Containment and exhaust system for polished circuit board components

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 on February 26, 2021, and U.S. Provisional Patent Application No. 63 / 165,652, filed on March 24, 2021, the disclosures of each of which are hereby incorporated by reference in their entireties for all purposes.

[0002] This disclosure generally relates to substrate processing equipment, and more specifically, to systems and apparatuses for improving chemical - mechanical planarization (CMP) performance for the planarization of thin films.

Background Art

[0003] During chemical - mechanical planarization or polishing (CMP), an abrasive and an acidic or alkaline slurry are applied to a rotating polishing pad / platen via a metering pump or a 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 corrosion in the CMP process. The interaction between the wafer being processed and the carrier can cause wafer breakage, non - uniformity, or other problems. Therefore, it is necessary to improve the performance of the wafer carrier to address the effects caused by the interaction between the wafer being processed and the carrier.

Summary of the Invention

[0004] For the purpose of outlining the present disclosure and the advantages achieved over the prior art, specific purposes and advantages of the present disclosure are described herein. Not all such purposes or advantages can be achieved in any embodiment. Therefore, for example, a person skilled in the art will recognize that the present invention can be embodied or performed in a manner that achieves or optimizes one advantage or group of advantages as taught herein, without necessarily achieving other purposes or advantages that may be taught or suggested herein.

[0005] One aspect of the disclosed technology is a chemical mechanical planarization (CMP) system, the system comprising: a polishing pad; a substrate carrier head configured to hold a wafer relative to 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 solution onto the polishing pad to clean the polishing pad; a chamber configured to contain at least one of the atomized liquid and the cleaning solution from the chamber; and an output configured to remove at least one of the atomized liquid and the cleaning solution from the chamber.

[0006] The chamber may comprise an inner chamber and an outer chamber arranged to surround the inner chamber.

[0007] The inner chamber and the outer chamber can be arranged coaxially.

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

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

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

[0011] The output may be equipped with an exhaust port, and the CMP may further include a scrubber coupled to the exhaust port and configured to reduce the levels 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 can be made of polyurethane.

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

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

[0016] The chamber may comprise an inner chamber and an outer chamber arranged to surround the inner chamber, with the spray bar positioned within the inner chamber.

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

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

[0019] The removal step may include a step of exhausting at least one of the atomizing coolant and the cleaning fluid from the chamber positioned on the surface.

[0020] The removal step may include a step of discharging at least one of the atomizing coolant and the cleaning liquid from the chamber positioned on the surface.

[0021] The chamber may comprise an inner chamber and an outer chamber arranged to surround the inner chamber.

[0022] The exhaust step may further include the step of flowing the atomized coolant from the inner chamber through the gap to the outer chamber, and from the outer chamber through the exhaust port.

[0023] The exhaust step may further include the step of flowing the atomized coolant from the exhaust port to the scrubber.

[0024] The method may further include the step of spraying a cleaning solution onto the polishing pad using a spray bar positioned inside the inner chamber.

[0025] The method may further include the step of spraying a cleaning solution 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, the chemical mechanical planarization (CMP) system including 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 within the chamber and spread a layer of the atomized liquid over a surface region of a portion of the polishing pad within the chamber, and a nozzle configured to perform at least one of spraying a cleaning liquid onto a portion of the polishing pad and spraying 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 skilled in the art from the following detailed description of the preferred embodiments, which reference the accompanying drawings, 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 concepts of the present invention will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, which reference the accompanying drawings. In the drawings, like reference numerals are used for like elements unless otherwise specified.

[0029] [Figure 1] A schematic view of a substrate processing system, showing a substrate carrier holding a substrate at a processing position. [Figure 2] A view of the substrate processing system of FIG. 1, showing a substrate carrier holding a substrate at a loading position. [Figure 3] 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. [Figure 4A]This is a block diagram showing a substrate carrier system that can be used to control the temperature of a wafer according to an aspect of the present disclosure. [Figure 4B] This block diagram shows another substrate carrier system that can be used to control the temperature of a wafer according to an aspect of the present disclosure. [Figure 5] Another partial cross-sectional view of a substrate carrier head that may be included as part of the wafer carrier shown in Figures 1 and 2, according to another embodiment. [Figure 6] This is an exploded top isometric view of one embodiment of a substrate carrier head according to an aspect of the present disclosure. [Figure 7] Figure 6 is an exploded bottom isometric view of the carrier head according to an aspect of this disclosure. [Figure 8] This is a cross-sectional view of the carrier head of Figure 6, according to an aspect of this disclosure. [Figure 9] This is a perspective view of another embodiment of a substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate, according to aspects of the present disclosure. [Figure 10] This is a cross-sectional view of the substrate carrier shown in Figure 9, taken along line AA in Figure 9. [Figure 11] This is another cross-sectional view of the substrate carrier in Figure 9, taken along line BB in Figure 9. [Figure 12] Figure 10 shows a cross-sectional perspective view of the base plate taken along line CC. [Figure 13] This plot shows the thermal conductivity of polyurethane as a function of temperature. [Figure 14A] This is an SEM image of the IC1000 microporous polyurethane (MPU) pad. [Figure 14B] This is a cross-sectional view of a polishing pad and wafer during CMP according to an aspect of this disclosure. [Figure 15] This is a schematic diagram of a substrate processing system including an integrated atomizer system according to an aspect of the present disclosure. [Figure 16] This plot shows the difference in pad temperature between Experiment 1 and Experiment 2. [Figure 17]This plot shows the relationship between ring pressure (psi) and platen temperature (°C) in a CMP system using a retaining ring. [Figure 18] This shows a retaining ring with a stepped shape. [Figure 19] This is a cross-sectional view of an exemplary CMP system, including a containment and exhaust system for atomizing coolant, according to an aspect of the present disclosure. [Figure 20] Figure 19 shows two exploded perspective views of the plenum forming the outer and inner chambers. [Figure 21A] Figure 19 provides additional diagrams of embodiments of the plenum forming the outer and inner chambers. [Figure 21B] Figure 19 provides additional diagrams of embodiments of the plenum forming the outer and inner chambers. [Figure 21C] Figure 19 provides additional diagrams of embodiments of the plenum forming the outer and inner chambers. [Figure 21D] Figure 19 provides additional diagrams of embodiments of the plenum forming the outer and inner chambers. [Figure 22A] An exemplary diagram of a CMP system, including a containment and exhaust system, including a spray device, is provided according to aspects of this disclosure. [Figure 22B] An exemplary diagram of a CMP system, including a containment and exhaust system, including a spray device, is provided according to aspects of this disclosure. [Figure 23] A schematic diagram of an example of a CMP system equipped with sensors is provided. [Modes for carrying out the invention]

[0030] The following text provides a detailed description of many different embodiments of the present invention, but it should be understood that the legal scope of the present invention is defined by the claims wording set forth at the end of the patent application. The detailed description should be interpreted as illustrative only and does not describe all possible embodiments of the present invention, as it would be impractical, if not impossible, to describe all possible embodiments. Many alternative embodiments can be carried out using either the current art or art developed after the filing date of this patent application, but they also remain within the scope of the claims defining the present invention.

[0031] (Chemical mechanical planarization (CMP)) The adoption and use of chemical mechanical planarization (CMP) for thin film planarization in the manufacture of semiconductor ICs, MEMS devices, and LEDs is common among companies that manufacture “chips” for these types of devices, among many other similar applications. This adoption includes the manufacture of chips for mobile phones, tablets and other portable devices, as well as for desktop and laptop computers. The growth of ultrafine technology and microfabrication is highly promising for the unprecedentedly widespread use and adaptation of digital devices in the medical, automotive, and Internet of Things ("IoT") sectors. Chemical mechanical planarization for thin film planarization was invented and developed in the early 1980s by scientists and engineers at IBM. Today, this process is widespread globally and is one of the technologies that truly enables the manufacture of many digital devices.

[0032] Integrated circuits are manufactured with multilayer and alternating layers of conductive materials (e.g., copper, tungsten, aluminum), insulating layers (e.g., silicon dioxide, silicon nitride), and semiconductor materials (e.g., polysilicon). As these layers are sequentially applied to the wafer surface, the device structure exhibits topographical irregularities due to the embedded devices. This is common in silicon dioxide insulating layers. These unwanted topographical irregularities are flattened or "planarized" using CMP before the next layer can be deposited, enabling proper interconnection between increasingly smaller device structures. In the case of copper layers, the copper deposits on the surface to fill contact vias, creating effective vertical pathways for electron movement between devices and layers. This procedure is repeated for each layer applied (usually by the deposition process). In the case of multiple conductive material layers (multiple metal layers), this can result in numerous polishing procedures (one for each layer of conductor, insulator, and semiconductor material) to ensure successful circuitry and interconnection between device structures.

[0033] In the CMP process, a substrate or wafer is held by a wafer carrier, which rotates and is typically pressed against a platen over a specific polishing period via an elastic membrane within the wafer carrier. CMP wafer carriers typically incorporate components for the precision polishing of generally flat and round workpieces, such as silicon wafers and / or films deposited thereon on the process head. These components include: 1) an elastic membrane to which compressed gas is applied on the top or back side, the pressure being transmitted 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 providing 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 fluid control devices such as metering pumps and mass flow control regulator systems. The slurry can then be delivered to the polishing platen using a single-pass distribution system. To improve performance, the slurry particles in the medium must be evenly distributed between the rotating wafer and the rotating polishing pad / platen.

