Temperature controlled substrate carrier and polishing components

Abstract

To provide temperature controlled polishing pads.SOLUTION: A CMP system includes the use of any type of atomizing system to cool a polishing pad of a CMP system or remove energy and / or heat from the polishing pad. The atomizing system can use any liquid medium in combination with any compressed gas through an orifice to cool the pad or remove the energy and / or heat from the pad, thereby allowing higher removal rates during CMP.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] (Incorporation by reference to any priority application) This application is a utility patent application claiming benefit of the earlier filing date of Provisional Patent Application No. 62 / 869,427, filed July 1, 2019, and of the earlier filing date of Provisional Patent Application No. 62 / 912,523, filed October 8, 2019, each of which is incorporated by reference herein in its entirety.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to substrate processing equipment, and more particularly to systems and apparatus for improving chemical mechanical planarization (CMP) performance for thin film planarization. [Background technology]

[0003] During chemical mechanical planarization or polishing (CMP), an abrasive and acidic or alkaline slurry is applied to a rotating polishing pad / platen via a metering pump or mass flow control regulator system. The wafer is held by a wafer carrier, which presses against the rotating polishing platen for a specific time. The wafer is polished or planarized by both abrasion and erosion in the CMP process. Interactions between the wafer and carrier during processing can cause wafer breakage, non-uniformity, or other issues. Therefore, there is a need to improve wafer carrier performance to address the effects caused by interactions between the wafer and carrier during processing. Summary of the Invention [Problem to be solved by the invention]

[0004] For purposes of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure are described herein. Not all such objects or advantages may be achieved in any particular embodiment. Thus, for example, one skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein, without necessarily achieving other objects or advantages as taught or suggested herein. [Means for solving the problem]

[0005] One aspect of the disclosed technology is a substrate carrier head including: a carrier body; a substrate holder attached to the carrier body including an opening configured to receive a substrate; an elastic membrane having a first surface configured to contact a surface of the substrate and a second surface opposite the first surface; a membrane cavity formed along the second surface; an inlet configured to allow liquid to flow into the membrane cavity; and an outlet configured to allow liquid to flow out of the membrane cavity.

[0006] According to one embodiment, the outlet is located at a radial position from the center of the carrier body than the inlet.

[0007] According to one embodiment, the inlet is located approximately in the center of the carrier body.

[0008] According to another aspect, the substrate carrier head further includes a secondary elastic membrane having a width less than a width of the elastic membrane.

[0009] According to another aspect, the substrate carrier further includes a fluid-tight seal between the elastic membrane and the carrier body.

[0010] Another aspect of the disclosed technology is a substrate carrier system including a substrate carrier head including a carrier body, a substrate holder attached to the carrier body and configured to hold a substrate on the carrier body, an elastic membrane having a first surface configured to contact a surface of the substrate and a second surface opposite the first surface, and a membrane cavity formed along the second surface and configured to allow a liquid to flow along the second surface; and a control system configured to adjust at least one of a pressure and a flow rate of the liquid through the membrane cavity.

[0011] According to one embodiment, the substrate carrier head further includes an inlet configured to allow liquid to flow into the membrane cavity and an outlet configured to allow liquid to flow out of the membrane cavity.

[0012] According to one embodiment, the control system is further configured to recirculate the liquid from the outlet to the inlet.

[0013] According to another aspect, the outlet is located at a radial position from the center of the carrier body than the inlet.

[0014] According to yet another aspect, the inlet is located approximately centrally in the carrier body.

[0015] According to yet another aspect, the control system is further configured to cool the liquid below ambient temperature.

[0016] According to one embodiment, the substrate carrier system further comprises a liquid source fluidly connected to the membrane cavity.

[0017] According to another aspect, the substrate carrier head further includes a secondary elastic membrane having a width less than a width of the elastic membrane.

[0018] According to yet another aspect, the elastic membrane is substantially completely imperforate.

[0019] According to yet another aspect, the control system includes a fluid backpressure regulator configured to control the fluid pressure.

[0020] According to one embodiment, the control system further includes an air pressure regulator configured to provide a signal to the fluid backpressure regulator to control the hydraulic pressure.

[0021] According to another aspect, the substrate carrier system further includes an air source fluidly connected to the air pressure regulator.

[0022] According to yet another aspect, the substrate carrier system further includes a liquid aspirator configured to provide a negative pressure to the liquid within the membrane cavity.

[0023] According to yet another aspect, the substrate carrier system further includes the substrate, wherein the substrate is a silicon carbide wafer.

[0024] According to one embodiment, the substrate carrier system further comprises a liquid, the liquid comprising water.

[0025] According to another aspect, the control system is further configured to rotate the substrate carrier head at a speed greater than 100 rpm.

[0026] According to yet another aspect, the control system is further configured to control the fluid pressure to greater than 6 psi.

[0027] According to yet another aspect, the control system is further configured to control the temperature of the substrate to less than 100° F. during chemical mechanical polishing (CMP).

[0028] According to one embodiment, the substrate carrier system further comprises the substrate, the substrate having a thickness of less than 600 μm.

[0029] According to another aspect, the substrate carrier system further includes a slurry delivery system configured to deliver processing slurry to the substrate at a rate less than 100 ml / min.

[0030] Yet another aspect of the disclosed technology is a method for cooling a substrate during chemical mechanical polishing (CMP) of the substrate, the method including holding a substrate in an opening of a substrate holder attached to a carrier body of a carrier head, supplying a liquid to a membrane cavity in the carrier head, and flowing the liquid into the membrane cavity along a first surface of an elastic membrane.

[0031] According to one embodiment, the method further includes adjusting at least one of the pressure and flow rate of the liquid through the membrane cavity.

[0032] According to another aspect, the method further includes the steps of: causing the liquid to enter the membrane cavity through an inlet; and causing the liquid to exit the membrane cavity through an outlet.

[0033] According to yet another aspect, the method further includes recirculating the liquid from the outlet to the inlet.

[0034] According to yet another aspect, the method further includes cooling the liquid to below ambient temperature.

[0035] According to one aspect, the method further includes controlling at least one of the flow rate and the pressure of the liquid in the membrane cavity to a selected value.

[0036] According to another aspect, the controlling step includes controlling the pressure of the liquid via a fluid backpressure regulator located downstream of the membrane cavity.

[0037] According to yet another aspect, the method further includes providing a negative pressure to the liquid to suck the substrate against the elastic membrane.

[0038] Yet another aspect of the disclosed technology is a substrate carrier head including a carrier body, a substrate holder attached to the carrier body including an opening configured to receive a substrate, a liquid cavity formed adjacent the opening in the substrate, an inlet configured to allow liquid to flow into the liquid cavity, and an outlet configured to allow liquid to flow out of the liquid cavity.

[0039] Another aspect of the disclosed technology is a chemical mechanical planarization (CMP) system that includes a polishing pad, a substrate carrier head configured to hold a wafer against the polishing pad, and an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of ​​the polishing pad to evaporate the liquid and extract heat directly from the surface of the polishing pad.

[0040] According to one embodiment, the atomizer is further configured to combine compressed gas with the liquid to force atomize the liquid through an orifice.

[0041] According to another aspect, the polishing pad is formed from polyurethane.

[0042] According to yet another aspect, the amount of liquid provided to the polishing pad is small enough to prevent a significant decrease in removal rate due to a change in the chemistry of the slurry applied to the polishing pad.

[0043] According to yet another aspect, the CMP system further includes a retaining ring having a stepped shape.

[0044] According to one embodiment, the retaining ring is formed from polyphenylene sulfide (PPS) or polyetheretherketone (PEEK).

[0045] According to another aspect, the retaining ring has a two-piece construction.

[0046] According to yet another aspect, the retaining ring has a surface area of ​​less than 15 square inches.

[0047] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments, which refer to the accompanying figures, and the invention is not limited to any particular preferred embodiment disclosed. [Brief explanation of the drawings]

[0048] The above and additional objects, features, and advantages of the inventive concept will be better understood through the following illustrative and non-limiting detailed description of embodiments of the invention, with reference to the accompanying drawings, in which like reference numerals are used for like elements unless otherwise specified.

[0049] [Figure 1] 1 is a schematic diagram of a substrate processing system showing a substrate carrier holding a substrate in a processing position. [Figure 2] 2 is a diagram of the substrate processing system of FIG. 1 showing a substrate carrier holding a substrate in a loading position. [Figure 3] 3 is a partial cross-sectional view of a substrate carrier head that may be included as part of the wafer carrier shown in FIGS. 1 and 2. FIG. [Figure 4A] FIG. 1 is a block diagram illustrating a substrate carrier system that can be used to control the temperature of a wafer according to aspects of the present disclosure. [Figure 4B] FIG. 10 is a block diagram illustrating another substrate carrier system that can be used to control the temperature of a wafer in accordance with aspects of the present disclosure. [Figure 5] 3 is another partial cross-sectional view of a substrate carrier head that may be included as part of the wafer carrier shown in FIGS. 1 and 2 according to another embodiment. [Figure 6] FIG. 1 is an exploded top isometric view of one embodiment of a substrate carrier head according to aspects of the present disclosure. [Figure 7] FIG. 7 is an exploded bottom isometric view of the carrier head of FIG. 6 according to an embodiment of the present disclosure. [Figure 8] 7 is a cross-sectional view of the carrier head of FIG. 6 according to an embodiment of the present disclosure. [Figure 9] 1 is a perspective view of another embodiment of a substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate in accordance with aspects of the present disclosure. [Figure 10] 10 is a cross-sectional view of the substrate carrier of FIG. 9 taken along line AA of FIG. 9. [Figure 11] 10 is another cross-sectional view of the substrate carrier of FIG. 9 taken along line BB of FIG. 9. [Figure 12] 11 is a cross-sectional perspective view of the bottom plate taken along line CC in FIG. 10. [Figure 13] 1 is a plot showing the thermal conductivity of polyurethane as a function of temperature. [Figure 14A] 1 is an SEM image of an IC1000 microporous polyurethane (MPU) pad. [Figure 14B] FIG. 2 is a cross-sectional view of a polishing pad and wafer during CMP according to an embodiment of the present disclosure. [Figure 15] 1 is a schematic diagram of a substrate processing system including an integrated atomizer system according to aspects of the present disclosure. [Figure 16] 1 is a plot showing the difference in pad temperature between Experiment 1 and Experiment 2. [Figure 17] 1 is a plot showing the relationship between ring pressure (psi) and platen temperature (° C.) for a CMP system using a retaining ring. [Figure 18] 1 shows a retaining ring having a stepped shape. DETAILED DESCRIPTION OF THE INVENTION

