Apparatus and method for controlling substrate polishing edge uniformity

Abstract

Disclosed herein are methods and apparatus for dispensing a polishing fluid onto a polishing pad in a chemical mechanical polishing (CMP) system. In particular, embodiments of the present disclosure relate to a CMP system having a first fluid supply arm and a second fluid supply arm positioned above the polishing pad to dispense a fluid, such as a polishing fluid or water, and / or provide vacuum pressure. The second fluid supply arm is configured to dispense a fluid or vacuum pressure onto the polishing pad to affect the polishing rate at the edge of the substrate.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure generally relate to chemical mechanical polishing (CMP) systems used in the manufacture of semiconductor devices. Specifically, embodiments herein relate to an apparatus and method for uniformly removing material across a surface of a substrate during CMP processing. [Background technology]

[0002] 2. Description of Related Art Chemical-mechanical polishing (CMP) is commonly used in semiconductor device manufacturing to planarize or polish a material layer deposited on a substrate surface. In a typical CMP process, a substrate is held in a substrate carrier that presses the backside of the substrate against a rotating polishing pad in the presence of a polishing fluid. The polishing fluid generally comprises an aqueous solution of one or more chemical components and abrasive particles suspended in the aqueous solution. Material is removed across the material layer surface of the substrate in contact with the polishing pad by a combination of chemical and mechanical action brought about by the polishing fluid and the relative motion of the substrate and polishing pad.

[0003]

[0003] The polishing liquid is typically dispensed onto the polishing pad from a first arm toward the center of the polishing pad, such that as the polishing pad rotates, the polishing liquid moves toward the outer edge of the polishing pad. The polishing liquid often accumulates near the edge of the substrate beneath the substrate carrier. The accumulation of polishing liquid near the substrate edge results in a non-uniform substrate material removal profile, with increased or decreased removal rates near the edge. Even when the polishing liquid is uniformly distributed beneath the substrate, interactions between the substrate and the substrate carrier's retaining ring can result in non-uniformities near the edge of the substrate during the CMP process.

[0004]

[0004] Therefore, what is needed in the art are articles and related methods that solve the above problems. Summary of the Invention

[0005]

[0005] Embodiments of the present disclosure generally relate to a method of polishing a substrate, comprising: The method includes: pressing a substrate against a surface of a pad of a polishing system using a carrier assembly, the pad having a pad radius and a central axis, the pad radius extending from the central axis; rotating the carrier assembly about an axis of rotation while translating the carrier assembly across the surface of the pad; dispensing a first fluid from a first fluid nozzle onto the pad at a first temperature and a first flow rate, the first fluid being supplied to the pad at a second radial distance measured from the central axis; and dispensing a second fluid from a second fluid nozzle onto the pad at a second flow rate and a second temperature, the second fluid being supplied to the pad at a third radial distance measured from the central axis such that the third radial distance is greater than the second radial distance.

[0006]

[0006] Embodiments of the present disclosure may also include an apparatus for processing a substrate, the apparatus comprising: a pad disposed on a platen, the pad having a pad radius and a central axis, the pad radius extending from the central axis; a carrier assembly configured to be disposed on a surface of the pad, the carrier assembly having a carrier radius extending from a rotation axis of the carrier assembly, the rotation axis being disposed at a first radial distance from the central axis; a first fluid supply arm having a first nozzle configured to provide a first fluid to a first point on the surface of the pad at a second radial distance from the central axis; and a second nozzle configured to provide a second fluid to a second point on the surface of the pad, the second point being disposed at a third radial distance from the central axis, the third radial distance being greater than or equal to the first radial distance and the second radial distance.

[0007]

[0007] So that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above will be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and therefore should not be considered as limiting the scope of the present disclosure, which may also admit of other equally effective embodiments. [Brief explanation of the drawings]

[0008] [Figure 1]

[0008] FIG. 1 is a schematic side view of a polishing system that can be used with the methods provided herein, according to one embodiment. [Figure 2]

[0009] FIG. 1B is a schematic plan view of the polishing system of FIG. 1A, according to one embodiment. [Figure 3A]

[0010] FIG. 3 is a schematic side view of a portion of the polishing system of FIGS. 1 and 2. [Figure 3B]

[0011] 3 is a schematic side view of a portion of the polishing system of FIGS. 1A and 2, according to one embodiment. FIG. [Figure 3C]

[0012] FIG. 3C is a simplified schematic plan view of a portion of the polishing system of FIGS. 3A and 3B. [Figure 4]

[0013] 4 illustrates a method of dispensing one or more fluids within the polishing system of FIGS. 1-3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0014] Appendix A contains additional information relevant to aspects of the disclosure provided herein.

[0010]

[0015] For ease of understanding, where possible, the same reference numerals have been used to designate identical elements that are common to multiple figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011]

[0016]

[0003] Embodiments of the present disclosure generally relate to an apparatus and method for improving planarization uniformity of a chemical mechanical polishing (CMP) process by controlling the supply of a polishing fluid onto a polishing pad in a CMP system and, in some cases, adjusting one or more physical properties or characteristics formed in the polishing pad. In particular, some of the embodiments disclosed herein include a CMP system including a first fluid supply arm disposed above the polishing pad and dispensing a first fluid, such as a polishing fluid or water, and a second fluid supply arm disposed above the polishing pad and dispensing a second fluid, such as a polishing fluid, air, or water, or providing a vacuum to remove a fluid disposed on the polishing pad.

[0012]

[0017] The first fluid supply arm is positioned to supply a polishing liquid to an inner portion of the polishing pad, such that the first fluid supply arm supplies a first fluid (e.g., a first polishing liquid) for polishing the substrate. The second fluid supply arm is positioned to supply one or more second fluids (e.g., a second polishing liquid, an aqueous chemical, a gas, etc.) and / or water, or to provide an exhaust nozzle (e.g., a vacuum) above the polishing pad to remove at least a portion of a fluid disposed on the surface of the polishing pad. The first and second fluid supply arms are positioned to supply polishing liquid and / or water to one or more portions of the polishing pad. In some embodiments, the first fluid supply arm supplies one or more first fluids closer to the center of the polishing pad, while the second fluid supply arm supplies one or more second fluids or creates an exhaust area closer to the outer edge of the polishing pad. The second fluid supply arm can be configured to dispense one or more second fluids or provide a vacuum to a location on the polishing pad radially outward from a location on the polishing pad where one or more first fluids are dispensed from the first fluid supply arm. In some embodiments, the second fluid supply arm is positioned such that one or more second fluids are dispensed or a vacuum is provided on another portion of the polishing pad at a desired location relative to the edge of the substrate while the substrate carrier presses the substrate against the polishing pad. The one or more second fluids or vacuum provided by the second fluid supply arm interact with the one or more first fluids dispensed by the first fluid supply arm as the substrate and polishing pad rotate to provide improved polishing results for processed substrates.

