Containment and exhaust system for substrate polishing parts

Abstract

A containment and evacuation system for a substrate polishing component is disclosed. In one aspect, a substrate carrier head includes 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, and a chamber configured to contain and evacuate the atomized liquid. A method of cooling a substrate during chemical mechanical polishing (CMP) of the substrate is also disclosed, the method includes providing a slurry to a surface of the polishing pad, performing at least one of the following: providing an atomized cooling liquid to the surface of the polishing pad, providing a cleaning liquid to the surface of the polishing pad, and removing at least a portion of at least one of the atomized cooling liquid and the cleaning liquid from a point proximate to the surface.

Description

[Technical field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 154,175, filed February 26, 2021, and U.S. Provisional Patent Application No. 63 / 165,652, filed March 24, 2021, the disclosures of each of which are incorporated by reference in their entirety and for all purposes.

[0002] The present disclosure relates generally to substrate processing equipment, and more particularly to systems and apparatus for improving chemical mechanical planarization (CMP) performance for planarization of thin films. [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 rotating wafer carrier and pressed against the polishing platen for a specific time. The wafer is polished or planarized by both abrasion and erosion in the CMP process. The interaction between the wafer and carrier during processing can cause wafer breakage, non-uniformity, or other issues. Therefore, there is a need to improve the performance of the wafer carrier to address the effects caused by the interaction between the wafer and carrier during processing. Summary of the Invention

[0004] For purposes of outlining 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 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 may be taught or suggested herein.

[0005] One aspect of the disclosed technology is a chemical mechanical planarization (CMP) system comprising a polishing pad, a substrate carrier head configured to hold a wafer against the polishing pad, at least one of the following: an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of ​​the polishing pad, and a spray device including at least one pad cleaning nozzle configured to spray a cleaning liquid onto the polishing pad to clean the polishing pad, a chamber configured to receive at least one of the atomized liquid and the cleaning liquid from the chamber, and an output configured to remove at least one of the atomized liquid and the cleaning liquid from the chamber.

[0006] The chamber may include an inner chamber and an outer chamber disposed to surround the inner chamber.

[0007] The inner chamber and the outer chamber may be coaxially disposed.

[0008] The atomizer may include an output nozzle configured to eject the atomized liquid within the inner chamber.

[0009] The outer chamber may be configured to have a lower pressure than the inner chamber.

[0010] The outer chamber may include an output configured to exhaust the atomized liquid.

[0011] The output may include an exhaust port, and the CMP may further include a scrubber coupled to the exhaust port and configured to reduce the level of any corrosive and / or toxic chemicals from the atomized liquid.

[0012] The atomized liquid can be configured to cool the polishing pad via evaporative cooling.

[0013] The polishing pad may be made of polyurethane.

[0014] The polishing pad may be further configured to polish the wafer when the wafer is formed of silicon carbide.

[0015] The spray device may include a spray bar disposed within the chamber.

[0016] The chamber may include an inner chamber and an outer chamber disposed surrounding the inner chamber, with the spray bar disposed within the inner chamber.

[0017] The CMP system may further include at least one exhaust plenum flush nozzle configured to spray a cleaning fluid into the outer chamber.

[0018] One aspect of the disclosed technology is a method of cooling a substrate during chemical mechanical polishing (CMP) of the substrate, the method including: supplying a slurry to a surface of a polishing pad; performing at least one of the following: supplying a misted coolant to the surface of the polishing pad; and supplying a cleaning liquid to the surface of the polishing pad; and removing at least a portion of at least one of the misted coolant and the cleaning liquid from a point proximate to the surface.

[0019] The removing step may include evacuating the at least one of the atomized cooling liquid and the cleaning liquid from a chamber disposed above the surface.

[0020] The removing step may include draining the at least one of the atomized cooling liquid and the cleaning liquid from a chamber disposed above the surface.

[0021] The chamber may include an inner chamber and an outer chamber disposed to surround the inner chamber.

[0022] The exhausting step may further include flowing the atomized cooling liquid from the inner chamber through a gap to the outer chamber and from the outer chamber through an exhaust port.

[0023] The exhausting step may further include flowing the atomized cooling liquid from the exhaust port to a scrubber.

[0024] The method may further include spraying a cleaning fluid onto the polishing pad with a spray bar disposed within the inner chamber.

[0025] The method may further include spraying a cleaning fluid into the outer chamber through at least one exhaust flush nozzle.

[0026] Another aspect of the disclosed technology is a chemical mechanical planarization (CMP) system comprising a polishing pad, a substrate carrier head configured to hold a wafer against the polishing pad, a chamber including a plenum configured to contain a liquid, and at least one of the following: an atomizer configured to atomize the liquid in the chamber and spread a layer of the atomized liquid over a surface area of ​​a portion of the polishing pad in the chamber, a nozzle configured to at least one of spray a cleaning liquid onto a portion of the polishing pad and spray a cleaning liquid onto an outer portion of the chamber, and an outlet configured to remove the cleaning liquid from the chamber.

[0027] 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 of ordinary skill 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 description of the drawings]

[0028] 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.

[0029] [Figure 1] 1 is a schematic diagram of a substrate processing system showing a substrate carrier holding a substrate in a processing position. [Diagram 2] 2 is a diagram of the substrate processing system of FIG. 1 showing a substrate carrier holding a substrate in a loading position; [Diagram 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 in accordance with aspects of the present disclosure. [Figure 4B] FIG. 1 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. [Diagram 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] 1 is an exploded top isometric view of one embodiment of a substrate carrier head according to aspects of the present disclosure. [Figure 7] 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. [Figure 11] 10 is another cross-sectional view of the substrate carrier of FIG. 9 taken along line BB of FIG. [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 a SEM image of an IC1000 microporous polyurethane (MPU) pad. [Figure 14B] FIG. 2 is a cross-sectional view of a polishing pad and a 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 an aspect of the present disclosure. [Figure 16] 1 is a plot showing the difference in pad temperature between Run 1 and Run 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. [Figure 19] 1 is a cross-sectional view of an exemplary CMP system including an atomized coolant containment and exhaust system according to an aspect of the present disclosure. [Figure 20] 20 is an exploded perspective view of two of the plenums forming the outer and inner chambers of FIG. 19. FIG. [Figure 21A] 20 provides an additional view of an embodiment of a plenum forming the outer and inner chambers of FIG. 19. [Figure 21B] 20 provides an additional view of an embodiment of a plenum forming the outer and inner chambers of FIG. 19. [Figure 21C] 20 provides an additional view of an embodiment of a plenum forming the outer and inner chambers of FIG. 19. [Figure 21D] 20 provides an additional view of an embodiment of a plenum forming the outer and inner chambers of FIG. 19. [Figure 22A] 1 provides an illustration of an exemplary CMP system including a containment and exhaust system that includes a spray device in accordance with an aspect of the present disclosure. [Figure 22B] 1 provides an illustration of an exemplary CMP system including a containment and exhaust system that includes a spray device in accordance with an aspect of the present disclosure. [Figure 23] 1 provides a schematic diagram of an example of a CMP system with a sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Although the following text describes 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 the patent application. The detailed description should be construed as merely exemplary and does not describe all possible embodiments of the present invention, since describing all possible embodiments is 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, and still fall within the scope of the claims that define the present invention.

