Apparatus and method for CMP temperature control

Abstract

To provide an apparatus and a method related to chemical mechanical polishing (CMP), more specifically related to temperature control during chemical mechanical polishing.SOLUTION: A polishing system 20 includes: a rotatable platen 24 to hold a polishing pad 30; a carrier head 70 to hold a substrate 10 against a polishing surface of the polishing pad 30 during a polishing process; and a temperature control system 100 including a source of heated or coolant fluid and a plenum having a plurality of openings 120 positioned over the platen 24 and separated from the polishing pad 30 for delivering the fluid onto the polishing pad 30. In the temperature control system 100, at least some of the openings 120 are each configured to deliver a different amount of the fluid onto the polishing pad 30.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to chemical mechanical polishing (CMP), and more particularly to temperature control during chemical mechanical polishing. [Background technology]

[0002] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductive, or insulating layers on a semiconductor wafer. Various manufacturing processes require planarization of layers on the substrate. For example, one manufacturing step involves depositing a filler layer over a non-planar surface and then planarizing the filler layer. For certain applications, the filler layer is planarized until the top surface of a patterned layer is exposed. For example, a metal layer can be deposited on a patterned insulating layer to fill the trenches and holes in the insulating layer. After planarization, the remaining metal within the trenches and holes in the patterned layer forms vias, plugs, and lines that provide conductive paths between thin-film circuits on the substrate. As another example, a dielectric layer can be deposited on a patterned conductive layer and then planarized to allow for subsequent photolithography steps.

[0003] Chemical mechanical polishing (CMP) is one accepted planarization method. This planarization method typically requires the substrate to be mounted on a carrier 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, pressing it against the polishing pad. A polishing slurry containing abrasive particles is typically supplied to the surface of the polishing pad. Summary of the Invention

[0004] The chemical mechanical polishing apparatus includes a rotatable platen that holds a polishing pad, a carrier that holds a substrate against the polishing surface of the polishing pad during the polishing process, and a temperature control system that includes a source of heated or coolant fluid and a plenum with multiple openings positioned above the platen and separated from the polishing pad that delivers fluid onto the polishing pad.

[0005] In one aspect, at least some of the openings are each configured to deliver a different amount of fluid onto the polishing pad.

[0006] In another aspect, a first plurality of radial locations along the plenum each have at least two laterally separated openings, and a second plurality of radial locations along the plenum each have a single opening.

[0007] In another aspect, the position and size of the openings are such that the mass flow rate of the heated fluid through the plurality of openings increases substantially parabolically with distance from the axis of rotation of the platen.

[0008] In a further aspect, a method of controlling polishing includes measuring a radial temperature profile of a first polishing pad during polishing of a substrate, determining a pattern of openings that provides a mass flow profile that compensates for non-uniformity in the radial temperature profile, obtaining a base plate having openings arranged in the pattern, installing the base plate in an arm of a temperature control system of a chemical mechanical polishing system to form a plenum with a plurality of openings positioned above a platen, and polishing a substrate using the second polishing pad of the chemical mechanical polishing system while supplying a heated fluid source to the plenum such that heated gas flows onto the second polishing pad through the plurality of openings.

[0009] Example implementations may include, but are not limited to, one or more of the following potential advantages: A desired temperature control profile for the polishing pad can be achieved by quickly and efficiently raising and lowering the temperature across the entire surface of the polishing pad. The temperature of the polishing pad can be controlled without the polishing pad coming into contact with a solid, such as a heat exchange plate, thereby reducing the risk of pad contamination and defects. Temperature variation across a polishing run can be reduced, which can improve the polishing predictability of the polishing process. Temperature variation from polishing run to polishing run can be reduced, which can improve wafer-to-wafer uniformity and improve the repeatability of the polishing process. Temperature variation across the substrate can be reduced, which can improve within-wafer uniformity.

[0010] Plates with different patterns of apertures can be swapped into the fluid dispenser to provide different temperature profiles, allowing for rapid testing of different temperature profiles or modifications to the polisher for processes requiring new temperature profiles.

[0011] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a polishing apparatus. [Figure 2] FIG. 1 is a schematic top view showing an example of a chemical mechanical polishing apparatus. [Figure 3] FIG. 2 is a schematic bottom view of the example heating delivery arm of FIG. 1. [Figure 4] FIG. 2 is a graph showing mass flow rate as a function of radial distance from the axis of rotation of the platen of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] Like reference numbers in the various drawings refer to like elements.