[0050] Although the following text sets forth detailed descriptions of many different embodiments of the present invention, it should be understood that the legal scope of the present invention is defined by the language of the claims set forth at the end of a patent application. The detailed description should be construed as merely exemplary and does not describe every possible embodiment of the present invention, as describing every possible embodiment would be impractical, if not impossible. Many alternative embodiments can be implemented, using either current technology or technology developed after the filing date of this patent application, that still fall within the scope of the claims that define the present invention.

[0051] (Chemical mechanical planarization (CMP)) The adoption and use of chemical mechanical planarization (CMP) for thin film planarization in the fabrication of semiconductor ICs, MEMS devices, and LEDs is common among companies that manufacture the "chips" for these types of devices, among many other similar applications. This adoption includes the fabrication of chips for desktop and laptop computers, as well as cell phones, tablets, and other portable devices. The growth of ultra-fine technology and microfabrication holds great promise for the ever-widening use and adaptation of digital devices in the medical field, automotive field, and the Internet of Things ("IoT"). Chemical mechanical planarization for thin film planarization was invented and developed by IBM scientists and engineers in the early 1980s. Today, this process is widespread worldwide and is one of the truly enabling technologies in the fabrication of many digital devices.

[0052] Integrated circuits are fabricated from multiple and alternating layers of conductive materials (e.g., copper, tungsten, aluminum, etc.), insulating layers (e.g., silicon dioxide, silicon nitride, etc.), and semiconductor materials (e.g., polysilicon). Because successive combinations of these layers are applied sequentially to the wafer surface, with devices embedded in the surface, topographical irregularities are introduced into the device structures, as in the case of silicon dioxide insulator layers. These unwanted topographical irregularities are flattened or "planarized" using CMP before the next layer is deposited to allow for proper interconnection between increasingly smaller device structures. In the case of copper layers, copper is deposited on the surface to fill contact vias, creating effective vertical paths for electron movement between devices and between layers. This procedure continues with each layer applied (usually applied by a deposition process). In the case of multiple conductive material layers (multiple metal layers), this can result in many polishing procedures (one for each layer of conductor, insulator, and semiconductor material) to successfully create circuitry and interconnections between device structures.

[0053] In the CMP process, a substrate or wafer is held by a wafer carrier, which rotates and is typically pressed against a polishing platen for a specific time via an elastic membrane within the wafer carrier. CMP wafer carriers typically incorporate components for precision polishing of typically flat, round workpieces, such as silicon wafers and / or films deposited thereon, from a process head. These components include: 1) an elastic membrane with compressed gas applied to its top or backside, which pressure is transferred through the membrane to the top or backside of the workpiece to remove material during CMP; and 2) one or more rigid support components that secure the membrane to its mating components, hold the membrane in its desired shape and dimensions, and / or provide a means for clamping the membrane to provide a sealed volume for sealing and containing the controlled gas pressure.

[0054] In the process, the slurry is applied to a rotating polishing pad via a fluid control device, such as a metering pump or mass flow control regulator system. The slurry can be delivered to the polishing platen via a single-pass distribution system. To improve performance, the slurry particles in the media must be evenly distributed between the rotating wafer and the rotating polishing pad / platen.

[0055] A force is applied to the backside of the wafer by the wafer carrier membrane, pushing the wafer into the pad, and both may move and generate a relative velocity. This motion and force causes abrasion by forcing the abrasive material against the substrate as a portion of the pad moves across the wafer surface. Corrosive chemicals in the slurry alter the material being polished on the wafer's surface. The combination of chemical alteration and the mechanical effect of this abrasion is called chemical-mechanical planarization or polishing (CMP). The material removal rate can easily be an order of magnitude higher when both chemical and mechanical effects are used simultaneously compared to either effect used alone. Similarly, the combined chemical and mechanical effects improve the smoothness of the polished surface.

[0056] During the polishing process, materials such as copper, dielectrics, and polysilicon are removed from the surface of the wafer. These tiny particles remain suspended in the slurry, become embedded in the polishing pad, or both. These particles scratch the surface of the film being polished, causing catastrophic failure of the circuitry, rendering the chip useless and significantly impacting yield.

[0057] Yield is the driving force that determines the success of many products at the manufacturing level, including integrated circuits, MEMS, and LEDs. Surface quality tolerances for CMP processes within semiconductor fabrication facilities ("fabs") and foundries are measured in nanometers and even angstroms. The ability to remove material as uniformly as possible from the surface of a wafer or film during CMP is critical. Therefore, carrier design technology is constantly evolving to improve this capability. Small non-uniformities in the flatness of wafers processed in a CMP system can reduce yield and increase waste. Non-uniformities or pressure differences across the diameter of wafer carriers and processing pads can cause wafer breakage. The cumulative costs of manufacturing solid-state devices are collectively referred to as "cost of ownership" (CoO), a term that also applies to each required manufacturing step. The CoO of the CMP process has one of the highest CoO figures of the 500–800 individual manufacturing steps required to produce semiconductor "chips" and related digital devices.

[0058] Wafers formed of silicon carbide are likely to become more common in many integrated circuit applications. For example, the automotive industry is expected to use silicon carbide wafers to manufacture integrated circuits due to certain advantages of silicon carbide wafers over traditional silicon wafers. For example, compared to silicon wafer-based integrated circuits, silicon carbide wafer-based integrated circuits may have lower power consumption and higher heat resistance. Therefore, as automobiles increasingly use integrated circuits to control various aspects of the vehicle, these control systems are increasingly being manufactured using silicon carbide wafers due to the desirable properties of silicon carbide wafers.

[0059] However, silicon carbide is a harder material than silicon. Therefore, compared to an otherwise similar silicon wafer-based CMP process, silicon carbide wafers may require higher pressures and / or velocities (e.g., relative velocity between the wafer surface and the polishing pad / platen) to achieve sufficient removal rates during CMP. Compared to similar silicon wafer-based CMP, these increased pressures and / or velocities can lead to increased heat generated during CMP of silicon carbide wafers. This increased heat can then adversely affect the wafer surface, the polishing pad, and / or the elastic membrane that contacts and applies pressure to the wafer. For example, excessive heat can lead to surface defects on the wafer. Excessive heat can melt the elastic membrane and / or polishing pad and / or cause the wafer to adhere to the membrane or lose it from the carrier, damaging the wafer and carrier and / or preventing the wafer from being unloaded from the carrier. Therefore, cooling the wafer and / or elastic membrane is necessary to reduce temperatures during polishing. It will be understood that aspects of the present disclosure may be implemented on substrates formed of materials other than silicon carbide, and may be implemented to cool, heat, or otherwise control a wafer, film, or other portion of a wafer carrier to a desired temperature during any stage of substrate processing with a substrate carrier, such as CMP.

[0060] The disclosed technology will be described with respect to particular embodiments and with reference to certain drawings. The disclosure is not limited thereto but only by the claims. The drawings described are merely schematic and are not limiting. In the drawings, the size of some of the elements may be exaggerated for illustrative purposes and may not be drawn to scale. The dimensions and relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.

[0061] (liquid-cooled CMP system) FIG. 1 is a schematic diagram of a chemical mechanical planarization system 100 for processing a polishing pad 110. The system 100 may include a wafer carrier 150 configured to hold and process a wafer. As used herein, the term "wafer" may refer to a semiconductor wafer (e.g., circular), but it is understood that the term may more broadly encompass other types of substrates of different shapes processed by polishing or planarization equipment, such as CMP equipment. Accordingly, in the following description, the terms "wafer" and "substrate" may be used interchangeably, except where the context specifically and clearly relates to only one of the terms "wafer" and "substrate." In the illustrated embodiment, the substrate carrier 150 is in a processing (e.g., lower) position and holds a substrate (not shown) against a polishing pad 110 with a film (not shown). The polishing pad 110 may be disposed on a support surface, such as the surface of a platen 120.

[0062] FIG. 2 is a diagram of the chemical mechanical planarization system of FIG. 1 , showing a substrate 155 held in a loaded (e.g., upper) position by a substrate carrier 150. The substrate 155 may be held, for example, by vacuum force. Referring to both FIGS. 1 and 2 , the system 100 may include a slurry delivery system 140 configured to deliver a processing slurry to the substrate 155 to enable chemical / mechanical planarization thereof against the polishing pad 110. The system 100 may include a pad conditioning arm 160 including a pad conditioner at its end, which may be configured to treat or "refresh" the surface roughness or other processing characteristics of the pad during or between processing cycles.