[0035] A wafer carrier film can exert force on the back of the wafer, pressing it against the pad, creating a relative velocity between the two. This motion and force cause wear on a portion of the pad as the abrasive moves across the wafer surface, pressing it against the substrate. Corrosive chemicals in the slurry alter the material being polished on the wafer surface. This combination of mechanical and chemical effects of wear is called chemical mechanical planarization or polishing (CMP). The rate of material removal can easily be an order of magnitude higher when both chemical and mechanical effects are used simultaneously compared to using 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, and polysilicon are removed from the wafer surface. These fine particles 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, leading to catastrophic circuit failures, rendering the chip unusable and significantly impacting yield.

[0037] Yield is a key factor determining the success of manufacturing many products, including integrated circuits, MEMS, and LEDs. Surface quality tolerances in CMP processes within 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 crucial. Therefore, carrier design technology is constantly evolving to improve this capability. Even small inconsistencies in the flatness of wafers processed in a CMP system can reduce yield and increase waste. Inconsistencies or pressure differences across the entire diameter of the wafer carrier and processing pad can cause wafer breakage. The cumulative cost of manufacturing solid-state devices is collectively called the "cost of ownership" (CoO), and this term also applies to each required manufacturing step. The CoO of the CMP process is one of the highest CoO values ​​among the 500-800 individual manufacturing steps required to manufacture a semiconductor "chip" and its associated digital devices.

[0038] Wafers made of silicon carbide are likely to become more common in many integrated circuit applications. For example, the automotive industry is expected to manufacture integrated circuits using silicon carbide wafers due to their specific advantages over conventional silicon wafers. For instance, compared to silicon wafer-based integrated circuits, silicon carbide wafer-based integrated circuits may have lower power consumption and higher heat resistance. Therefore, as automobiles increasingly use integrated circuits to control various aspects of the vehicle, these control systems are increasingly being manufactured using silicon carbide wafers because silicon carbide wafers possess desirable properties.

[0039] However, silicon carbide is a harder material than silicon. Therefore, silicon carbide wafers may require higher pressure and / or speed (e.g., relative speed between the wafer surface and the polishing pad / platen) to achieve a sufficient removal rate during CMP compared to otherwise similar silicon wafer-based CMP processes. Such higher pressure and / or speed can increase the heat generated during CMP of silicon carbide wafers compared to similar silicon wafer-based CMP. Such increased heat can then adversely affect the wafer surface, the polishing pad, and / or the elastic film that contacts and applies pressure to the wafer. For example, excessive heat can lead to surface defects in the wafer. Excessive heat can melt the elastic film and / or polishing pad, and / or cause the wafer to adhere to the film or lose it from the carrier, damaging the wafer and carrier, and / or preventing the wafer from being unloaded from the carrier. Therefore, the wafer and / or elastic film need to be cooled to lower the temperature during polishing. It will be understood that aspects of this disclosure may be implemented on substrates formed of materials other than silicon carbide, and may be implemented at any stage of a substrate process having a substrate carrier, such as CMP, to cool, heat, or otherwise control a wafer, film, or other part of a wafer carrier to a desired temperature.

[0040] The surface temperature of the CMP pad can be a critical variable in the CMP process. The pad temperature can vary significantly depending on many variables, including idle time before process initiation, wafer and platen rotation speed, wafer pressure, slurry flow rate, the number of wafers processed on the platen, slurry temperature, and other variables. Aspects of the embodiments described herein can maintain the pad surface temperature essentially constant, for example, at about 50°C, across a wide range of these variables. This is attributed to the heat of vaporization 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 these embodiments, as temperature stability is critical to the stability of the CMP process.

[0041] CMP tools are typically connected to an external exhaust source. The primary purpose of this is to remove fumes that may be produced by the evaporation of the slurry, particularly toxic, volatile (strong fumes such as ammonia) and / or corrosive slurries. The exhaust connection is usually located on the bottom deck or ceiling of the grinding machine. In either case, the airflow caused by the exhaust does not come into close proximity to the surface of the grinding pad where the slurry is distributed and 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 (proximity) of the slurry, and is highly constrained to increase (maximize) fume collection by reducing (e.g., minimizing) propagation to a wider area / volume within the grinding machine and / or operating environment. This results in significant improvements for worker safety, environmental considerations, and machine lifespan.

[0042] The disclosed technology is described with reference to specific drawings in relation to specific embodiments. This disclosure is not limited thereto and is limited only by the claims. The drawings provided are for illustrative purposes only and are not limiting. In the drawings, the sizes of some elements may be exaggerated for illustrative purposes and may not be drawn to scale. Dimensions and relative dimensions do not necessarily correspond to actual reductions for the implementation of this disclosure.

[0043] (Liquid-cooled CMP system) Figure 1 is a schematic diagram of a chemical mechanical planarization system 100 for processing a polishing pad 110. The system 100 may include a wafer carrier 150 configured to hold and process a wafer. As used herein, the term “wafer” may refer to a semiconductor wafer (e.g., circular), but it will be understood that it may more broadly encompass other types of substrates of different shapes that are processed by polishing or planarization equipment such as CMP equipment. Thus, in the following description, the terms “wafer” and “substrate” may be used interchangeably unless the context specifically relates to only one of “wafer” or “substrate.” In the illustrated embodiment, the substrate carrier 150 is in a processing (e.g., lower) position and holds a substrate (not shown) relative to a polishing pad 110 with a film (not shown). The polishing pad 110 may be placed on a support surface such as the surface of a platen 120.

[0044] Figure 2 is a diagram of the chemical mechanical planarization system of Figure 1, showing a substrate 155 held in a mounted (e.g., top) position by a substrate carrier 150. The substrate 155 can be held by, for example, a vacuum force. Referring to both Figures 1 and 2, the system 100 may include a slurry feeding system 140 configured to feed a processing slurry onto the substrate 155 and allow it to be chemically / mechanically planarized against a polishing pad 110. The system 100 may also include a pad adjusting arm 160 with a pad adjuster at its end, which may be configured to treat or "refresh" the surface roughness or other processing characteristics of the pad during or between processing cycles.

[0045] In the system 100 shown in Figures 1 and 2, the polishing pad 110 is located on the upper surface of the platen 120, which rotates counterclockwise around a vertical axis. Other orientations and directions of movement can also be achieved.

[0046] The slurry delivery system 140 can deliver a slurry containing abrasive and corrosive particles to the surface of the treated polishing pad 130. The polishing slurry is typically a colloidal suspension of abrasive particles, i.e., colloidal silica, colloidal alumina, or colloidal ceria in an aqueous medium. In various embodiments, the slurry delivery system 140 includes a metering pump, a mass flow control regulator system, or other suitable fluid delivery components.

[0047] The substrate carrier 150 can, for example, hold the substrate 155 in a vacuum, so that the surface of the substrate 155 to be polished faces the polishing pad 110. The abrasive particles and corrosive chemicals in the slurry deposited on the polishing pad 110 by the slurry feeding system 140 mechanically and chemically polish the substrate by abrasion and corrosion, respectively. The substrate carrier 155 and the polishing pad 110 can move relative to each other in any of several different ways to provide polishing. For example, the substrate carrier 150 can apply a downward force to the platen 120 so that the substrate 155 is pressed against the polishing pad 110. As further described herein, the substrate 155 can be pressed against the polishing pad 110 using a pressure film (not shown). The abrasive particles and corrosive chemicals in the slurry between the substrate 155 and the polishing pad 110 can provide chemical and mechanical polishing as the polishing pad 110 and the substrate carrier 155 move relative to each other. The relative movement between the polishing pad and the substrate carrier can be configured in various ways, and either or both can be configured to vibrate, move linearly, and / or rotate counterclockwise and / or clockwise relative to each other.

[0048] The pad adjustment arm 160 can adjust the surface of the polishing pad 110 by force pressing the polishing pad 110, thereby causing relative movement of the polishing pad and the substrate carrier 150, such as the relative motion described above. The pad adjustment arm 160 in the illustrated embodiment can vibrate and has a rotating pad adjuster at its end that contacts the polishing pad 110.

[0049] Figure 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 Figures 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 the carrier head) may include a support base 380 to which the film assembly 305 is mounted. The support base 380 may be any suitable configuration for providing support to the film assembly. The support base 380 can be mounted and connected to the rest of the substrate carrier head 300 in a CMP system (not shown). The support base 380 may include a carrier body, a substrate holder, a support plate, and / or other components as described elsewhere herein for supporting a wafer (e.g., the film assembly 305) and / or for connecting the rest of the carrier head 300 to the CMP system.

[0050] The film assembly 305 may include, as shown, a support plate 310, an elastic film 320, a film holder such as a film clamp 330, and an optional external pressure ring 340. The support plate 310 supports the wafer during processing and may be any suitable configuration for, for example, mounting the film assembly 305 to a support base 380. For example, the support plate 310 may be mounted to the support base 380 using one or more bolts or other suitable mounting elements. The support plate 310 may be mounted to the support base 380 at various positions, such as along the outer circumference of the support base 380.