[0014] Chemical mechanical polishing works by combining mechanical polishing and chemical etching at the interface between the substrate, polishing fluid, and polishing pad. During the polishing process, friction between the substrate surface and the polishing pad generates a significant amount of heat. In addition, some processes also include an in-situ pad conditioning step, in which a conditioning disk, e.g., a disk coated with abrasive diamond particles, is pressed against the rotating polishing pad to condition and texture the polishing pad surface. The polishing conditioning process can also generate heat. For example, in a typical copper CMP process with a nominal downforce pressure of 2 psi and a removal rate of 8000 Å / min, the surface temperature of a polyurethane polishing pad can increase by approximately 30°C.

[0015] Chemical variables in the CMP process, such as the onset and rate of the reactions involved, and mechanical variables, such as the surface friction coefficient and viscoelasticity of the polishing pad, are both highly dependent on temperature. As a result, variations in the surface temperature of the polishing pad can lead to changes in removal rate, polishing uniformity, erosion, dishing, and residue. By tighter control of the surface temperature of the polishing pad during polishing, temperature variations can be reduced, and polishing performance, such as measured by wafer-to-wafer non-uniformity or wafer-to-wafer non-uniformity, can be improved.

[0016] Several techniques have been proposed for temperature control. As one example, a coolant can be flowed through the platen. As another example, the temperature of the polishing liquid delivered to the polishing pad can be controlled. However, these techniques can be insufficient. For example, the platen must supply or pass heat through the body of the polishing pad itself to control the temperature of the polishing surface. Because polishing pads are generally made of plastic materials and are poor thermal conductors, heat control from the platen can be difficult. On the other hand, the polishing liquid may not have significant thermal mass.

[0017] A technique that can address these challenges is to have a dedicated temperature control system (separate from the polishing liquid supply) that delivers a temperature-controlled medium, such as a liquid, steam, or mist, to the polishing surface of the polishing pad (or to the polishing liquid on the polishing pad).

[0018] A further challenge is that the temperature rise along the radius of the rotating polishing pad during the CMP process is often not uniform. Without being limited to any particular theory, different sweep profiles of the polishing head and pad conditioner can, in some cases, have different residence times in each radial region of the polishing pad. Additionally, the relative linear velocity between the polishing pad and the polishing head and / or pad conditioner also varies along the radius of the polishing pad. Furthermore, the polishing fluid can act as a heat sink, cooling the polishing pad in the area where it is distributed. These effects can contribute to uneven heating on the polishing pad surface, resulting in variations in within-wafer removal rates.

[0019] A technique that can address these challenges is to have a dispenser with fluid flow openings that are spaced and sized to provide non-uniform mass flow along the radius of the polishing pad. In particular, the pattern of openings along the arm of the dispenser, including the size of the openings and the radial spacing of the openings, can be customized based on the details of the desired temperature control profile.

[0020] 1 and 2 show an example of a polishing station 20 of a chemical mechanical polishing system. The polishing station 20 includes a rotatable, disk-shaped platen 24 on which a polishing pad 30 rests. The platen 24 is operable to rotate about an axis 25 (see arrow A in FIG. 2). For example, a motor 22 can rotate a drive shaft 28 to rotate the platen 24. The polishing pad 30 can be a two-layer polishing pad having an outer polishing layer 34 and a softer backing layer 32.

[0021] The polishing station 20 may include a supply port 39 that dispenses a polishing liquid 38, such as a polishing slurry, onto the polishing pad 30. While the exact location of the supply port 39 may vary between different implementations, the supply port 39 is typically positioned at the end of an arm near the center of the polishing pad 30. For example, the supply port 39 may be positioned at the end of a heated delivery arm 110 (see FIG. 1). As another example, the supply port 39 may be positioned at the end of a slurry supply arm 170 (see FIG. 2). The polishing station 20 may include a pad conditioner device 90 having a conditioning disk 92 (see FIG. 2) to maintain the surface roughness of the polishing pad 30. The conditioning disk 90 may be positioned at the end of an arm 94 that can rotate to sweep the disk 90 radially across the polishing pad 30.