[0031] (Chemical mechanical planarization (CMP)) The adoption and use of chemical mechanical planarization (CMP) for the planarization of thin films in the manufacturing of semiconductor ICs, MEMS devices, and LEDs is common among companies that manufacture the "chips" of these types of devices, among many other similar applications. This adoption includes the manufacturing of chips for cell phones, tablets, and other portable devices, as well as for desktop and laptop computers. 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 the planarization of thin films was invented and developed in the early 1980s by IBM scientists and engineers. Today, the process is widespread on a global scale and is one of the truly enabling technologies in the manufacturing of many digital devices.

[0032] Integrated circuits are fabricated with 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). Successive combinations of these layers are applied sequentially to the wafer surface, with devices embedded in the surface, resulting in topographical irregularities in the device structures. This is common with silicon dioxide insulator layers. These unwanted topographical irregularities are flattened or "planarized" using CMP before the next layer can be deposited to allow proper interconnection between device structures of smaller and smaller size. In the case of copper layers, copper is deposited on the surface to fill contact vias, making effective vertical paths for the movement of electrons between devices and between layers. This procedure continues with each layer that is 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 achieve successful circuitry and interconnection between device structures.

[0033] In the CMP process, the substrate or wafer is held by a wafer carrier, which rotates and is usually pressed against a platen through an elastic membrane in the wafer carrier for a certain time of polishing. The CMP wafer carrier usually incorporates components for precision polishing of generally flat and round workpieces, such as silicon wafers and / or films deposited thereon, in a process head. These components include 1) an elastic membrane with compressed gas applied to its top or back side, which pressure is transferred through the membrane to the top or back side of the workpiece to remove material during CMP, and 2) one or more rigid support components that provide a means for fixing the membrane to its mating components, holding the membrane in its desired shape and dimensions, and / or clamping the membrane to provide a sealed volume for sealing and containing a controlled gas pressure.

[0034] During the process, the slurry is applied to the rotating polishing pad via a fluid control device such as a metering pump and a mass flow control regulator system. The slurry can be delivered to the polishing platen with a single pass distribution system. To improve performance, the slurry particles in the media need to be evenly distributed between the rotating wafer and the rotating polishing pad / platen.

[0035] 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. The motion and force causes wear on a portion of the pad by forcing the abrasive against the substrate as it moves across the wafer surface. Corrosive chemicals in the slurry change the material being polished on the surface of the wafer. This combination of mechanical effects of wear and chemical changes is called chemical mechanical planarization or polishing (CMP). The rate of material removal can easily be an order of magnitude higher using both chemical and mechanical effects simultaneously compared to either one alone. Similarly, the combined use of chemical and mechanical effects improves the smoothness of the surface after polishing.

[0036] During the polishing process, materials such as copper, dielectrics, polysilicon, etc. are removed from the surface of the wafer. These tiny particles either remain suspended in the slurry, become embedded in the polishing pad, or both. These particles cause scratches on the surface of the film being polished, which can cause catastrophic failure of the circuitry, rendering the chip useless and significantly impacting yield.

[0037] Yield is the driving force that determines the success at the manufacturing level of many products, such as integrated circuits, MEMS, and LEDs. Surface quality tolerances of CMP processes in semiconductor manufacturing 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 toward improving this capability. Small non-uniformities in the flatness of wafers processed in a CMP system can reduce yields and increase waste. Non-uniformities or pressure differences across the diameter of the wafer carrier and processing pads can cause wafer breakage. The cumulative costs of manufacturing solid-state devices are collectively referred to as "cost of ownership" (CoO), and the term also applies to each of the manufacturing steps required. The CoO of the CMP process has one of the highest CoO figures of the 500-800 individual manufacturing steps required to manufacture semiconductor "chips" and their associated digital devices.

[0038] 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 consume less power and be more heat resistant. Thus, as automobiles use more and more 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.

[0039] However, silicon carbide is a harder material than silicon. Thus, silicon carbide wafers may require higher pressures and / or velocities (e.g., relative velocity between the surface of the wafer and the polishing pad / platen) to achieve sufficient removal rates during CMP compared to an otherwise similar silicon wafer-based CMP process. Such higher pressures and / or velocities may increase heat generated during CMP of silicon carbide wafers compared to similar silicon wafer-based CMP. Such increased heat may in turn 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 may lead to surface defects on the wafer. Excessive heat may 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. Thus, cooling of the wafer and / or elastic membrane is required to reduce the temperature during polishing. It will be understood that aspects of the present disclosure may be practiced with substrates formed of materials other than silicon carbide, and may be practiced 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 involving a substrate carrier, such as CMP.

[0040] The surface temperature of the CMP pad can be an important variable in CMP processing. The pad temperature can vary widely depending on many variables, such as the idle time before the process begins, the rotation speed of the wafer and platen, the wafer pressure, the slurry flow rate, the number of wafers being processed on the platen, the slurry temperature, and other variables. Aspects of the embodiments described herein can maintain the pad surface temperature essentially constant, e.g., about 50° C., over a wide range of these variables. This is believed to be due to the heat of evaporation of the atomized water applied to the pad surface, which keeps the pad surface at a constant temperature, largely independent of the extent to which these other variables cause large temperature fluctuations. This is another important advantage of the present embodiments, since temperature stability is critical to the stability of the CMP process.

[0041] CMP tools are usually connected to an external exhaust source. Its main purpose is to remove fumes that may result from the evaporation of the slurry, especially slurries that may be toxic, volatile (strong fumes such as ammonia) and / or corrosive. The exhaust connection is usually on the bottom deck or ceiling of the polisher. In either case, the airflow caused by the exhaust is not close to the surface of the polishing pad where the slurry is dispensed and where the fumes are generated. According to the present invention, the airflow caused by the exhaust is applied directly to the pad surface, at the point of use (close to) the slurry, and is highly constrained to reduce (e.g., minimize) its spread to larger areas / volumes within the polisher and / or operating environment and increase (e.g., maximize) the collection of fumes. This is a significant improvement for operator safety, environmental friendliness, and machine life.

[0042] The disclosed technology will be described with respect to certain 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 non-limiting. In the drawings, the size of some elements may be exaggerated for illustrative purposes and not drawn to scale. The dimensions and relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.

[0043] (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. It will be understood that the term "wafer" as used herein may refer to a semiconductor wafer (e.g., circular), but may more broadly encompass other types of substrates of different shapes that are processed by a polishing or planarization equipment, such as a CMP equipment. Thus, 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 "wafer" of "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 membrane (not shown). The polishing pad 110 may be disposed on a support surface, such as the surface of a platen 120.

