034] The load cup 205 may include one or more sensors that may be configured to detect a presence of the substrate 290 when the substrate 290 is seated atop the substrate supports 210. For example, the sensors may include inductive proximity sensors, mass sensors, optical sensors, and / or other sensors that are capable of determining when the substrate 290 is at the predetermined horizontal and vertical position. In some embodiments, the sensors may be integrated into spring-loaded pins or other members that may be depressed when the substrate 290 pushes down on the sensors. In some embodiments, the sensors may beintegrated into the substrate supports 210, the substrate alignment pins 215, and / or the electrically conductive members 220. In some embodiments, the sensors may be distinct components from the supports 210, the substrate alignment pins 215, and / or the electrically conductive members 220.

[0035] The system 200 may include a vertical support 225 that may be positioned radially outward of the load cup 205. A top surface of the vertical support 225 may extend vertically beyond a top surface of the load cup 205. The vertical support 225 may provide a mounting location for various components of the system 200 as will be described in greater detail below. The vertical support 225 may be or include one or more columns, plates, walls, and / or other structural members that may support components of the system 200.

[0036] The system 200 may include a rinse assembly 230 that is mounted on the vertical support 225. For example, the rinse assembly 230 may include a fluid source 235 that may store a rinse solution for delivery to backside of the substrate 290. The rinse solution may include a liquid that may rinse any remaining polishing slurry from the backside of the substrate 290 without damaging the substrate 290. For example, in some embodiments, the rinse solution may include deionized water, acidic solutions, basic solutions, a cleaning chemistry, and / or other substrate-compatible liquid. In some embodiments, the rinse solution may be or include a chemistry that may further help remove any electric charge on the substrate 290. The fluid source 235 may be located proximate the load cup 205 in some embodiments, while in other embodiments, the fluid source 235 may be located a noticeable distance (e.g., more than 1 foot, more than 2 feet, more than 3 feet, more than 4 feet, more than five feet, more than ten feet, etc.) from the load cup 205. The rinse assembly 230 may include one or more fluid delivery lines 240 that may each extend between and fluidly couple the fluid source 235 with a fluid applicator, such as one or more spray nozzles 245. The rinse assembly 230 may include a pump or other fluid flow device that may help facilitate flow of the rinse solution to the spray nozzle 245. In some embodiments, the pump may form part of the fluid source 235, however the pump may be a separate component in other embodiments.

[0037] As illustrated, the rinse assembly 230 includes a single spray nozzle 245, however the rinse assembly 230 may include any number of spray nozzles 245, such as one or more spray nozzles, two or more spray nozzles, three or more spray nozzles, four or more spray nozzles, five or more spray nozzles, or more. As will be discussed in greater detail below, in embodiments with multiple spray nozzles, some or all of the spray nozzles may be at a sameor different vertical and / or angular position relative to the load cup 205. Each spray nozzle 245 may be mounted vertically above load cup 205. More specifically, each spray nozzle 245 may be positioned above atop surface of the substrate supports 210 and may be oriented at a downward angle to deliver a rinse solution to an entire backside of the substrate 290 when the substrate 290 is seated atop the substrate supports 210. In some embodiments, the downward angle of the spray nozzle 245 may be between 0 and 45 degrees relative to horizontal, between 5 degrees and 30 degrees, or between 10 degrees and 20 degrees. In some embodiments, the downward angle of the spray nozzle 245 may be fixed while in other embodiments the spray nozzle 245 may include an actuator that enables the downward angle of the spray nozzle 245 to be adjusted. A width or arc of the rinse solution delivered the spray nozzle 245 may be fixed or adjusted in various embodiments. In some embodiments, the arc of the rinse solution may be sufficiently wide so as to cover an entire diameter of the substrate 290, which may depend on a distance from the spray nozzle 245 to the substrate 290. In a particular embodiment, the arc of spray produced by the spray nozzle 245 may be between 15 and 110 degrees, between 30 degrees and 110 degrees, between 45 degrees and 110 degrees, between 60 degrees and 110 degrees, or between 90 degrees and 110 degrees. In some embodiments, a smaller stream, such as a substantially linear flow of cleaning solution, may be utilized.