[0063] 1 and 2, the polishing pad 110 rests on top of a platen 120 that rotates counterclockwise about a vertical axis. Other orientations and directions of movement are also possible.

[0064] The slurry delivery system 140 can deliver a slurry containing abrasive and corrosive particles to the surface of the treated polishing pad 130. The polishing slurry is typically a colloidal suspension of abrasive particles, i.e., colloidal silica, colloidal alumina, or colloidal ceria, in an aqueous medium. In various embodiments, the slurry delivery system 140 includes a metering pump, a mass flow control regulator system, or other suitable fluid delivery components. .

[0065] The substrate carrier 150 can hold the substrate 155, for example, by vacuum, so that the surface of the substrate 155 to be polished faces the polishing pad 110. The abrasive particles and corrosive chemicals in the slurry deposited on the polishing pad 110 by the slurry delivery system 140 mechanically and chemically polish the substrate by abrasion and erosion, respectively. The substrate carrier 155 and polishing pad 110 can move relative to one another in any of several different ways to provide polishing. For example, the substrate carrier 150 can apply a downward force against the platen 120 to press the substrate 155 against the polishing pad 110. As described further herein, the substrate 155 can be pressed against the polishing pad 110 using a pressure membrane (not shown). The abrasive particles and corrosive chemicals in the slurry between the substrate 155 and the polishing pad 110 can provide chemical and mechanical polishing as the polishing pad 110 and the substrate carrier 155 move relative to one another. The relative motion between the polishing pad and the substrate carrier can be configured in a variety of ways, with either or both configured to oscillate, move linearly, and / or rotate counterclockwise and / or clockwise relative to one another.

[0066] The pad conditioning arm 160 can condition the surface of the polishing pad 110 by pressing against the polishing pad 110 with force, accompanied by relative movement thereof, such as that described above with respect to the polishing pad and substrate carrier 150. The pad conditioning arm 160 in the illustrated embodiment can oscillate and includes a rotating pad conditioner at its end that contacts the polishing pad 110.

[0067] 3 is a partial cross-sectional view of a substrate carrier head 300 that may be included as part of the substrate carrier 150 shown in FIGS. 1 and 2. The substrate carrier head 300 includes a film assembly 305 for a chemical mechanical planarization (CMP) system. In some embodiments, the substrate carrier head 300 (also referred to herein as a carrier head) may include a support base 380 to which the film assembly 305 is mounted. The support base 380 may be of any suitable configuration for providing support to the film assembly. The support base 380 may mount and connect the remainder of the substrate carrier head 300 to a CMP system (not shown). The support base 380 may include a carrier body, a substrate holder, a support plate, and / or other components described elsewhere herein that support a wafer (e.g., the film assembly 305) and / or connect the remainder of the carrier head 300 to the CMP system.

[0068] The membrane assembly 305 may include, as shown, a support plate 310, an elastic membrane 320, a membrane retainer such as a membrane clamp 330, and an optional external pressure ring 340. The support plate 310 supports the wafer during processing and may be of any suitable configuration for, for example, attaching the membrane assembly 305 to a support base 380. For example, the support plate 310 may be attached to the support base 380 using one or more bolts or other suitable attachment elements. The support plate 310 may be attached to the support base 380 at various locations, such as along the periphery of the support base 380.

[0069] The support plate 310 may be of any suitable configuration for supporting a wafer, for example, through the elastic membrane 320. The elastic membrane 320 may be secured to the support plate 310 in several different ways. The elastic membrane 320 may be secured to the support plate 310 before or after the support plate 310 is secured to the support base 380. The elastic membrane 320 may be secured to the support plate 310 using any of several suitable different membrane retainer retention elements, such as membrane clamps 330. In some embodiments, the membrane clamps 330 may be spring-loaded. In other embodiments, the membrane clamps 330 may be securely fastened using a fastening mechanism (e.g., nuts and bolts, etc.). The membrane clamps 330 may secure an outer portion (e.g., outer edge) of the membrane 320 to a corresponding portion of the support plate 310 and / or the support base 380. The membrane retainers may be of any suitable configuration for securing at least a portion of the membrane 320 to the support plate 310 and / or the support base 380.

[0070] The elastic membrane 320 can be secured to the support plate 310 so that the membrane 320 can hold the substrate 370 against the polishing pad and process the substrate, for example, as described above with reference to FIGS. 1 and 2 . The membrane can include a (e.g., downward-facing) first surface configured to contact the (e.g., upward-facing) surface of the substrate. The membrane 320 can have sufficient elasticity and flexibility so that, in combination with the polishing pad material and process parameters, the membrane 320 can apply more uniform pressure across the substrate 370. In some embodiments, the elasticity and flexibility of the membrane 320 can also help reduce substrate breakage. The membrane 320 and support plate 310 can be configured to allow liquid to flow between the membrane 320 and the support plate 310, pressing the membrane 320 against the substrate 370 during planarization. For example, the membrane 320 can be configured to allow liquid to flow along the upward-facing second surface, e.g., the surface opposite the aforementioned first membrane surface. The support plate 310 can be spaced apart from the membrane 320 to form a gap or membrane cavity 360 therebetween. The membrane cavity 360 can be formed when the membrane 320 is in a resting (e.g., unpressurized) state. The membrane cavity 360 can be sealed. In some embodiments, a liquid-tight seal can be formed within the membrane cavity 360 to prevent liquid from leaking from the membrane cavity 360 when the liquid is pressurized. Thus, the membrane cavity 360 can form a liquid cavity through which liquid can be circulated. A seal can be formed between a portion of the membrane 320 and a portion of the carrier body (e.g., the plate 310 and / or the base 380), for example, at the membrane clamp 330. As used herein, a sealed membrane cavity includes a membrane cavity in fluid communication with an inlet and / or an outlet that can be selectively sealed (e.g., opened and closed by a valve).

[0071] In some embodiments, when the membrane 320 is at rest, a portion of the membrane 320, e.g., its upward-facing surface, rests on or is adjacent to a corresponding portion of the plate 310, e.g., its downward-facing surface. Then, the membrane cavity 360 is formed when the membrane 320 is expanded (e.g., pressurized via liquid). The membrane cavity 360 can redistribute and account for fluctuations in liquid pressure against the membrane 320, and therefore against the substrate 370, during planarization. Liquid can be provided to the backside of the membrane 320 and enter the membrane cavity 360 via an inlet 350, as shown. The inlet 350 can be located within the support plate 310, or the liquid can be supplied via other configurations. Liquid can also be removed from the membrane cavity 360 via an outlet 355. Each of the inlet 350 and outlet 355 can be modified differently depending on the application (e.g., a circular tube, a square tube, etc.). In some embodiments, a vacuum may be applied to the cavity 360 via the inlet and / or outlet to hold the wafer 370 underneath the membrane assembly, as further described herein.

[0072] In some embodiments, the membrane cavity 360 can be formed by spacing the membrane 320 away from the support plate 310. For example, the support plate 310 can include a recessed interior portion to form the cavity. In the illustrated embodiment, the membrane assembly 305 can include an optional external pressure ring 340 to form the membrane cavity 360. In other embodiments, the membrane assembly 305 can be assembled without a pressure ring. For example, the elastic membrane 320 can rest directly against the support plate 310 without the membrane cavity 360 separating the membrane 320 from the support plate 310, e.g., when no liquid is present in the membrane cavity 360. In some embodiments, the membrane assembly 305 can include one or more pressure rings 340 arranged concentrically. The one or more pressure rings 340 can include a channel (not shown) that allows liquid to flow from one side of the pressure ring 340 to the other side of the pressure ring 340.

[0073] In another embodiment, the wafer carrier can include a multi-zone carrier. For example, the membrane 320 can be a multi-zone membrane. Each zone of the multi-zone membrane can include a corresponding membrane cavity configured to receive liquid and / or be controlled (e.g., separately) in a similar manner as described herein for a single-zone carrier having a single-zone cavity. For example, the membrane 320 can have grooves (e.g., depressions) and / or raised portions of the membrane 320 that effectively separate various zones of the membrane 320. In a non-limiting example, the grooves can be arranged in a series of concentric circles emanating from the center of the membrane. In another example, the grooves and raised portions can be irregularly shaped (e.g., interconnecting circles, non-circular depressions, circular patterns scattered across the surface of the membrane) to improve the distribution of pressure applied across the substrate 370 when attached to the membrane assembly 305. In some embodiments, the system can apply different pressures to one or more zones of the multi-zone membrane to tailor the removal rate of each zone. For example, a zone to which higher pressure is applied may experience a higher removal rate. The system may also be able to adjust the temperature of the liquid provided to one or more zones to adjust the removal rate. For example, a higher temperature (e.g., less cooling) can be applied to a particular zone to increase the removal rate compared to another zone. The effect of temperature changes on removal rate can be relatively less than the effect of pressure changes. Therefore, temperature can be used as a fine-tuning variable when adjusting the removal rate of a single or multi-zone system. For example, the pressure of a first zone can be controlled to be the same as, greater than, or less than the pressure of a second zone. The temperature of the first zone can be controlled to be the same as, greater than, or less than the temperature of the second zone.

[0074] The membrane 320 can be flexible so that it can conform to the structure it surrounds. In some cases, the membrane 320 can be convex. For example, the membrane 320 can sag in the center. The membrane 320 can also be shaped like a cone so that a small area of ​​the membrane 320 contacts the substrate surface for more precise polishing.