[0044] FIG. 2 is a diagram of the chemical mechanical planarization system of FIG. 1, showing a substrate 155 held in a loaded (e.g., top) position by a substrate carrier 150. The substrate 155 may be held by, for example, vacuum force. With reference to both FIG. 1 and FIG. 2, the system 100 may include a slurry delivery system 140 configured to deliver a process slurry to the substrate 155 and enable it to be chemically / mechanically planarized 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 process characteristics of the pad during or between process cycles.

[0045] 1 and 2, the polishing pad 110 rests on top of a platen 120 that rotates counterclockwise about a vertical axis, although other orientations and directions of movement can be implemented.

[0046] The slurry delivery system 140 can deliver a slurry containing abrasive and corrosive particles to the treated surface of the 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.

[0047] 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 by the slurry delivery system 140 on the polishing pad 110 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 such that the substrate 155 is pressed 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 of 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 being configured to oscillate, translate, and / or rotate counterclockwise and / or clockwise relative to one another.

[0048] The pad conditioning arm 160 can condition the surface of the polishing pad 110 by pressing against the polishing pad 110 with a force, with the polishing pad and the substrate carrier 150 moving relative to each other, such as the relative movements described above. 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.

[0049] 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 attached. The support base 380 may be of any suitable configuration for providing support to the film assembly. The support base 380 may be attached to 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 a CMP system.

[0050] The membrane assembly 305 may include a support plate 310, an elastic membrane 320, a membrane retainer such as a membrane clamp 330, and an optional external pressure ring 340, as shown. The support plate 310 may be of any suitable configuration for supporting a wafer during processing, 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.

[0051] 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 a number of 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 by using any of a number of suitable different membrane retainer retaining 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 by 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.

[0052] The elastic membrane 320 can be secured to the support plate 310 such 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 Figures 1 and 2. The membrane can include a (e.g., downward) first surface configured to contact the (e.g., upward) surface of the substrate. The membrane 320 can have sufficient elasticity and flexibility such that, in combination with the polishing pad material and process parameters, the membrane 320 can apply a 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 and press 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 second surface, e.g., the upward surface opposite the first membrane surface described above. 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 in the membrane cavity 360 to prevent liquid from leaking out of 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. The seal can be formed, for example, between a portion of the membrane 320 and a portion of the carrier body (e.g., the plate 310 and / or the base 380) 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., valved open or closed).

[0053] In some embodiments, when the membrane 320 is at rest, a portion of the membrane 320, e.g., its upwardly facing surface, is on or adjacent to a corresponding portion of the plate 310, e.g., its downwardly facing surface. The membrane cavity 360 is then 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 thus 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 can provide liquid 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., circular tube, square tube, etc.). In some embodiments, a vacuum can be provided to the cavity 360 via the inlet and / or outlet to hold the wafer 370 under the membrane assembly, as described further herein.

[0054] 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, for example, 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 in concentric circles. 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.

[0055] 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 similarly (e.g., separately) as described herein for a single-zone carrier with 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 isolate 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 interspersed 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, the removal rate can be higher in zones to which higher pressure is applied. 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) may be applied to a particular zone to increase the removal rate compared to another zone. The effect of temperature change on the removal rate may be relatively lower than the effect of pressure change. Thus, temperature may be used as a fine tuning variable when adjusting the removal rate of a single zone or multi-zone system. For example, the pressure of a first zone may be controlled to be the same as, greater than, or less than the pressure of a second zone. The temperature of the first zone may be controlled to be the same as, greater than, or less than the temperature of the second zone.

[0056] The membrane 320 can be flexible so that it conforms to the structure it surrounds. In some cases, the membrane 320 can be convex. For example, the membrane 320 can be slack 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 finer polishing.

[0057] The membrane material may be any elastic material suitable for planarization, as described herein, for example, 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, the membrane material 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 heat transfer properties of the material. 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 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 Martoxid® owned by Martinswerk GMBH.

[0058] One or more membrane assemblies can be implemented in a single CMP system, which may have controls (e.g., variable speed motor controls, etc.) that utilize feedback from the system during operation to more precisely control the CMP process.

[0059] In an exemplary embodiment, the film 320 may be planarized. For example, the film 320 may be made to be flat within a desired tolerance and / or to match a surface roughness within a desired tolerance. For example, the film 320 may undergo a planarization procedure in which the film is placed over a polishing pad. Also, the film 320 may be introduced into a chemical slurry that causes the film 320 to be planarized. Additionally, the surface roughness of the film 320 may be improved throughout this planarization process. Surface roughness may be important for films used in conjunction with CMP processes for at least two reasons: sealability and stiction. The planarization process may reduce the surface roughness to improve sealability between the substrate 370 and the film 320 for handling purposes. At the same time, the surface roughness may be increased to prevent stiction (i.e., the film sticking to the substrate due to surface tension) and improve the release of the substrate from the film after processing. Control mechanisms may be used during 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.

[0060] As discussed 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 liquid along a 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.

[0061] 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 containers, 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, to provide 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, as described herein. 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 piece 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 in the membrane cavity 360. For example, the control system 440 can include a fluid back pressure 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 back pressure 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 with 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.

[0062] 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. Depending on the embodiment, other liquids can also be used.

[0063] A liquid source 410 selectively provides liquid to the membrane cavity 360 (e.g., via a rotary union 435 via a valve 425). The rotary union may include a set of fluid channels that allow the liquid source 410 to provide liquid to an inlet 350 of the carrier head 500 and receive liquid exiting the substrate carrier head 300 via an 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 exit the membrane cavity 360 via the outlet 355, for example, to a fluid backpressure regulator 445.

[0064] 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 fluid back pressure regulator 445 can be directly controlled by the control processor without including the air pressure regulator 415. 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 a portion of the liquid to drain to the liquid drain port 450. The liquid drain port 450 can include a T-connection 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 can be configured to control the pressure applied to the substrate during CMP to control the pressure of the liquid in the membrane cavity 360. 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. Thus, the fluid backpressure regulator 445 may be configured to regulate 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.

[0065] 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 a negative pressure (e.g., a 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, which provides support to the backside of the elastic membrane 320, may include holes for providing the above-mentioned vacuum (to give the wafer a suction cup effect) and / or for allowing positive pressure of the liquid in the membrane cavity 360 to separate the substrate 370 from the elastic membrane 320.

[0066] In some embodiments, excess liquid exiting the liquid ejection port 450 can simply be discarded, forming a non-recirculating system. However, in other embodiments, excess liquid exiting the liquid ejection 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.

[0067] 4B is a block diagram illustrating another substrate carrier system that can be used to control the temperature of a wafer according to an embodiment of the present disclosure. With reference 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 the carrier head 300 or 600), a platen 740, an output pressure gauge 745, a recirculation / vacuum valve 750, and a vacuum isolator 755.

[0068] In the embodiment of Figure 4B, a 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 a fluid back pressure regulator 445 upstream of the carrier head 500 can be implemented in the embodiment of Figure 4A.

[0069] 3, 4A, and 4B, when the liquid flows through the membrane cavity 360 along the backside of the elastic membrane 320, heat generated by friction of 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 during 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.

