Patent Description:
During chemical mechanical planarization or polishing (CMP), an abrasive and either acidic or alkalinic slurry is applied via a metering pump or mass-flow-control regulator system onto a rotating polishing pad/platen. A wafer is held by a wafer carrier which is rotated and pressed against a polishing platen for a specified period of time. The wafer is polished or planarized by both abrasion and corrosion during the CMP process. The pressures and forces between the wafer and the carrier during processing may cause wafer breakage or non-uniformity. Thus, there is a need to improve wafer carrier performance to increase CMP efficiency and reduce the cost of manufacturing. Documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, disclose known substrate carrier heads.

The present invention is defined in independent claim <NUM>.

According to an embodiment, W1 is greater than W2.

According to an aspect, the substrate carrier head further comprises a single first membrane cavity formed between the first substrate support portion and the carrier body.

According to another aspect, the substrate carrier head further comprises a single second membrane cavity formed between the second substrate support portion and the inner support plate.

According to the present invention, the substrate carrier head further comprises an outer support plate configured to support an outer section of the first substrate support portion.

According to still yet another aspect, the outer support plate comprises a central opening configured to surround the second substrate support portion.

According to another aspect, the outer support plate, first membrane, and second membrane are configured such that the second substrate support portion can pass through the central opening.

According to the present invention, at least one of the outer support plate and the inner support plate comprise a plurality of holes configured to extend through a thickness of the at least one of the outer support plate and the inner support plate, and to provide fluid communication between at least one of the first cavity and the first substrate support portion and the second cavity and the second substrate support portion.

According to still yet another aspect, the plurality of holes comprises a first plurality of holes extending through the thickness of the outer support plate, and a second plurality of holes extending through the thickness of the inner support plate.

According to another aspect, the second plurality of holes comprises a center hole extending through the center of the inner support plate, wherein the center hole is the same cross-sectional area as at least one of the other plurality of holes.

According to yet another aspect, each of the plurality of holes are round, and the same diameter relative to each other.

According to still yet another aspect, each of the plurality of holes has an area less than about <NUM> in2.

According to another aspect, the second substrate support portion directly contacts at least the inner section of the first substrate support portion.

According to yet another aspect, the substrate carrier head further comprises a bladder configured to move the outer support plate relative to at least one of the carrier body, the second resilient membrane, and the inner support plate.

According to still yet another aspect, the substrate carrier head further comprises a substrate sensor with a diameter less than or equal to about <NUM>,<NUM> (<NUM> inches).

According to another aspect, the substrate carrier head further comprises a substrate sensor with an adjustable spring force.

According to yet another aspect, the inner plate and the outer plate are substantially coplanar with respect to each other, having a coplanarity of at most about <NUM>.

According to still yet another aspect, at least one of the inner plate and the outer plate comprise a flat surface with a flatness of at most about <NUM>.

According to another aspect, the substrate retainer comprises a substantially unbroken outer surface.

Another aspect of the disclosed technology is a chemical mechanical planarization system, comprising the substrate carrier head of any one of the above aspects or embodiments.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures.

The above, as well as additional objects, features and advantages of the present inventive concept, will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings.

Although the following text sets forth a detailed description of numerous different embodiments of the invention, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of the patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment of the invention since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention.

The adoption and use of chemical mechanical planarization (CMP) for the planarization of thin films in the manufacture of semiconductor ICs, MEMS devices, and LEDs, among many other similar applications, is common among companies manufacturing "chips" for these types of devices. This adoption includes the manufacture of chips for mobile telephones, tablets and other portable devices, plus desktop and laptop computers. The growth in nanotechnology and micro-machining holds great promise for ever-widespread use and adaptation of digital devices in the medical field, in the automotive field, and in the Internet of Things (the "IoT"). Chemical mechanical planarization for the planarization of thin films was invented and developed in the early <NUM>'s by scientists and engineers at the IBM Corporation. Today, this process is widespread on a global basis and is one of the truly enabling technologies in the manufacture of many digital devices.