[0051] The support plate 310 can be any suitable configuration for supporting a wafer through an elastic membrane 320. The elastic membrane 320 can be fixed to the support plate 310 in several different ways. The elastic membrane 320 can be fixed to the support plate 310 before or after the support plate 310 is fixed to the support base 380. The elastic membrane 320 can be fixed to the support plate 310 by using any of several suitable different membrane retainer holding elements, such as a membrane clamp 330. In some embodiments, the membrane clamp 330 may be spring-loaded. In other embodiments, the membrane clamp 330 can be securely fastened by using a fastening mechanism (e.g., nuts and bolts). The membrane clamp 330 can fix the outer portion (e.g., outer edge) of the membrane 320 to the corresponding portion of the support plate 310 and / or support base 380. The membrane retainer can be any suitable configuration for fixing at least a portion of the membrane 320 to the support plate 310 and / or support base 380.

[0052] The elastic film 320 can be fixed to the support plate 310 so that the film 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 film may include a first surface (e.g., downward) configured to contact the surface (e.g., upward) of the substrate. The film 320 can have sufficient elasticity and flexibility, and as a result, in combination with the polishing pad material and process parameters, the film 320 can apply more uniform pressure across the substrate 370. In some embodiments, the elasticity and flexibility of the film 320 may also help reduce substrate damage. The film 320 and support plate 310 can be configured to allow a liquid to flow between the film 320 and the support plate 310, pressing the film 320 against the substrate 370 during planarization. For example, the film 320 can be configured to allow a liquid to flow along an upward second surface, e.g., an upward surface opposite to the aforementioned first film surface. The support plate 310 can be spaced apart from the membrane 320 to form a gap or membrane cavity 360 between them. The membrane cavity 360 can be formed when the membrane 320 is in a stationary (e.g., unpressurized) state. The membrane cavity 360 can be sealed. In some embodiments, a liquid-tight seal can be formed within the membrane cavity 360 to prevent the 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 the liquid can circulate. The seal can be formed, for example, in a membrane clamp 330, between a portion of the membrane 320 and a portion of the carrier body (e.g., plate 310 and / or base 380). As used herein, a sealed membrane cavity includes a membrane cavity that is in fluid communication with an inlet and / or outlet that can be selectively sealed (e.g., opened and closed by a valve).

[0053] In some embodiments, when the membrane 320 is stationary, a portion of the membrane 320, for example, its upward surface, is on or near a corresponding portion of the plate 310, for example, its downward surface. The membrane cavity 360 is formed when the membrane 320 is expanded (e.g., pressurized through a liquid). The membrane cavity 360 can redistribute and account for fluctuations in liquid pressure with respect to the membrane 320 and therefore to the substrate 370 during planarization. The liquid can be supplied to the back side of the membrane 320 through an inlet 350, as shown in the figure, and enter the membrane cavity 360. The inlet 350 can be located within the support plate 310, or the liquid can be supplied through other configurations. The liquid can also be removed from the membrane cavity 360 through an outlet 355. Each of the inlet 350 and the outlet 355 may be modified differently depending on the application (e.g., circular tube, square tube, etc.). In some embodiments, as further described herein, a vacuum can be provided to the cavity 360 via an inlet and / or outlet to hold the wafer 370 on the underside of the film assembly.

[0054] In some embodiments, the membrane cavity 360 can be formed by separating the membrane 320 from the support plate 310. For example, the support plate 310 may include a recessed internal portion to form the cavity. In the illustrated embodiment, the membrane assembly 305 may include an optional external pressure ring 340 to form the membrane cavity 360. In other embodiments, the membrane assembly 305 may be assembled without a pressure ring. For example, the elastic membrane 320 can rest directly against the support plate 310 without a membrane cavity 360 separating the membrane 320 from the support plate 310, for example, if no liquid is present in the membrane cavity 360. In some embodiments, the membrane assembly 305 may include one or more pressure rings 340 arranged concentrically. One or more pressure rings 340 may include channels (not shown) that allow 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 may include a multizone carrier. For example, the film 320 may be a multizone film. Each zone of the multizone film may include a corresponding film cavity configured to receive liquid and / or be controlled similarly (e.g., separately) as described herein for a single-zone carrier having a single-zone cavity. For example, the film 320 may have grooves (e.g., depressions) and / or raised portions of the film 320 that effectively isolate the different zones of the film 320. In a non-limiting example, the grooves may be arranged in a series of concentric circles originating from the center of the film. In another example, to improve the distribution of pressure applied across the substrate 370 when mounted on the film assembly 305, the grooves and raised portions may have an irregular shape (e.g., interconnected circles, non-circular depressions, circular patterns scattered across the surface of the film). In some embodiments, the system may adjust the removal rate of each zone by applying different pressures to one or more zones of the multizone film. For example, zones to which higher pressure is applied may have a higher removal rate. The system may also be able to adjust the temperature of the liquid supplied to one or more zones to control the removal rate. For example, a higher temperature (e.g., less cooling) can be applied to a particular zone to increase the removal rate compared to another zone. The effect of temperature changes on the removal rate may be relatively lower than the effect of pressure changes. Therefore, temperature can be used as a fine-tuning variable when adjusting the removal rate of a single-zone or multi-zone system. For example, the pressure in the first zone can be controlled to be the same as, greater than, or less than the pressure in the second zone. The temperature in the first zone can be controlled to be the same as, greater than, or less than the temperature in the second zone.

[0056] The film 320 may be flexible to conform to the surrounding structure. In some cases, the film 320 may be convex. For example, the film 320 may be slack in the center. For more precise polishing, the film 320 may also be cone-shaped so that small areas of the film 320 contact the substrate surface.

[0057] The membrane material may be any elastic material suitable for planarization and, for example, for use in a carrier head for a CMP process, as described herein. 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 of vinyl, rubber, silicone rubber, synthetic rubber, nitrile, thermoplastic elastomer, fluoroelastomer, hydrated acrylonitrile butadiene rubber, or a combination of urethane and polyurethane. In certain embodiments, the material of the elastic membrane 320 may be selected based on the heat transfer properties of the material in order to effectively cool (or heat or control the temperature of) the substrate. Therefore, when cooling a substrate such as a silicon carbide substrate, a material with 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, which has a thermal conductivity that can help cool the substrate. In some embodiments, the elastic film 320 may include inorganic additives that increase the thermal conductivity of the elastic film 320, thereby improving heat transfer between the temperature-controlled liquid and the substrate. Examples of inorganic additives that increase thermal conductivity may include a range of additives manufactured under Martoxid®, owned by Martinswerk GMBH.

[0058] One or more film assemblies can be implemented within a single CMP system. The CMP system may have a control unit (e.g., a variable-speed motor control unit) that utilizes feedback from the system during operation to more precisely control the CMP process.

[0059] In exemplary embodiments, the film 320 can be planarized. For example, the film 320 can be planarized to a desired tolerance and / or to match a desired surface roughness. For example, the film 320 can undergo a planarization procedure in which the film is subjected to an abrasive pad. Alternatively, the film 320 can be introduced into a chemical slurry that planarizes the film 320. Furthermore, the surface roughness of the film 320 can be improved throughout this planarization process. Surface roughness can be important for films used in conjunction with CMP processes for at least two reasons: sealing and sticking. The planarization process can reduce surface roughness to improve sealing between the substrate 370 and the film 320 for handling purposes. At the same time, surface roughness can be increased to prevent sticking (i.e., the film adhering to the substrate due to surface tension) and to improve the release of the substrate from the film after processing. To achieve a desired balance between low and high surface roughness, control mechanisms can be used during the planarization process (described below). The control mechanism may be located outside the apparatus used to planarize the film.

[0060] As described above, when polishing a substrate at higher pressure and / or speed, certain substrates such as silicon carbide substrates may be involved, and the friction between the substrate and the rotating polishing pad / platen can result in temperatures high enough to adversely affect the substrate 370 and / or the elastic film 360. Therefore, one aspect of the present disclosure relates to flowing a liquid along the surface of the elastic film 360 to cool the elastic film 360 and the substrate 370. Figure 4A is a block diagram showing a substrate carrier system 400 that can be used to control the temperature of a substrate according to an aspect of the present disclosure.

[0061] Referring to Figure 4A, the substrate carrier system 400 may include a gas source, such as a compressed dry air (CDA) source 405, and a liquid source 410. The gas and liquid sources may be provided via containers at the facility, on site, and / or may be part of the recirculation system described herein. The system 400 may include one or more valves, such as valves 420, 425, and 427, to provide selective vacuum, gas, or liquid flow. The system 400 may include a vacuum source, such as an air-driven aspirator 430. The system 400 may include a carrier head 500 having a membrane cavity 360, an inlet 350, and an outlet 355, which is similar to those described herein with respect to carrier head 300 (Figures 3 and 5), carrier head 600 (Figures 6-8), or other carrier heads that provide temperature control. The system 400 may include movable elements, such as a rotating union 435 configured to provide relative movement between the carrier head and the polishing head. The rotating union 435 may be part of the carrier head or a separate part attached thereto. System 400 may include a control system 440. The control system 440 may include pressure and / or flow regulators configured to control the pressure and / or flow rate at the inlet and / or outlet of the membrane cavity 360. For example, the control system 440 may include a fluid back pressure regulator 445, and in some embodiments, a pneumatic regulator 415. In some embodiments, the control system 440 may further include a control processor (not shown) configured to control one or more of the pneumatic regulator 415, the fluid back pressure regulator 445, and / or other components of the substrate carrier system 400. It will be understood that the control system 440 may include one or more sensors configured to sense various process parameters such as flow rate, pressure, and temperature in order to provide open-loop or closed-loop control using the control processor. For example, temperature, flow rate, and / or pressure sensors may be implemented to sense the temperature, flow rate, and / or pressure of the liquid fluidically communicating with the membrane cavity.