[0070] 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 radial location farther from the center of the carrier body than 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 in the flow of liquid from the inlet 350 to the outlet 355 due to centripetal forces. Although a single inlet 350 and a single outlet 355 are shown in FIG. 3, in some embodiments, multiple inlets 350 and / or outlets may be included. 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.

[0071] 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 outer 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 under the membrane assembly 305. These components may have similar functions as those described in connection with FIG. 3.

[0072] 5, the inlet 350 and the outlet 355 can be located at opposing locations, such as 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.

[0073] It will be appreciated 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, although a single inlet 350 and outlet 355 are shown in the cross-sectional views of Figures 3 and 5, two or more inlets 350 and two or more outlets 355 may be provided. The one or more inlets or one or more outlets may be provided at different locations (e.g., near the outer periphery) on opposite sides of the elastic membrane 320 so that the liquid flows more uniformly along the elastic membrane 320. In some embodiments, the one or more inlets 350 may 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 may be positioned at approximately the same radial location relative to the one or more outlets 355, but may also be positioned at different circumferential locations. The one or more inlets 350 or one or more outlets 355 may be positioned approximately at the center of the elastic membrane 320.

[0074] (Liquid-cooled multi-film 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.

[0075] 6-8, the substrate carrier head 600 may include a carrier body 21 to support 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 the substrate held within the opening 40 and prevent lateral movement thereof. The holder 20 may be a separate or integrally formed part and may be of the same or different material as the carrier body 21. The substrate holder may include a substantially unbroken outer surface 42, or the outer surface may have grooves or other indentations to improve slurry flow.

[0076] 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 one another, for example, without an intervening structure. 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 be pressed against one another.

[0077] The membranes 25, 30 may be flexible so that each conforms to adjacent structures. The membrane material may be any elastic material, such as a material suitable for receiving back pressure and transferring the back pressure to a substrate held within the carrier head. In some embodiments, the membrane material may be one of rubber or synthetic rubber materials. As mentioned above, the membrane material may also be one of ethylene propylene diene monomer (M class) (EPDM) rubber or silicone. Alternatively, the membrane material 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 the substrate, in certain embodiments, the material of the elastic membranes 25, 30 may be selected based on the heat transfer properties of the material. Thus, when cooling a substrate such as a silicon carbide substrate, a material with a higher thermal conductivity may be desirable. In some embodiments, the elastic membranes 25, 30 may include inorganic additives that increase the thermal conductivity of the elastic membranes 25, 30 to improve heat transfer between the temperature controlled liquid and the substrate.

[0078] 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 rather aid in attaching the membranes 25, 30 to other portions of the carrier.

[0079] For example, the first elastic membrane 25 may 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 to 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 may be configured to attach the first elastic membrane 25 to the remainder of the carrier head 600, the remaining portion of the first elastic membrane 25 may include, for example, shorter vertical and horizontal portions wrapped in a serpentine shape around and / or between outer portions of the outer support plate 36 (described further below).

[0080] The second elastic membrane 30 may 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 may be disposed between the first substrate support and the carrier body 21. The first and second substrate supports may be stacked against each other and may be directly stacked (i.e., in contact with each other) with respect to each other. The second substrate portion may be stacked on top of the first substrate portion in the orientation shown. The second substrate support may be configured to selectively provide a force against the interior of the first non-perforated substrate support as shown. The outer surface of the second substrate support may directly contact at least the inner surface of the interior of the first substrate support. With this configuration, the second elastic membrane 30 may provide improved process and uniformity over the substrate, for example, improved control of center removal rate in a CMP process.

[0081] The remaining portion of the second elastic membrane 30 (other than the second substrate support portion) can be configured to attach the second elastic membrane 30 to the remainder of the carrier head 600, and the remaining portion of the second elastic membrane 30 can include, for example, a short vertical portion at its outer edge and a horizontal lip extending from a distal end of the vertical portion.

[0082] The membranes 25, 30 (or other membranes herein) may each include a non-porous portion, or the membranes 25, 30 may each 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 the corresponding sealed membrane cavity. Thus, for example, a membrane that has holes at its periphery for mounting purposes, but is fluidly isolated (e.g., sealed) from the membrane cavity, may be "substantially completely non-porous". The membranes 25, 30, or portions thereof, may 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. Each of the first and second substrate supports may be non-porous to form a first non-porous substrate support and a second non-porous substrate support, respectively.

[0083] The carrier head can include an inner support plate 33. Once assembled, the inner support plate can be fixed to prevent relative movement with respect to the carrier body 21. The inner support plate 33 can include a generally planar, rigid support surface configured to support a substrate retained on the second substrate support portion of the second elastic membrane 30 during processing.

[0084] The carrier can include an outer support plate 36. The outer support plate 36 can include a generally planar, rigid support surface configured to support a substrate held on the first substrate support of the first elastic membrane 25. In some embodiments, the outer support plate 36 can support a portion of the first substrate support of the first elastic membrane 25. For example, the outer support plate 36 can include a central opening 41 surrounded by an outer plate portion that can support a corresponding outer portion of the first substrate support of the second elastic membrane 30 during processing. The central opening 41 can be configured to surround the second substrate support. In some embodiments, the width W1 of the first substrate support can 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 can 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 an inner portion of a substrate held in the carrier 600, and the outer support plate 36 can support an outer portion of a substrate held in the carrier 600.

[0085] The films herein can be single-zone or multi-zone films. For example, the films can have grooves (e.g., dimples) and / or raised portions that effectively isolate 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 dimples, 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 the material removal rate in different regions of the substrate by applying a temperature-controlled liquid to one or more associated zones of the elastic film.

[0086] In some embodiments, either or both elastic membranes may be single-zone membranes configured such 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, which is formed between relatively small tolerances between parts, not easily seen 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 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 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 the first elastic membrane 25 may be cooled during the CMP process.

[0087] 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 such 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 back pressure regulator 445. The second membrane cavity may increase in volume when the corresponding second elastic membrane 30 is pressurized with a CDA.

[0088] 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.

[0089] (Comparison between silicon substrate and silicon carbide substrate) Due to the differences between silicon and silicon carbide substrates, many of the parameters associated with the CMP process performed for each type of process may differ. As a result of these variations in parameters, silicon carbide CMPs that are designed to be cooled in accordance with embodiments of the present disclosure may generate excessive heat. Table 1 below summarizes example values ​​for typical silicon and silicon carbide substrate CMP processes. [Table 1(1)]

[0090] 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 silicon carbide substrates, the substrate carrier head may rotate at speeds of 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.

[0091] The pressure applied to the substrate may also exceed the range typical for polishing silicon carbide substrates as compared to polishing silicon substrates, where, for example, to polish silicon carbide substrates, 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 a pressure of about 15 psi, or any range therebetween.

[0092] In a typical polishing of a silicon substrate, the temperature does not drop significantly above or 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 may 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 may 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 temperature control to increase the temperature during some processes may be advantageous, as well as to reduce the temperature or to maintain the temperature at a desired target. 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.

[0093] Embodiments herein may enable processing of substrates of reduced thickness. For example, silicon carbide substrates may have thicknesses less than typical silicon substrate thicknesses of about 600-800 μm. For example, silicon carbide substrates may have thicknesses 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, may have a thickness of about 350 μm.