Integrated circuits are manufactured with multiple layers and alternating layers of conducting materials (e.g., copper, tungsten, aluminium, etc.), insulating layers (e.g., silicon dioxide, silicon nitride, etc.), and semiconducting material (e.g., polysilicon). A successive combination of these layers is sequentially applied to the wafer surface, but because of the implanted devices on the surface, topographical undulations are built up upon the device structures, as is the case with silicon dioxide insulator layers. These unwanted topographical undulations are often flattened or "planarized" using CMP, before the next layer can be deposited, to allow for proper interconnect between device features of ever decreasing size. In the case of copper layers, the copper is deposited on the surface to fill contact vias and make effective vertical paths for the transfer of electrons from device to device and from layer to layer. This procedure continues with each layer that is applied (usually applied by a deposition process). In the case of multiple layers of conducting material (multiple layers of metal), this could result in numerous polishing procedures (one for each layer of conductor, insulator, and semiconductor material) in order to achieve successful circuitry and interconnects between device features.

During the CMP process, the substrate or wafer is held by a wafer carrier which is rotated and pressed, generally via a resilient membrane within the wafer carrier, against the polishing platen for a specified period of time. CMP wafer carriers typically incorporate components for precision polishing of generally flat and round workpieces such as silicon wafers and/or films deposited on them on the process head. These components include: <NUM>) the resilient membrane, with compressed gas applied to the top surface or back side of the membrane; said pressure is then transmitted via the membrane to the top surface or back side of the workpiece in order to effect the material removal during CMP; <NUM>) one or more rigid support components which provide means for: fastening the membrane to its mating components, holding the membrane to its desired shape and dimension, and/or clamping the membrane to provide a sealed volume for sealing and containing the controlled gas pressure.

During the process, slurry is applied onto the rotating polishing pad through a fluid control device, such as a metering pump or mass-flow-control regulator system. The slurry can be brought to the polishing platen in a single-pass distribution system. For better performance, the slurry particles in their media should be distributed evenly between the rotating wafer, and the rotating polishing pad/platen.

A force is applied to the backside of the wafer by the wafer carrier membrane to press it into the pad and both may have motion to create a relative velocity. The motion and force leads to portions of the pad creating abrasion by pushing the abrasive against the substrate while it moves across the wafer surface. The corrosive chemicals in the slurry alter the material being polished on the surface of the wafer. This mechanical effect of abrasion combined with chemical alteration is called chemical mechanical planarization or polishing (CMP). The removal rate of the material can be easily an order of magnitude higher with both the chemical and mechanical effects simultaneously compared to either one taken alone. Similarly, the smoothness of the surface after polishing is improved by using chemical and mechanical effects together.

During the polishing process, material such as copper, a dielectric, or polysilicon is removed from the surface of the wafer. These microscopic particles either remain in suspension in the slurry or become embedded in the polishing pad or both. These particles cause scratches on the surface of the film being polished, and thus catastrophic failures in the circuitry rendering the chip useless, thus becoming a major negative effect upon yield.

Yield is the driving force in determining success at the manufacturing level for many products including integrated circuits, MEMS, and LEDs. The surface quality tolerances for a CMP process 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 important. Therefore, carrier design technology is constantly evolving toward improving this capability. Small non-uniformities in the flatness of a wafer that has been processed in a CMP system can result in decreased yield and increased waste. Non-uniformities or pressure differentials across the diameters of the wafer carrier and the process pad can cause wafer breakage. The accumulated costs of manufacturing a solid state device are together termed the "Cost-of-Ownership" (CoO) and this term is also applied to each of the required manufacturing steps. The CoO of the CMP process is one of the highest CoO figures in the <NUM> to <NUM> individual manufacturing steps required to make a semiconductor "chip" and its associated digital device.

While carrier designs incorporating various embodiments of resilient membrane concepts work well in terms of uniform material removal, there remain some non-optimum characteristics in their typical process performance. Essentially, despite substantial efforts to minimize them, certain practical deficiencies and anomalies still exist, which cause non-uniform pressure application to the wafer and associated non-uniform material removal. Such anomalies include, but are not necessarily limited to: variations in flatness of any rigid components contacting the membrane, and variations in planarization (and thus uniformity) with respect to the center and/or the edge of the wafer, relative to other portions of the wafer, or to each other.