[0013]

[0018] As described further below, the second fluid supply arm can be movable and move in a synchronized pattern with the substrate carrier so as to supply one or more second fluids to the polishing pad or position an exhaust region at a fixed distance from the substrate carrier as the substrate carrier moves relative to the polishing pad and the platen supporting the polishing pad. Alternatively, the second fluid supply arm can be configured to supply one or more second fluids to the polishing pad or position an exhaust region at a desired radius of the polishing pad that coincides with a desired position on the substrate carrier and substrate. In some embodiments, the second fluid supply arm moves or is positioned to accommodate changes in the position of the substrate carrier from the first carrier position to the second carrier position and supplies one or more second fluids to a portion of the polishing pad or positions an exhaust region over a portion of the polishing pad, such that the first fluid dispensed by the nozzle of the first fluid supply arm is altered by the supply of the second fluid or the removal of a portion of the first fluid by vacuum to intersect with the desired portion of the substrate carrier as the platen rotates under the substrate carrier.

[0014]

[0019] It has been found that the results of a CMP process can be controlled by altering the distribution and / or concentration of the polishing liquid disposed between the substrate and the surface of the polishing pad during processing. In some embodiments, planarization uniformity is improved by altering the composition of the polishing liquid near the edge of the substrate when the substrate is at or near the edge of the polishing pad during polishing. A first fluid supply arm is generally used to distribute one or more first fluids across the polishing pad so that the dispensed fluid is disposed under the substrate carrier while the substrate carrier translates across the polishing pad. If polishing liquid accumulates between the retaining ring and the substrate during polishing, the polishing rate near the edge of the substrate can be accelerated or decelerated depending on the type of polishing liquid, the concentration of the polishing liquid, the composition of the polishing liquid, the thickness of the accumulated polishing liquid, the rotation speed of the substrate, and the temperature of the polishing liquid.

[0015]

[0020] The accumulation of polishing liquid near the edge of the substrate can be controlled by supplying fluid from both the first and second fluid supply arms. Because the first fluid supply arm supplies one or more fluids that interact with the entire substrate, it is difficult to control the accumulation of polishing liquid near the edge of the substrate using fluid dispensed from the first fluid supply arm. It has been discovered that utilizing a second fluid supply arm configured to vary the properties of the fluid dispensed on the polishing pad can better control the concentration and amount of one or more polishing liquids near the edge of the substrate. Various embodiments disclosed herein provide additional process parameters that can be used to control the interaction of fluids contacting the substrate during the polishing process. In some embodiments, the process parameters include the ability to control the composition and / or amount of fluid provided near or present at a desired location on the substrate (e.g., the edge of the substrate) without interacting with other portions of the substrate (e.g., the interior or central portions of the substrate). In some embodiments disclosed herein, the edge of the substrate is defined as the outermost 10 mm of the substrate, and therefore the central portion of the substrate is the innermost 140 mm of radius for a 300 mm substrate.

[0016]

[0021] In embodiments in which the liquid dispensed from the second fluid supply arm includes a polishing liquid, the amount of polishing liquid accumulating near the edge and / or other regions of the substrate can be varied, such as by increasing the amount provided or by changing the composition. In embodiments in which the fluid dispensed by the second fluid supply arm is water or a chemical solution (e.g., an acid, base, or additive), the water or chemical solution can alter the polishing liquid at a location on the substrate surface, such as near the edge of the substrate, thereby reducing the composition of the polishing liquid accumulating near the edge and / or other regions of the substrate. Typical polishing liquids used in CMP processes can include an aqueous solution of one or more chemical components and one or more types of abrasive particles suspended in the aqueous solution. Accumulation of polishing liquid near the edge of the substrate during CMP processing, or an increase or decrease in fluid component concentration, such as the concentration of abrasive particles and / or the chemical composition of the polishing liquid, can accelerate or decelerate the removal rate near the edge of the substrate. By dispensing liquid from the second fluid supply arm or evacuating an area of ​​the polishing pad, the polishing rate at the substrate edge can be controlled by controlling the supply of one or more fluids to desired locations relative to the substrate and polishing pad. In addition to the first fluid supplied by the first supply arm, controlling the supply of one or more fluids typically includes controlling the relative position of the supply of one or more fluids with respect to the region of the substrate. In some embodiments, the amount and type of one or more second fluids supplied to the polishing pad by the second fluid supply arm are controlled to achieve more uniform substrate polishing results. In some embodiments, the amount of one or more first fluids passed under one or more regions of the substrate during polishing by removing a portion of the first fluid with a vacuum nozzle is controlled to achieve more uniform substrate polishing results. The amount and type of fluid varies depending on the type of polishing being completed, such as a metal, silicon, oxide, or dielectric polishing process. In some embodiments, a metrology tool can be positioned in the polishing system to measure the thickness of the substrate edge and determine the removal rate. The amount of liquid dispensed or fluid removed by the vacuum nozzle can then be controlled based on the removal rate measured by the metrology tool.

[0017]

[0022] In some embodiments, the polishing pad has polishing control grooves formed in the outer portion of the polishing pad near the edge of the polishing pad. The polishing control grooves can be, for example, 5 millimeters (mm) to 30 millimeters wide. Used in conjunction with the first and second supply arms described above, the polishing control grooves also help control fluid accumulation, fluid component concentrations, and the amount of physical contact between the substrate and the polishing pad near the edge of the substrate during CMP processing, thereby affecting the removal rate near the edge of the substrate. In some embodiments, the polishing control grooves can be located near the periphery of the polishing pad. In some embodiments, a first polishing control groove can be formed near the periphery of the polishing pad, and a second polishing control groove can be formed near the center of the polishing pad. Positioning and holding a substrate over polishing control grooves positioned at the edge and / or center of the polishing pad can help reduce non-uniformity of the polished substrate, especially at the edge of the substrate.

[0018]

[0023] 1 is a schematic side view of a polishing system 100 that can be used with the methods provided herein, according to one embodiment. The polishing system 100 generally comprises a frame (not shown) and a plurality of panels 101 that define a substrate processing environment 103. The polishing system 100 includes a plurality of polishing stations 102 (one shown) and a plurality of substrate carrier assemblies 104 (one shown) that are disposed within the substrate processing environment 103.

[0019]

[0024] 1 , the polishing station 102 includes a platen 106, a polishing pad 105 mounted on and secured to the platen 106, a pad conditioner assembly 110 for cleaning and / or rejuvenating the surface of the polishing pad, a first fluid delivery arm 112 for dispensing one or more first fluids onto the polishing pad 105, a second fluid delivery arm 138 for dispensing one or more second fluids (e.g., a polishing liquid, a chemical solution, and / or water) onto the polishing pad 105, a rotating substrate carrier assembly 104 configured to be positioned over the polishing pad 105, and a controller 160. The controller 160 is connected to each component (e.g., a rotation motor) that controls the movement of the platen 106, the pad conditioner assembly 110, the first fluid delivery arm 112, and the second fluid delivery arm 138. Here, the platen 106 is positioned above a base plate 114 and surrounded by a platen shield 120 (both shown in cross section), which collectively define a drain basin 116. The drain basin 116 is used to collect fluid spun radially outward from the platen 106 and drain the fluid through a drain 118 in fluid communication therewith.