[0094] Polishing silicon carbide substrates using embodiments herein may also allow for the use of slower 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.

[0095] Polishing silicon carbide substrates using embodiments herein may also allow for the use of flow rates lower than the typical slurry flow rates for polishing silicon substrates of 100-200 ml / min. For example, the slurry delivery system 140 may deliver process slurry to the silicon carbide substrate at flow rates 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.

[0096] As used herein, "silicon" with respect to "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) of 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) of greater than about 11 may be processed. In some embodiments, substrates with hardness (Mohs hardness) of between about 8.5-10, or 9-9.5 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, silicon substrates may be included to provide temperature control of the process. Additionally, substrates other than silicon or silicon carbide substrates may be implemented.

[0097] (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 show one embodiment of a "rigid backed" substrate carrier that may be used as part of a substrate carrier system (e.g., the system of FIG. 4A or FIG. 4B) for controlling the temperature of a substrate in accordance with aspects of the present disclosure. In particular, FIG. 9 is a perspective view of another embodiment of a substrate carrier that may be used as part of a substrate carrier system for controlling the temperature of a substrate in accordance with 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.

[0098] 9 and 10, the 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 plate and the lower plate can be joined together to form a seam 810, for example, by furnace brazing. The liquid cooling passage 815 can be machined into the lower plate, and then the lower plate and the upper plate can be furnace brazed together to form a 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 .

[0099] In the embodiments of Figures 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 can be rigid since it does not include an elastic membrane. A carrier film, not shown, may 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 Figure 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 material) as described above in connection with the elastic membrane embodiment. For example, a system similar to that shown in Figure 4A or 4B, with the membrane cavity 360 replaced with a liquid cooling passage, can be used to circulate or recirculate a liquid for cooling the substrate during CMP.

[0100] (CMP system with temperature-controlled polishing pad) As discussed 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, leading to deformation, melting, glazing, and breakdown of the chemistry (e.g., slurry chemistry). Thus, in certain implementations, the amount and / or rate of removal is not limited by the mechanical system, but by the inability to remove the heat generated by the process. If the heat can be effectively removed, the mechanical system of the equipment can be pushed to its limits to increase the removal rate. This increases throughput and allows processes that are not currently available to be performed.

[0101] FIG. 13 is a plot showing the thermal conductivity of polyurethane as a function of temperature. In particular, FIG. 13 illustrates why thermal management of heat within a polyurethane pad can be difficult. Thermal management can be difficult when using polyurethane pads because bulk polyurethane has a relatively low thermal conductivity (λ). In certain embodiments, the typical operating temperature for these pads is between 293K (20°C) and 323K (50°C), between 0.0225-0.0275 W / mK.

[0102] Even with platen cooling, there may be a limit to the amount of heat from the pad that can be removed by thermal conduction to the platen, and furthermore, heat removal by convection and radiation may be negligible at typical operating temperatures of the pad.

[0103] 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 negate the benefits of increasing the pressure 838 and velocity 840 by diluting the slurry 836 used to polish the wafer 834 and reducing the removal rate.

[0104] To prevent the added liquid from diluting the surface, the liquid (such as 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 well suited for cooling the pad surface. Thus, 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.

[0105] FIG. 15 is a schematic diagram of a substrate processing system including an atomizer system according to aspects of the disclosure. As shown in FIG. 15, the system can include an atomizer 905 configured to atomize 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) to allow water to evaporate and heat to be extracted directly from the surface of the pad 910. The amount of heat removed (watts) for one embodiment was calculated as 0.1 ml / s flow rate x 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 value of watts 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.).

[0106] (Example of comparison of pad cooling using liquid atomizer) Below, experimental data is provided for several experiments performed to test the cooling of polishing pads using liquid cooling as described herein. For each of Experiments 1, 2, 4, and 5 shown below, wafers made of AlTiC were used.

[0107] Experiment 1 is shown in Table 1 (high pressure, high speed, no cooling to the platen by a chiller, no carrier cooling, no atomizer). [Table 1(2)]

[0108] 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]

[0109] FIG. 16 is a plot showing normalized removal rate versus temperature before and after application of the atomizer nozzle to the Si wafer in experiment 3.

[0110] Experiment 4 is shown in Table 3 (high pressure, high speed, no cooling to the platen by the chiller, cooling starts at the carrier, no atomizer). [Table 3]

[0111] 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]

[0112] (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.

[0113] In an exemplary embodiment, the retaining ring may have a surface area of ​​18.9 square inches. A commanded downward force of about 240 pounds may be applied to the retaining ring of this embodiment, exerting a pressure of about 12.7 psi on the pad surface. In some embodiments, the system may 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. Using a separate retaining ring with a surface area of ​​about 5 square inches to reduce the contact area of ​​the retaining ring may exert a pressure of about 48 psi on the pad. Reducing the contact area between the retaining ring and the polishing pad may also reduce heat generated during polishing, which is particularly advantageous for certain wafers, such as silicon carbide wafers. Thus, the pad pressure may 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 may be increased wear on the retaining ring. For example, a smaller surface area of ​​the retaining ring and a higher applied pressure may cause the retaining ring to wear faster.

[0114] The increased wear of 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 material that is more wear resistant. However, using such a harder material for the retaining ring can result in the wafer being damaged due to the fragility of the wafer. Certain types of wafers are fragile and therefore more likely to be damaged if a harder material is used for the retaining ring. FIG. 18 shows a retaining ring 1000 having a stepped shape. Although not shown, in certain embodiments, the retaining ring 1000 can be formed of two different materials. In particular, different materials such as polyphenylene sulfide (PPS) and polyether ether ketone (PEEK) can be used where the wafer contacts the ring to prevent the retaining ring from damaging the wafer while reducing wear on the retaining ring.

[0115] To reduce retaining ring wear, the CMP process disclosed herein can use a retaining ring 1000 with a small 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 exterior material, such as aluminum oxide, zirconium oxide, boron nitride, boron carbide, silicon carbide, and stainless steel. The retaining ring 1000 can further include an interior material with an engineered polymer compatible with substrate contact, such as PPS, PEEK, Torlon®, Rulon®, polysulfone (PSU), Ultem® polyetherimide (PEI), or polyvinylidene fluoride (PVDE).

[0116] Using an exterior material with sufficient hardness can minimize wear on the ring during CMP and extend the useful 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 to reduce heat generated by contact between the face of the retaining ring and the polishing pad.

[0117] (Containment and exhaust of atomized cooling liquid) The use of atomized liquid to cool the substrate as described herein can be particularly advantageous for substrates formed of materials having a higher hardness than traditional materials used for silicon wafers. This is because polishing such "hard" substrates can generate excess heat, limiting the removal rate that can be achieved before overheating damages the substrate and / or CMP equipment. One example of a material that can generate more heat compared to traditional wafers is silicon carbide. However, aspects of the present disclosure are also applicable to other materials that can be used for the substrate.