[0038] As noted above, the spray nozzle 245 may include one or more actuators 250 that may translate the spray nozzle 245 in a vertical direction (e.g., to adjust the downward angle) and / or a horizontal direction (e.g., to adjust a lateral orientation). Translation of the spray nozzle 245 may involve movement of the entire spray nozzle 245 and / or may involve rotating the spray nozzle 245 about one or more axis to adjust only an angular orientation of the spray nozzle 245. The movement of the actuator 250 may be done prior to the delivery of the rinse solution and / or may be done while delivering the rinse solution. For example, in some embodiments, the actuator 250 may adjust the lateral (e.g., horizontal angle) and / or vertical orientation (e.g., vertical / downward angle) of the spray nozzle 245 while delivering the rinse solution, which may enable the rinse solution to be delivered directly onto a large portion or entirety of the backside of the substrate 290. For example, the downward angle may be adjusted dunng delivery of the rinse solution such that the spray of rinse solution may be moved from one end of the substrate 290 to the other (or partially along the diameter) to get the highest pressure flow of rinse solution at all or large regions of the substrate 290, rather than relying on washout (e.g., rinse solution flowing across the backside of the substrate 290after contacting the substrate 290) to fully clean the substrate 290. Similarly, the lateral angle of the spray nozzle 245 may be adjusted during delivery of the rinse solution such that the spray of rinse solution may be moved from lateral side of the substrate 290 to the other (or partially along the diameter). For example, the actuator 250 may translate the spray nozzle 245 such that the rinse solution sweeps across the length and / or width of the substrate 290.

[0039] In some embodiments, to further improve contact between the spray of rinse solution and the substrate 290, the substrate 290 may be rotated during the delivery of the rinse solution. For example, the substrate supports 210 may be coupled with a rotational actuator (not shown) that may rotate substrate supports 210 about the central axis (or other vertical axis) of the load cup 205. When the substrate 290 is seated atop the substrate supports 210, rotation of the substrate supports 210 may cause a corresponding rotation of the substrate 290. Rotation of the substrate 290 may enable the rinse solution from the spray nozzle 245 to be sprayed directly onto a greater surface area of the substrate 290.

[0040] The spray nozzle 245 may be configured to spray the rinse solution at a flow rate of between 0.5 L / min and 5 L / min, between 1 L / min and 2.5 L / min, or between 1 L / min and 1.5 L / min. In some embodiments, the flow rate may be constant, while in other embodiments the flow rate may be varied. For example, the spray nozzle 245, fluid source 235, and / or other component of the rinse assembly 230 may include a flow meter regulator that is configured to vary or otherwise set a flow rate of the rinse solution delivered by the spray nozzle 245. The flow rate may be varied gradually, such as by ramping up and / or ramping down the flow rate duration a duration of cleaning the substrate 290. In some embodiments, the flow rate may be pulsed between a high flow rate and low flow rate while spraying the substrate 290. It will be appreciated that the flow rate may be varied in any manner that provides the necessary rinsing.

[0041] In some embodiments, the rinse assembly 230 may include a monitoring system 260, which may be configured to detect a presence of slurry on the backside of the substrate 290. For example, the monitoring system 260 may include one or more sensors that may be used to determine whether the substrate 290 has been fully rinsed of slurry. In some embodiments, the sensors may include, without limitation, optical sensors (e.g.. cameras), inductive sensors, and / or other sensors. The use of the monitoring system 260 may enable the duration of spraying the substrate 290 to be customized for a given substrate. For example, once the monitoring system 260 determines that a given substrate does not includeany slurry, the spray of the rinse solution may be halted. In other embodiments, the duration of the spray of the rinse solution may be delivered for a set period of time that is equal for each substrate 290.

[0042] In some embodiments, the load cup sensors that detect a presence of the substrate 290 when the substrate 290 is seated atop the substrate supports 210 may be in communication with the rinse assembly 230. For example, once the substrate 290 is detected, the sensors may send a signal to the rinse assembly 230 that causes the rinse assembly 230 to deliver the rinse solution to the substrate 290. In embodiments in which the load cup 205 is configured to rotate the substrate 290, the sensors may send a signal to the load cup 205 that causes the actuator to rotate the substrate supports 210 and the substrate 290.

[0043] In some embodiments, the system 200 may include a head cleaning assembly 270 that may be configured to rinse all or a portion of the substrate carrier or carrier head before or after the substrate 290 has been transferred to the load cup 205. For example, water or other rinsing solution may be delivered to a top and / or lateral side of the carrier head via one or more additional spray nozzles.