[0020]

[0025] Generally, the rotating substrate carrier assembly 104 is swept back and forth across a desired area of ​​the platen 106 while the platen 106, and therefore the polishing pad 105, rotates about a platen axis B thereunder. In some configurations, the substrate carrier assembly 104 rotates and moves radially relative to the polishing pad 105 and platen 106 so as to move along the radius of the rotating polishing pad 105. In other configurations, the substrate carrier assembly 104 rotates and moves in an arcuate path relative to the center of the CMP polishing system (not shown), and therefore rotates and moves in a non-radial direction across the polishing pad 105 and platen 106. The substrate carrier assembly 104 rotates and moves using a first actuator assembly (not shown) positioned above the carrier head 146. The first actuator assembly is connected by a shaft to the carrier head 146 of the substrate carrier assembly 104, which may include a track or set of tracks (not shown) to enable movement of the carrier head 146 in either a radial or arcuate path across the surface of the pad. A first fluid is supplied to the polishing pad 105 using a first fluid supply arm 112 positioned thereon and is further supplied to the polishing interface between the polishing pad 105 and the substrate 148 by rotation of the polishing pad 105 about the platen axis B. Often, the first fluid supply arm 112 further includes multiple nozzles, including a first supply extension member 136 and a first supply nozzle 134. The multiple nozzles are used to supply one or more first fluids, such as a relatively high-pressure stream of polishing liquid and / or cleaner fluid, e.g., deionized water, to one or more locations along the surface of the polishing pad 105. An example of a first fluid may include, but is not limited to, a polishing solution including one or more surfactants, one or more chelating agents, one or more oxidizing agents, one or more corrosion inhibitors, one or more polar solvents, and deionized water. The composition may also further include one or more pH adjusters and / or abrasive particles.Abrasive particles that can be used in the CMP composition can include, but are not limited to, alumina (Al2O3), silica (SiO2), titania (TiO2), or ceria (CeO2) particles, or other abrasives known in the art and used in conventional CMP compositions.

[0021]

[0026] As shown in the enlarged cross-sectional view of the substrate carrier assembly 104 and the second fluid supply arm 138 in Figure 3A, the substrate carrier assembly 104 includes a carrier head 146, a carrier ring assembly 149 connected to the carrier head 146, and a flexible membrane 150 positioned radially inward of the carrier ring assembly 149 to hold and press the substrate 148 against the polishing pad 105 during processing while the substrate carrier assembly rotates about the carrier axis A.

[0022]

[0027] Returning to FIG. 1 , the second fluid supply arm 138 includes a second actuator 140, a base plate 114, a second supply extension member 142, and a second supply nozzle 144. The second actuator 140 is movable about a second supply arm axis E such that the second supply extension member 142 pivots about the second supply arm axis E. The second supply extension member 142 is coupled to the second actuator 140 at a first distal end of the second supply extension member 142. The second supply nozzle 144 is disposed at the opposite end of the second supply extension member 142 so as to be disposed at the second distal end of the second supply extension member 142. The second supply nozzle 144 is directed downward toward the polishing pad 105. The second delivery nozzle 144 is configured to provide one or more second fluids, such as a polishing liquid, various chemical components, additives, and / or water, onto the polishing pad 105 near the outer edge of the substrate carrier assembly 104. The various chemical components may include, but are not limited to, one or more surfactants, one or more chelating agents, one or more oxidizing agents, one or more corrosion inhibitors, one or more polar solvents, and one or more pH adjusters. In some embodiments, the second delivery nozzle 144 may be one or more of a single-flow distribution nozzle, a spray gun nozzle, a flat fan jet spray nozzle, an atomizing nozzle, or a megasonic nozzle, or a combination thereof.

[0023]

[0028] The metrology unit 165 includes a measurement unit 162 and a window 168 disposed in the polishing pad 105. The measurement unit 162 is configured to measure the thickness of the substrate, including the substrate edge, and determine the removal rate across the substrate and substrate edge during polishing. In some embodiments, the process of dispensing one or more liquids from the second fluid supply arm can then be controlled based on the removal rate measured by the metrology tool. The measurement unit 162 can measure the thickness of the substrate edge by emitting a radiation beam through the window 168 onto the substrate 148 as the substrate passes over it. The radiation beam is then reflected back to the measurement unit 162, and the thickness and / or removal rate at the edge of the substrate 148 is determined. The window 168 is an optically transparent window, such as a clear quartz window or a transparent polymer.

[0024]

[0029] A controller 160 is connected to each of the platen 106, the pad conditioner assembly 110, the metrology unit 165, the first fluid supply arm 112, the second fluid supply arm 138, and the substrate carrier assembly 104. In some aspects of the CMP polishing process, the controller 160 coordinates the rotation of the platen 106 and the distribution of the first fluid, the second fluid, or water onto the polishing pad 105 by either the first or second fluid supply arm 112, 138. In some embodiments, the controller 160 uses measurements from the metrology unit 165 to determine when one or both of the first or second fluids are supplied to the polishing pad 105 or when a vacuum is applied. The controller 160 can also control the movement of the substrate carrier assembly 104 and increase or decrease the amount of pressure exerted on one or more regions of the substrate by the membrane 150 within the substrate carrier assembly 104.

[0025]

[0030] FIG. 2 is a schematic plan view of the polishing system 100 of FIG. 1 according to one embodiment. As described with reference to FIG. 1, the pad conditioner assembly 110, the first fluid supply arm 112, the second fluid supply arm 138, and the substrate carrier assembly 104 are each positioned above the polishing pad 105. In one example, the polishing pad 105 is rotated counterclockwise about the platen axis B ( FIG. 1 ) by a rotary actuator (not shown) coupled to the platen 106. The conditioner mounting plate 130 and the substrate carrier assembly 104 also generally rotate counterclockwise when viewed from above. In the embodiment of FIG. 2, the polishing pad 105, the conditioner mounting plate 130 of the pad conditioner assembly 110, and the substrate carrier assembly 104 each rotate in the same direction. In some embodiments, the polishing pad 105, the platen 106, the conditioner mounting plate 130, and the substrate carrier assembly 104 rotate clockwise. In some embodiments, one or more of the polishing pad 105, platen 106, conditioner mounting plate 130, and substrate carrier assembly 104 rotate in a clockwise direction, while other components rotate in a counterclockwise direction.

[0026]

[0031] In some embodiments, the polishing pad has a radius that is between about 10 inches (254 mm) and about 30 inches (762 mm), e.g., between about 12 inches (305 mm) and about 20 inches (508 mm), e.g., between about 14 inches (356 mm) and about 16 inches (406 mm). In some embodiments, at least a portion of the first fluid supply arm 112 is configured to supply fluid at at least 50% of the pad radius, e.g., greater than at least 60% of the pad radius, e.g., greater than at least 80% of the pad radius. In some embodiments, the first fluid supply arm 112 is configured to supply fluid at about 50% to about 90% of the pad radius, e.g., between about 60% and about 85% of the pad radius. The first fluid supply arm 112 is configured to supply fluid to a position approximately 200 mm to approximately 360 mm inward from the edge of the polishing pad 105, for example, approximately 210 mm to approximately 360 mm inward, for example, approximately 225 mm to approximately 360 mm inward.