In order to reduce the presence, magnitude and effects of such anomalies, the present application discloses embodiments of an improved substrate carrier for a CMP apparatus. These embodiments improve the flatness tolerances and substrate surface quality, when implemented in a CMP apparatus, and reduced likelihood of wafer breakage, resulting in increased yield and decreased cost of operation. It will be understood that although embodiments of the substrate carriers described herein are disclosed within the context of CMP equipment, they can be similarly implemented within other applications. Additionally, the substrate carrier methods and equipment described herein can be implemented separately, e.g., without the full CMP systems shown. Additionally, other CMP equipment can implement embodiments of the substrate carriers described herein, including multiple-head CMP systems, single head CMP systems, orbital CMP systems, or other CMP systems. For example, the substrate carrier methods and equipment described herein can be implemented within sub-aperture CMP systems. A sub-aperture CMP system can include a polishing pad which is smaller in diameter than the wafer. The wafer is typically oriented face-up with slurry dispensed on its surface, while the wafer and pad are rotated and the pad sweeps across the wafer.

The disclosed technology will be described with respect to particular embodiments and with reference to certain drawings. The disclosure is not limited thereto but only by the claims. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.

<FIG> is a schematic illustration of a chemical mechanical planarization system <NUM> for treating a polishing pad <NUM>. System <NUM> can include a wafer carrier <NUM> configured to hold and process a wafer. It will be understood that the term "wafer" as used herein may refer to a circular, semiconductor wafer, but can more broadly encompass other types of substrates with different shapes which are processed by polishing or planarizing equipment, such as CMP equipment. In the illustrated embodiment, the wafer carrier <NUM> is in a processing (e.g., lower) position, holding the wafer (not shown) against a polishing pad <NUM> with a membrane (not shown). The polishing pad <NUM> can be positioned on a supporting surface, such as a surface of a platen <NUM>.

<FIG> is a view of the chemical mechanical planarization system of <FIG>, showing a wafer <NUM> held by the wafer carrier <NUM> in a loading (e.g., upper) position. The wafer <NUM> can be held, for example, by force of a vacuum. Referring to both <FIG>, system <NUM> can include a slurry delivery system <NUM> configured to deliver the processing slurry to the wafer <NUM>, and allow it to be chemically/mechanically planarized against the polishing pad <NUM>. System <NUM> can include a pad conditioning arm <NUM>, which includes a pad conditioner at its end, which can be configured to treat or "refresh" the surface roughness, or other processing characteristics of the pad, during or between processing cycles.

In the system <NUM> of <FIG>, polishing pad <NUM> is on the top surface of platen <NUM> which rotates counter clockwise about a vertical axis. Other orientations and directions of movement can be implemented.

The slurry delivery system <NUM> can deliver a slurry containing abrasive and corrosive particles to a surface of the treated polishing pad <NUM>. The polishing slurries are typically colloidal suspensions of abrasive particles, i.e. colloidal silica, colloidal alumina, or colloidal ceria, in a water based medium. In various embodiments, the slurry delivery system <NUM> includes a metering pump, mass-flow-control regulator system, or other suitable fluid delivery components.

The wafer carrier <NUM> can hold wafer <NUM>, for example, with a vacuum, so that the surface of the wafer <NUM> to be polished faces towards polishing pad <NUM>. Abrasive particles and corrosive chemicals in the slurry deposited by the slurry delivery system <NUM> on the polishing pad <NUM> mechanically and chemically polish the wafer through abrasion and corrosion, respectively. The wafer carrier <NUM> and polishing pad <NUM> can move relative to each other in any of a number of different ways, to provide the polishing. For example, the wafer carrier <NUM> can apply a downward force against the platen <NUM> so that the wafer <NUM> is pressed against the polishing pad <NUM>. The wafer <NUM> can be pressed against the polishing pad <NUM> with a pressurized membrane (not shown), as will be described further herein. Abrasive particles and corrosive chemicals of the slurry between the wafer <NUM> and the polishing pad <NUM> can provide chemical and mechanical polishing as the polishing pad <NUM> and wafer carrier <NUM> move relative to each other. The relative motion between polishing pads and wafer carriers can be configured in various ways, and either or both can be configured to oscillate, move linearly, and/or rotate, counter clockwise and/or clockwise relative to each other.