[0118] Although the mist coolant can effectively cool the substrate / CMP system to increase removal rates, the mist can combine with the slurry that is generated during the CMP process. One potential drawback of using mist coolant is that some of the slurry chemicals may become airborne or migrate more easily out of the processing environment (e.g., from the pad, platen, and / or substrate) compared to CMP processes that do not use mist coolant for cooling. This can be important because slurries used to process silicon carbide substrates (or other less common materials such as gold or gallium nitride) can be more corrosive and / or toxic than slurries used for traditional silicon wafer materials. As such, some of the corrosive and / or toxic chemicals may escape the system via the mist and pose a health hazard, become a source of contamination, or become a source of corrosion for nearby machines / systems.

[0119] An embodiment of the present disclosure relates to a system that can capture and exhaust atomized liquid to reduce or prevent the escape of atomized corrosive and / or toxic chemicals into the environment. Figure 19 is a cross-sectional view of an exemplary portion of a CMP system including a containment and exhaust system 1100 for atomized cooling liquid according to an embodiment of the present disclosure. As shown in Figure 19, the containment and exhaust system 1100 includes an atomizer 1102 configured to cool a polishing pad 1110, an outer exhaust / low pressure chamber 1104, an inner cooling chamber 1106, and an output configured as an exhaust port 1108.

[0120] The outer chamber 1104 and the inner chamber 1106 can be formed using two separate plenums. The inner plenum can be configured, for example, in a nested configuration, to fit within the outer plenum. The inner and outer plenums can be coaxial with each other. The atomizer 1102 can discharge atomized liquid into the inner chamber 1106 to cool the rotating polishing pad 1110. For example, the atomizer 1102 can include an output nozzle for discharging the atomized liquid. The atomizer 1102 can be disposed at least partially within the inner chamber 1106. The outer chamber 1104 can have a lower pressure than the inner chamber 1104 to draw the atomized liquid and slurry (e.g., slurry particles in air) from the inner chamber 1104 and exhaust the atomized liquid and slurry to a scrubber via an output (e.g., exhaust port 1108). The atomized liquid and slurry can flow from the inner chamber 1106 to the outer chamber 1104 through one or more openings that allow flow therethrough, such as, for example, the gap 1112. The exhaust port 1108 can be connected to an exhaust line configured to have a negative pressure of about -1.5 to -4.0 inches. The scrubber can remove or reduce the level of any corrosive and / or toxic chemicals from the atomized liquid. In an exemplary embodiment, the exhaust can have a flow rate of about 1500 to 2000, or about 1800 (e.g., 1877 linear feet / minute, and about 36.49 cubic feet / minute), although aspects of the disclosure are not limited thereto. The inner and / or outer plenums can be positioned near or, in some embodiments, in contact with the polishing pad 1110 to reduce leakage of the atomized liquid and slurry between the polishing pad 1110 and the plenum. A typical gap distance may be about 1 mm, or may range from 0 mm (plenum touching the pad surface) to about 25 mm, or any range in between. If the plenum is touching the pad surface, holes or slots may be added to the bottom of the outer plenum to allow exhaust to flow into and through the outer plenum.Alternatively, the bottom of the inner plenum may be lower than the bottom of the outer plenum, so that only the inner plenum contacts the pad and the outer plenum has clearance from the pad, or vice versa. Alternatively, the height of the bottom of the plenums may be varied as well, with both having some clearance from the pad. In this manner, the exhaust induced airflow may be applied directly to the pad surface at (close to) the point of use of the slurry, and may be highly constrained to increase collection of atomized liquid and / or slurry fumes with reduced propagation to a larger area / volume within the polisher and / or operating environment.

[0121] Figure 20 provides two exploded perspective views of the plenums that form the outer chamber 1104 and the inner chamber 1106 of Figure 19. As shown in Figure 20, the outer chamber 1104 and the inner chamber 1106 are sized such that the inner chamber 1104 can be contained in a coaxial configuration by the outer chamber 1104. As shown, each plenum can be formed from separate pieces that are attached during assembly.

[0122] Figures 21A-D provide additional views of an embodiment of the portions of the plenum that form the outer chamber 1104 and inner chamber 1106 of Figure 19. In particular, Figure 21A is a close-up view of the outer chamber 1104 and inner chamber 1106, Figure 21B is a side view showing air and liquid (e.g., water) input ports formed on the side of the outer chamber 1104 that supply air and water to the atomizer 1102, Figure 21C is a diagram showing the overall layout of the assembled plenum, and Figure 21D is a top view of the assembled plenum.

[0123] (Integrated high pressure pad rinse and exhaust plenum flush) During CMP processing, it may be advantageous to maintain a clean polishing pad between wafer process runs to reduce contamination from used process particles and chemicals and thus improve process yield. In certain embodiments, a spray bar may be used to spray water onto the polishing pad. Although aspects of the present disclosure are provided using water (e.g., deionized water) as an exemplary liquid for cleaning the polishing pad, the disclosure is not limited thereto and other liquids (e.g., cleaning liquids) may be used to clean the polishing pad. Exemplary liquids that may be used to clean the polishing pad include surfactants and SC-1 (e.g., a mixture of water, ammonia, and hydrogen peroxide). Furthermore, although aspects of the present disclosure are described within the context of spray bar embodiments, it will be understood that spray devices configured to direct one or more streams of liquid of various shapes and sizes onto the polishing pad may be implemented to provide similar pad cleaning benefits and functionality.

[0124] One problem with the use of spray bars is that it can be difficult or impossible to control the water and by-products (also commonly referred to as augmented slurry due to the water introduced by the spray bar) that are expelled from the pad in response to spraying water onto the pad. Uncontrolled (e.g., unrestrained) distribution of the slurry can result in unwanted material being left on the pad and / or the slurry being sprayed into areas of the CMP system that are not designed to handle water and / or slurry (e.g., areas away from the polishing pad). In some circumstances, the slurry can eventually dry out, which can also be problematic, for example, due to particulate contamination. Thus, if wet or dried liquids resulting from the pad spray cleaning process are left uncontained, they can contaminate the CMP system and cause unnecessary downtime for the CMP system, for example, to clean the dried slurry from the system or to repair parts damaged by the ingress of liquid.

[0125] To address the above problems, aspects of the present disclosure relate to a CMP system in which a spray bar can be disposed within the cooling chamber. Figures 22A and 22B provide diagrams of an exemplary CMP system 1200 including a containment and exhaust system that includes a spray bar, according to aspects of the present disclosure.

[0126] 22A and 22B, a CMP system 1200 includes an atomizer 1202 configured to cool a polishing pad 1208, an outer exhaust / low pressure chamber 1204, an inner cooling chamber 1210, and an output (e.g., exhaust port 1206), which may be similar to the system 1100 and its components shown in, for example, FIGS. 19-21D. Here, the CMP system 1200 further includes a spray device (e.g., spray bar) 1212. In the illustrated embodiment, the spray bar 1212 is incorporated into a coaxial cooling system that includes the outer cooling chamber 1204 and the inner cooling chamber 1210. In FIG. 22A, the outer chamber (exhaust / low pressure chamber) 1204 is indicated using cross-hatching.