[0027]

[0032] The first fluid supply arm 112 is configured to dispense the first fluid over a majority of the polishing pad 105 to distribute the fluid radially inward of the substrate carrier assembly 104, and the first fluid supply arm 112 is configured to provide fluid to the polishing pad such that the dispensed fluid overlaps the entire radial position occupied by the substrate carrier assembly 104 above the polishing pad 105. The first fluid supply arm 112 dispenses the first fluid, such as polishing liquid and / or water, onto the polishing pad 105 at a first radial position. The first radial position is a position radially inward from the innermost edge of the substrate carrier assembly 104 relative to a central axis B of the polishing pad 105.

[0028]

[0033] A second fluid supply arm 138 is also positioned above the polishing pad 105 and, in some configurations, is positioned on the opposite side of the platen 106 from the first fluid supply arm 112. In one embodiment, the second fluid supply arm 138 and the first fluid supply arm 112 are positioned above opposing quadrants or halves (as shown in FIG. 2) of the polishing pad 105. The second fluid supply arm 138 dispenses a second fluid, such as polishing liquid and / or water, onto the polishing pad 105. The second fluid is dispensed onto the polishing pad 105 at a second radial position. The second radial position is a position radially inward from the outermost edge of the edge treatment region 344 (FIGS. 3A-3C) relative to the central axis B (FIG. 1) of the polishing pad 105. The second fluid is mixed with the first fluid to adjust the amount and composition of the polishing fluid near the edge of the substrate 148 when the substrate is positioned in the edge processing region 344 as the carrier head 146 and substrate 148 translate across the polishing pad 105. In some embodiments, the mixture of the first and second fluids increases or decreases the amount or concentration of one or more components of the first fluid over a portion of the substrate 148. In one example, the one or more components of the first fluid that can be adjusted by the addition of the second fluid include the amount and / or concentration of abrasive particles (e.g., silica-based abrasives, ceria-based abrasives, and alumina-based abrasives), water, or other chemical solutions (e.g., acids, bases, inhibitors, etc.) over a portion of the substrate 148, such as the edge of the substrate 148.

[0029]

[0034] The second fluid supply arm 138 is movable about a second supply axis E (FIG. 1). The second fluid supply arm 138 rotates about the second supply axis E to change the position of the second supply nozzle 144 above the polishing pad 105. The second fluid supply arm 138 can move between a first position and a second position. As the substrate carrier assembly 104 moves across the polishing pad, the movement of the second fluid supply arm 138 can be synchronized with the movement of the substrate carrier assembly 104 to maintain a similar radial entry point of the second fluid along the outer periphery of the substrate carrier assembly 104. Alternatively, the second fluid supply arm 138 can be movable relative to the surface of the polishing pad, allowing the radial entry point along the outer periphery of the substrate carrier assembly 104 to be adjusted throughout the process. In some embodiments, it is contemplated that the second fluid supply arm 138 may have the ability to rotate through one or more angles about the second supply axis E, such that the second fluid supply arm 138 can rotate from about 5 to about 180 degrees about the second supply axis E.

[0030]

[0035] 1 and 2. FIG. 3A is a schematic side view of a portion of the polishing system 100 of FIGS. 1 and 2. More specifically, FIG. 3A shows a close-up side view of the substrate carrier assembly 104 and the second fluid delivery arm 138. The carrier head 146, carrier ring assembly 149, flexible membrane 150, polishing pad 105, platen 106, and substrate 148 are as described above. The substrate 148 is shown pressed against the polishing pad 105 by the flexible membrane 150. The flexible membrane 150 typically applies an adjustable amount of pressure across different concentric regions of the substrate 148 during polishing to improve planarization of the substrate surface. The flexible membrane 150 is coupled to the substrate carrier assembly by a membrane clamp (not shown).

[0031]

[0036] In some embodiments, a temperature control unit 304 and a fluid source 302 are fluidly connected to the second fluid supply arm 138. The temperature control unit 304 and the fluid source 302 are connected to and controlled by the controller 160. The fluid source 302 supplies one or more second fluids to the second fluid supply arm 138, which are dispensed onto the polishing pad 105. The fluid source 302 includes one or more fluid sources configured to provide one or more second fluids, such as a polishing liquid, a chemical solution, and / or water. Each of the one or more second fluid sources provided by the fluid source 302 is configured to provide the respective fluid at a desired flow rate and pressure. The polishing fluid source may provide one or more fluids, including a chemical solution (e.g., an acid, a base, an inhibitor, etc.) and / or a slurry-containing solution (e.g., a solution containing abrasive particles (e.g., silica, ceria, or alumina-based abrasives)) used in substrate polishing. The second fluid may also include a polishing rate enhancer, such as HO. The water source may be a deionized water source. The fluid may also be a polishing rate inhibitor, such as benzotriazole (BTA). The fluid source may be a typical post-CMP cleaning agent, such as PlanarClean® or PL6502. The fluid source 302 may include a pump or multiple pumps (one for each fluid).

[0032]

[0037] The fluid source 302 is fluidly connected to the temperature control unit 304 by a first conduit 306. In some embodiments, the temperature control unit 304 is integrated into the fluid source 302, and the first conduit 306 can be eliminated. The temperature control unit 304 controls the temperature of the fluid supplied to the second fluid supply arm 138 and the second supply nozzle 144 via a second conduit 308. The temperature control unit 304 can include a resistive heating element disposed therein for heating the fluid. The temperature control unit 304 can also include cooling channels disposed therein for cooling the fluid or for cooling the heating element. The temperature control unit 304 can heat or cool the fluid to a temperature suitable for enhancing or inhibiting the CMP polishing process. By controlling the temperature of the fluid supplied to a first region (e.g., the edge region) of the substrate during the polishing process, along with other CMP process control variables described herein (e.g., fluid volume, fluid component concentration, applied pressure, etc.), it is believed that the chemical activity of the abrasive particles and / or their interaction with the substrate surface can be adjusted to tailor the removal rate in the first region of the substrate relative to other regions of the substrate. In one example, the temperature of one or more second fluids supplied to the edge region of the polishing pad, and thus to a portion of the substrate disposed in the edge region during a portion of the polishing process, is controlled to a temperature lower than the temperature of the first fluid and the polishing pad surface during the polishing process to reduce the chemical activity of the combined fluid in contact with the edge region and, in some cases, to alter the properties of the polishing pad material in the edge region. The temperature control unit 304 is located outside the second fluid supply arm 138 to reduce the volume occupied by the second fluid supply arm 138 and reduce the effect of heating or cooling on the volume surrounding the second fluid supply arm 138.

[0033]

[0038] The second supply nozzle 144 can include multiple nozzles, such as a first nozzle 310 a, a second nozzle 310 b, and a third nozzle 310 c. The first, second, and third nozzles 310 a, 310 b, and 310 c are disposed along a bottom surface 348 of the second supply extension member 142, such as the bottom surface of the second supply extension member 142. The first, second, and third nozzles 310 a, 310 b, and 310 c can be angled to eject fluid supplied through the first, second, and third nozzles 310 a, 310 b, and 310 c in a direction other than a vertical direction (Z direction) perpendicular to the top surface 350 of the polishing pad 105. For example, the nozzle or nozzles can be positioned 25 mm to 75 mm from the edge of the polishing pad 105 and angled relative to the top surface 350 of the polishing pad 105 to direct fluid toward the pad edge to avoid spraying fluid toward a central region of the pad 105 during processing. While shown in FIG. 3A as being arranged along multiple radial positions, the nozzles can be arranged at the same radial distance along the second supply extension member 142 from the second supply axis E such that each of the first, second, and third nozzles 310 a, 310 b, 310 c ejects fluid at a similar radial position on the polishing pad 105. While three nozzles are shown herein as the second supply nozzle 144, it is contemplated that other quantities of nozzles, such as one nozzle, two nozzles, four nozzles, five nozzles, or six nozzles, can be utilized to provide one or more different fluids to the surface of the polishing pad 105.