Pad conditioning arm <NUM> can condition the surface of polishing pad <NUM>, by pressing against polishing pad <NUM> with a force, with relative movement therebetween, such as the relative motion described above with respect to the polishing pad and wafer carrier <NUM>. The pad conditioning arm <NUM> in the illustrated embodiment can oscillate, with a rotating pad conditioner at its end, which contacts the polishing pad <NUM>.

<FIG> is an exploded top isometric view of an embodiment of a substrate carrier head <NUM>. <FIG> is an exploded bottom isometric view of the carrier head <NUM> in <FIG>. <FIG> is a cross-sectional view of the carrier head <NUM> in <FIG>. Embodiments of carrier head <NUM> can be implemented within various types of substrate processing apparatus. For example, the carrier head <NUM> can be implemented in CMP systems, such as those described with reference to <FIG>, or other types of CMP systems.

With reference to one or more of <FIG>, the substrate carrier head <NUM> can include a carrier body <NUM> to support various components of the carrier head <NUM>. The carrier head can include a substrate retainer <NUM> attached to the carrier body <NUM>. The retainer <NUM> can be configured to retain and support a substrate on the carrier head <NUM>. For example, the substrate retainer can include an aperture <NUM> configured to receive a substrate. The aperture <NUM> can form sidewalls extending partially or completely through the thickness of the substrate retainer to support, and thus prevent lateral movement, of a substrate held within aperture <NUM>. The retainer <NUM> can be a separate or integrally formed piece and can be the same or different material, with respect to the carrier body <NUM>. The substrate retainer can include a substantially unbroken outer surface <NUM>, or the surface can have grooves or other recesses to improve slurry flow.

The carrier head <NUM> can include a first resilient membrane <NUM> and a second resilient membrane <NUM>. The membranes, or portions thereof, can be stacked or positioned adjacent to each other, for example without intervening structure. The membranes <NUM>, <NUM> can together press a substrate against a substrate processing platen during substrate processing, as described above with respect to CMP processing in <FIG>. Portions of membranes <NUM>, <NUM> can press against each other.

The membranes may be flexible such that each conforms to an adjacent structure. The membrane material may be any resilient material, for example, material suitable for receiving a back pressure, and transferring that back pressure against a substrate held within a carrier head. In some embodiments, the membrane material may be one of rubber or a synthetic rubber material. The membrane material may also be one of Ethylene propylene diene monomer (M-class) (EPDM) rubber or silicone. Alternatively, it may be one or more combinations of vinyl, rubber, silicone rubber, synthetic rubber, nitrile, thermoplastic elastomer, fluorelastomers, hydrated acrylonitrile butadiene rubber, or urethane and polyurethane formas.

The membranes <NUM>, <NUM> can include portions that provide support to a substrate held within carrier <NUM>. Such substrate support portions can be distinguished from other portions of the membranes which do not support the substrate, but assist in attaching the membranes to other portions of the carrier.

For example, the first resilient membrane <NUM> can include a first substrate support portion with a width W1 as shown. The first substrate support portion as shown is the horizontal portion of first membrane <NUM> which extends and provides support across its width W1 to a substrate held within the aperture <NUM> of the substrate retainer <NUM>. The remainder of the first resilient membrane <NUM> (i.e., the portions that are not the first substrate support portion), which can include, for example, the shorter vertical and horizontal portions wrapping in a serpentine shape around and/or between an outer portion of an outer support plate <NUM> (described further below), a membrane backing support <NUM>, the substrate retainer <NUM> and the carrier body <NUM>, can be configured to provide attachment of the first membrane <NUM> to the rest of the carrier head <NUM>.

The second resilient membrane <NUM> can include a second substrate support portion with a width W2. The second substrate support portion as shown is the horizontal portion of second membrane <NUM> which extends and provides support across its width W2 to an inner, central portion of a substrate held within the aperture <NUM> of the substrate retainer <NUM>. The second substrate support portion can be positioned between the first substrate support portion and the carrier body <NUM>. The first and second substrate support portions can be stacked with respect to each other, and can be stacked directly on each other (i.e., contacting each other). The second substrate portion can be stacked above the first substrate portion, in the orientation shown. The second substrate support portion can be configured to selectively provide a force against an inner section of the first imperforated substrate support portion as shown. An outer surface of the second substrate support portion can directly contact an inner surface of at least the inner section of the first substrate support portion. This configuration can allow the second membrane <NUM> to provide improved process and uniformity on a substrate, for example, to provide improved center removal rate control in a CMP process.