[0075] The membrane material may be any elastic material suitable for planarization, as described herein, for example, suitable for use in a carrier head for a CMP process. In some embodiments, the membrane material may be one of rubber or synthetic rubber materials. The membrane material may also be one of ethylene propylene diene monomer (M class) (EPDM) rubber or silicone. Alternatively, it may be one or more combinations of vinyl, rubber, silicone rubber, synthetic rubber, nitrile, thermoplastic elastomer, fluoroelastomer, hydrated acrylonitrile butadiene rubber, or urethane and polyurethane forms. To effectively cool (or heat or control the temperature of) a substrate, in certain embodiments, the material of the elastic membrane 320 may be selected based on the material's heat transfer properties. Thus, when cooling a substrate such as a silicon carbide substrate, a material with a higher thermal conductivity may be desirable. For example, in some embodiments, the membrane material may be an elastomer such as silicone, including those available under the trademark Arlon®, owned by Rogers Corporation, that has a thermal conductivity that can aid in cooling the substrate. In some embodiments, the elastic membrane 320 may include inorganic additives that increase the thermal conductivity of the elastic membrane 320 to improve heat transfer between the temperature-controlled liquid and the substrate. Examples of inorganic additives that increase thermal conductivity may include the range of additives manufactured under the trademark Martoxid, owned by Martinswerk GMBH.

[0076] One or more membrane assemblies can be implemented within a single CMP system, which may include controls (e.g., variable speed motor controls) that utilize feedback from the system during operation to more precisely control the CMP process.

[0077] In an exemplary embodiment, the film 320 can be planarized. For example, the film 320 can be made flat within a desired tolerance and / or tailored to match a surface roughness within a desired tolerance. For example, the film 320 can undergo a planarization procedure in which the film is subjected to a polishing pad. Alternatively, the film 320 can be introduced into a chemical slurry that planarizes the film 320. Furthermore, the surface roughness of the film 320 can be improved throughout this planarization process. Surface roughness can be important for films used in conjunction with CMP processes for at least two reasons: sealing and stiction. The planarization process can reduce surface roughness to provide improved sealing between the substrate 370 and the film 320 for handling purposes. At the same time, the surface roughness can be increased to prevent stiction (i.e., the film adhering to the substrate due to surface tension) and improve substrate release from the film after processing. Control mechanisms can be used in the planarization process (described below) to achieve a desired balance between low and high surface roughness. The control mechanism can be external to the device used to planarize the film.

[0078] As explained above, when polishing a substrate at higher pressures and / or speeds, which may be relevant for certain substrates, such as silicon carbide substrates, friction between the substrate and the rotating polishing pad / platen may result in temperatures high enough to adversely affect the substrate 370 and / or the elastic membrane 360. Accordingly, one aspect of the present disclosure relates to flowing a liquid along the surface of the elastic membrane 360 ​​to cool the elastic membrane 360 ​​and the substrate 370. Figure 4A is a block diagram illustrating a substrate carrier system 400 that may be used to control the temperature of a substrate according to an aspect of the present disclosure.

[0079] Referring to FIG. 4A, the substrate carrier system 400 can include a gas source, such as a compressed dry air (CDA) source 405, and a liquid source 410. The gas and liquid sources can be provided via facility, on-site reservoirs, and / or can be part of a recirculation system described herein. The system 400 can include one or more valves, such as valves 420, 425, and 427, for providing selective vacuum, gas, or liquid flow. The system 400 can include a vacuum source, such as an air-driven aspirator 430. The system 400 can include a carrier head 500 with a membrane cavity 360, an inlet 350, and an outlet 355, similar to those described herein with respect to the carrier head 300 ( FIGS. 3 and 5 ), the carrier head 600 ( FIGS. 6-8 ), or other carrier heads that provide temperature control. The system 400 can include a movable element, such as a rotary union 435, configured to provide relative movement between the carrier head and the polishing head. The rotary union 435 can be part of the carrier head or a separate component attached thereto. The system 400 can include a control system 440. The control system 440 can include pressure and / or flow regulators configured to control the pressure and / or flow rate at the inlet and / or outlet within the membrane cavity 360. For example, the control system 440 can include a fluid backpressure regulator 445, and in some embodiments, an air pressure regulator 415. In some embodiments, the control system 440 can further include a control processor (not shown) configured to control one or more of the air pressure regulator 415, the fluid backpressure regulator 445, and / or other components of the substrate carrier system 400. It will be appreciated that the control system 440 can include one or more sensors configured to sense various process parameters, such as flow rate, pressure, temperature, etc., to provide open-loop or closed-loop control using the control processor. For example, temperature, flow rate, and / or pressure sensors can be implemented to sense the temperature, flow rate, and / or pressure of a liquid in fluid communication with the membrane cavity.

[0080] The liquid used for cooling can be selected based at least in part on the heat transfer properties of the liquid. In one embodiment, the liquid can be water. In another embodiment, the liquid can be designed to have higher heat transfer properties than water, for example, the liquid can be Galden HT heat transfer fluid. Other liquids can also be used depending on the embodiment.

[0081] A liquid source 410 selectively provides liquid to the membrane cavity 360 (e.g., via a valve 425 and a rotary union 435). The rotary union may include a set of fluid channels that allow the liquid source 410 to provide liquid to the inlet 350 of the carrier head 500 and receive liquid exiting the substrate carrier head 300 via the outlet 355 while rotating the carrier head 500. Liquid received from the liquid source can flow into the membrane cavity 360 via the inlet 350 and can flow out of the membrane cavity 360 via the outlet 355, for example, to a fluid backpressure regulator 445.

[0082] The CDA source 405 provides CDA to the air pressure regulator 415 so that the air pressure regulator 415 can control the fluid back-pressure regulator 445. In some embodiments, the air pressure regulator 415 is not included, and the fluid back-pressure regulator 445 can be directly controlled by the control processor. The fluid back-pressure regulator 445 controls the pressure of the liquid in the membrane cavity 360 by maintaining a desired pressure of the liquid upstream of the fluid back-pressure regulator 445. Thus, the fluid back-pressure regulator 445 can reduce excess pressure when the liquid pressure is higher than the desired pressure by allowing some of the liquid to drain to the liquid exhaust port 450. The liquid exhaust port 450 can include a T-junction or valve to provide selective flow between the regulator 445, the aspirator 430, and / or the optional heat exchanger 460. The fluid back-pressure regulator 445 controls the pressure of the liquid in the membrane cavity 360, and therefore can be configured to control the pressure applied to the substrate during CMP. The pressure of the liquid provided by the liquid source may be higher than the expected range of pressures applied to the substrate 370 during CMP. Therefore, the fluid backpressure regulator 445 may be configured to adjust the pressure of the liquid in the membrane cavity 360 by reducing the pressure of the fluid to a desired level. The pressure in the membrane 360 ​​may be controlled by an additional or alternative pressure regulator located upstream of the membrane cavity 360.

[0083] The CDA source 405 also provides CDA to the air-driven liquid aspirator 430 via the valve 420. The valve 427 can be used to control how liquid is provided to the membrane cavity 360 between flowing the liquid, providing negative pressure (e.g., via the air-driven liquid aspirator 430), and venting the membrane cavity 360. When providing negative pressure, the air-driven liquid aspirator 430 is configured to provide negative pressure (e.g., vacuum) to the liquid in the membrane cavity 360. In certain embodiments, the air-driven liquid aspirator 430 can also include an exhaust for the CDA, where the flow of CDA through the air-driven liquid aspirator 430 controls the negative pressure provided to the liquid. The negative pressure can be used to provide suction between the elastic membrane and the substrate 370, allowing the substrate carrier head 300 to pick up the substrate for processing functions. That is, the negative pressure provided by the air-driven liquid aspirator 430 can hold the substrate 370 under the elastic membrane 320. The support plate that provides support to the backside of the elastic membrane 320 may include holes to provide the above-mentioned vacuum (to give the wafer a suction cup effect) and / or to allow positive pressure of the liquid in the membrane cavity 360 to separate the substrate 370 from the elastic membrane 320.

[0084] In some embodiments, excess liquid exiting the liquid exit port 450 can simply be discarded, forming a non-recirculating system. However, in other embodiments, excess liquid exiting the liquid exit port 450 can be recirculated back to the liquid source 410. In certain embodiments, the system 400 can further include an optional heat exchanger 460 configured to condition (e.g., cool) the temperature of the liquid before returning it to the liquid source 410 and entering the carrier head.

[0085] 4B is a block diagram illustrating another substrate carrier system that can be used to control the temperature of wafers according to aspects of the present disclosure. Referring to FIG. 4B, the substrate carrier system 700 can include a chiller 705, a pressure set point 710, a back pressure regulator (BPR) 715, an input pressure gauge 720, a flow meter 725, a water "on" valve 730, a carrier 735 (such as a carrier head 300 or 600), a platen 740, an output pressure gauge 745, a recirculation / vacuum valve 750, and a vacuum isolator 755.

[0086] In the embodiment of Figure 4B, the back pressure regulator (BPR) 715 is located upstream of the carrier 735. This configuration can provide a higher flow rate than a configuration in which the BPR 715 is located downstream of the carrier 735. The higher flow rate can improve cooling of the substrate through the elastic membrane. A similar placement of the fluid back pressure regulator 445 upstream of the carrier head 500 can be implemented in the embodiment of Figure 4A.

[0087] 3, 4A, and 4B, as the liquid flows through the membrane cavity 360 along the backside of the elastic membrane 320, heat generated by friction in the polishing process is transferred from the substrate 370 to the liquid through the elastic membrane 320. The substrate carrier system 400 can control the liquid to have a sufficient flow rate along the elastic membrane 320 to remove excess heat generated in the polishing process. For example, a liquid flow controller (e.g., control system 440) can be implemented upstream or downstream of the membrane cavity 360.