[0062] The liquid used for cooling can be selected at least partially based on the heat transfer properties of the liquid. In one embodiment, the liquid may be water. In another embodiment, the liquid may be designed to have higher heat transfer properties than water, for example, the liquid may be a Garden HT heat transfer fluid. Other liquids may also be used depending on the embodiment.

[0063] The liquid source 410 selectively supplies liquid to the membrane cavity 360 (for example, via a valve 425 and a rotating union 435). The rotating union may include a set of fluid channels that allow the liquid source 410 to supply liquid to the inlet 350 of the carrier head 500 and to receive liquid flowing out of the substrate carrier head 300 via an outlet 355 while rotating the carrier head 500. The liquid received from the liquid source can flow into the membrane cavity 360 via the inlet 350 and out of the membrane cavity 360 via the outlet 355, for example, to a fluid back pressure regulator 445.

[0064] CDA source 405 provides CDA to pneumatic regulator 415 so that pneumatic regulator 415 can control fluid back pressure regulator 445. In some embodiments, fluid back pressure regulator 445 can be controlled directly by a control processor without including pneumatic regulator 415. 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 fluid back pressure regulator 445. Thus, fluid back pressure regulator 445 can reduce excess pressure when the fluid pressure is higher than the desired pressure by allowing some of the liquid to flow out to the liquid discharge port 450. The liquid discharge port 450 may include a T-connector or valve to provide selective flow between regulator 445, suction device 430, and / or optional heat exchanger 460. Fluid back pressure regulator 445 can be configured to control the pressure applied to the substrate during CMP in order to control the pressure of the liquid in the membrane cavity 360. The pressure of the liquid supplied by the liquid source may be higher than the expected range of pressure applied to the substrate 370 during CMP. Therefore, the fluid back pressure regulator 445 can be configured to regulate the pressure of the liquid in the membrane cavity 360 by reducing the fluid pressure to a desired level. The pressure in the membrane 360 ​​can 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 valve 420. Valve 427 can be used to control the method of providing liquid to the membrane cavity 360 between allowing liquid to flow, providing negative pressure (e.g., via the air-driven liquid aspirator 430), and venting the membrane cavity 360. When providing negative pressure, the air-driven liquid aspirator 430 is configured to provide negative pressure (e.g., vacuum) to the liquid in the membrane cavity 360. In certain embodiments, the air-driven liquid aspirator 430 may also include an exhaust section 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. That is, the negative pressure provided by the air-driven liquid aspirator 430 can hold the substrate 370 on the underside of the elastic membrane 320. The support plate that provides support on the back side of the elastic film 320 may include holes to provide the vacuum (to give the wafer a suction effect) and / or to allow positive pressure of the liquid in the film cavity 360 to separate the substrate 370 from the elastic film 320.

[0066] In some embodiments, excess liquid flowing out of the liquid discharge port 450 can simply be discarded, forming a non-recirculating system. However, in other embodiments, excess liquid flowing out of the liquid discharge port 450 may be recirculated and returned to the liquid source 410. In certain embodiments, the system 400 may further include an optional heat exchanger 460 configured to adjust (e.g., cool) the temperature of the liquid before returning it to the liquid source 410 and flowing it into the carrier head.

[0067] Figure 4B is a block diagram showing another substrate carrier system that can be used to control the temperature of a wafer according to an aspect of the present disclosure. Referring to Figure 4B, the substrate carrier system 700 may include a cooling device 705, a pressure setting point 710, a back pressure regulator (BPR) 715, an input pressure gauge 720, a flow meter 725, a water "on" valve 730, a carrier 735 (such as a carrier head 300 or 600), a platen 740, an output pressure gauge 745, a recirculation / vacuum valve 750, and a vacuum separator 755.

[0068] In the embodiment shown in Figure 4B, the back pressure regulator (BPR) 715 is located upstream of the carrier 735. This configuration can provide a higher flow rate than the configuration in which the BPR 715 is located downstream of the carrier 735. The higher flow rate can improve the cooling of the substrate through the elastic membrane. A similar arrangement of the fluid back pressure regulator 445 upstream of the carrier head 500 can be implemented in the embodiment shown in Figure 4A.

[0069] Referring to Figures 3, 4A, and 4B, as the liquid flows through the membrane cavity 360 along the back side of the elastic membrane 320, the heat generated by friction during the polishing process is transferred from the substrate 370 to the liquid via 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 mounted upstream or downstream of the membrane cavity 360.

[0070] The inlet and outlet can be configured in various ways to influence the flow of liquid (and therefore temperature control) within the membrane cavity. In the embodiment shown in Figure 3, the inlet 350 may be located approximately in the center of the body of the substrate carrier head 300, and the outlet 355 may be located radially further from the center of the carrier body than the inlet 350, for example, near the outer edge of the elastic membrane 320. The rotation of the substrate carrier head 300 during polishing can assist the flow of liquid from the inlet 350 to the outlet 355 due to centripetal force. Although a single inlet 350 and a single outlet 355 are shown in Figure 3, some embodiments may include multiple inlets 350 and / or outlets. For example, multiple outlets 355 may be spaced near the outer edge of the elastic membrane 320 and / or along a radial (or circumferential) path extending from the center of the carrier body.

[0071] Figure 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 Figures 1 and 2, according to another embodiment. Similar to the embodiment in Figure 3, the substrate carrier head 300 of the embodiment in Figure 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 also include a support plate 310, an elastic membrane 320, a membrane clamp 330, and an optional external pressure ring 340. The membrane assembly 305 may be configured to hold the substrate 370 against the polishing pad during planarization and to provide a vacuum to hold the substrate 370 below the membrane assembly 305. These components may have similar functions to those described in relation to Figure 3.

[0072] As shown in Figure 5, the inlet 350 and outlet 355 may be located at opposing positions, for example, near the outer edge of the elastic membrane 320. Therefore, the liquid flowing from the inlet 350 can flow from one side of the elastic membrane 320 (e.g., the edge) to the outlet 355 located on the opposite side of the elastic membrane 320 (e.g., the edge).

[0073] It will be understood that the inlets 350 and outlets 355 described herein can be provided in any suitable configuration (e.g., shape, size, position, number, etc.) to improve temperature control and liquid distribution. For example, a single inlet 350 and outlet 355 is shown in the cross-sectional views of Figures 3 and 5, but two or more inlets 350 and two or more outlets 355 may be provided. One or more inlets or one or more outlets can be provided at various positions on the opposite side of the elastic membrane 320 (e.g., near the outer edge) so that the liquid flows more uniformly along the elastic membrane 320. In some embodiments, one or more inlets 350 can be positioned radially inward relative to one or more outlets 355 with respect to the center of the elastic membrane 320, and vice versa. In some embodiments, one or more inlets 350 can be positioned at approximately the same radial position relative to one or more outlets 355, but they can also be positioned at different circumferential positions. One or more inlets 350 or one or more outlets 355 can be positioned approximately in the center of the elastic membrane 320.

[0074] (Liquid-cooled multi-layer CMP system) Figure 6 is an exploded top isometric view of one embodiment of the 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 the one described with reference to Figures 1 and 2, or in other types of CMP systems. The carrier head 600 can be implemented in the substrate carrier system of Figure 4A and may include some features of the carrier heads of Figures 3 and 5 (and vice versa).

[0075] Referring to one or more of Figures 6 to 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 substrates on the carrier head 600. For example, the substrate holder may include an opening 40 configured to receive a substrate. The opening 40 may support a substrate held within the opening 40 and prevent its lateral movement by forming side walls that extend partially or completely through the thickness of the substrate holder. The holder 20 may be a separate or integrally formed part and may be made of the same or different material as the carrier body 21. The substrate holder may include a substantially seamless outer surface 42, or its outer surface may have grooves or other depressions to improve slurry flow.

[0076] The carrier head 600 may include a first elastic film 25 and a second elastic film 30. The films or parts thereof can be stacked or arranged adjacent to each other, for example, without intervening structures. Together, the films 25 and 30 can press the substrate against the substrate processing platen during substrate processing, as described above with respect to the CMP processing in Figures 1 and 2. Parts of the films 25 and 30 can be pressed against each other.

[0077] The membranes 25 and 30 may be flexible so as to conform to the adjacent structures. The membrane material may be any elastic material, for example, a material suitable for receiving back pressure and transferring that back pressure to the substrate held in the carrier head. In some embodiments, the membrane material may be one of rubber or synthetic rubber materials. As described 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 of vinyl, rubber, silicone rubber, synthetic rubber, nitrile, thermoplastic elastomer, fluoroelastomer, hydrated acrylonitrile butadiene rubber, or a combination of urethane and polyurethane. In certain embodiments, to effectively cool the substrate, the material of the elastic membranes 25 and 30 may be selected based on the heat transfer properties of the material. Therefore, when cooling a substrate such as a silicon carbide substrate, a material with higher thermal conductivity may be desirable. In some embodiments, the elastic films 25, 30 may include inorganic additives that enhance the thermal conductivity of the elastic films 25, 30 and improve heat transfer between the temperature-controlled liquid and the substrate.