[0022] Carrier head 70 is operable to hold substrate 10 against polishing pad 30. Carrier head 70 is suspended from a support structure 72, e.g., a carousel or track, and is connected by drive shaft 74 to a carrier head rotation motor 76 so that the carrier head can rotate about axis 71. Optionally, carrier head 70 can be oscillated laterally, e.g., on a carousel slider, by movement along the track or by rotational oscillation of the carousel itself.

[0023] Carrier head 70 may include a retaining ring 84 that holds the substrate. In some implementations, retaining ring 84 may include a lower plastic portion 86 that contacts the polishing pad and an upper portion 88 of a harder material.

[0024] In operation, the platen is rotated about its central axis 25 and the carrier head is rotated about its central axis 71 and translated laterally across the upper surface of the polishing pad 30 .

[0025] Carrier head 70 may include a flexible membrane 80 having a substrate mounting surface that contacts the backside of substrate 10, and a plurality of pressurizable chambers 82 that apply different pressures to different areas, e.g., different radial areas, on substrate 10. The carrier head may also include a retaining ring 84 that holds the substrate.

[0026] In some implementations, the polishing station 20 includes a temperature sensor 64 that monitors the temperature of the polishing station or components of the polishing station / within the polishing station, such as the temperature of the polishing pad and / or the slurry thereon. For example, the temperature sensor 64 may be an infrared (IR) sensor, such as an IR camera, positioned above the polishing pad 30 and configured to measure the temperature of the polishing pad 30 and / or the slurry 38 thereon. In particular, the temperature sensor 64 is configured to measure the temperature at multiple points along the radius of the polishing pad 30 to generate a radial temperature profile. For example, the IR camera may have a field of view spanning the radius of the polishing pad 30.

[0027] In some implementations, the temperature sensor is a contact sensor rather than a non-contact sensor. For example, the temperature sensor 64 can be a thermocouple or an IR thermometer positioned on or in the platen 24. Additionally, the temperature sensor 64 can be in direct contact with the polishing pad.

[0028] In some implementations, multiple temperature sensors can be spaced at different radial locations across the polishing pad 30 to provide the temperature at multiple points along the radius of the polishing pad 30. This technique can be used instead of or in addition to an IR camera.

[0029] 1 is positioned to monitor the temperature of the polishing pad 30 and / or the slurry 38 on the pad 30, the temperature sensor 64 can be positioned inside the carrier head 70 to measure the temperature of the substrate 10. The temperature sensor 64 can be in direct contact with the semiconductor wafer of the substrate 10 (i.e., a contact sensor). In some implementations, multiple temperature sensors are included in the polishing station 22, for example, to measure the temperature of different components of / within the polishing station.

[0030] The polishing system 20 also includes a temperature control system 100 that controls the temperature of the polishing pad 30 and / or the slurry 38 on the polishing pad. The temperature control system 100 can include a heating system 102 and / or a cooling system 104. At least one of the cooling system 102 and the heating system 104, and in some implementations both, operate by delivering a temperature-controlled medium, such as a liquid, water vapor, or mist, onto the polishing surface 36 of the polishing pad 30 (or onto a polishing liquid already on the polishing pad).

[0031] For the heating system 102, the heating medium can be a gas, such as steam or heated air, or a liquid, such as heated water, or a combination of gas and liquid. The medium is at a temperature higher than room temperature, for example, between 40 and 120°C, for example, between 90 and 110°C. The medium can be water, such as substantially pure deionized water, or water containing additives or chemicals. In some implementations, the heating system 102 uses a mist of steam. The steam can contain additives or chemicals.

[0032] The heating medium can be delivered to the plenum 116 of the heating delivery arm 110 by flowing it from a source 108, such as a steam generator, through a fluid delivery line 118, which can be provided by piping, flexible tubing, a solid passageway, or some combination thereof.

[0033] An example heating system 102 includes an arm 110 that extends over the platen 24 and polishing pad 30 from the edge of the polishing pad to the center of the polishing pad 30, or at least near the center (e.g., within 5% of the total radius of the polishing pad). The arm 110 can be supported by a base 112, which can be supported on the same frame 40 as the platen 24. The base 112 can include one or more actuators, such as a linear actuator that raises and lowers the arm 110 and / or a rotary actuator that rotates the arm 110 laterally over the platen 24. The arm 110 is positioned to avoid collisions with other hardware components, such as the polishing head 70 and pad conditioner disk 92.