[0088] The inlets and outlets can be configured in various ways to affect the flow of liquid (and therefore temperature control) within the membrane cavity. In the embodiment of FIG. 3 , the inlet 350 can be located approximately at the center of the body of the substrate carrier head 300, and the outlet 355 can be located at a location radially from the center of the carrier body relative to the inlet 350, e.g., near the outer periphery of the elastic membrane 320. Rotation of the substrate carrier head 300 during polishing can aid the flow of liquid from the inlet 350 to the outlet 355 due to centripetal forces. While a single inlet 350 and a single outlet 355 are shown in FIG. 3 , multiple inlets 350 and / or outlets can be included in some embodiments. For example, the multiple outlets 355 can be located near the outer periphery of the elastic membrane 320 and / or spaced apart along a radial (or circumferential) path extending from the center of the carrier body.

[0089] FIG. 5 is another partial cross-sectional view of a substrate carrier head 300 that may be included as part of the substrate carrier 150 shown in FIGS. 1 and 2 , according to another embodiment. Similar to the embodiment of FIG. 3 , the substrate carrier head 300 of the embodiment of FIG. 5 includes a membrane assembly 305, an inlet 350, an outlet 355, a membrane cavity 360, and a support base 380. The membrane assembly 305 may include a support plate 310, an elastic membrane 320, a membrane clamp 330, and an optional external pressure ring 340. The membrane assembly 305 may be configured to hold a substrate 370 against a polishing pad during planarization and to provide a vacuum to hold the substrate 370 beneath the membrane assembly 305. These components may have similar functions to those described in connection with FIG. 3 .

[0090] 5, the inlet 350 and outlet 355 may be located at opposing locations, for example, near the outer periphery of the elastic membrane 320. Thus, liquid flowing from the inlet 350 can flow from one side (e.g., the edge) of the elastic membrane 320 to the outlet 355 located on the opposite side (e.g., the edge) of the elastic membrane 320.

[0091] It will be understood that the inlets 350 and outlets 355 described herein can be provided in any suitable configuration (e.g., shape, size, location, quantity, etc.) to improve temperature control and liquid distribution. For example, while a single inlet 350 and outlet 355 are shown in the cross-sectional views of FIGS. 3 and 5 , two or more inlets 350 and two or more outlets 355 can be provided. The one or more inlets or one or more outlets can be provided at different locations on opposite sides of the elastic membrane 320 (e.g., near the outer periphery) to more uniformly flow liquid along the elastic membrane 320. In some embodiments, the one or more inlets 350 can be positioned radially inward relative to the one or more outlets 355 with respect to the center of the elastic membrane 320, or vice versa. In some embodiments, the one or more inlets 350 can be positioned at approximately the same radial location but different circumferential locations relative to the one or more outlets 355. The one or more inlets 350 or one or more outlets 355 can be positioned approximately at the center of the elastic membrane 320.

[0092] (Liquid-cooled multi-layer CMP system) Figure 6 is an exploded top isometric view of one embodiment of a substrate carrier head 600. Figure 7 is an exploded bottom isometric view of the carrier head 600 of Figure 6. Figure 8 is a cross-sectional view of the carrier head 600 of Figure 6. Embodiments of the carrier head 600 can be implemented in various types of substrate processing equipment. For example, the carrier head 600 can be implemented in a CMP system such as those described with reference to Figures 1 and 2, or other types of CMP systems. The carrier head 600 can be implemented in the substrate carrier system of Figure 4A and can include some features of the carrier heads of Figures 3 and 5, and vice versa.

[0093] 6-8 , a substrate carrier head 600 may include a carrier body 21 for supporting various components of the carrier head 600. The carrier head may include a substrate holder 20 attached to the carrier body 21. The holder 20 may be configured to hold and support a substrate on the carrier head 600. For example, the substrate holder may include an opening 40 configured to receive a substrate. The opening 40 may form sidewalls that extend partially or completely through the thickness of the substrate holder to support and prevent lateral movement of a substrate held within the opening 40. The holder 20 may be a separate or integrally formed component and may be of the same or a different material as the carrier body 21. The substrate holder may include a substantially continuous outer surface 42, or the outer surface may have grooves or other indentations to improve slurry flow.

[0094] Carrier head 600 can include a first elastic membrane 25 and a second elastic membrane 30. The membranes, or portions thereof, can be stacked or positioned adjacent to each other, for example, without intervening structures. Together, membranes 25, 30 can press a substrate against a substrate processing platen during substrate processing, as described above with respect to the CMP process of Figures 1 and 2. Portions of membranes 25, 30 can press against each other.

[0095] The membranes 25, 30 may be flexible so that they can conform to adjacent structures. The membrane material may be any elastic material, such as a material suitable for receiving backpressure and transferring that backpressure to a substrate held within the carrier head. In some embodiments, the membrane material may be a rubber or synthetic rubber material. As described above, the membrane material may also be ethylene propylene diene monomer (M-class) (EPDM) rubber or silicone. Alternatively, it may be vinyl, rubber, silicone rubber, synthetic rubber, nitrile, thermoplastic elastomer, fluoroelastomer, hydrated acrylonitrile butadiene rubber, or a combination of one or more of the following forms of urethane and polyurethane. To effectively cool the substrate, in certain embodiments, the material of the elastic membranes 25, 30 may be selected based on the material's heat transfer characteristics. Therefore, when cooling a substrate such as a silicon carbide substrate, a material with higher thermal conductivity may be desirable. In some embodiments, the elastic membranes 25, 30 may include an inorganic additive that increases the thermal conductivity of the elastic membranes 25, 30 to improve heat transfer between the temperature-controlled liquid and the substrate.

[0096] The elastic membranes 25, 30 (and other membranes herein) may include portions that provide support to a substrate held within the carrier 600 (and other carriers herein). Such substrate supports may be distinguished from other portions of the membranes 25, 30 that do not support the substrate but that help attach the membranes 25, 30 to other portions of the carrier.

[0097] For example, the first elastic membrane 25 can include a first substrate support having a width W1, as shown. The first substrate support shown is a horizontal portion of the first elastic membrane 25 that extends across its width W1 to provide support for a substrate held within the opening 40 of the substrate holder 20. The remaining portion of the first elastic membrane 25 (i.e., the portion that is not the first substrate support), the membrane backing support 17, the substrate holder 20, and the carrier body 21 can be configured to attach the first elastic membrane 25 to the remainder of the carrier head 600, and the remaining portion of the first elastic membrane 25 can include, for example, shorter vertical and horizontal portions that are wrapped in a serpentine shape around and / or between outer portions of the outer support plate 36 (described further below).

[0098] The second elastic membrane 30 can include a second substrate support having a width W2. The second substrate support shown is a horizontal portion of the second elastic membrane 30 that extends across its width W2 to and provides support to an inner, central portion of a substrate held within the opening 40 of the substrate holder 20. The second substrate support can be disposed between the first substrate support and the carrier body 21. The first and second substrate supports can be stacked against each other or directly stacked (i.e., in contact with each other). The second substrate portion can be stacked on top of the first substrate portion in the orientation shown. The second substrate support can be configured to selectively apply force to the interior of the first, non-porous substrate support, as shown. The outer surface of the second substrate support can directly contact at least the inner surface of the interior of the first substrate support. This configuration allows the second elastic membrane 30 to provide improved process and substrate uniformity, for example, improved center removal rate control in a CMP process.

[0099] The remainder of the second elastic membrane 30 (other than the second substrate support) can be configured to attach the second elastic membrane 30 to the remainder of the carrier head 600, and can include, for example, a short vertical portion at its outer edge and a horizontal lip extending from the distal end of the vertical portion.

[0100] Each of the membranes 25, 30 (or other membranes herein) can include a non-porous portion, or each of the membranes 25, 30 can be substantially completely non-porous. For example, a membrane is "substantially completely non-porous" if there are no holes through its surface that are in fluid communication with a corresponding sealed membrane cavity. Thus, for example, a membrane having holes around its periphery for mounting purposes but fluidly isolated (e.g., sealed) from the membrane cavity can be "substantially completely non-porous." The membranes 25, 30, or portions thereof, can be non-porous to provide a sealed cavity while allowing for expansion and contraction of the membrane using hydraulic pressure or vacuum during processing without leakage of liquid. The first and second substrate supports can be non-porous to form a first non-porous substrate support and a second non-porous substrate support, respectively.

[0101] The carrier head may include an inner support plate 33. Once assembled, the inner support plate may be fixed to prevent relative movement with respect to the carrier body 21. The inner support plate 33 may include a generally planar, rigid support surface configured to support a substrate held on the second substrate support portion of the second elastic membrane 30 during processing.

[0102] The carrier may include an outer support plate 36. The outer support plate 36 may include a generally planar, rigid support surface configured to support a substrate held by the first substrate support of the first elastic membrane 25. In some embodiments, the outer support plate 36 may support a portion of the first substrate support of the first elastic membrane 25. For example, the outer support plate 36 may include a central opening 41 surrounded by an outer plate portion that may support a corresponding outer portion of the first substrate support of the second elastic membrane 30 during processing. The central opening 41 may be configured to surround the second substrate support. In some embodiments, the width W1 of the first substrate support may be greater than the width W2 of the second substrate support. In some embodiments, the outer support plate 36, the first elastic membrane 25, and the second elastic membrane 30 may be configured to allow the second substrate support to pass through the central opening 41 of the outer support plate 36. Thus, in some embodiments, during processing, the inner support plate 33 can support the inner portion of a substrate held in the carrier 600, and the outer support plate 36 can support the outer portion of a substrate held in the carrier 600.