[0034]

[0039] The second delivery nozzle 144 can be one or more of any number of nozzle types, including, but not limited to, a single-flow distribution nozzle, a spray gun jet nozzle, a flat fan jet spray nozzle, an atomizing nozzle, or a megasonic nozzle. In one embodiment, the second delivery nozzle 144 includes a distribution nozzle with a distribution hole size of 0.5 mm to 5.0 mm, capable of achieving a second fluid flow rate of up to 1 liter per minute. In one embodiment in which one or more spray gun jet nozzles are used, the fluid used is a mixture of deionized water and nitrogen, where the deionized water is supplied at a flow rate of 0.1 to 1 liter per minute and the nitrogen is supplied at a flow rate of 10 to 300 slm. Optionally, a cleaning agent, such as PlanarClean® and / or PL6502, is dispensed from the spray gun jet nozzle. The second fluid can be dispensed at a temperature between 0°C and 95°C, e.g., between 1°C and 90°C, or between 18°C ​​and 60°C. In one embodiment, where one or more flat fan jet spray nozzles are used to inject the fluid in a flat fan spray pattern, the flat fan spray angle is between 25 degrees and 180 degrees. In one embodiment, where one or more spray nozzles are used, the fluid used is a mixture of deionized water and nitrogen.

[0035]

[0040] In one embodiment, the fluid provided from the second supply arm includes a supply of fluid from a megasonic nozzle. The megasonic nozzle includes one or more elements, such as a megasonic actuator, configured to apply megasonic energy in the form of waves in an alternating current according to a sinusoidal or other pattern into the provided second fluid to generate a megasonic working fluid. The second fluid can be supplied from a first fluid source 302 adapted to supply deionized water and / or a cleaning solution (i.e., an acid or base solution) at a rate of up to 5 liters per minute and at a temperature of 20-60°C. The megasonic nozzle can be configured to apply megasonic energy in an alternating current in a sinusoidal pattern at a rate of approximately 100 kHz to 5 MHz, e.g., 950 kHz, to generate the megasonic working fluid provided to the upper surface 350 of the polishing pad 105. The megasonic nozzle can be configured to supply megasonic energy at multiple frequencies, e.g., at least two different frequencies. It is believed that supplying megasonic energy to a fluid in contact with and / or present on the surface of the polishing pad can be useful for removing abrasive particles bonded to or present on the surface of the polishing pad. Thus, supplying megasonic energy can be used to change the composition (e.g., the amount of abrasive particles) of the fluid positioned on the surface of the polishing pad. In some CMP process sequences, one or more second fluids can include cleaning chemicals, such as PlanarClean® and / or PL6502, which are used before, during, or after the polishing process as a rinse agent to remove abrasive particles embedded in, bonded to, or present on the surface of the polishing pad.

[0036]

[0041] The separation distance 318 between the bottoms of the first, second, and third nozzles 310a, 310b, and 310c and the upper surface 350 of the polishing pad 105 is about 5 mm to about 120 mm, for example, about 10 mm to about 100 mm, for example, about 10 mm to about 50 mm. The separation distance 320 between the bottom surface 348 of the second supply extension member 142 and the upper surface 350 of the polishing pad 105 is about 10 mm to about 160 mm, for example, about 10 mm to about 150 mm, for example, about 10 mm to about 100 mm, for example, about 10 mm to about 50 mm. The separation distance 320 is about 10 mm larger to avoid the fluid meniscus on the pad contacting the second supply extension member 142.

[0037]

[0042] In one embodiment, each of the first, second, and third nozzles 310a, 310b, and 310c is configured to dispense a different type of second fluid, each having a different composition. In another embodiment, the first, second, and third nozzles 310a, 310b, and 310c are configured to dispense both a first fluid composition and a second fluid composition, such as a polishing liquid, a chemical solution, and water, simultaneously or sequentially in a timed sequence. In one embodiment, the first nozzle 310a is configured to dispense a polishing liquid, and the second and third nozzles 310b and 310c are configured to dispense water. In one embodiment, the first nozzle 310a is configured to dispense a polishing liquid, and the second and third nozzles 310b and 310c are configured to dispense water, with each nozzle providing water at a different temperature and / or flow rate. In one embodiment, the first nozzle 310a is configured to dispense water, and the second and third nozzles 310b and 310c are configured to dispense a polishing liquid. In one example, the first nozzle 310a is configured to dispense water, and the second and third nozzles 310b, 310c are configured to dispense a different polishing liquid from each nozzle at the same or different temperatures and / or flow rates. In some embodiments, there are multiple types of polishing liquids, and each of the polishing liquids can be dispensed from a different nozzle at a desired temperature and flow rate.

[0038]

[0043] The water, chemical solution, and polishing liquid can be dispensed simultaneously or separately. In one embodiment, water is dispensed from the first nozzle 310a while the second and third nozzles 310b, 310c simultaneously dispense the polishing liquid. In one embodiment, the polishing liquid is dispensed from the first nozzle 310a, and the second and third nozzles 310b, 310c simultaneously dispense water. Alternatively, the polishing liquid and water are dispensed at different times. In yet another embodiment, the water and polishing liquid are mixed before reaching the first, second, and third nozzles 310a, 310b, 310c to change the concentration of the polishing liquid before dispensing onto the polishing pad 105. In embodiments in which the water and polishing liquid are pre-mixed, the water and polishing liquid can be mixed either in the fluid source 302, the temperature control unit 304, or within the conduits 306, 308, 312.

[0039]

[0044] The second supply nozzle 144 supplies fluid to the upper surface 350 of the polishing pad 105 in an edge treatment region 344 that is located a distance from the center of the polishing pad 105 to the outer periphery of the polishing pad 105. The edge treatment region 344 in some embodiments can be configured to be anywhere along the radius of the polishing pad 105, while in other embodiments it is located between the carrier axis A and the outer edge of the substrate carrier assembly 104. In one embodiment, the edge treatment region 344 includes polishing control grooves 108.

[0040]

[0045] In some embodiments, the polishing rate within a region of the substrate can be further varied and controlled by controlling the timing, flow rate, and / or pressure of the fluid provided to the surface of the polishing pad. It has been found in some CMP processes that the polishing rate at the edge of the substrate can be varied by positioning the supply of the second fluid in a desired region of the polishing pad (e.g., the edge polishing region 344) and then adjusting the timing and duration of the supply of the second fluid. For example, the flow of the second fluid can be pulsed on and off for a desired duration during processing. In some embodiments, the flow of the second fluid need not be continuous during CMP polishing. In one example, the supply of the second fluid can be controlled based on a specific event within the CMP polishing process, such as when a specific layer of material on the substrate is exposed during the CMP polishing process, or based on in-situ metrology sensor feedback. In some embodiments, the flow of the second fluid can be pulsed, for example, on for 1 second and off for 1 second. The timing of the pulses and the on / off time ratio can be adjusted.