[0034] A plurality of openings 120 are formed in the bottom surface of the arm 110. Each opening 120 is configured to direct a heated fluid 114, such as a gas or water vapor, e.g., steam, onto the polishing pad 30. The openings 120 can be provided by holes or slots through the base plate 122. Alternatively, or in addition, some or all of the openings can be provided by nozzles fixed to the bottom of the base plate 122. A center plate 124 can be sandwiched between the base plate 122 and the top plate 126, and an aperture through the center plate 124 can provide the plenum 116. The openings 120 can be sufficiently small and the pressure in the plenum 116 can be sufficiently high so that the heated fluid forms a mist onto the polishing pad 30. The size of the openings can be set to be non-adjustable, for example, during polishing operations. For example, the passages can be machined to widen them so that the base plate 122 can be removed from the polishing arm and the openings or nozzles can be replaced.

[0035] As described in more detail below with reference to FIG. 3, the plurality of openings 120 are arranged in the bottom surface in a pattern that facilitates effective temperature control of the polishing pad 30 and / or the slurry 38 on the polishing pad according to a desired temperature profile.

[0036] While FIG. 1 depicts the openings 120 as being uniformly sized and evenly spaced along the length of the arm 110, this is not a requirement. That is, the openings 120 can be unevenly distributed radially, angularly, or both. For example, as shown in FIG. 2, two or more openings 120 can be positioned along the transverse direction of the arm 110. Openings 120 at different radial distances from the center of the platen 24 can be of different sizes, e.g., different diameters. Furthermore, openings at the same radial distance, i.e., positioned along a line along the transverse direction, can be of different sizes. In addition, while FIGS. 1 and 2 depict nine and twelve openings, respectively, there can be more or fewer openings, e.g., between 3 and 200 openings. Furthermore, while FIG. 2 depicts circular openings, the openings can be rectangular, e.g., square, elongated slots, or other shapes.

[0037] The various openings 120 can direct different amounts of heated fluid 114, e.g., steam, onto different areas on the polishing pad 30, e.g., different radial or angular areas. Adjacent areas may overlap. Optionally, some of the openings 120 can be oriented so that the central axis of the mist from that opening is at an oblique angle to the polishing surface 36. The heated fluid, e.g., steam, can be directed from one or more of the openings 144 to have a horizontal component in a direction opposite to the direction of motion of the polishing pad 30 in the region of impingement, such as caused by rotation of the platen 24.

[0038] The arm 110 can be supported by the base 112 such that the opening 120 is separated from the polishing pad 30 by a gap 130. The gap 130 can be 0.5 to 5 mm. In particular, the gap can be selected so that heat from the heated fluid does not dissipate significantly before it reaches the polishing pad. For example, the gap 130 can be selected so that vapor emitted from the opening does not condense before it reaches the polishing pad.

[0039] In some implementations, process parameters, such as flow rate, pressure, temperature, and / or liquid to gas mixture ratio, can be independently controlled for different groups of openings 120. This would require the arm to include multiple plenums, each connected to an independently controllable heater, to independently control the temperature of the heated fluid, e.g., vapor temperature, for each plenum.

[0040] For the cooling system 104, the coolant can be a gas, e.g., air, or a liquid, e.g., water. The coolant can be at room temperature or chilled below room temperature, e.g., 5-15°C. In some implementations, the cooling system 104 uses a mist of air and liquid, e.g., an aerosolized mist of liquid, e.g., water. In particular, the cooling system can have a nozzle that generates an aerosolized mist of water chilled below room temperature. In some implementations, a solid material can be mixed with the gas and / or liquid. The solid material can be a chilled material, e.g., ice, or a material that absorbs heat when dissolved in water, e.g., by a chemical reaction.

[0041] The cooling medium can be delivered in the coolant delivery arm by flowing through one or more apertures, such as holes or slots, optionally formed in the nozzle, which can be provided by a manifold connected to a coolant source.

[0042] 2, an example cooling system 104 includes an arm 140 that extends over the platen 24 and polishing pad 30. The arm 140 can be constructed similarly to the arm 110 of the heating system, except as described below.