[0078] The elastic films 25, 30 (and other films specified herein) may include portions that provide support to a substrate held within a carrier 600 (and other carriers specified herein). Such substrate support portions can be distinguished from other portions of the films 25, 30 that do not support the substrate but help attach the films 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 shown first substrate support is a horizontal portion of the first elastic membrane 25, which extends across its width W1 to a substrate held within the opening 40 of the substrate holder 20 and provides support thereto. The remaining portion of the first elastic membrane 25 (i.e., the portion that is not the first substrate support), the membrane backing support 17, the substrate holder 20, and the carrier body 21 can be configured to attach the first elastic membrane 25 to the rest of the carrier head 600, and the remaining portion of the first elastic membrane 25 may include shorter vertical and horizontal portions that are wrapped in a meandering shape around and / or between the outer portion of the outer support plate 36 (which will be further described 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, which extends across its width W2 to the inner central portion of the substrate held within the opening 40 of the substrate holder 20, providing support thereto. The second substrate support can be positioned between the first substrate support and the carrier body 21. The first and second substrate support can be stacked relative to each other and can be stacked directly against each other (i.e., in contact with each other). The second substrate can be stacked on top of the first substrate in the orientation shown. The second substrate support can be configured to selectively provide force to the interior of the first non-porous substrate support, as shown. The outer surface of the second substrate support can be in direct contact with at least the inner surface of the first substrate support. This configuration allows the second elastic membrane 30 to provide improved process and uniformity on the substrate, and can provide, for example, improved control of the 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 remaining portion of the carrier head 600, and the remaining portion of the second elastic membrane 30 may include, for example, a short vertical portion at its outer edge and a horizontal lip extending from the distal end of the vertical portion.

[0082] The membranes 25, 30 (or other membranes herein) may each contain non-porous portions, 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 penetrating the surface that is 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 any part thereof, may be non-porous in order to provide a sealed cavity while allowing expansion and contraction of the membrane using hydraulic pressure or vacuum during processing without leakage of liquid. The first and second substrate supports may each be non-porous in order to form the first non-porous substrate support and the second non-porous substrate support, respectively.

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

[0084] The carrier may include an outer support plate 36. The outer support plate 36 may include a generally planar rigid support surface configured to support a substrate held in the first substrate support portion of the first elastic membrane 25. In some embodiments, the outer support plate 36 may support a portion of the first substrate support portion of the first elastic membrane 25. For example, the outer support plate 36 may include a central opening 41 surrounded by an outer plate portion that can support the corresponding outer portion of the first substrate support portion of the second elastic membrane 30 during processing. The central opening 41 may be configured to surround the second substrate support portion. In some embodiments, the width W1 of the first substrate support portion may be greater than the width W2 of the second substrate support portion. In some embodiments, the outer support plate 36, the first elastic membrane 25, and the second elastic membrane 30 may be configured so that the second substrate support portion can pass through the central opening 41 of the outer support plate 36. Therefore, in some embodiments, during processing, the inner support plate 33 can support the inner portion of the substrate held by the carrier 600, and the outer support plate 36 can support the outer portion of the substrate held by the carrier 600.

[0085] The films described herein may be single-zone films or multi-zone films. For example, a film may have grooves (e.g., depressions) and / or raised portions that effectively isolate different zones within each film. In a non-limiting example, the grooves may be arranged in a series of concentric circles originating from the center of the film. In another example, to improve the distribution of pressure applied across the substrate during processing, the grooves and raised portions may have an irregular shape (e.g., interconnected circles, non-circular depressions, circular patterns scattered across the surface of the film). In some embodiments, the zones can be used to control or adjust the material removal rate in different areas of the substrate by applying a temperature-controlled liquid to one or more related zones of the elastic film.

[0086] In some embodiments, either or both of the elastic membranes may be single-zone membranes configured such that each zone receives pressure or vacuum only from a single cavity on the back side of each membrane. A “single cavity” is defined as a single volume in a common fluidic communication and is not limited to a specific shape. The cavity may include a small volume in a common fluidic communication, which is formed between relatively small tolerances between parts, not readily visible in Figure 8. For example, the carrier 600 may include a single first membrane cavity formed in a relatively small open space between the first substrate support portion of the first elastic membrane 25 and a portion of the carrier body 21 and / or outer support plate 36. The first membrane cavity can provide fluidic communication from a liquid source 410 to the back side of the first substrate support portion of the first elastic membrane 25. Thus, by flowing a temperature-controlled liquid along the back side of the first elastic membrane 25, the substrate and the first elastic membrane 25 can be cooled during the CMP process.

[0087] In some embodiments, the carrier 600 may include, for example, a single second membrane cavity formed between the second substrate support portion of the second elastic membrane 30 and the inner support plate 33. The second membrane cavity may be fluidically isolated from the first membrane cavity so as not to leak liquid from the first membrane cavity into the second membrane cavity. The volume of the first membrane cavity may increase when the liquid in the first elastic membrane 25 is pressurized, for example, via a fluid back pressure regulator 445. The volume of the second membrane cavity may increase when the corresponding second elastic membrane 30 is pressurized by the 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 a texture and / or liquid channels. The texture and / or liquid channels may allow a liquid to flow between the first elastic membrane 25 and the second elastic membrane 30, thereby allowing the liquid to cool the area of ​​the substrate that overlaps with the second elastic membrane 30.

[0089] (Comparative example of silicon substrate and silicon carbide substrate) Due to the difference between silicon substrates and silicon carbide substrates, numerous parameters associated with the CMP process performed in each type of process may differ. As a result of these parameter variations, silicon carbide CMP, which is designed to be cooled in the embodiments of this disclosure, may generate excessive heat. Table 1 below summarizes examples of 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 specific implementation. In some implementation configurations, the substrate carrier head may rotate at speeds exceeding the typical range of rotational speeds used for silicon during the processing of silicon carbide substrates. For example, to polish a silicon carbide substrate, the substrate carrier head may rotate at speeds exceeding approximately 100 rpm, approximately 110 rpm, approximately 125 rpm, approximately 150 rpm, or approximately 175 rpm, up to a maximum of approximately 200 rpm, or any range in between.

[0091] The pressure applied to the substrate may also exceed the typical range for polishing silicon carbide substrates compared to polishing silicon substrates. Here, for example, to polish a silicon carbide substrate, the control system 440 can control the hydraulic pressure to a maximum of approximately 15 psi, or any range in between, exceeding approximately 6 psi, 7 psi, 8 psi, 9 psi, 10 psi, 11 psi, 12 psi, 13 psi, or 14 psi.

[0092] In typical polishing of silicon substrates, the temperature does not significantly exceed or fall below the ambient temperature (e.g., room temperature). However, without active temperature control (e.g., cooling) of the silicon carbide substrate, the temperature of the silicon carbide substrate and polishing pad can rise above approximately 100°F. By cooling the substrate (e.g., silicon carbide substrate) according to embodiments of this disclosure, the temperature of the substrate and polishing pad can be reduced by approximately 10°F, 20°F, 30°F, 40°F, 50°F, 60°F, 70°F, 80°F, 90°F, up to 100°F, or any range in between, compared to the process temperature that would occur without active temperature control. As described elsewhere, it is expected that temperature control that increases the temperature during some processes can be advantageous, as can control the temperature, or maintain the temperature at a desired target. Therefore, in some embodiments, the temperature of the CMP process can be controlled to be 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 the desired target temperature, or within any range in between.

[0093] Embodiments of this specification can enable the processing of substrates with reduced thickness. For example, a silicon carbide substrate may also have a thickness thinner than a typical silicon substrate, which is about 600-800 μm. For example, a silicon carbide substrate may have a thickness of less than about 600 μm, less than about 500 μm, less than about 450 μm, less than about 400 μm, a minimum of about 350 μm, or any range in between, or in some embodiments, a thickness of about 350 μm.

[0094] Polishing a silicon carbide substrate using the embodiments described herein may also allow for the use of slower material removal rates than those typical for silicon substrates. For example, material removal rates that can be implemented on a silicon carbide substrate may be less than approximately 50 μm / h, less than 40 μm / h, less than 30 μm / h, less than 20 μm / h, less than 10 μm / h, a minimum of 5 μm / h, and any range in between.

[0095] Polishing silicon carbide substrates using the embodiments of this specification may also allow the use of flow rates lower than the typical slurry flow rates for silicon substrate polishing, which are 100-200 ml / min. For example, the slurry feeding system 140 can feed the processing 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, a minimum of about 50 ml / min, or any range in between.

[0096] As used herein, "silicon" in relation to "silicon wafer" or "silicon substrate" means the conventional material used to form a silicon wafer, which is typically a high-purity single-crystal material. Embodiments herein enable the processing of substrates with higher hardness than conventional silicon substrates, such as silicon carbide substrates. For example, substrates with hardness (Mohs hardness) exceeding approximately 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, and 11, and any range between them, can be processed with reduced damage. In some embodiments, substrates having a hardness (Mohs hardness) greater than approximately 11 can be processed. In some embodiments, substrates having a hardness (Mohs hardness) between approximately 8.5 and 10, or between 9 and 9.5, can be processed. Substrates having a hardness higher than the hardness of silicon in a silicon substrate can be processed. Non-silicon substrates within a silicon substrate can be processed. In some embodiments, a silicon substrate can be included to provide process temperature control. Furthermore, substrates other than silicon or silicon carbide substrates can be mounted.