[0103] The films herein can be single or multi-zone films. For example, the films can have grooves (e.g., depressions) and / or raised portions that effectively separate various zones within each film. In a non-limiting example, the grooves can be arranged in a series of concentric circles emanating from the center of the film. In another example, the grooves and raised portions can be irregularly shaped (e.g., interconnecting circles, non-circular depressions, circular patterns scattered across the surface of the film) to improve the distribution of pressure applied across the substrate during processing. In some embodiments, the zones can be used to control or adjust material removal rates in different regions of the substrate by applying a temperature-controlled liquid to one or more associated zones of the elastic film(s).

[0104] In some embodiments, either or both elastic membranes may be single-zone membranes, configured so that each zone receives pressure or vacuum only from a single cavity behind each membrane. A "single cavity" is defined as a single volume in common fluid communication and is not limited to a particular shape. A cavity may include a small volume in common fluid communication, formed due to relatively small tolerances between parts not readily visible in FIG. 8 . For example, the carrier 600 may include a single first membrane cavity formed in a relatively small open space between the first substrate support portion of the first elastic membrane 25 and a portion of the carrier body 21 and / or outer support plate 36. The first membrane cavity may provide fluid communication from the liquid source 410 to the backside of the first substrate support portion of the first elastic membrane 25. Thus, by flowing a temperature-controlled liquid along the backside of the first elastic membrane 25, the substrate and first elastic membrane 25 may be cooled during a CMP process.

[0105] In some embodiments, the carrier 600 may include a single second membrane cavity formed, for example, between the second substrate support of the second elastic membrane 30 and the inner support plate 33. The second membrane cavity may be fluidly isolated from the first membrane cavity so that liquid does not leak from the first membrane cavity to the second membrane cavity. The first membrane cavity may increase in volume when the liquid in the first elastic membrane 25 is pressurized, for example, via the fluid backpressure regulator 445. The second membrane cavity may increase in volume when the corresponding second elastic membrane 30 is pressurized with a CDA.

[0106] In some embodiments, the bottom surface of the second elastic membrane 30 and / or the top surface of the first elastic membrane 25 may include texture and / or liquid channels. The texture and / or liquid channels may allow liquid to flow between the first elastic membrane 25 and the second elastic membrane 30, allowing the liquid to cool the area of ​​the substrate that overlaps the second elastic membrane 30.

[0107] (Comparison between silicon substrate and silicon carbide substrate) Due to the differences between silicon and silicon carbide substrates, many parameters associated with the CMP process performed for each type of process may differ. These variations in parameters can result in excessive heat generation in silicon carbide CMPs that are designed to be cooled in accordance with embodiments of the present disclosure. Table 1 below summarizes example values ​​for typical silicon and silicon carbide substrate CMP processes. [Table 1(1)]

[0108] The parameters used for CMP of silicon carbide substrates may vary depending on the particular implementation. In some implementations, during processing of silicon carbide substrates, the substrate carrier head may rotate at speeds that exceed the typical range of rotational speeds used for silicon. For example, to polish a silicon carbide substrate, the substrate carrier head may rotate at speeds greater than about 100 rpm, greater than about 110 rpm, greater than about 125 rpm, greater than about 150 rpm, or greater than about 175 rpm up to about 200 rpm, or any range therebetween.

[0109] The pressure applied to the substrate may also exceed the range typical for polishing silicon carbide substrates compared to polishing silicon substrates, where, for example, to polish a silicon carbide substrate, the control system 440 may control the fluid pressure to greater than about 6 psi, greater than about 7 psi, greater than about 8 psi, greater than about 9 psi, greater than about 10 psi, greater than about 11 psi, greater than about 12 psi, greater than about 13 psi, or greater than about 14 psi up to about 15 psi, or any range therebetween.

[0110] In typical polishing of silicon substrates, the temperature does not significantly exceed or fall below the ambient temperature of the environment (e.g., room temperature). However, without active temperature control (e.g., cooling) of the silicon carbide substrate, the temperature of the silicon carbide substrate and polishing pad can increase by more than about 100°F. By cooling the substrate (e.g., silicon carbide substrate) according to aspects of the present disclosure, the temperature of the substrate and polishing pad can be reduced by more than about 10°F, more than 20°F, more than 30°F, more than 40°F, more than 50°F, more than 60°F, more than 70°F, more than 80°F, more than 90°F up to 100°F, or any range of temperatures therebetween, compared to the temperature of the process occurring without active temperature control. As noted elsewhere, it is anticipated that controlling the temperature in some processes may be advantageous not only to reduce the temperature or maintain the temperature at a desired target, but also to increase the temperature. Thus, in some embodiments, the temperature of the CMP process can be controlled to within (plus or minus) 0°F, 10°F, 20°F, 30°F, 40°F, 50°F, 60°F, 70°F, 80°F, 90°F, or 100°F of a desired target temperature, or any range therebetween.

[0111] Embodiments herein may enable processing of substrates of reduced thickness. For example, silicon carbide substrates may also have thicknesses less than the typical silicon substrate thickness of about 600-800 μm. For example, silicon carbide substrates may have thicknesses of less than about 600 μm, less than about 500 μm, less than about 450 μm, less than about 400 μm, down to about 350 μm, or any range therebetween, or in some embodiments, about 350 μm.

[0112] Polishing silicon carbide substrates using embodiments herein may also allow for the use of lower material removal rates than are typical for silicon substrates. For example, material removal rates that may be implemented for silicon carbide substrates may be less than about 50 μm / h, less than 40 μm / h, less than 30 μm / h, less than 20 μm / h, less than 10 μm / h, down to 5 μm / h, and any range therebetween.

[0113] Polishing silicon carbide substrates using embodiments herein may also allow for the use of flow rates lower than the typical slurry flow rates of 100-200 ml / min for polishing silicon substrates. For example, the slurry delivery system 140 may deliver process slurry to the silicon carbide substrate at a flow rate of less than about 100 ml / min, less than about 90 ml / min, less than about 75 ml / min, less than about 60 ml / min, down to about 50 ml / min, or any range therebetween.

[0114] As used herein, "silicon" with respect to a "silicon wafer" or "silicon substrate" refers to the conventional material used in forming silicon wafers, which is typically a high-purity single-crystal material. Embodiments herein may enable processing of substrates with higher hardness than conventional silicon substrates, such as silicon carbide substrates. For example, substrates with hardness (Mohs hardness) greater than about 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, and any range therebetween, may be processed with reduced breakage. In some embodiments, substrates with hardness (Mohs hardness) greater than about 11 may be processed. In some embodiments, substrates with hardness (Mohs hardness) between about 8.5 and 10, or between 9 and 9.5, may be processed. Substrates with hardness greater than that of silicon in silicon substrates may be processed. Substrates that are not silicon in silicon substrates may be processed. In some embodiments, a silicon substrate may be included to provide temperature control for the process. Additionally, substrates other than silicon or silicon carbide substrates may be implemented.

[0115] (Liquid-cooled CMP system with rigid wafer support plate) Aspects of the present disclosure may also be applied to other CMP systems that do not use an elastic membrane. For example, FIGS. 9-12 illustrate one embodiment of a "rigid-back" substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate (e.g., the system of FIG. 4A or 4B ) according to aspects of the present disclosure. In particular, FIG. 9 is a perspective view of another embodiment of a substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate according to aspects of the present disclosure. FIG. 10 is a cross-sectional view of the substrate carrier of FIG. 9 taken along line AA of FIG. 9 . FIG. 11 is another cross-sectional view of the substrate carrier of FIG. 9 taken along line BB of FIG. 9 . FIG. 12 is another cross-sectional view of the bottom plate taken along line CC of FIG. 10 .

[0116] 9 and 10 , inlet and outlet lines 805 provide a path for circulating liquid through the wafer support plate 310. The support plate includes an upper plate and a lower plate that can be joined together to form a liquid cavity (e.g., liquid cooling passage) 815 therebetween. The upper and lower plates can be joined together to form a seam 810, for example, by furnace brazing. The liquid cooling passages 815 can be machined into the lower plate, and the lower and upper plates can be furnace brazed together to form the sealed liquid cooling passage 815. Similar to the embodiment shown in FIGS. 3 and 8 , the substrate carrier head can include a carrier body 21 for supporting various components of the carrier head. The carrier head can include a substrate holder 20 attached to the carrier body 21. The support plate 310 can be attached to each of the carrier body 21 and the substrate holder 20. In some embodiments, the entire periphery of plate 310 (including the top of plate 310 ) may be surrounded by retainer 20 and / or body 21 .

[0117] In the embodiments of FIGS. 9-12, the support plate 310 and substrate holder 20 can hold and support a substrate without the use of an elastic membrane. In some embodiments, the substrate carrier does not include an elastic membrane, and therefore the substrate carrier can be rigid. Although not shown, a carrier film can be included between the support plate 310 and the substrate to provide a cushion between the substrate and the support plate 310. As shown in FIG. 12, liquid cooling passages can be routed to cover substantially the entire area of ​​the support plate 310, such that no portion of the support plate 310 is more than a threshold distance from the liquid cooling passages. The liquid cooling passages can be machined into one or more of the bottom and top plates of the support plate 310. This allows the substrate carrier to be used to provide temperature control (e.g., cooling) of a substrate (such as a substrate formed of silicon carbide or other materials) as described above in connection with the elastic membrane embodiment. For example, a system similar to that shown in FIG. 4A or 4B, in which the membrane cavity 360 is replaced with a liquid cooling passage, can be used to circulate or recirculate a liquid for cooling a substrate during CMP.