[0043] Along the rotational direction of the platen 24, the arm 140 of the cooling system 104 can be positioned between the heating arm 110 of the system 110 and the carrier head 70. Along the rotational direction of the platen 24, the arm 140 of the cooling system 104 can be positioned between the arm 110 of the heating system 110 and the slurry delivery arm 170. For example, the arm 110 of the cooling system 110, the arm 140 of the heating system 104, the slurry delivery arm 170, and the carrier head 70 can be positioned in that order along the rotational direction of the platen 24.

[0044] The exemplary cooling system 102 includes a plurality of openings 144 on the bottom of the arm 140. Each opening 144 is configured to deliver a coolant, e.g., a liquid such as water, or a gas such as air, onto the polishing pad 30. Similar to the openings 120 for the heated fluid, the openings 144 can be arranged on the bottom surface in a pattern that facilitates effective temperature control of the polishing pad 30 and / or the slurry 38 on the polishing pad according to a desired temperature profile.

[0045] The cooling system 102 can include a liquid cooling medium source 146a and / or a gas source 146b (see FIG. 2). In some implementations, the liquid from the medium source 146a and the gas from the gas source 146b can be mixed in a mixing chamber, for example, in or on the arm 140, before being directed through the opening 144. For example, the air and gas can be mixed in a plenum.

[0046] The polishing system 20 may also include a controller 90 that controls the operation of various components, such as the temperature control system 100. The controller 90 may be coupled to the heating source 108 and / or the coolant sources 146a, 146b to control the flow rate of the heating fluid and / or the coolant. For example, the controller 90 may control a valve or a liquid flow controller (LFC) in the fluid delivery line 118. The controller 90 may be configured to receive temperature measurements from the temperature sensor 64. The controller 90 may compare the measured temperature with a desired temperature and generate feedback signals to control mechanisms (e.g., actuators, power supplies, pumps, valves, etc.) for the flow rates of the respective heating and coolant fluids. The feedback signals are used by the controller 90, for example, based on an internal feedback algorithm, to cause the control mechanisms to adjust the amount of cooling or heating so that the polishing pad and / or slurry reach (or at least approach) the desired temperature.

[0047] While FIG. 2 shows separate arms for each subsystem, e.g., heating system 102, cooling system 104, and rinsing system 106, the various subsystems can be included in a single assembly supported by a common arm. For example, the assembly can include a cooling module, a rinsing module, a heating module, a slurry delivery module, and optionally a wiper module. Each module can include a body, e.g., an arc-shaped body, that can be secured to a common mounting plate, which can be secured at the end of the arm such that the assembly is positioned above the polishing pad 30. Various fluid delivery components, e.g., plenums, piping, passages, etc., can extend within each body. In some implementations, the modules can be separately separable from the mounting plate. Each module can have similar components that perform the functions of the arms of the associated system described above.

[0048] 3 shows a schematic bottom view of an example heated delivery arm 110 of FIG. 1. The arm 110 can be generally straight and have a substantially uniform width along its length, although other shapes, such as a circular sector (known as a "pie slice"), an arc, or a triangular wedge (all as a bottom view of the system), can be used to achieve the desired effectiveness in controlling the temperature of the polishing pad 30 and / or the slurry 38 on the polishing pad. For example, the heated delivery arm 110 can be curved, forming, for example, an arc, or a portion of a spiral.

[0049] The heating delivery arm 110 may have a single inlet 119 through which the heating medium enters the plenum 116 of the arm 110. The inlet 119 may be located at a distal end of the arm 110 relative to the axis of rotation of the platen 24.

[0050] The heated delivery arm 110 has a plurality of openings 120 arranged in a pattern on its bottom surface 110a, for example, through a base plate 122. The pattern of openings 120 across the bottom surface of the heated delivery arm 110, including the size of the openings and their radial or angular spacing, can be designed to meet the specific needs of various temperature control profiles. In some cases, the temperature control profile can define the mass flow rate of the heated fluid stream onto the polishing pad as a function of radial distance from the axis of rotation of the platen. For example, the mass flow rate can increase parabolically with distance from the axis of rotation.

[0051] In operation, the platen rotates in a direction tangential to the longitudinal direction of the arm 110. Therefore, for convenience, the longitudinal direction of the arm 110 is also referred to as the radial direction.