The remainder of the second resilient membrane <NUM> (relative to the second substrate support portion), which can include, for example, the short vertical portion at its outer edges, and the horizontal lip extending from the distal end of the vertical portion, can be configured to provide attachment of the second membrane <NUM> to the rest of the carrier head <NUM>.

The membranes <NUM>, <NUM> can each include imperforated portion(s), or the membranes <NUM>, <NUM> can each be substantially entirely imperforated. The membranes <NUM>, <NUM>, or sections thereof, can be imperforated, to allow for expansion and contraction of the membranes using pressure or vacuum, during processing. Thus, such as the first and second substrate support portions can each be imperforated to form a first imperforated substrate support portion, and a second imperforated substrate support portion, respectively.

The carrier head can include an inner support plate <NUM>. The inner support plate can be fixed, to prevent relative motion, once assembled, relative to the carrier body <NUM>. The inner support plate <NUM> can include a generally planar, rigid support surface configured to support a substrate held upon the second substrate support portion of the second membrane <NUM> during processing.

The carrier can include an outer support plate <NUM>. The outer support plate <NUM> can include a generally planar, rigid support surface configured to support a substrate held upon the first substrate support portion of the first membrane <NUM>. In some embodiments, the outer support plate <NUM> can support a section of the first substrate support portion of the first membrane <NUM>. For example, the outer support plate <NUM> can include a central opening <NUM> surrounded by an outer plate portion which can support a corresponding outer section of the first substrate support portion of the second membrane <NUM> during processing. The central opening <NUM> can be configured to surround the second substrate support portion. In some embodiments, the width W1 of the first substrate support portion can be greater than the width W2 of the second substrate support portion. In some embodiments, the outer support plate <NUM>, first membrane <NUM>, and second membrane <NUM> can be configured such that the second substrate support portion can pass through the central opening <NUM> of the outer support plate <NUM>. Thus, in some embodiments, the inner support plate <NUM> can support an inner portion of a substrate held upon the carrier <NUM>, and the outer support plate <NUM> can support an outer portion of a substrate held upon the carrier <NUM>, during processing.

The membranes herein may be single, or multi-zoned membranes. For example, the membranes may have grooves (e.g., indentations) and/or raised portions that effectively segregate various zones within each of the membranes. In a non-limiting example, the grooves may be arranged in a series of concentric circles originating from the center of the membrane. In another example, the grooves and raised portions may be irregularly shaped (e.g., interconnecting circles, non-circular indentations, circular patterns scattered across the surface of the membrane) in order to improve distribution of pressure applied across the substrate during processing.

In some embodiments, either or both membranes can be a single zone membrane wherein each zone is configured to receive pressure or vacuum from only a single cavity on the backside of each membrane. "Single cavity" is defined as a single volume in common fluid communication, and not be limited to a particular shape. The cavity can comprise a small volume in common fluid communication, which is formed between relatively small tolerances between components, without being readily viewable on <FIG>. For example, carrier <NUM> can include a single first membrane cavity formed within relatively small open spaces between the first substrate support portion of the first membrane <NUM> and portions of the carrier body <NUM> and/or the outer support plate <NUM>. The first membrane cavity can provide fluid communication from a vacuum or pressure source to the backside of the first substrate support portion of the first membrane <NUM>. In some embodiments, carrier <NUM> can include a single second membrane cavity formed, for example, between the second substrate support portion of the second membrane <NUM> and the inner support plate <NUM>. The first and/or second cavities can increase in volume upon pressurization of the corresponding first and second membranes <NUM>, <NUM>.

In some embodiments, the cavities can comprise a portion of the volume formed by the vacuum/pressure source to the membranes <NUM>, <NUM>, and/or any holes in the corresponding plates <NUM>, <NUM>. For example, the second membrane <NUM> can, in a non-pressurized and non-vacuum state (quiescent state), be in direct contact with the inner support plate <NUM>. Under such a scenario, the carrier still includes a cavity which provides backpressure (or vacuum) to the second membrane <NUM>, via the aforementioned small tolerancing between components, the volume within the pressure/vacuum supply, and/or the holes in plate <NUM>. The second membrane cavity can provide fluid communication from a vacuum or pressure source to the backside of the second substrate support portion of the second membrane <NUM>. In some embodiments, carrier <NUM> can include only the first and second single membrane cavities, with only the first and second substrate support portions of only the first membrane <NUM> and the second membrane <NUM>.