[0041]

[0046] 3A and 3C, in one embodiment, the polishing pad 105 has at least one polishing control groove 108 formed in the polishing surface 350. Each polishing control groove 108 is a recessed area of ​​the polishing pad 105. Each polishing control groove 108 may be, for example, a circular annular groove and may be concentric with the axis of rotation B of the platen 106. Each polishing control groove 108 provides an area within the edge treatment region 344 of the polishing pad 105 that does not contribute to polishing.

[0042]

[0047] The walls of the abrasive control grooves 108 are perpendicular to the abrasive surface 350. The bottom of the abrasive control grooves 108 is parallel to the abrasive surface 350, although in some embodiments, the bottom of the abrasive control grooves 108 can be angled relative to the abrasive surface 350. The bottom of the abrasive control grooves 108 can have a rectangular or U-shaped cross section. The abrasive control grooves 108 can be 10 to 80 mils deep, for example, 10 to 60 mils deep.

[0043]

[0048] In some embodiments, the pad 105 includes polishing control grooves 108 located near the outer edge of the polishing pad 105, e.g., within 15%, e.g., 10% (radially) of the outer edge. For example, the grooves 108 may be located at a radial distance R1 of 14 inches from the center of a platen having a 30-inch diameter. The polishing control grooves 108 are wide enough that positioning a portion of the substrate 148 over the groove significantly reduces the polishing rate of that portion, resulting in a more uniformly polished substrate. In particular, for edge compensation, the grooves 108 are wide enough so that an annular band at the edge of the substrate, e.g., a band at least 3 mm wide, e.g., a band 3 to 15 mm wide, e.g., a band 3 to 10 mm wide, has a reduced polishing rate. The polishing control grooves 108 may have a width of 3 to 50 mm, e.g., 5 to 50 mm, e.g., 3 to 10 mm, e.g., 10 to 20 mm.

[0044]

[0049] Figure 3B is a schematic side view of one embodiment of a portion of the polishing system 100 shown in Figure 3A. More specifically, Figure 3B shows a close-up side view of the substrate carrier assembly 104 and second fluid supply arm 138 shown in Figure 3A, but Figure 3B shows a vacuum nozzle 314 attached to the end of the second fluid supply arm 138 instead of, or in addition to, one or more of the fluid supply nozzles 310a-310c. A vacuum source 316 is connected to the vacuum nozzle 314 through the second fluid supply arm 138 to provide a vacuum along the edge processing region 344 to remove and control the volume of slurry disposed along the edge of the substrate during processing. The reduced slurry volume in the edge processing region 344 (Figures 3A-3C) can be used to reduce the polishing rate of a portion of the substrate when that portion is disposed within the edge processing region 344. Therefore, adjusting the amount of slurry positioned in the edge treatment region 344 is used to provide more uniform polishing results across the substrate by reducing the typically high polishing rate generated at the edge of the substrate. The suction flow rate and / or vacuum pressure generated by the vacuum source 316 are controlled using the controller 160. In some embodiments, the vacuum nozzle 314 is positioned 1 to 5 mm above the top surface of the substrate. In one embodiment, the vacuum nozzle 314 is provided with fluid supply nozzles 310a-310c. In one embodiment, the vacuum nozzle 314 includes multiple vacuum nozzles, such as 2 to 6 vacuum nozzles. In one embodiment, the polishing control groove 108 is positioned in the edge treatment region 344 of the polishing pad 105, and the vacuum nozzle 314 is positioned to remove fluid from the polishing control groove 108 during processing.

[0045]

[0050] 3C is a simplified schematic plan view of a portion of the polishing system 100 of FIG. 3A. The polishing pad 105 is shown, simplified by not showing the pad conditioner assembly 110 (FIG. 2). The polishing pad 105 exhibits optional polishing control grooves 108 in the edge treatment region 344. A first fluid supply arm 112 dispenses fluid to a first point 354 on the polishing pad 105 such that a first fluid provided from the first fluid supply arm 112 covers a central portion of the polishing pad 105 and traverses the edge treatment region 344 of the polishing pad 105 as the pad rotates. As described above, a second fluid supply arm 138 dispenses one or more second fluids to and / or removes material from a second point 358 located near the inner edge of the edge treatment region 344 of the polishing pad. As indicated by the arrow pointing from the second point 358, fluid dispensed from the second fluid supply arm is directed toward the edge treatment region 344 to adjust the properties of the fluid(s) positioned within the edge treatment region 344. During processing, as the substrate 148 moves to a position where the substrate edge portion 148a is positioned within the edge treatment region 344, the polishing rate of the substrate edge portion 148a is reduced compared to the polishing rate of the substrate center portion 148b, improving polishing uniformity across the substrate.

[0046]

[0051] In one embodiment, the nozzles described above as relating to supplying fluid or vacuum from the second fluid supply arm 138 are not integrated into the second fluid supply arm 138, but instead are integrated into the first fluid supply arm 112 to achieve the same result.

[0047]

[0052] 4 illustrates a method 400 for dispensing polishing fluid from the polishing system 100 of FIGS. 1-3. Method 400 includes a first step 402, a second step 404, and a third step 406. Although shown in sequential order herein, the steps in method 400 may be performed in an alternate order, may be performed simultaneously, and / or may include additional steps.

[0048]

[0053] A first step 402 involves initiating polishing of a substrate, such as substrate 148, and dispensing a first fluid from a first fluid delivery arm, such as first fluid delivery arm 112 disclosed in FIGS. 1 and 2. The first fluid is provided to the surface of the polishing pad at a first flow rate and a first temperature. The substrate is held by substrate carrier assembly 104 and pressed against a polishing pad, such as polishing pad 105 disclosed herein. In this example, the polishing pad is rotated in a counterclockwise direction. The substrate carrier assembly 104 may also rotate in a counterclockwise direction while oscillating along the radius of the polishing pad. The first fluid is dispensed from one or more nozzles along the first fluid delivery arm at a radius of the polishing pad, typically within the inner 50% of the radius of the polishing pad.

[0049]

[0054] The first fluid is a polishing liquid for polishing the substrate. The polishing liquid may include a mixture containing a slurry and / or a chemical solution and may include particles suspended therein to aid in substrate polishing. The first fluid is supplied within the inner half of the radius of the polishing pad and flows along a first flow path. In some embodiments, the first fluid is distributed to a location on the polishing pad radially inward of the substrate carrier assembly at one or more moments in time relative to the central axis B of the polishing pad. In some embodiments, the first fluid is supplied at a location such that the first fluid interacts with the entire substrate surface as it moves outward along the rotating polishing pad. The first fluid moves outward along the polishing pad due to the rotation of the polishing pad and the centrifugal force imparted to the first fluid by the rotation of the pad. As the fluid moves outward along the polishing pad, the first fluid can be said to move downstream, such that the first fluid is supplied at an upstream location and flows downstream and radially outward from the center of the polishing pad toward the edge of the polishing pad.

