Conditioner Assembly and Polishing Apparatus Including the Same

This U.S. non-provisional application claims priority under 35 USC § 119 to Korean Patent Application No. 10-2024-0060734, filed on May 8, 2024, in the Korean Intellectual Property Office, the disclosure of which is herein incorporated by reference in its entirety.

Example embodiments relate to a conditioner assembly and a polishing apparatus including the same.

Chemical mechanical polishing (CMP) may be a process of polishing a substrate, a layer formed on the substrate, or a structure formed on the substrate. Such a polishing process may be referred to as a planarization process.

A polishing apparatus is used as an apparatus for performing such a CMP process. The polishing apparatus may include a polishing pad that is in contact with a surface of an object to be planarized (for example, a substrate) in a state in which a surface of the substrate is exposed. The surface of the substrate may be polished by rotating/vibrating the substrate and/or a polishing pad in a state in which the substrate and the polishing pad are in contact with each other.

However, long-term and repeated use of the polishing pad may diminish polishing effectiveness thereof due to by-products generated during a polishing process. Therefore, the polishing pad needs to be periodically conditioned. As a result, the polishing apparatus requires a conditioner assembly to condition the polishing pad.

Example embodiments provide a conditioner assembly for significantly reducing defects that may occur due to by-products during a polishing process.

Example embodiments provide a highly reliable polishing apparatus for significantly reducing defects that may occur due to by-products during a polishing process.

According to an example embodiment, a polishing apparatus includes a rotatable platen configured to support a polishing pad, a chemical mechanical polishing (CMP) head configured to hold an object to be processed on the platen, a fluid supply device configured to supply a polishing fluid onto the polishing pad, and a conditioner assembly configured to condition the polishing pad. The conditioner assembly may include a conditioner disk, a disk head including a disk plate coupled to the conditioner disk and a protective wall protruding upwardly from the disk plate. The disk plate and the protective wall are a monolithic structure of polymer resin. A conditioner spindle portion has one end connected to a conditioner arm and an opposite end fastened to the disk head. The protective wall extends peripherally around the conditioner spindle portion and is radially spaced apart from the conditioner spindle portion. A height of the disk head in a vertical direction may be 0.3 to 0.7 times a distance from a lower surface of the disk head to a lower surface of the conditioner arm.

According to an example embodiment, a conditioner assembly for conditioning a polishing pad of a polishing apparatus includes a conditioner disk, a disk head having a disk plate coupled to the conditioner disk and a protective wall protruding upwardly from the disk plate, wherein the disk plate and the protective wall are a monolithic structure of polymer resin. A conditioner spindle portion has one end connected to a conditioner arm and an opposite end fastened to the disk head. The protective wall extends peripherally around the conditioner spindle portion and is radially spaced apart from the conditioner spindle portion. A height of the disk head in a vertical direction may be 0.3 to 0.7 times a distance from a lower surface of the disk head to a lower surface of the conditioner arm.

According to an example embodiment, a conditioner assembly for conditioning a polishing pad of a polishing apparatus, includes a conditioner disk, a disk head having a disk plate coupled to the conditioner disk, and a protective wall protruding upwardly from the disk plate. The disk plate and the protective wall are a monolithic structure of polymer resin. A conditioner spindle portion has one end connected to a conditioner arm and an opposite end fastened to the disk head. The protective wall extends peripherally around the conditioner spindle portion and is radially spaced apart from the conditioner spindle portion. An outer side surface of the protective wall is convexly curved.

Hereinafter, example embodiments will be described with reference to the accompanying drawings.

Example embodiments relate to a polishing apparatus used in a process of manufacturing semiconductor devices. A polishing apparatus is an apparatus for polishing a substrate (for example, a semiconductor wafer) used to manufacture a semiconductor device, or polishing various layers formed on a surface of the substrate. In a polishing process, a substrate to be polished (for example, the substrate, or at least one of the various layers formed on the surface of the substrate) may be placed on a polishing pad. While a polishing fluid is supplied between the substrate to be processed and the polishing pad, the substrate to be processed and the polishing pad may be moved relative to each other to polish a surface of an object to be processed.

is a perspective view of a polishing apparatus according to an example embodiment, andis a schematic cross-sectional view of the polishing apparatus of.

Referring to, a polishing apparatusaccording to an example embodiment includes a stageincluding a polishing pad, a CMP assemblyplacing a substrate to be processed (hereinafter referred to as a “target substrate”) S on the polishing padand polishing the target substrate S, a conditioner assemblyconditioning the polishing pad, and a fluid supply devicedistributing a polishing fluid.