In some embodiments, at least one of the outer support plate <NUM> and the inner support plate <NUM> can include a plurality of holes, as shown. The holes can be configured to extend through a thickness of the outer support plate and/or the inner support plate. The plurality of holes can include a plurality of holes extending through the thickness of the outer support plate <NUM>. The plurality of holes can include a plurality of holes extending through the thickness of the inner support plate.

The holes can provide fluid communication between a vacuum and/or pressure source and the backside of membranes <NUM> and <NUM>. For example, the plurality of holes can provide fluid communication between the first cavity and the backside of the first substrate support portion. The plurality of holes can provide fluid communication between the second cavity and the backside of the second substrate support portion. In the embodiments that include the first and second membrane cavities, the holes can allow fluid communication between the first membrane cavity and the backside of membrane <NUM>, and between the second membrane cavity and the backside of membrane <NUM>. When subjected to vacuum, the corresponding substrate support portions of membranes <NUM> and/or <NUM> can be pulled at least partially into the corresponding plurality of holes, to form corresponding dimples in the membranes, as show in <FIG>. Such dimples can provide a suction cup effect to hold a substrate on the substrate support portion of the membrane <NUM> within carrier <NUM>. Providing pressure or releasing vacuum to the membranes <NUM> and/or <NUM> can allow a substrate to be released from carrier <NUM>.

The size and/or shape of the holes can be selected to reduce substrate breakage and improve uniformity. Each of the plurality of holes can be the same or different shapes or sizes relative to each other. One or more of the holes can be round. As shown for illustrative purposes, each of the plurality of holes are round, and each are the same diameter relative to each other. In some embodiments, the holes can be sized at or below a threshold, to reduce substrate breakage during processing. For example, each of the plurality of holes can be sized to have an area less than, or less than or equal to about: <NUM> in<NUM>, <NUM> in<NUM>, <NUM> in<NUM>, <NUM> in<NUM>, <NUM> in<NUM>, <NUM> in<NUM>, or <NUM> in<NUM> or any range therebetween that reduces substrate breakage relative to holes with an area greater than or equal to <NUM> in<NUM>, while still being large enough to provide the suction cup effect while under vacuum, as described elsewhere herein. In some embodiments, each of the plurality of holes are round, with a diameter less than, or less than or equal to about: <NUM> in, <NUM> in, <NUM> in, <NUM> in, <NUM> in, <NUM> in, <NUM> in, or any range therebetween that reduces substrate breakage relative to round holes with a diameter greater than or equal to <NUM> in<NUM>, while still being large enough to provide the suction cup effect while under vacuum, as described elsewhere herein.

In some embodiments, the plurality of holes can include a center hole extending through a center of the inner support plate <NUM>. The center hole can be the same cross-sectional area as at least one of the other plurality of holes extending through the inner support plate <NUM>.

The carrier <NUM> can include a substrate sensor <NUM> configured to detect whether a substrate is held within carrier <NUM>. The sensor <NUM> can comprise an adjustable spring, such that sensor <NUM> has an adjustable spring force. Thus, the amount of force that sensor <NUM> imparts upon a substrate held within carrier <NUM>, can be adjusted below a desired threshold, to reduce the probability of substrate damage. In some embodiments, the cross sectional area of the sensor <NUM> can be sized at or below a threshold, to reduce substrate breakage during processing. In some embodiments, the sensor <NUM> can be sized to have a diameter less than, or less than or equal to about: <NUM> in, <NUM> in, <NUM> in, <NUM> in, <NUM> in, or any corresponding cross sectional area (regardless of shape), or any range therebetween, that reduces substrate breakage relative to a sensor with a larger diameter, while still being capable of providing said sensing functionality.