[0097] (Liquid-cooled CMP system with rigid wafer support plate) Aspects of this disclosure can also be applied to other CMP systems that do not use elastic membranes. For example, Figures 9 to 12 show one embodiment of a “rigid backed” substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate (e.g., the system of Figure 4A or Figure 4B) according to aspects of this disclosure. In particular, Figure 9 is a perspective view of another embodiment of a substrate carrier that can be used as part of a substrate carrier system for controlling the temperature of a substrate according to aspects of this disclosure. Figure 10 is a cross-sectional view of the substrate carrier of Figure 9 taken along line AA of Figure 9. Figure 11 is another cross-sectional view of the substrate carrier of Figure 9 taken along line BB of Figure 9. Figure 12 is another cross-sectional view of the bottom plate taken along line CC of Figure 10.

[0098] Referring to Figures 9 and 10, the inlet and outlet lines 805 provide pathways 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., a liquid cooling passage) 815 between them. The upper and lower plates 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 and upper plates can be furnace brazed together to form a sealed liquid cooling passage 815. Similar to the embodiments shown in Figures 3 and 8, the substrate carrier head may include a carrier body 21 for supporting various components of the carrier head. The carrier head may include a substrate holder 20 attached to the carrier body 21. The support plate 310 may be attached to the carrier body 21 and the substrate holder 20, respectively. In some embodiments, the entire circumference of the plate 310 (including the top of the plate 310) may be surrounded by the retainer 20 and / or the body 21.

[0099] In the embodiments shown in Figures 9 to 12, the support plate 310 and the substrate holder 20 can hold and support the substrate without using an elastic membrane. In some embodiments, the substrate carrier does not include an elastic membrane, so the substrate carrier can be rigid. A carrier film, not shown, may be included between the support plate 310 and the substrate to provide cushioning between the substrate and the support plate 310. As shown in Figure 12, the liquid cooling passage can be routed to cover substantially the entire area of ​​the support plate 310 such that no part of the support plate 310 exceeds a threshold distance from the liquid cooling passage. The liquid cooling passage can be machined into one or more of the bottom and top plates of the support plate 310. Thus, the substrate carrier can be used to provide temperature control (e.g., cooling) of the substrate (such as a substrate formed of silicon carbide or other material), as described above in relation to embodiments of elastic membranes. For example, a system similar to that shown in Figure 4A or 4B is used, in which the membrane cavity 360 is replaced by a liquid cooling passage, and this system can be used to circulate or recirculate liquid for cooling the substrate during CMP.

[0100] (CMP system with temperature-controlled polishing pads) As described above, chemical mechanical polishing machines can remove material from many different substrates using a combination of downward force (pressure), platen speed (friction), and the chemical properties of the abrasive. 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 may be limited by the temperature of the pads in contact with the wafer. High temperatures can cause pad failure, leading to deformation, melting, glazing, and destruction of chemical properties (e.g., the chemical properties of the slurry). Therefore, in certain implementations, the amount and / or rate of removal is limited not by the mechanical system, but by the inability to remove the heat generated by the process. If the heat can be effectively removed, the mechanical system of the equipment can be pushed to its limits, increasing the removal rate. This improves throughput and enables processes that are not currently available.

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

[0102] Even with platen cooling, there may be limitations to the amount of heat that can be removed from the pad through heat conduction to the platen. Furthermore, heat removal by convection and radiation may be negligible at the pad's typical operating temperature.

[0103] Figure 14A is an SEM image 830 of an IC1000 microporous polyurethane (MPU) polishing pad. Figure 14B is a cross-sectional view of the polishing pad 832 and wafer 834 during CMP according to an aspect of the present disclosure. The presence of micropores in an 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 may dilute the slurry 836 used to polish the wafer 834, and the benefits of increasing pressure 838 and speed 840 may be negated by reducing the removal rate.

[0104] To prevent the added liquid from diluting the surface, the liquid (such as water) can be supplied in a manner that utilizes the latent heat of vaporization of the liquid. Water is very suitable for cooling the pad surface because it has a latent heat of vaporization of approximately 2260 J / g. Therefore, the pad can be cooled using a small amount of water, thereby cooling the pad without substantially affecting the chemical properties of the slurry 836. In some embodiments, if a decrease in the removal rate due to a change in the chemical properties of the slurry 836 is to be considered, the amount of water used to cool the pad may be small enough to result in a net improvement in the removal rate.

[0105] Figure 15 is a schematic diagram of a substrate processing system including an atomizer system according to an aspect of the present disclosure. As shown in Figure 15, the system may include an atomizer 905 configured to atomize a liquid and spread a very thin layer of liquid over a large surface area of ​​a pad 910 (which can be fixed to a platen 915), allowing the water to evaporate and heat to be directly extracted from the surface of the pad 910. In one embodiment, the amount of heat removed (watts) was calculated to be 226 W = 226 J / g × 0.1 ml / s flow rate. Experiments using a hot plate equipped with an ammeter showed that the actual wattage for an exemplary flow rate of 0.1 ml / s was 204 W. In various examples provided below, systems including the atomizer 905 were able to lower the pad temperature by 14 °C (25.2 °F).

[0106] (Comparative example of pad cooling using a liquid atomizer) Below, we provide experimental data for several experiments performed to test the cooling of polishing pads using the liquid cooling described herein. For each of the 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 of the platen by a cooling device, no cooling of the carrier, no atomizer). [Table 1(2)]

[0108] Experiment 2 is shown in Table 2 (high pressure, high speed, no cooling of the platen by a cooling device, no cooling of the carrier, atomizer started). [Table 2]

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

[0110] Experiment 4 is shown in Table 3 (high pressure, high speed, no cooling of the platen by a cooling device, carrier cooling started, no atomizer). [Table 3]

[0111] Experiment 5 is shown in Table 4 (high pressure, high speed, no cooling of the platen by a cooling device, carrier cooling started, atomizer started). [Table 4]

[0112] (CMP system with retaining ring) Figure 17 is a plot showing the relationship between ring pressure (psi) and platen temperature (°C) in a CMP system using a retaining ring. As shown in Figure 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 approximately 240 pounds applied to the retaining ring in this embodiment can exert a pressure of approximately 12.7 psi on the pad surface. In some embodiments, the system can provide a commanded pressure (e.g., in psi units) to the ring. In one embodiment, each psi of pressure on the ring results in a force of 24 pounds. By using another retaining ring with a surface area of ​​approximately 5 square inches to reduce the contact area of ​​the retaining ring, a pressure of approximately 48 psi can be applied to the pad. Reducing the contact area between the retaining ring and the polishing pad can also reduce the heat generated during polishing, which is particularly advantageous for certain wafers, such as silicon carbide wafers. Therefore, since the downward force is spread across the entire available surface area of ​​the retaining ring, the pad pressure may be related to the surface area of ​​the retaining ring. One effect of reducing the contact area of ​​the retaining ring may be increased wear of the retaining ring. For example, as the surface area of ​​the retaining ring decreases and the pressure applied increases, the retaining ring may wear out faster.

[0114] Increased wear on the retaining ring can be mitigated, at least partially, by changing the material of the portion of the retaining ring in contact with the pad to a harder material with better wear resistance. However, using such a hard material for the retaining ring may cause the wafer to break due to the wafer's fragility. Certain types of wafers are more fragile, and using a hard material for the retaining ring increases the likelihood of breakage. Figure 18 shows a retaining ring 1000 having a stepped shape. Although not shown, in certain embodiments, the retaining ring 1000 can be formed from two different materials. In particular, different materials such as polyphenylene sulfide (PPS) and polyetheretherketone (PEEK) can be used in the area where the wafer is in contact with the ring to reduce wear on the retaining ring while preventing the retaining ring from damaging the wafer.

[0115] To reduce wear of the retaining ring, the CMP process disclosed herein can use a retaining ring 1000 having a small surface area and a two-piece structure. For example, in some embodiments, the retaining ring may 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 may include a hard, low-wear external material such as aluminum oxide, zirconium oxide, boron nitride, boron carbide, silicon carbide, and stainless steel. The retaining ring 1000 may further include an internal material having a polymer designed to be compatible with substrate contact, such as PPS, PEEK, Torlon®, Rulon®, polysulfone (PSU), Ultem® polyetherimide (PEI), or polyvinylidene fluoride (PVDE).

[0116] By using an external material with sufficient hardness, ring wear during CMP can be minimized, extending the service life of the retaining ring. As shown in Figure 5, the retaining ring may also have stepped contact surfaces to reduce the contact area in order to reduce the heat generated by the contact between the surface of the retaining ring and the polishing pad.

[0117] (Containment and exhaust of atomized coolant) As described herein, using an atomizing solution to cool the substrate can be particularly advantageous for substrates formed from materials with higher hardness than conventional materials used for silicon wafers. This is because polishing such “hard” substrates can generate excessive heat, limiting the removal rate that can be achieved before overheating damages the substrate and / or the CMP equipment. Silicon carbide is an example of a material that may generate even more heat compared to conventional wafers. However, aspects of this disclosure are also applicable to other materials that can be used for substrates.