[0050]

[0055] The substrate carrier assembly holds a substrate thereunder and includes a substrate retaining ring thereunder. In some processes, the substrate retaining ring helps prevent the substrate from slipping out from under the substrate carrier assembly. Therefore, the substrate retaining ring may contact the edge of the substrate, potentially resulting in uneven removal rates along the edge of the substrate during the polishing process. Accumulation of a first fluid may occur in one or more regions of the substrate surface and the substrate retaining ring. The accumulation of the first fluid also affects the removal rate in one or more regions of the substrate surface, such as near the edge of the substrate. Accumulation of polishing fluid in different regions of the substrate surface may result in either an increase or decrease in the removal rate near the edge of the substrate. In one exemplary embodiment, the decrease in removal rate may occur due to the creation of a barrier layer between the affected substrate region (e.g., the substrate edge) and the polishing pad. In yet another exemplary embodiment, the accumulation of polishing fluid may increase the removal rate by exposing the substrate to a greater amount of abrasive. The opposite may also be true: reducing the buildup of polishing fluid near the edge of the substrate may increase or decrease the removal rate, depending on the application and the polishing fluid used. Thus, a second fluid, such as deionized water or additional polishing fluid, may be dispensed onto the polishing pad and configured to interact with the first fluid near the edge of the substrate. The second fluid may change the composition of the fluid provided to the edge of the substrate and / or thin or thicken the buildup of polishing fluid near the edge of the substrate.

[0051]

[0056] During processing, the carrier assembly is translated across the surface of the pad while rotating the carrier assembly about the carrier axis, causing a first radial distance measured from the central axis to the axis of rotation to vary between a first radial value and a second radial value as the carrier assembly is translated across the surface of the pad.

[0052]

[0057] A pad conditioner assembly, such as pad conditioner assembly 110, may be used during first step 402 to clean or rejuvenate the polishing pad. The pad conditioner assembly rotates counterclockwise along with the substrate carrier assembly and polishing pad. The pad conditioner assembly is positioned above the polishing pad and physically contacts the polishing pad as the pad conditioner assembly moves across the polishing pad.

[0053]

[0058] The second step 404 is generally performed after the first step 402, but in some embodiments, it can be performed first or simultaneously with the first step 402. The second step 404 includes dispensing one or more second fluids from a second fluid supply arm, such as the second fluid supply arm 138. The one or more second fluids are provided to the surface of the polishing pad at a second flow rate and a second temperature. The second fluids can be different from the first fluid provided by the first supply arm. The first and second flow rates and the first and second temperatures of the first and second fluids can be the same or different. The second fluid is dispensed onto the polishing pad at a location that intersects with the desired portion of the substrate, for example, about 140 mm, e.g., about 150 mm, from the central axis B of the polishing pad. In some embodiments, the second fluid is dispensed to an edge treatment region 344, which is an outer area of ​​the polishing pad, such that the second fluid is delivered to a portion of the substrate through the polishing pad that is at least greater than 50% of the radius of the polishing pad from the central axis B of the polishing pad, e.g., greater than about 75% of the radius of the polishing pad from the central axis B of the polishing pad, e.g., greater than about 80% of the radius of the polishing pad from the central axis B of the polishing pad, e.g., about 80% to about 95% of the radius of the polishing pad from the central axis B of the polishing pad, e.g., about 90% to about 95% of the radius of the polishing pad from the central axis B of the polishing pad. The second fluid is dispensed from one or more nozzles along the second fluid delivery arm, as described above, and impinges on the polishing pad along the edge treatment region 344. The second fluid flows along a second flow path. The starting point of the second flow path is outward from the starting point of the first flow path, such that the second flow path is dispensed outside the point at which the first fluid is dispensed relative to the central axis B. The second fluid modifies the composition of the first fluid to reduce the polishing rate in the edge polishing region.

[0054]

[0059] The mixture of the first and second fluids can modify the properties of the fluid near the edge of the substrate. The second fluid can be either a polishing liquid, a chemical solution, or water. As described above, the polishing liquid can include a chemical solution and / or a slurry. In some embodiments, the polishing liquid is dispensed from the second fluid supply arm as the second fluid to increase the amount of polishing liquid near the edge of the substrate. In some embodiments, water is dispensed from the second fluid supply arm as the second fluid to adjust one or more properties of the first fluid provided from the first supply arm. In some cases, the second fluid, including water, is provided to reduce the amount of polishing liquid near the edge of the substrate, control the temperature and / or concentration of the combined first and second fluids, and / or thin polishing liquid that may have accumulated near the edge of the substrate.

[0055]

[0060] In some embodiments, both the substrate carrier assembly and the second fluid supply arm are movable and move during the second step 404. The substrate carrier assembly moves along the top surface of the polishing pad to move the substrate to different positions along the polishing pad. The second fluid supply arm can be controlled to follow the movement of the substrate carrier assembly while it is moving. The second fluid supply arm can follow the substrate carrier assembly by moving with the substrate carrier assembly.

[0056]

[0061] In some embodiments, the second fluid supply arm is configured to move such that the radial location where fluid is dispensed from the second fluid supply arm intersects the substrate carrier assembly at the same location, such that as the substrate carrier assembly moves, the dispensed fluid intersects the substrate at the same radial location on the substrate. In this embodiment, the second fluid supply arm always dispenses the second fluid from the center of the substrate carrier assembly to a similar radius of the substrate carrier assembly. This tracking can include swinging the second fluid supply arm about axis E to extend further over the polishing pad or to reduce the amount of extension over the polishing pad.

[0057]

[0062] In some embodiments, the second fluid supply arm is configured to move such that the flow path created by the supply of fluid from the second fluid supply arm always intersects the substrate carrier assembly at the same relative position on the substrate carrier assembly. In this embodiment, rotation of the second fluid supply arm about axis E is controlled such that the end of the flow path of fluid from the second fluid supply arm consistently intersects the substrate carrier assembly at a similar radial and angular position relative to the carrier axis A.

[0058]

[0063] The type of second fluid dispensed by the first and second fluid dispense arms depends on the material being polished from the substrate. In embodiments in which oxides are polished by the polishing system, the temperature of the second fluid can be controlled by a temperature control unit, such as temperature control unit 304.

[0059]

[0064] The second step 404 may include simultaneous dispensing of the first fluid, or the dispensing of the first fluid may be stopped during the second step 404. Rotation of the polishing pad and substrate carrier assembly is maintained even when the dispensing of the first fluid is stopped. In some embodiments, the rotational speed of the polishing pad and / or substrate carrier assembly is decreased or increased during the second step, but rotation continues without stopping the polishing pad or substrate carrier assembly.

[0060]

[0065] A metrology unit, such as metrology unit 165, can measure the thickness of the substrate to estimate the removal rate caused by polishing. The metrology unit is connected to a controller, which can determine the appropriate amount of second fluid and the temperature of the second fluid to be utilized, if a second fluid is used, so that the controller determines the dispense rate from the second fluid supply arm based on the measured thickness of the substrate. In some embodiments, the temperature of the second fluid is increased to increase the polishing rate at the edge of the substrate. In other embodiments, the temperature of the second fluid is decreased to decrease the polishing rate at the edge of the substrate. The metrology unit can be an inductive metrology unit (e.g., eddy current) or a spectral metrology unit (e.g., optical metrology).