[0118] (CMP system with temperature-controlled polishing pad) As described above, chemical-mechanical polishers can remove material from many different substrates using a combination of downward force (pressure), platen speed (friction), and abrasive chemistry. These materials include, but are not limited to, silicon, AlTiC, GaSi, SiC, glass, quartz, and other materials. The amount of pressure and friction applied to the wafer can be limited by the temperature of the pad the wafer is in contact with. High temperatures can cause pad failure, resulting in deformation, melting, glazing, and breakdown of the chemistry (e.g., slurry chemistry). Therefore, in certain implementations, the amount and / or rate of removal is limited not by the mechanical system but by the inability to remove the heat generated by the process. Effective heat removal can push the equipment's mechanical system to its limits, increasing removal rates. This increases throughput and enables processes that are not currently available.

[0119] Figure 13 is a plot showing the thermal conductivity of polyurethane as a function of temperature. In particular, Figure 13 illustrates why thermal management of heat within polyurethane pads can be difficult. Bulk polyurethane has a relatively low thermal conductivity (λ), which can make thermal management difficult when using polyurethane pads. In certain embodiments, the typical operating temperature for these pads is between 293 K (20°C) and 323 K (50°C), with a thermal conductivity of 0.0225-0.0275 W / mK.

[0120] Even with platen cooling, there may be a limit to the amount of heat from the pad that can be removed by conduction to the platen. Additionally, heat removal by convection and radiation may be negligible at typical operating temperatures of the pad.

[0121] FIG. 14A is an SEM image 830 of an IC1000 microporous polyurethane (MPU) polishing pad. FIG. 14B is a cross-sectional view of a polishing pad 832 and a wafer 834 during CMP, according to an embodiment of the present disclosure. The presence of micropores in the exemplary IC1000 microporous polyurethane (MPU) pad 832 can significantly reduce the thermal conductivity (λ). One technique that can be used to remove heat from the pad 832 is to cool the surface of the pad 832. In some embodiments, a liquid can be used to cool the pad 832. For example, water is a very good cooling medium. However, using more than 10 ml / m of water can dilute the slurry 836 used to polish the wafer 834, potentially negating the benefits of increased pressure 838 and velocity 840 by reducing the removal rate.

[0122] To prevent the added liquid from diluting the surface, the liquid (e.g., water) can be delivered in a manner that takes advantage of the liquid's latent heat of vaporization. Water has a latent heat of vaporization of approximately 2260 J / g, making it suitable for cooling the pad surface. Therefore, small amounts of water can be used to cool the pad, thereby cooling the pad without substantially affecting the chemistry of the slurry 836. In some embodiments, when considering the reduction in removal rate due to changes in the chemistry of the slurry 836, the amount of water used to cool the pad may be small enough to result in a net improvement in removal rate.

[0123] FIG. 15 is a schematic diagram of a substrate processing system including an atomizer system according to an aspect of the present disclosure. As shown in FIG. 15, the system can include an atomizer 905 configured to atomize a liquid and spread a very thin layer of liquid over a large surface area of ​​a pad 910 (which can be secured to a platen 915), allowing water to evaporate and heat to be extracted directly from the surface of the pad 910. The amount of heat removed (in watts) in one embodiment is 0.1 ml / s flow rate × 2260 J / g = 226 W. Experiments using a hot plate with an ammeter showed that for an exemplary 0.1 ml / s flow rate, the actual wattage value was 204 W. In various examples provided below, a system including the atomizer 905 was able to reduce the temperature of the pad by 14° C. (25.2° F.).

[0124] (Comparative example of pad cooling using a liquid atomizer) Below is provided experimental data for several experiments conducted to test the cooling of polishing pads using liquid cooling as described herein. For each of Experiments 1, 2, 4, and 5 below, wafers made of AlTiC were used.

[0125] Experiment 1 is shown in Table 1 (high pressure, high speed, no cooling to the platen by a cooling device, no cooling of the carrier, no atomizer). [Table 1(2)]

[0126] Experiment 2 is shown in Table 2 (high pressure, high speed, no cooling to the platen by the cooling device, no cooling of the carrier, atomizer activated). [Table 2]

[0127] FIG. 16 is a plot showing the normalized removal rate versus temperature before and after application of the atomizer nozzle to the Si wafer of Experiment 3.

[0128] Experiment 4 is shown in Table 3 (high pressure, high speed, no cooling to the platen by the cooling device, cooling starts at the carrier, no atomizer). [Table 3]

[0129] Experiment 5 is shown in Table 4 (high pressure, high speed, no cooling to the platen by the cooling device, carrier cooling started, atomizer started). [Table 4]

[0130] (CMP system with retaining ring) 17 is a plot showing the relationship between ring pressure (psi) and platen temperature (° C.) for a CMP system using a retaining ring. As shown in FIG. 17, there is a substantially linear relationship between ring pressure and platen temperature.

[0131] In an exemplary embodiment, the retaining ring may have a surface area of ​​18.9 square inches. A commanded downward force of approximately 240 pounds applied to the retaining ring of this embodiment can exert a pressure of approximately 12.7 psi on the pad surface. In some embodiments, the system can provide the commanded pressure (e.g., in psi) to the ring. In one embodiment, each psi of pressure on the ring results in 24 pounds of force. Reducing the contact area of ​​the retaining ring by using a separate retaining ring with a surface area of ​​approximately 5 square inches can exert a pressure of approximately 48 psi on the pad. Reducing the contact area between the retaining ring and the polishing pad can also reduce the heat generated during polishing, which is particularly advantageous for certain wafers, such as silicon carbide wafers. Therefore, pad pressure can be related to the surface area of ​​the retaining ring, as the downward force is spread across the available surface area of ​​the retaining ring. One effect of reducing the contact area of ​​the retaining ring can be increased wear on the retaining ring. For example, a smaller surface area of ​​the retaining ring and higher applied pressure can result in faster retaining ring wear.

[0132] The increased wear on the retaining ring can be at least partially mitigated by changing the material of the portion of the retaining ring that contacts the pad to a harder, more wear-resistant material. However, using such a hard material for the retaining ring can result in wafer breakage due to the wafer's fragility. Certain types of wafers are more fragile, and using a harder material for the retaining ring increases the likelihood of breakage. Figure 18 shows a retaining ring 1000 with a stepped shape. Although not shown, in certain embodiments, the retaining ring 1000 can be formed from two different materials. Using another material, such as polyphenylene sulfide (PPS) or polyether ether ketone (PEEK), can reduce wear on the retaining ring while preventing the retaining ring from breaking the wafer, especially when the wafer is in contact with the ring.

[0133] To reduce retaining ring wear, the CMP processes disclosed herein can use a retaining ring 1000 with a low surface area and two-piece construction. For example, in some embodiments, the retaining ring can have a surface area of ​​less than 15 square inches, less than 12 square inches, less than 10 square inches, less than 8 square inches, or less than 5 square inches for a 150 mm carrier. For example, the retaining ring 1000 can include a hard, low-wear rate outer material, such as aluminum oxide, zirconium oxide, boron nitride, boron carbide, silicon carbide, stainless steel, or the like. The retaining ring 1000 can further include an inner material with an engineered polymer compatible with substrate contact, such as PPS, PEEK, Torlon®, Rulon®, polysulfone (PSU), Ultem polyetherimide (PEI), or polyvinylidene fluoride (PVDE).

[0134] Using an outer material with sufficient hardness can minimize ring wear during CMP and extend the service life of the retaining ring. As shown in Figure 5, the retaining ring can also have a stepped contact surface to reduce the contact area and reduce the heat generated by contact between the retaining ring face and the polishing pad.

[0135] (summary) The atomization system described herein includes the use of any type of atomization system to cool or remove energy and / or heat from a polishing pad in a CMP system. The atomization system can use any liquid medium in combination with any compressed gas through an orifice to cool or remove energy and / or heat from the pad, thereby enabling higher removal rates during CMP. Aspects of the present disclosure also relate to the use of any adiabatic cooling system to cool or remove energy and / or heat from the polishing pad. When using an atomizer, the system can be further configured to control the temperature of the atomized fluid as an additional means to control the temperature of the pad surface during CMP. Yet another aspect of the present disclosure relates to the application of cooling and / or temperature-control gas (such as compressed air) flowing through a vortex cooling nozzle as an additional means to cool the pad surface without adversely affecting the CMP process and consumables.

[0136] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect or embodiment described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other aspects or embodiments. Various aspects of the novel systems, apparatus, and methods are described more fully below with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art should understand that the scope of the disclosure is intended to cover any aspect of the novel systems, apparatus, and methods disclosed herein, whether implemented independently or in combination with other aspects described. For example, an apparatus can be realized or a method can be practiced using any number of the aspects described herein. Moreover, the scope of the disclosure is intended to cover such apparatus or methods that are implemented using other structure, functions, or structures and functions in addition to or other than the various aspects of the disclosure described herein. It should be understood that any aspect disclosed herein may be embodied by one or more elements of a claim.

[0137] Additionally, unless a term is expressly defined in this patent using the phrase "As used herein, the term . . . is herein defined to mean . . . " or similar phrase, there is no intention to expressly or impliedly limit the meaning of that term beyond its plain or ordinary meaning, and such term should not be construed as limited in scope based on any statement made anywhere in this patent (other than the claim language). To the extent that terms set forth in the final claims of this patent are referred to in this patent in a manner consistent with a single meaning, this is done solely for clarity to avoid confusing the reader, and no intention is made that such claim term be limited, by implication or otherwise, to that single meaning.