[0044] FIG. 3 illustrates a schematic partial cross-sectional side elevation view of an exemplary CMP polishing 300 according to some embodiments of the present technology. The system 300 may show a partial view of the components being discussed and may include any of the features described in relation to polishing systems 100 and 200. For example, the system 300 may include a load cup 305, which may be similar to load cups 155 and 205. The system 300 may include a rinse assembly 330, which may be similar to rinse assembly 230. As illustrated, rinse assembly 330 includes multiple spray nozzles 345. For example, a first spray nozzle 345a is positioned at a first vertical height relative to the load cup 305, while a second spray nozzle 345b is positioned at a different, second vertical height relative to the load cup 305. The spray nozzles 345 may be at a same or different angular position relative to the load cup 305. While shown with two spray nozzles 345, it will be appreciated that any number of spray nozzles may be included in various embodiments.

[0045] FIG. 4 illustrates a schematic partial top plan view of an exemplary CMP polishing 400 according to some embodiments of the present technology7. The system 400 may show a partial view of the components being discussed and may include any of the features described in relation to polishing systems 100, 200, and 300. For example, the system 400 may include a load cup 405, which may be similar to load cups 155, 205, and 305. The system 400 mayinclude a rinse assembly 430, which may be similar to rinse assemblies 230 and 330. As illustrated, rinse assembly 430 includes multiple spray nozzles 445. For example, a first spray nozzle 445a is positioned at a first angular position relative to the load cup 405, while a second spray nozzle 445b is positioned at a different, second angular position relative to the load cup 405. The spray nozzles 445 may be at a same or different vertical height relative to the load cup 305. While shown with two spray nozzles 445, it will be appreciated that any number of spray nozzles may be included in various embodiments.

[0046] FIG. 5 shows exemplary operations in a method 500 for rinsing a backside of a substrate according to some embodiments of the present technology. Method 500 may be performed using a CMP polishing system (such as system 100, 200, 300, or 400) that includes a rinse assembly, such as rinse assemblies 230, 330, and 430 described herein. Method 500 may include operations prior to the substrate nnsing in some embodiments. For example, prior to the rinsing, a substrate may have one or more polishing operations performed as well as any deposition, etch, or other process operations performed. Method 500 may include a number of operations that may be performed automatically within a system to limit manual interaction, and to provide increased efficiency and precision over manual operations. Method 500 may be performed as part of or in conjunction with a conventional CMP polishing process.

[0047] Method 500 may include detecting, using one or more sensors, that a substrate is seated atop a plurality' of substrate supports of a chemical mechanical polishing system at operation 505. For example, the sensors may be integrated into one or more components of a load cup of the system. The substrate may be positioned with a backside of the substrate facing upward. At operation 510, a rinse solution may be sprayed onto the backside of the substrate via one or more spray nozzles for a period of time upon detecting that the substrate is seated atop the plurality of substrate supports. The period of time may be a predetermined period of time that is the same for all substrates in some embodiments. In other embodiments, an endpoint for the period of time may be set based on data from one or more sensors, such as optical sensors and / or inductive sensors, that are configured to detect a presence of slurry' on the backside of the substrate.

[0048] In some embodiments, method 500 may include moving the spray nozzle in a vertical direction and / or a honzontal direction while spraying the rinse solution. For example, the spray nozzle may be rotated about one or more axes to sweep the rinse solutionover the surface of the substrate. In some embodiments, the flow rate of the rinse solution may be held constant while spraying the substrate, while in other embodiments the flow rate may be pulsed or otherwise varied while spraying the substrate. In some embodiments, the substrate may be rotated while the rinse assembly is delivered.

[0049] In the preceding description, for the purposes of explanation, numerous details have been set forth in order to provide an understanding of various embodiments of the present technology. It will be apparent to one skilled in the art, however, that certain embodiments may be practiced without some of these details, or with additional details.

[0050] Having disclosed several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present technology. Accordingly, the above description should not be taken as limiting the scope of the technology.

[0051] Where a range of values is provided, it is understood that each interv ening value, to the smallest fraction of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Any narrow er range between any stated values or unstated intervening values in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and low er limits of those smaller ranges may independently be included or excluded in the range, and each range where either, neither, or both limits are included in the smaller ranges is also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

[0052] As used herein and in the appended claims, the singular forms “a’', “an’", and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a heater” includes a plurality of such heaters, and reference to “the protrusion” includes reference to one or more protrusions and equivalents thereof known to those skilled in the art, and so forth.