[0052] 3, the openings 120 are evenly distributed radially and are more closely packed away from the axis of rotation of the platen, but the openings can be distributed differently to form other patterns. For example, the openings 120 can be unevenly spaced along the radial direction, i.e., at uneven intervals. As another example, the openings 120 can be more closely packed along the longitudinal edges of the arm 110.

[0053] At least some of the openings 120 have different sizes and / or shapes, and therefore deliver different amounts of heated fluid onto the polishing pad, for example, in terms of mass flow rate. In addition, the size distribution of the openings 120 can be weighted more heavily toward larger openings further from the axis of rotation of the platen. As shown, the openings at the distal end of the arm are generally larger than the openings at the end of the arm closer to the axis of rotation of the platen.

[0054] At least some of the openings 120, e.g., openings grouped by tuples 132 or quadruples 134, are laterally separated along the transverse direction of arm 110. As such, some radial locations along arm 110 each have at least two laterally separated openings, and some other radial locations along arm 110 each have a single opening. That is, at least one pair of openings is positioned at the same radial distance from the axis of rotation of the platen.

[0055] 4, as a specific example, a desired temperature control profile, as shown by the solid curve, defines a mass flow rate as a nonlinear, monotonically increasing function of radial distance from the platen's axis of rotation. More specifically, the openings 120 are arranged to have a parabolic flow rate, which should result in a temperature profile that increases approximately linearly along radial distance from the platen's axis of rotation (because area increases parabolically with radius, with larger radial areas requiring more heated fluid).

[0056] 4 shows a plot including a vertical axis defining mass flow rate in units of kilograms per second (kg / s) and a horizontal axis defining radial distance in terms of how many circumferential rows are spaced from the axis of rotation of the platen. For example, the rows can be equally spaced apart, such as 0.2 to 4 cm, e.g., 0.6 to 1.0 cm.

[0057] By using the heating distribution arm 110 of FIG. 3, the temperature control system 100 can deliver heated fluid at respective mass flow rates that closely align with the solid curve as shown by the scattered dots, thereby effectively controlling the temperature of the polishing pad and / or slurry on the polishing pad according to a desired temperature control profile.

[0058] To change the distribution of the heating fluid, the arm 110 can be removed and replaced with a new lower plate 112 having a different pattern of openings. In some implementations, the lower plate 112 can be removed from the arm without removing the arm 110 from the base 112. Thus, different plates with different patterns of openings can be used to provide different temperature profiles. This also allows for rapid testing of different temperature profiles or modifications of the polisher for processes requiring new temperature profiles.

[0059] For example, the radial temperature profile can be measured while polishing a substrate without temperature control by the arm. A pattern of apertures that provides a mass flow profile that compensates for the non-uniformity of the radial temperature profile is calculated, for example, as the inverse of the radial temperature profile. A base plate with apertures arranged in a pattern can be manufactured or selected from a set of pre-manufactured base plates. The base plate is then mounted on the arm and used while polishing a substrate.

[0060] The above-described polishing apparatus and method can be applied in various polishing systems. Either the polishing pad or the carrier head, or both, can move to provide relative motion between the polishing surface and the substrate. For example, the platen can orbit rather than rotate. The polishing pad can be a circular (or some other shape) pad fixed to the platen. The polishing layer can be a standard abrasive material (e.g., polyurethane with or without a filter), a soft material, or a fixed-abrasive material.

[0061] The term relative positioning is used to refer to relative positioning within the system or substrate, and it should be understood that the polishing surface and substrate can be held in a vertical orientation or some other orientation during the polishing operation.

[0062] The functional operations of the controller 90 may be implemented using one or more computer program products, i.e., one or more computer programs tangibly embodied in a non-transitory computer-readable storage medium, that are executed by or control the operation of a data processing device (e.g., a programmable processor, a computer, or multiple processors or computers).

[0063] A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the present invention. For example, while a heated fluid is described above, the arms of a cooling system can be similarly configured, except that a coolant flows through the arms rather than a heated fluid. Similar advantages apply when a cooling system has arms 140 with similar physical structures. For example, the radial profile of the coolant mass flow rate can compensate for temperature non-uniformities, in this case by reducing the temperature rather than increasing it.