[0118] While atomizing coolants can effectively cool the substrate / CMP system to increase removal rates, they can combine with the slurry generated during the CMP process. One potential drawback of using atomizing coolants is that, compared to CMP processes that do not use atomizing coolants for cooling, some of the chemicals in the slurry may become airborne or migrate more easily from the processing environment (e.g., from the pads, platen, and / or substrate). This can be significant 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 conventional silicon wafer materials. Therefore, some of the corrosive and / or toxic chemicals may leach from the system via the atomizing coolant, potentially causing health hazards, becoming a source of contamination, or corroding nearby machinery / systems.

[0119] Aspects of the present disclosure relate to systems capable of capturing and exhausting atomized liquid in order to reduce or prevent the release 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 an atomized coolant containment and exhaust system 1100, according to aspects 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 so as to fit within the outer plenum. The inner and outer plenums can be coaxial with respect to 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 may include an output nozzle for discharging the atomized liquid. At least a portion of the atomizer 1102 can be located within the inner chamber 1106. The outer chamber 1104 may have a lower pressure than the inner chamber 1104 in order to draw the atomized liquid and slurry (e.g., slurry particles in the air) from the inner chamber 1104 and exhaust the atomized liquid and slurry to the 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 through them, such as a gap 1112. The exhaust port 1108 may 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 levels of any corrosive and / or toxic chemicals from the atomized liquid. In one exemplary embodiment, the exhaust may have a flow rate of about 1500 to 2000 or about 1800 (e.g., 1877 linear feet / min and about 36.49 cubic feet / min), but the embodiments of this disclosure are not limited thereto. The inner and / or outer plenums may be positioned near the polishing pad 1110, 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 approximately 1 mm, but it can range from 0 mm (where the plenum is in contact with the pad surface) to approximately 25 mm, or any range in between. If the plenum is in contact with the pad surface, a hole or slot may be added to the bottom of the outer plenum to allow exhaust to flow into and pass through the outer plenum.Alternatively, the bottom surface of the inner plenum may be lower than the bottom surface 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. The height of the bottom surfaces of the plenums can also be varied in a similar manner, with both having some clearance from the pad. In this way, the airflow induced by the exhaust can be applied directly to the pad surface at the slurry application point (proximity), and can be highly constrained to reduce propagation to a wider area / volume within the polishing machine and / or operating environment, thereby increasing the collection of atomizing liquid and / or slurry fumes.

[0121] Figure 20 provides two exploded perspective views of the plenum forming the outer chamber 1104 and inner chamber 1106 in Figure 19. As shown in Figure 20, the outer chamber 1104 and inner chamber 1106 are sized such that the inner chamber 1104 can be coaxially enclosed by the outer chamber 1104. As shown, each plenum can be formed from separate parts that are assembled during construction.

[0122] Figures 21A–D provide additional illustrations of embodiments of the plenum portions forming the outer chamber 1104 and inner chamber 1106 in Figure 19. In particular, Figure 21A is an enlarged view of the outer chamber 1104 and inner chamber 1106; Figure 21B is a side view showing the 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] (Integration of high-pressure pad rinse and exhaust plenum flush) During CMP processing, it may be advantageous to maintain a clean polishing pad during wafer process execution to reduce contamination by used process particles and chemicals, and thus improve process yield. In certain embodiments, water can be sprayed onto the polishing pad using a spray bar. While embodiments of this 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 solutions) can be used to clean the polishing pad. Exemplary liquids that can be used to clean the polishing pad include surfactants and SC-1 (e.g., a mixture of water, ammonia, and hydrogen peroxide). Furthermore, although embodiments of this disclosure are described in the context of embodiments of a spray bar, it will be understood that spray devices can be implemented that are configured to direct one or more flows of liquids of various shapes and sizes onto the polishing pad to provide similar pad cleaning advantages 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 (commonly referred to as slurry diluted with water due to the water introduced by the spray bar) discharged from the pad in response to spraying water onto the pad. Uncontrolled (e.g., unsuppressed) 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 not designed to handle water and / or slurry (e.g., areas away from the polishing pad). In some situations, the slurry may 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, the CMP system can become contaminated, potentially resulting in unnecessary downtime for the CMP system, for example, to clean out dried slurry from the system or to repair parts damaged by liquid ingress.

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

[0126] Referring to Figures 22A and 22B, the CMP system 1200 includes an atomizer 1202 configured to cool the 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 Figures 19-21D, for example. Here, the CMP system 1200 further includes a spray device (e.g., a spray bar) 1212. In the illustrated embodiment, the spray bar 1212 is incorporated into a coaxial cooling system including the outer cooling chamber 1204 and the inner cooling chamber 1210. In Figure 22A, the outer chamber (exhaust / low-pressure chamber) 1204 is shown using cross-hatching.

[0127] The spray bar 1212 includes a plurality of pad cleaning nozzles 1213 configured to spray water (e.g., directly) onto the pad 1208 (e.g., downward) to clean the pad, for example, after wafer processing. The spray bar 1211 and / or its nozzles 1213 may be partially or completely located within a portion of the exhaust system 1200. For example, the spray bar 1211 and / or its nozzles 1213 may be partially or completely located 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 located 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 pad cleaning benefits of the spray bar while preventing the water and slurry from being sprayed onto other parts of the CMP system other than the pads and internal features of the system 1200. The exhaust port 1206 may be configured to remove (e.g., exhaust) the water / slurry generated while the spray device 1212 is operating from the polishing pad and inner chamber 1210, through the gap to the outer chamber 1204, and then to the scrubber via the exhaust port 1206. Alternatively or additionally, an output for removing these by-products via a drain may also be implemented, as further described below. The spray device 1212 is not limited to any particular quantity of nozzles or any particular manifold or "rod-shaped" configuration, and may include one or more pad cleaning nozzles of various sizes, shapes, and orientations to provide similar pad cleaning functionality.

[0128] System 1200 may include one or more exhaust plenum flush nozzles 1214. The exhaust plenum flush nozzle may be a component of the spraying device 1212 or a separate component with a separate liquid supply. The flush nozzle may use the same cleaning fluid from the same cleaning fluid supply source as the pad cleaning nozzle described herein, or a different cleaning fluid from a different cleaning fluid supply source. The exhaust plenum flush nozzle 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 spraying of the rinse fluid into the plenum formed by the outer chamber 1204. In this way, the nozzle 1214 can flush water / slurry from the outer chamber 1204 through the exhaust port 1206 to the 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 in or otherwise contaminate a portion of the plenum formed by the outer chamber 1204. The exhaust plenum flush nozzle 1214 can prevent the accumulation of such unwanted contaminants by flushing any unwanted water / slurry from the outer chamber 1204 and allowing it to be exhausted through the exhaust port 1206. The outer chamber 1204 can also provide redundancy to the inner chamber 1210 by containing water / slurry that may escape into the gap formed between the inner chamber 1210 and the polishing pad 1208.

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

[0130] The coaxial plenum can control and protect the CMP system from unwanted excess spray from the spray bar 1212, and at the same time, it can push the slurry generated when cleaning the polishing pad 1208 into the scrubber via the exhaust port 1206.

[0131] Aspects of the present disclosure relating to a combination of spray devices such as a spray bar 1212 in coaxial cooling plenums 1204 and 120 offer at least two advantages. First, the relatively high volume and velocity of pressurized spray water provided by the spray bar 1212 helps flush any accumulation of spills in the cooling chamber components, including the inner chamber 1210, the outer chamber 1204, and the exhaust port 1206. Second, integrating the spray manifold 1212 into the cooling chamber assembly reduces the space 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 equipped with a sensor 1310. For example, Figure 23 may be a modified version of the substrate processing system 100 shown in Figure 1. Components of the chemical mechanical planarization system 1300 that are similar to those in Figure 1 may not be described in detail with respect to Figure 23.

[0133] The chemical mechanical planarization system 1300 may be equipped with one or more detectors. Sensor 1310 may consist of a temperature sensor positioned on and / or embedded within another component of the system 1300. Detector 1310 may be positioned to observe 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 separate from the polishing pad (e.g., a position above the polishing pad and / or a position 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. Detector 1310 may be configured to monitor the temperature of the polishing pad 110 when the polishing pad 110 is being cooled in 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 indicating the temperature and, in response, control the flow of the atomizing liquid from the atomizer. Such control can be implemented to provide in-situ measurement and control of the pad surface temperature in order to maintain a desired surface temperature of the polishing pad.

[0134] (summary) The atomization systems described herein include the use of any type of atomization system for cooling the polishing pads of a CMP system or for removing energy and / or heat from the polishing pads. The atomization system can use any liquid medium in combination with any compressed gas via an orifice to cool the pads or remove energy and / or heat from the pads, thereby enabling a higher removal rate during CMP. Aspects of the disclosure also relate to the use of any adiabatic cooling system for cooling the pads or for removing energy and / or heat from the pads. When an atomizer is used, the system can be further configured to control the temperature of the atomized fluid as an additional means for controlling the temperature of the pad surface during CMP. Further different aspects of the disclosure relate to the application of a cooling and / or temperature-controlled gas (such as compressed air) flowing through a vortex cooling nozzle as an additional means for cooling the pad surface without adversely affecting the CMP process and consumables. It will be understood that the embodiments of the exhaust system described herein can be employed in CMP processes using corrosive or other hazardous slurries, such as those used in silicon carbide substrate processes, or other more corrosive processes (e.g., potassium permanganate-based slurries, periodates, ferric nitrates), or other less corrosive, benign slurries (e.g., potassium hydroxide, ammonium hydroxide). For example, in any process, regardless of the type of slurry, the atomized liquid of the embodiments described herein may condense on the apparatus, causing "fogging" or other adverse effects. Furthermore, the containment and exhaust system described herein can be implemented to contain and exhaust an atomizer configured to cool the polishing, either alone or in combination with a spray device for cleaning the polishing pads, and vice versa.