[0053] Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”, “include(s)”, and “including”, when used in this specification and in the following claims, are intended to specify the presence of stated features, integers, components, or operations, butthey do not preclude the presence or addition of one or more other features, integers, components, operations, acts, or groups.

Claims

WHAT IS CLAIMED IS:

1. A chemical mechanical polishing system, comprising:a plurality of substrate supports;a rinse assembly mounted above the plurality of substrate supports, wherein the rinse assembly comprises:a spray nozzle, wherein the spray nozzle is directed at a downward angle and is configured to deliver a rinse solution to an entire backside of a substrate seated atop the plurality' of substrate supports;a fluid source; anda fluid delivery line that fluidly couples the fluid source with the spray nozzle.

2. The chemical mechanical polishing system of claim 1, further comprising:an electrically conductive member that is positioned to contact a surface of the substrate when the substrate is seated atop the plurality of substrate supports.

3. The chemical mechanical polishing system of claim 2, wherein: the electrically conductive member comprises a sensor that detects a presence of the substrate when the substrate is seated atop the plurality of substrate supports.

4. The chemical mechanical polishing system of claim 1, wherein: the spray nozzle comprises an actuator that is configured to translate the spray nozzle in one or both of a vertical direction and a horizontal direction while delivering the rinse solution.

5. The chemical mechanical polishing system of claim 1, wherein: the downward angle of the spray nozzle is between 0 and 45 degrees relative to horizontal.

6. The chemical mechanical polishing system of claim 1, wherein: an arc of spray produced by the spray nozzle is between 15 and 110 degrees.

7. The chemical mechanical polishing system of claim 1, wherein: a flow rate of the spray nozzle is between 0.5 L / min and 5 L / min.

8. The chemical mechanical polishing system of claim 1, wherein: the rinse solution comprises at least one of deionized water, an acidic solution, a basic solution, or a cleaning chemistry.

9. The chemical mechanical polishing system of claim 1, further comprising:a plurality of alignment pins that are configured to mechanically seat the substrate at a predetermined horizontal and vertical position atop the plurality of substrate supports.

10. The chemical mechanical polishing system of claim 9. wherein: at least one of the plurality of alignment pins has a tapered inner surface that tapers downward toward the predetermined horizontal and vertical position.

11. A chemical mechanical polishing system, comprising:a load cup comprising:a plurality of substrate supports; anda plurality of substrate alignment pins; anda rinse assembly mounted above the plurality of substrate supports, wherein the rinse assembly comprises:a spray nozzle, wherein the spray nozzle is directed at a downward angle and is configured to deliver a rinse solution to an entire backside of a substrate seated atop the plurality of substrate supports;a fluid source; anda fluid delivery line that fluidly couples the fluid source with the spray nozzle.

12. The chemical mechanical polishing system of claim 11, wherein: the spray nozzle is configured to vary a flow rate of the rinse solution while delivering the rinse solution.

13. The chemical mechanical polishing system of claim 11, wherein: the rinse assembly comprises a flow meter regulator that is configured to set a flow rate of the rinse solution delivered by the spray nozzle.

14. The chemical mechanical polishing system of claim 11, wherein:the spray nozzle comprises a first spray nozzle;the rinse assembly further comprises a second spray nozzle; and the first spray nozzle and the second spray nozzle are at different angular positions relative to a central axis of the load cup.

15. The chemical mechanical polishing system of claim 11, further comprising:one or more sensors that are configured to detect a presence of slurry on the backside of the substrate.

16. A method of rinsing a backside of a substrate, comprising: detecting, using one or more sensors, that a substrate is seated atop a plurality of substrate supports of a chemical mechanical polishing system, wherein the substrate is positioned with a backside of the substrate facing upward; andspraying a rinse solution onto the backside of the substrate via a spray nozzle for a period of time upon detecting that the substrate is seated atop the plurality of substrate supports.

17. The method of rinsing a backside of a substrate of claim 16, further comprising:moving the spray nozzle in one or both of a vertical direction and a horizontal direction while spraying the rinse solution.

18. The method of rinsing a backside of a substrate of claim 16, wherein: the period of time comprises a predetermined period of time.

19. The method of rinsing a backside of a substrate of claim 16, further comprising:monitoring a presence of slu - on the backside of the substrate using one or more sensors; andsetting an endpoint for the period of time based on data from the one or more sensors.

20. The method of rinsing a backside of a substrate of claim 16, further comprising:varying a flow rate of the rinse solution while spraying the rinse solution.

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