[0138] Conditional language such as "can," "can," "could," or "may," unless otherwise specified or interpreted otherwise within the context of use, is generally intended to convey that some embodiments include certain features, elements, and / or steps, but other embodiments do not. Thus, such conditional language is generally not intended to suggest that the features, elements, and / or steps are somehow essential to one or more embodiments, or that one or more embodiments necessarily include logic for determining whether these features, elements, and / or steps are included in or performed in any particular embodiment, with or without user input or prompting.

[0139] Unless otherwise specified, conjunctive language such as the phrase "at least one of X, Y, and Z" is understood in the context in which it is generally used to convey that an item, term, etc. can be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that a particular embodiment requires the presence of at least one X, at least one Y, and at least one Z.

[0140] As used herein, language of degree, such as the terms "approximately," "about," "generally," and "substantially," refers to a value, amount, or characteristic that approaches a stated value, amount, or characteristic that still performs a desired function and / or achieves a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within 10%, 5%, 1%, 0.1%, and / or 0.01% of the stated amount, depending on the desired function or intended result.

[0141] While specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications of the systems and methods described herein may be made without departing from the spirit of the present disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure.

[0142] It should be understood that features, materials, properties, or groups described in connection with a particular aspect, embodiment, or example are applicable to any other aspect, embodiment, or example described here or elsewhere in this specification, except where incompatible. All features disclosed herein (including the accompanying claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of such embodiments described above. Protection extends to any novel, or any novel combination, of features disclosed herein (including the accompanying claims, abstract, and drawings), or to any novel, or any novel combination of steps of any method or process so disclosed.

[0143] Also, certain features that are described in the context of a single embodiment of the disclosure can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described above as functioning in a particular combination, one or more features from the claimed combination can, in some cases, be deleted from the combination, and the combination can be claimed as a subcombination or a variation of the subcombination.

[0144] Furthermore, while operations may be depicted in the figures or described in the specification in a particular order, such operations need not be performed in the particular order or sequence shown, nor need all operations be performed, to achieve desirable results. Other operations not shown or described may be incorporated into the example methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between the operations described. Furthermore, in other embodiments, operations may be rearranged or reordered. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the embodiment, certain steps described above may be removed, and other steps may be added. Furthermore, features and attributes of specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. Additionally, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments. It should also be understood that the described components and systems may typically be integrated into a single product or packaged into multiple products. For example, any of the components of the energy storage systems described herein may be provided separately or may be integrated together (e.g., packaged together or attached together) to form the energy storage system.

[0145] For purposes of this disclosure, certain aspects, advantages, and novel features have been described herein. Not necessarily all such advantages may be achieved in accordance with a particular embodiment. Thus, for example, one skilled in the art will recognize that the invention may be embodied or carried out in a way that achieves one advantage or group of advantages as taught herein, without necessarily achieving other advantages as taught or suggested herein.

[0146] The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the apparatus and methods disclosed herein.

[0147] The scope of the present disclosure is not intended to be limited by the specific disclosure of preferred embodiments here or elsewhere herein, but rather may be defined by the claims, as presented here or elsewhere herein, or as presented in the future. Claim language is to be interpreted broadly based on the language used in the claims, and not limited to the examples described herein or pending in the application, which examples are to be construed as non-exclusive.

Claims

1. A carrier body; a substrate holder attached to the carrier body, the substrate holder including an opening configured to receive a substrate; an elastic membrane having a first surface configured to contact a surface of the substrate and a second surface opposite the first surface; a membrane cavity formed along the second surface; an inlet configured to allow liquid to enter the membrane cavity; an outlet configured to allow liquid to exit the membrane cavity; a substrate carrier head including:

2. The substrate carrier head of claim 1 , wherein the outlet is located at a greater radial distance from the center of the carrier body than the inlet.

3. The substrate carrier head of claim 2 , wherein the inlet is located approximately centrally in the carrier body.

4. The substrate carrier head of claim 1 , further comprising a secondary elastic membrane having a width less than the width of the elastic membrane.

5. The substrate carrier head of claim 1 , further comprising a fluid-tight seal between the elastic membrane and the carrier body.

6. 1. A substrate carrier head, comprising: A carrier body; a substrate holder attached to the carrier body and configured to hold a substrate to the carrier body; an elastic membrane having a first surface configured to contact a surface of the substrate and a second surface opposite the first surface; a membrane cavity formed along the second surface configured to allow liquid to flow along the second surface; a substrate carrier head including: a control system configured to adjust at least one of a pressure and a flow rate of the liquid through the membrane cavity; a substrate carrier system comprising:

7. the substrate carrier head an inlet configured to allow liquid to enter the membrane cavity; an outlet configured to allow liquid to exit the membrane cavity; The substrate carrier system of claim 6 further comprising:

8. The substrate carrier system of claim 7 , wherein the control system is further configured to recirculate the liquid from the outlet to the inlet.

9. The substrate carrier system of claim 7 , wherein the outlet is located at a greater radial position from a center of the carrier body than the inlet.

10. The substrate carrier system of claim 9 , wherein the inlet is located approximately centrally in the carrier body.

11. The substrate carrier system of claim 6 , wherein the control system is further configured to cool the liquid to below ambient temperature.

12. a liquid source fluidly connected to the membrane cavity; The substrate carrier system of claim 6 further comprising:

13. the substrate carrier head A secondary elastic membrane having a width narrower than the width of the elastic membrane The substrate carrier system of claim 6 further comprising:

14. The substrate carrier system of claim 13 , wherein said elastic membrane is substantially completely imperforate.

15. The substrate carrier system of claim 6 , wherein the control system includes a fluid backpressure regulator configured to control fluid pressure.

16. 16. The substrate carrier system of claim 15, wherein the control system further comprises an air pressure regulator configured to provide a signal to the fluid backpressure regulator to control the liquid pressure.

17. an air source fluidly connected to the air pressure regulator; The substrate carrier system of claim 16 further comprising:

18. a liquid aspirator configured to provide a negative pressure to the liquid within the membrane cavity; The substrate carrier system of claim 6 further comprising:

19. The substrate carrier system of claim 6 , further comprising said substrate, said substrate being a silicon carbide wafer.

20. The substrate carrier system of claim 6 , further comprising a liquid, wherein the liquid comprises water.

21. The substrate carrier system of claim 6 , wherein the control system is further configured to rotate the substrate carrier head at a speed greater than 100 rpm.

22. The substrate carrier system of claim 6 , wherein the control system is further configured to control the liquid pressure to a pressure greater than 6 psi.

23. The substrate carrier system of claim 6 , wherein the control system is further configured to control the temperature of the substrate to less than 100° F. during chemical mechanical polishing (CMP).

24. The substrate carrier system of claim 6 , further comprising said substrate, said substrate having a thickness of less than 600 μm.

25. The substrate carrier system of claim 6 , further comprising a slurry delivery system configured to deliver processing slurry to the substrate at a rate of less than 100 ml / min.

26. 1. A method of cooling a substrate during chemical mechanical polishing (CMP) of the substrate, comprising: holding a substrate within an opening in a substrate holder attached to a carrier body of a carrier head; providing a liquid to a membrane cavity in the carrier head; flowing the liquid along a first surface of an elastic membrane into the membrane cavity; A method comprising:

27. adjusting at least one of the pressure and flow rate of the liquid through the membrane cavity.

27. The method of claim 26, further comprising:

28. allowing the liquid to flow through an inlet into the membrane cavity; allowing the liquid to exit the membrane cavity through an outlet; 27. The method of claim 26, further comprising:

29. Recirculating the liquid from the outlet to the inlet.

30. The method of claim 28, further comprising:

30. cooling the liquid to below ambient temperature.

27. The method of claim 26, further comprising:

31. controlling at least one of the flow rate and the pressure of the liquid in the membrane cavity at a selected value.

27. The method of claim 26, further comprising:

32. 32. The method of claim 31, wherein the controlling step includes controlling the pressure of the liquid via a fluid backpressure regulator located downstream of the membrane cavity.

33. providing a negative pressure to the liquid to suck the substrate against the elastic membrane; 27. The method of claim 26, further comprising:

34. A carrier body; a substrate holder attached to the carrier body, the substrate holder including an opening configured to receive a substrate; a liquid cavity formed adjacent the opening in the substrate; an inlet configured to allow liquid to enter the liquid cavity; an outlet configured to allow liquid to exit the liquid cavity; a substrate carrier head including:

35. A polishing pad; a substrate carrier head configured to hold a wafer against the polishing pad; an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of ​​the polishing pad to evaporate the liquid and extract heat directly from the surface of the polishing pad; 1. A chemical mechanical planarization (CMP) system comprising:

36. 36. The CMP system of claim 35, wherein the atomizer is further configured to combine a compressed gas with the liquid to force the liquid through an orifice to atomize it.

37. 36. The CMP system of claim 35, wherein the polishing pad is formed of polyurethane.

38. 36. The CMP system of claim 35, wherein the amount of liquid provided to the polishing pad is small enough to prevent a significant decrease in removal rate due to a change in the chemistry of a slurry applied to the polishing pad.

39. 36. The CMP system of claim 35, further comprising a retaining ring having a stepped configuration.

40. 40. The CMP system of claim 39, wherein the retaining ring is formed from polyphenylene sulfide (PPS) or polyetheretherketone (PEEK).

41. 36. The CMP system of claim 35, wherein the retaining ring has a two-piece construction.

42. 36. The CMP system of claim 35, wherein the retaining ring has a surface area of ​​less than 15 square inches.

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