[0064] Accordingly, other embodiments are within the scope of the following claims.

Claims

1. a rotatable platen for holding a polishing pad; a carrier that holds a substrate against the polishing surface of the polishing pad during the polishing process; a temperature control system including a source of heated or coolant fluid and a plenum positioned above the platen and separated from the polishing pad, the plenum having a plurality of openings for delivering the fluid onto the polishing pad, at least some of the openings being configured to deliver different amounts of the fluid onto the polishing pad; A chemical mechanical polishing apparatus comprising:

2. The device of claim 1 , wherein said at least some of said openings have different sizes.

3. The apparatus of claim 1 , comprising at least one pair of openings positioned the same radial distance from the axis of rotation of the platen.

4. The apparatus of claim 1 , wherein the openings are non-uniformly spaced along a radial distance from the axis of rotation of the platen.

5. The apparatus of claim 4 including a first plurality of radial locations along the plenum, each location of the first plurality of radial locations having at least two laterally separated openings.

6. The apparatus of claim 5 including a second plurality of radial locations along the plenum, each location of the second plurality of radial locations having a single opening.

7. 2. The apparatus of claim 1, wherein the size of the openings and the radial spacing of the openings are such that the mass flow rate of the fluid stream onto the polishing pad is a function of radial distance from the axis of rotation of the platen.

8. The apparatus of claim 7 , wherein the mass flow rate is a non-linear function of radial distance of the platen from the axis of rotation.

9. The apparatus of claim 7 , wherein the mass flow rate is a monotonically increasing function of radial distance of the platen from the axis of rotation.

10. 10. The apparatus of claim 9, wherein the mass flow rate is a parabolically increasing function of radial distance of the platen from the axis of rotation.

11. The apparatus of claim 1 , wherein the fluid comprises a heated gas.

12. The apparatus of claim 11 , wherein the gas comprises steam.

13. 12. The apparatus of claim 11, wherein the temperature control system includes a coolant source and a second plenum positioned above the platen and separated from the polishing pad, the second plenum having a second plurality of second openings for delivering the coolant onto the polishing pad, at least some of the second openings each configured to deliver a different amount of the coolant onto the polishing pad.

14. a platen for holding a polishing pad; a carrier that holds a substrate against the polishing surface of the polishing pad during the polishing process; a temperature control system including a source of heated fluid and a plurality of openings positioned above the platen that deliver heated gas from a plenum onto the polishing pad, wherein a first plurality of radial locations along the plenum each have at least two laterally separated openings and a second plurality of radial locations along the plenum each have a single opening; A chemical mechanical polishing apparatus comprising:

15. 15. The apparatus of claim 14, wherein the temperature control system includes a coolant source and a second plenum positioned above the platen and separated from the polishing pad, the second plenum having a second plurality of openings for delivering the coolant onto the polishing pad, a first plurality of radial positions along the second plenum each having at least two laterally separated second openings, and a second plurality of radial positions along the plenum each having a single second opening.

16. a rotatable platen for holding a polishing pad; a carrier that holds a substrate against the polishing surface of the polishing pad during the polishing process; a temperature control system including a source of heated fluid and a plenum positioned above the platen and separated from the polishing pad, the plenum having a plurality of openings for delivering heated fluid onto the polishing pad, the openings being positioned and sized such that a mass flow rate of the heated fluid through the plurality of openings increases substantially parabolically with distance from the axis of rotation of the platen; A chemical mechanical polishing apparatus comprising:

17. measuring a radial temperature profile of the first polishing pad during polishing of the substrate; determining a pattern of openings that provides a mass flow profile that compensates for non-uniformity in the radial temperature profile; obtaining a base plate having openings arranged in said pattern; placing the base plate within an arm of a temperature control system of a chemical mechanical polishing system to form a plenum with the plurality of openings positioned above the platen; polishing a substrate using the second polishing pad of the chemical mechanical polishing system while supplying a heating or coolant fluid source to the plenum such that the fluid flows through the plurality of openings onto the second polishing pad; A method for controlling abrasion, comprising:

18. The method of claim 17 , wherein obtaining the base plate comprises manufacturing the base plate.

19. The method of claim 17 , wherein obtaining the base plate comprises selecting the base plate from a plurality of pre-manufactured base plates.

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