[0061]

[0066] In some processes, a metering unit is not utilized, and instead the second fluid is dispensed in a timed sequence such that the second fluid is dispensed at set intervals during the polishing process. In some embodiments, the second fluid is dispensed continuously, but the flow rate and / or temperature of the second fluid is adjusted over time.

[0062]

[0067] The third step 406 includes stopping polishing of the substrate and the dispensing of the first and second fluids. The third step 406 is performed after each of the first and second steps 402, 404 is completed. The polishing of the substrate and the dispensing of the first and second fluids are stopped when the polishing step being performed on the substrate is completed. As mentioned above, in some embodiments, the second fluid supply arm 138 supplies fluid to the polishing pad to remove fluid from the pad surface using a vacuum and / or to control the composition of the polishing fluid to control the polishing rate at the edge of the substrate.

[0063]

[0068] In some embodiments, the third step includes applying a cleaning chemical, such as, for example, PlanarClean® and / or PL6502, for a desired period of time to remove abrasive particles embedded, bonded, or present within the surface of the polishing pad in the edge region. In some embodiments, the third step may include applying megasonic energy to the fluid or cleaning chemical to remove abrasive particles embedded, bonded, or present within the surface of the polishing pad.

[0064]

[0069]

[0003] Embodiments disclosed herein relate to a second fluid supply arm configured to supply a second fluid to a polishing pad in a CMP system. The second fluid supply arm differs from the first fluid supply arm in that the second fluid supply arm is configured to distribute fluid to the edge of a substrate while significantly reducing the impact on the amount of polishing fluid near the center of the substrate. In some embodiments, the fluid supplied by the second fluid supply arm significantly affects the polishing rate only in the outermost 10 mm of the substrate. For example, for a 300 mm diameter substrate, the polishing rate in the outermost 10 mm of the substrate is affected, while the polishing rate in the innermost 140 mm is substantially unchanged.

[0065]

[0070] The processes used in the above disclosure may vary depending on the type of polishing process. Some polishing processes may utilize a temperature control unit and a metering unit, while other processes may not utilize a temperature control unit or a metering unit. Similarly, some polishing processes may utilize an automated dispensing process based on previous experimental results and may not utilize a metering unit. When the polishing process described herein relates to an oxide polishing process, a temperature control unit and a metering unit may be utilized. When the polishing process described herein relates to a metal polishing process, the process may be automated and the controller may dispense the second fluid at predetermined intervals without the use of a metering unit. As described above, while temperature control units and metering units are primarily utilized during oxide polishing processes, it is contemplated that temperature control units and metering units may also be utilized in metal processes, such as tungsten polishing processes.

[0066]

[0071] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

Claims

1. 1. An apparatus for processing a substrate, comprising: a pad disposed on a platen, the pad having a pad radius and a central axis, the pad radius extending from the central axis; a carrier assembly configured to be disposed on a surface of the pad, the carrier assembly having a carrier radius extending from a rotational axis of the carrier assembly, the rotational axis being disposed a first radial distance from the central axis; a first fluid delivery arm having a first nozzle configured to provide a first fluid to a first point on a surface of the pad at a second radial distance from the central axis; a second nozzle configured to provide a second fluid to a second point on the surface of the pad, the second point being located at a third radial distance from the central axis, the third radial distance being greater than or equal to the first radial distance and the second radial distance; An apparatus comprising:

2. The apparatus of claim 1 , wherein the second nozzle is positioned on a second fluid delivery arm positionable over a portion of the surface of the pad.

3. The apparatus of claim 1 , wherein the second nozzle is positioned on the first fluid delivery arm.

4. 1. An apparatus for processing a substrate, comprising: A platen, a pad disposed on the platen, the pad having a pad radius extending from a central axis; a carrier assembly disposed on the pad, the carrier assembly having a carrier radius extending from an axis of rotation of the carrier assembly; a first fluid delivery arm configured to provide a first fluid to a first point on the pad; a second fluid supply arm configured to provide a second fluid to a second point on the pad, the second point being located at a radial distance from the central axis, the radial distance being greater than about 75% of the pad radius; and An apparatus comprising:

5. 1. A method of polishing a substrate, comprising: pressing the substrate against a surface of a pad of a polishing system using a carrier assembly, the pad having a pad radius and a central axis, the pad radius extending from the central axis; rotating the carrier assembly about an axis of rotation while translating the carrier assembly across the surface of the pad; dispensing a first fluid from a first fluid nozzle onto the pad at a first flow rate, the first fluid being supplied to the pad at a second radial distance measured from the central axis; dispensing a second fluid from a second fluid nozzle onto the pad at a second flow rate, the second fluid being supplied to the pad at a third radial distance measured from the central axis such that the third radial distance is greater than the second radial distance; A method comprising:

6. The method of claim 5 , wherein the first fluid and the second fluid are different.

7. The method of claim 5 , wherein the flow rates of the first fluid and the second fluid are different.

8. 6. The method of claim 5, wherein the first fluid is at a first temperature and the second fluid is at a second temperature, the temperatures being controlled by a temperature control unit to adjust the polishing rate.

9. The method of claim 8 , wherein the first fluid and the second fluid have different temperatures.

10. 6. The method of claim 5, wherein the second fluid is dispensed onto the pad at a radial location outward from an innermost edge of the carrier assembly relative to the central axis of the pad, but inward from an outermost edge of the carrier assembly relative to the central axis of the pad.

11. 6. The method of claim 5, wherein the carrier assembly and the second fluid nozzle are both movable and track each other so that the fluid dispensed from the second fluid supply nozzle intersects the same portion of the carrier assembly as the carrier assembly translates across the surface of the pad.

12. 6. The method of claim 5, wherein the pad has abrasion control grooves, the abrasion control grooves having a depth of about 10 mils to about 80 mils and a width of about 3 to 50 millimeters.

13. The method of claim 12 , wherein the polishing control grooves are positioned near an outer edge of the pad.

14. The method of claim 13 , wherein the polishing control grooves are positioned within 15% of the outer edge of the pad in radius.

15. The method of claim 5 , further comprising providing vacuum pressure from a vacuum nozzle, the vacuum nozzle being positioned approximately 1 to 5 millimeters above the top surface of the substrate.

16. The method of claim 15 , wherein applying vacuum pressure along the edge of the substrate removes fluid from the edge of the substrate.

17. The method of claim 12 , further comprising applying a vacuum pressure along an edge of the substrate to remove fluid from the polishing control grooves.

18. The method of claim 5 , wherein the second fluid is provided through a plurality of nozzles having at least a first and a second nozzle.

19. 20. The method of claim 18, wherein the plurality of nozzles are angled to eject the second fluid at an angle relative to the top surface of the pad that is not perpendicular to the pad.

20. 20. The method of claim 19, wherein the plurality of nozzles are further angled to eject the second fluid toward the pad edge and to avoid spraying the second fluid toward the center of the pad.

Images