[0127] The spray bar 1212 includes a number of pad cleaning nozzles 1213 configured to spray water (e.g., downward) onto (e.g., directly onto) the pad 1208 to clean the pad, e.g., after a wafer processing run. The spray bar 1211 and / or its nozzles 1213 may be disposed partially or completely within a portion of the exhaust system 1200. For example, the spray bar 1211 and / or its nozzles 1213 may be disposed partially or completely within a plenum corresponding to the outer chamber 1204 or the inner chamber 1210. In the illustrated embodiment, both the nozzles 1213 and the spray bar 1211 are disposed within a plenum formed within the inner chamber 1210. The inner chamber 1210 may be configured to contain some, most, or substantially all of the water / slurry generated while the spray bar 1212 is operating, thereby providing the benefits of spray bar pad cleaning while preventing the water and slurry from being sprayed onto other parts of the CMP system other than the pad and the internal features of the system 1200. The exhaust port 1206 may be configured to remove (e.g., exhaust) water / slurry generated during operation of the spray device 1212 from the polishing pad and inner chamber 1210, through the gap, to the outer chamber 1204, and out the exhaust port 1206 to a scrubber. Alternatively or additionally, an output may be implemented to remove these by-products via a drain, as described further below. The spray device 1212 is not limited to any particular quantity of nozzles, or to any particular manifold or "bar" shape, but may include one or more pad cleaning nozzles of various sizes, shapes, and orientations to provide similar pad cleaning functions.

[0128] The system 1200 may include one or more exhaust plenum flush nozzles 1214. The exhaust plenum flush nozzles may be part of the spray device 1212 or may be a separate part with a separate liquid supply. The flush nozzles may use a similar cleaning fluid from the same cleaning fluid source as the pad cleaning nozzles described herein, or a different cleaning fluid from a different cleaning fluid source. The exhaust plenum flush nozzles 1214 may be configured to provide an exhaust area water rinse 1205 by spraying water or other suitable cleaning fluid (e.g., upward) into the plenum formed by the outer chamber 1204. The exhaust area water rinse 1205 is shown in blue to illustrate the upward spray of the rinse fluid into the plenum formed by the outer chamber 1204. In this manner, the nozzles 1214 may flush the water / slurry from the outer chamber 1204 through the exhaust port 1206 to a scrubber. For example, during the water / slurry exhaust of the lower chamber 1210 described above, some amount of water / slurry may enter the outer chamber 1204 in a direction away from the exhaust port 1206. Such unwanted slurry / water may accumulate or otherwise contaminate a portion of the plenum formed by the outer chamber 1204. The exhaust plenum flush nozzle 1214 may prevent the accumulation of such unwanted contaminants by flushing any unwanted water / slurry from the outer chamber 1204 so that it is exhausted through the exhaust port 1206. The outer chamber 1204 may also provide redundancy to the inner chamber 1210 by containing any water / slurry that may escape into a gap formed between the inner chamber 1210 and the polishing pad 1208.

[0129] In some embodiments, rather than exhausting the unwanted water / slurry through the exhaust port 1206, cleaning liquid (from cleaning the polishing pad and / or outer chamber 1204) and / or other by-products from the rinsing and cleaning steps of the processes herein may be exhausted from within one or both of the plenums formed by the chambers 1210, 1214 to a location outside one or both of the inner chamber 1210 and the outer chamber 1204. For example, one or more of the rinsing liquid, cleaning liquid, and / or other by-products may be exhausted from the plenum in the outer chamber 1210 through an output (e.g., a gap) formed between the inner chamber 1210 and the outer chamber 1204 into the inner chamber 1210. One or more of the rinsing liquid, cleaning liquid, and / or other by-products may be exhausted from the plenum in the inner chamber 1204 through a second gap disposed between the inner chamber 1210 and / or the outer chamber 1204 and the polishing pad 1208 to a location outside the coaxial plenum. In some embodiments, the system 1200 may include an additional exhaust configured to capture unwanted rinsing liquid, cleaning liquid, and / or other by-products from the polishing pad 1208, or may simply allow unwanted water / slurry to flow freely off the polishing pad 1208, for example, to a drain system separate from and external to the plenums in the chambers 1204 and / or 1210.

[0130] The coaxial plenum can control and protect the CMP system from unwanted overspray from the spray bar 1212 while at the same time pushing slurry generated when cleaning the polishing pad 1208 out through the exhaust port 1206 to a scrubber.

[0131] Aspects of the present disclosure relating to the combination of spray devices such as the spray bar 1212 in the coaxial cooling plenums 1204 and 120 provide at least two advantages. First, the relatively high volume and velocity of pressurized atomized water provided by the spray bar 1212 helps flush any buildup of effluent within the cooling chamber components, including the inner chamber 1210, the outer chamber 1204, and the exhaust port 1206. Second, by integrating the spray manifold 1212 into the cooling chamber assembly, less space is required above the polishing pad 1208 compared to mounting these two assemblies separately.

[0132] Figure 23 is a schematic diagram of a chemical mechanical planarization system 1300 including a sensor 1310. For example, Figure 23 may be a modified version of the substrate processing system 100 shown in Figure 1. Parts of the chemical mechanical planarization system 1300 that are similar to parts of Figure 1 may not be described in detail with respect to Figure 23.

[0133] The chemical mechanical planarization system 1300 may be implemented with one or more detectors. The sensor 1310 may consist of a temperature sensor disposed on and / or embedded within another component of the system 1300. The detector 1310 may be positioned to view at least a portion of the polishing pad 1100. For example, the detector may be configured to remotely monitor the temperature of at least a portion of the polishing pad from a location other than the polishing pad (e.g., a location above the polishing pad and / or a location at a distance from the polishing pad). For example, an infrared temperature detector such as a pyrometer or other non-contact temperature detector may be implemented. The detector 1310 may be configured to monitor the temperature of the polishing pad 110, for example, when the polishing pad 110 is being cooled by the atomizer (e.g., when a wafer is placed on the platen and processed). A controller such as the controller 440 described above may be implemented to receive a signal transmitted from the temperature sensor 1310 indicative of the temperature and, in response, to control the flow of the atomized liquid from the atomizer. Such control can be implemented to provide in situ pad surface temperature measurement and control to maintain a desired surface temperature of the polishing pad.

[0134] (summary) The misting system described herein includes the use of any type of misting system to cool or remove energy and / or heat from the polishing pad of a CMP system. The misting 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 pad. When using a mister, the system can be further configured to control the temperature of the misted 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. It will be understood that the embodiments of the exhaust system herein can be employed in CMP processes using corrosive or otherwise hazardous slurries, such as those used in silicon carbide substrate processes, or other more corrosive processes (e.g., potassium permanganate-based slurries, periodates, ferric nitrate), or other less corrosive and benign slurries (potassium hydroxide, ammonium hydroxide, etc.). For example, in any process, regardless of the type of slurry, the atomized liquid of the embodiments herein can condense on the equipment, causing "fogging" or other adverse effects. Furthermore, the containment and exhaust system herein can be implemented to contain and exhaust an atomizer configured to cool the polishing, alone or in combination with a spray device for cleaning the polishing pad, and vice versa.