[0135] The term “exemplary” is used herein to mean “serving as an example, case, or illustration.” Any aspect or embodiment described herein as “exemplary” should not necessarily be construed as being preferable or advantageous to other aspects or embodiments. Various aspects of the novel systems, apparatus, and methods are fully described below with reference to the accompanying drawings. However, this disclosure can be embodied in many different forms and should not be construed as being limited to any particular structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure is thorough and complete and fully conveys the scope of this disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art should understand that the scope of this 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 herein. For example, an apparatus can be realized or a method can be implemented using any number of aspects described herein. Furthermore, the scope of this disclosure is intended to cover such apparatus or methods implemented using, in addition to, the various aspects of this disclosure described herein, or other structures, functions, or structures and functions. It should be understood that any aspect disclosed herein may be embodied by one or more elements of the claims.

[0136] Furthermore, unless a term is explicitly defined in this Patent using the phrase "As used herein, the term... is defined herein to mean..." or a similar phrase, there is no intention to explicitly or implicitly limit the meaning of that term beyond its obvious or ordinary meaning, and such term should not be construed as having a limited scope based on any statement made in any section of this Patent (excluding the language of the claims). Insofar as the terms used in the last claim of this Patent refer to this Patent in a manner consistent with a single meaning, such clarifications are made solely for the purpose of avoiding confusion for the reader, and there is no intention to implicitly or otherwise limit such claim terms to that single meaning.

[0137] Conditional words such as “can,” “possible,” “may,” or “may” are generally intended to convey that certain features, elements, and / or steps are included in certain embodiments but not in other embodiments, unless otherwise specified or interpreted in the context in which they are used. Therefore, such conditional words are not generally intended to suggest that features, elements, and / or steps are required in any way in one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without user input or prompting, whether these features, elements, and / or steps are included in any particular embodiment or whether they are performed in any particular embodiment.

[0138] Conjunctions such as "at least one of X, Y, and Z" are generally understood in contexts where they are used to indicate that an item, term, etc., may be X, Y, or Z, unless otherwise specified. Therefore, such conjunctions are 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, terms of degree such as “approximately,” “about,” “generally,” and “substantially” represent values, quantities, or characteristics close to the stated values, quantities, or characteristics that still perform the desired function and / or achieve the desired results. For example, the terms “approximately,” “about,” “generally,” and “substantially” may mean quantities within the range of less than 10%, less than 5%, less than 1%, less than 0.1%, and / or less than 0.01% of the stated quantity, depending on the desired function or desired result.

[0140] While specific embodiments have been described, these embodiments are presented merely as examples and are not intended to limit the scope of this disclosure. In fact, the novel methods and systems described herein can be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications of the systems and methods described herein can be made without departing from the spirit of this disclosure. The appended claims and their equivalents are intended to cover forms or modifications that fall within the scope and spirit of this disclosure.

[0141] Any features, materials, properties, or groups described in relation to a particular aspect, embodiment, or example should be understood to be applicable to any other aspect, embodiment, or example described in this section or any other section of this specification, unless otherwise incompatible. All features disclosed herein (including the accompanying claims, abstract, and drawings), and / or all steps of any method or process so as disclosed, can be combined in any combination, except for any combination in which at least some of such features and / or steps are mutually exclusive. The protection is not limited to the details of such embodiments described above. The protection extends to any novel features disclosed herein (including the accompanying claims, abstract, and drawings), or to any novel steps of any method or process so as disclosed, or to any novel combination of such methods or processes.

[0142] Furthermore, certain features described in this disclosure in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable partial combination in multiple embodiments. Furthermore, features may be described above as functioning in a particular combination, but one or more features from a claimed combination may, in some cases, be removed from the combination, and the combination may be claimed as a partial combination or a variation of a partial combination.

[0143] Furthermore, while operations may be depicted in drawings or described in the specification in a specific order, such operations do not need to be performed in a specific order or sequence shown, nor do not all operations need to be performed, in order to achieve the desired results. Other operations not illustrated or described may be incorporated into 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 rearranged. Those skilled in the art will understand that in some embodiments, the actual steps taken in the illustrated and / or disclosed processes may differ from those shown in the drawings. Depending on the embodiment, certain steps described above may be omitted, or other steps may be added. Furthermore, the features and attributes of the particular embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of this disclosure. It should also 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 the above components and systems can typically be integrated into a single product or packaged into multiple products. For example, any component of the energy storage system described herein may be provided separately or integrated together (e.g., packaged together or mounted together) to form an energy storage system.

[0144] For the purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not all such advantages can necessarily be achieved according to a particular embodiment. Therefore, for example, a person skilled in the art will recognize that the disclosure can be embodied or practiced in a manner that achieves one advantage or group of advantages as taught herein, but does not necessarily have to achieve other advantages as taught or suggested herein.

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

[0146] The scope of this disclosure is not intended to be limited by any specific disclosure of preferred embodiments in this section or any other section of this specification, but may be defined by the claims, as presented in this section or any other section of this specification, or as may be presented in the future. The language of the claims should be interpreted broadly on the basis of the language used in the claims, and these examples should be interpreted as non-exclusive, without limitation to the examples described herein or any examples under examination of this application.

Claims

1. A chemical mechanical planarization (CMP) system, Polishing pad and A substrate carrier head configured to hold a wafer relative to the polishing pad, An atomizer configured to atomize a liquid and spread the atomized liquid layer over the surface area of ​​the polishing pad, A chamber configured to contain the atomized liquid, the chamber comprising an inner chamber and an outer chamber arranged to surround the inner chamber, wherein the outer chamber is configured to have a lower pressure than the inner chamber, and the inner chamber and the outer chamber are located above the surface area of ​​the polishing pad, An output configured to remove the atomized liquid from the chamber, A system that includes these features.

2. The system according to claim 1, wherein the inner chamber and the outer chamber are arranged in a nested configuration.

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

4. The system according to claim 1, wherein the output is configured to exhaust the atomized liquid from the chamber.

5. The output is equipped with an exhaust port, A scrubber connected to the exhaust port and configured to reduce the levels of any corrosive and / or toxic chemicals from the atomized liquid. The system according to claim 4, further comprising the above.

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

7. The system according to claim 1, wherein the polishing pad is made of polyurethane.

8. The system according to claim 1, wherein the polishing pad is further configured to polish the wafer if the wafer is made of silicon carbide.

9. A method for cooling a substrate during chemical mechanical polishing (CMP), A step of supplying slurry to the surface of a polishing pad of a CMP system, wherein the CMP system A substrate carrier head configured to hold a wafer relative to the polishing pad, An atomizer configured to atomize a liquid and spread the atomized liquid layer over the surface area of ​​the polishing pad, A chamber configured to contain the atomized liquid, the chamber comprising an inner chamber and an outer chamber arranged to surround the inner chamber, wherein the outer chamber is configured to have a lower pressure than the inner chamber, and the inner chamber and the outer chamber are located above the surface area of ​​the polishing pad, Output and, A step comprising, The method of cooling the substrate during chemical mechanical polishing (CMP) of the substrate is: The steps include supplying an atomizing coolant to the surface of the polishing pad using the atomizer, It further includes, The method of cooling the substrate during chemical mechanical polishing (CMP) of the substrate is: Using the output, the steps include removing at least a portion of the atomized coolant from a point close to the surface, Methods that further include this.

10. The method according to claim 9, wherein the removal step includes the step of exhausting the atomizing coolant from the chamber.

11. The method according to claim 9, wherein the removal step includes the step of discharging the atomizing coolant from the chamber.

12. The output is equipped with an exhaust port, The method according to claim 10, wherein the exhaust step further includes the step of flowing the atomized coolant from the inner chamber through the gap to the outer chamber, and from the outer chamber through the exhaust port.

13. The method according to claim 12, wherein the exhaust step further includes the step of flowing the atomized coolant from the exhaust port to the scrubber.

14. A chemical mechanical planarization (CMP) system, Polishing pad and A substrate carrier head configured to hold a wafer relative to the polishing pad, A chamber comprising a plenum configured to contain a liquid, the chamber comprising an inner chamber and an outer chamber positioned to surround the inner chamber, wherein the outer chamber is configured to have a lower pressure than the inner chamber, and the inner and outer chambers are located above the surface area of ​​the polishing pad, The aforementioned chemical mechanical planarization (CMP) system is: An atomizer configured to atomize the liquid in the chamber and spread the layer of atomized liquid over a portion of the surface area of ​​the polishing pad in the chamber, Furthermore, The aforementioned chemical mechanical planarization (CMP) system is: An outlet configured to remove the atomized liquid from the chamber, The CMP system is further equipped with additional features.

15. The system according to claim 1, wherein the gap distance between the inner chamber and the outer chamber and the surface area of ​​the polishing pad is in the range of about 0 mm to about 25 mm.

16. The system according to claim 1, wherein the surface area of ​​the polishing pad is larger than the area occupied by the opening of the chamber.

Images