<FIG> is a cross-sectional view showing co-planarity between components of the carrier head <NUM> in <FIG>. Referring to one or more of <FIG>, in some embodiments, the carrier <NUM> can be configured to allow relative movement (and thus relative positioning) between the outer support plate <NUM> and at least one of the carrier body <NUM>, the second resilient membrane <NUM>, and the inner support plate <NUM>. Such embodiments can allow the inner plate <NUM> and the outer plate <NUM> to be substantially coplanar with respect to each other. Such coplanarity can be implemented during processing, to reduce non-uniform forces on a substrate, and reduce substrate breakage. In some embodiments, the inner plate <NUM> and the outer plate <NUM> can be substantially coplanar with respect to each other within a range between substantially <NUM> and <NUM>, approximately <NUM> and <NUM>, for example at most about <NUM>. In some embodiments, the flatness of the inner plate <NUM> and the outer plate <NUM> can range between substantially <NUM> and <NUM>, approximately <NUM> and <NUM>, for example, at most about <NUM>, or at most about <NUM>.

The aforementioned relative movement and positioning between the outer support plate <NUM> and at least one of the carrier body <NUM>, the second resilient membrane <NUM>, and the inner support plate <NUM> can be provided in different ways. For example, the outer support plate <NUM> can be engaged with a bladder <NUM>, which is attached to body <NUM> with a bladder retainer <NUM>. Bladder <NUM> can receive vacuum or pressure from a vacuum or pressure source, to move outer support plate <NUM> relative to one or more of carrier body <NUM>, second resilient membrane <NUM>, and the inner support plate <NUM>. Bladder <NUM> can move outer support plate <NUM> through direct contact therebetween, or through intervening support structure.

The carrier body <NUM> can be supported by additional support structure, for interfacing carrier head <NUM> with the remainder of a substrate processing tool. For example, carrier body <NUM> can be attached to a mounting base <NUM> that allows carrier head <NUM> to mount to the remainder of a substrate processing tool. The carrier head <NUM> can be configured to allow relative movement between the carrier body <NUM> and the mounting base <NUM>. For example, carrier head <NUM> can include a rolling diaphragm <NUM>, which can receive pressure or vacuum from a pressure or vacuum source, to provide said relative movement. The rolling diaphragm <NUM> can be supported in different ways. For example, an outer diaphragm support <NUM> can secure an outer portion of the diaphragm <NUM> to the body <NUM>, and an inner portion of the diaphragm <NUM> can be secured between a first inner diaphragm support <NUM> and a second inner diaphragm support <NUM>.

The pressure and/or vacuum sources (not shown) that can provide pressure and/or vacuum to one or more of the first substrate support portion, the second substrate support portion, the bladder <NUM>, and the diaphragm <NUM> can be implemented in different ways. For example, the carrier <NUM> can include manifold(s), fitting(s), tubing, piping, channels, or other components, to provide pressure/vacuum as described herein. For example, the base <NUM>, support <NUM>, a central shaft <NUM>, or other components, can provide the fluid communication described herein.

Claim 1:
A substrate carrier head (<NUM>) comprising:
a carrier body (<NUM>);
a substrate retainer (<NUM>) attached to the carrier body (<NUM>), the substrate retainer (<NUM>) comprising an aperture (<NUM>) configured to receive a substrate;
a first resilient membrane (<NUM>) comprising a first imperforated substrate support portion with a width W1;
a second resilient membrane (<NUM>) comprising a second imperforated substrate support portion with a width W2, the second imperforated substrate support portion positioned between the first substrate support portion and the carrier body and configured to selectively provide a force against at least an inner section of the first imperforated substrate support portion; and
an inner support plate (<NUM>) fixed relative to the carrier body (<NUM>) to prevent relative motion of the inner support plate (<NUM>) relative to the carrier body (<NUM>), the inner support plate (<NUM>) comprising a support surface configured to support a substrate held upon the second imperforated substrate support portion; characterized in that the substrate carrier head further comprises
an outer support plate (<NUM>) configured to support an outer section of the first substrate support portion,
wherein at least one of the outer support plate (<NUM>) and the inner support plate (<NUM>) comprise a plurality of holes configured to extend through a thickness of the at least one of the outer support plate (<NUM>) and the inner support plate (<NUM>), to provide fluid communication between at least one of the first cavity and the first substrate support portion and the second cavity and the second substrate support portion.