[0135] 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, one 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 implemented using other structures, 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.

[0136] It should also be understood that unless a term is expressly defined in this patent using the sentence "As used herein, the term . . . is defined herein to mean . . . " or a similar sentence, there is no intention to expressly or impliedly limit the meaning of the term beyond its plain or ordinary meaning, and such terms should not be construed as limited in scope based on any statement made in any section of 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 intended that such claim terms be limited, by implication or otherwise, to that single meaning.

[0137] Conditional language such as "can," "can be," "could," or "may," unless otherwise specified or interpreted otherwise in the context in which it is used, is generally intended to convey that certain features, elements, and / or steps are included in certain embodiments but not in other embodiments. Thus, such conditional language is generally not intended to suggest that the features, elements, and / or steps are somehow required in one or more embodiments or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included in or performed in any particular embodiment, with or without user input or prompting.

[0138] Conjunctive language such as the phrase "at least one of X, Y, and Z," unless otherwise specified, is understood in the context in which it is commonly 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.

[0139] As used herein, language of degree, such as the terms "approximately," "about," "generally," and "substantially," refers to a value, amount, or characteristic that is close to 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 mean an amount that is within less than 10%, less than 5%, less than 1%, less than 0.1%, and / or less than 0.01% of the stated amount, depending on the desired function or intended result.

[0140] Although specific embodiments have been described, these embodiments are presented as examples 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 appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure.

[0141] Features, materials, properties, or groups described in connection with a particular aspect, embodiment, or example should be understood to be applicable to any other aspect, embodiment, or example described in this section or other sections of 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.

[0142] Moreover, certain features that are described in the present disclosure in the context of separate embodiments 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 a 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.

[0143] Furthermore, although 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 exemplary 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, the features and attributes of certain embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. Also, it should be understood that the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and that the above-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.

[0144] For purposes of this disclosure, certain aspects, advantages, and novel features are 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 disclosure may be embodied or practiced in a manner that achieves one advantage or group of advantages as taught herein, but not necessarily achieve other advantages as taught or suggested herein.

[0145] The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

[0146] The scope of the present disclosure is not intended to be limited by the specific disclosure of preferred embodiments in this section or elsewhere herein, but may be defined by the claims, as presented in this section or elsewhere herein, or as presented in the future. The language of the claims should be interpreted broadly based on the language used in the claims, and not limited to the examples described herein or during the prosecution of this application, which examples should be interpreted as non-exclusive.

Claims

1. 1. A chemical mechanical planarization (CMP) system comprising: A polishing pad; a substrate carrier head configured to hold a wafer against the polishing pad; below: an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of ​​the polishing pad; a spray device including at least one pad cleaning nozzle configured to spray a cleaning fluid onto the polishing pad to clean the polishing pad; and at least one of a chamber configured to contain at least one of the atomized liquid and the cleaning liquid, the chamber comprising an inner chamber and an outer chamber disposed to surround the inner chamber, the outer chamber configured to have a lower pressure than the inner chamber; an output configured to remove at least one of the atomized liquid and the cleaning liquid from the chamber; A system comprising:

2. The system of claim 1 , wherein the inner chamber and the outer chamber are coaxially disposed.

3. The system includes the atomizer, The system of claim 1 , wherein the atomizer comprises an output nozzle configured to eject the atomized liquid within the inner chamber.

4. The system of claim 1 , wherein the output is configured to exhaust at least one of the atomized liquid and the cleaning liquid from the chamber.

5. the output comprises an exhaust port; a scrubber coupled to the exhaust port and configured to reduce the level of any corrosive and / or toxic chemicals from the atomized liquid. The system of claim 4 further comprising:

6. The system includes the atomizer, The system of claim 1 , wherein the atomized liquid is configured to cool the polishing pad via evaporative cooling.

7. The system of claim 1 , wherein the polishing pad is formed of polyurethane.

8. 10. The system of claim 1, wherein the polishing pad is further configured to polish the wafer when the wafer is formed of silicon carbide.

9. The system comprises the spray device, The system of claim 1 , wherein the spray device comprises a spray bar disposed within the chamber.

10. The system of claim 9 , wherein the spray bar is disposed within the inner chamber.

11. at least one exhaust plenum flush nozzle configured to spray a cleaning fluid into the outer chamber; The system of claim 10 further comprising:

12. 1. A method of cooling a substrate during chemical mechanical polishing (CMP) of the substrate, comprising: supplying a slurry to a surface of a polishing pad of a CMP system, the CMP system comprising: a substrate carrier head configured to hold a wafer against the polishing pad; At least one of: i) an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of ​​the polishing pad; and ii) a spray device including at least one pad cleaning nozzle configured to spray a cleaning liquid onto the polishing pad to clean the polishing pad; a chamber configured to contain at least one of the atomized liquid and the cleaning liquid, the chamber comprising an inner chamber and an outer chamber disposed to surround the inner chamber, the outer chamber configured to have a lower pressure than the inner chamber; Output, and below: using the atomizer to deliver atomized cooling liquid to the surface of the polishing pad; applying a cleaning fluid to the surface of the polishing pad using the spray device; and performing at least one of: using the output to remove at least a portion of at least one of the atomized cooling fluid and the cleaning fluid from a point proximate to the surface; A method comprising:

13. The method of claim 12 , wherein removing comprises evacuating the at least one of the atomized cooling liquid and the cleaning liquid from the chamber.

14. The method of claim 12 , wherein removing comprises draining the at least one of the atomized cooling liquid and the cleaning liquid from the chamber.

15. The output comprising an exhaust port, The method of claim 13 , wherein exhausting further comprises: flowing the at least one of the atomized cooling liquid and the cleaning liquid from the inner chamber through a gap to the outer chamber and from the outer chamber through the exhaust port.

16. The method of claim 15 , wherein exhausting further comprises flowing the at least one of the atomized cooling liquid and the cleaning liquid from the exhaust port to a scrubber.

17. The method of claim 12 , further comprising spraying the cleaning fluid onto the polishing pad with a spray bar disposed within the inner chamber.

18. The method of claim 12 further comprising spraying the cleaning fluid into the outer chamber through at least one exhaust flush nozzle.

19. 1. A chemical mechanical planarization (CMP) system comprising: A polishing pad; a substrate carrier head configured to hold a wafer against the polishing pad; A chamber including a plenum configured to contain a liquid, the chamber comprising an inner chamber and an outer chamber disposed to surround the inner chamber, the outer chamber configured to have a lower pressure than the inner chamber; below: an atomizer configured to atomize a liquid in the chamber and spread a layer of the atomized liquid over a surface area of ​​a portion of the polishing pad within the chamber; A nozzle, spraying a cleaning fluid onto a portion of the polishing pad; and spraying a cleaning fluid onto an exterior portion of the chamber. At least one of an outlet configured to remove the cleaning fluid from the chamber; A CMP system comprising:

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