The stagemay include a platen, a polishing padmounted on an upper surface of the platen, and a driving spindle.

The platenmay have a plate shape (for example, a circular plate shape) with a flat upper surface.

The platenmay be connected to the driving spindle, and may rotate around a rotation axisof the driving spindle. A drive motor, not illustrated, may be provided at the driving spindleto drive the platen, and rotational force may be provided to the platenthrough the driving spindle.

In an example embodiment, the platenmay perform motions other than rotational motion, for example, linear motion. For example, the platenmay perform rotational motion, linear movement, or a combination thereof. Linear motion may include not only a movement in one direction but also reciprocating motion, and rotational motion may include spinning, revolving, angular rotation, eccentric motion, or combinations thereof.

A polishing padmay be provided on the platen. The polishing padmay be used to come into contact with a surface of the target substrate S and polish the surface of the target substrate S.

During the polishing process, the target substrate S may be placed on the polishing padand may rotate and/or linearly move while in contact with the polishing pad.

Sizes (for example, areas) of the polishing padand the platenplaced therebelow may be larger than a size (for example, an area) of the target substrate S.

A material of the polishing padmay vary depending on conditions of a material of a surface to be processed (hereinafter referred to a “target surface”) of the target substrate S or polishing particles. For example, the polishing padmay be formed of a foamed polyurethane-based hard pad, a suede-based soft pad, or a sponge. In addition, the polishing padmay be formed of a material having a hardness or rigidity corresponding to a mechanical hardness or rigidity of the target surface. The polishing padmay also have a multilayer structure including a plurality of stacked pads. In the polishing padhaving the multilayer structure, at least a portion of the plurality of stacked pads may have different hardnesses (or rigidities), so that overall hardness or rigidity of the polishing padmay be determined.

In an example embodiment, at least one groove, not illustrated, for improving polishing efficiency of the target substrate S may be formed in an upper surface of the polishing pad. The groove may have at least one of various shapes (for example, a concentric circular shape, a radial shape, and a spiral shape). The groove may facilitate uniform supply of a polishing fluid between the polishing padand the target substrate S, or may facilitate discharge of by-products generated after the polishing process.

The CMP assemblymay hold the target substrate S on a lower surface thereof, and may support the target substrate S. The CMP assemblymay move the target substrate S such that the target surface of the target substrate S is provided on the upper surface of the polishing pad.

The CMP assemblymay include a CMP headfor holding and supporting the target substrate S, and a CMP spindleconnected to the CMP headto be rotatable together with the CMP head. A CMP drive motor, not illustrated, for rotating the CMP spindlemay be connected to the CMP spindle.

The target substrate S may include a substrate requiring polishing treatment, or a substrate on which at least one layer and/or structure requiring polishing treatment is formed. The substrate and the substrate on which at least one layer and/or structure is formed may be used in the manufacturing process of semiconductor devices. For example, the target substrate S may include a semiconductor substrate formed of a semiconductor material, as well as a metal substrate, a glass substrate, a plastic substrate, or the like. The semiconductor substrate may include a semiconductor element such as silicon (Si) or germanium (Ge), or a compound semiconductor such as silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs), or indium phosphide (InP), but example embodiments are not limited thereto. In addition, the target substrate S may include at least one organic layer, an inorganic layer, an organic-inorganic composite layer, or a metal layer formed on the substrate.

The CMP headmay be configured to be movable in a direction, perpendicular to the surface of the polishing pad. The CMP spindlemay be connected to the CMP headsuch that the CMP headis rotatable around an axis. The CMP drive motor may provide rotational force to the CMP spindle.

The target substrate S may be held on the lower surface of the CMP headby vacuum suction. In a state in which the CMP headholds and supports the target substrate S, the CMP headmay rotate around the rotation axisof the CMP spindlewhile applying pressure to the target substrate S towards the polishing pad.

In an example embodiment, the CMP headmay perform motions other than the rotational motion. For example, the CMP headmay be connected to an arm movable in a radial direction of the platen, and may move in the radial direction within a plane of the platen. The CMP headand the target substrate S supported on the CMP headmay also perform a lateral (horizontal) linear motion, a rotational motion, or a combination of the rotational motion and the linear motion on the upper surface of the polishing pad. In an example embodiment, the CMP headmay be swept between inner and outer sides of the platenon the upper surface of the polishing pad.

In an example embodiment, the platenmay perform a rotational motion and/or a linear motion simultaneously with the sweeping of the CMP head. Alternatively, the platenmay perform a rotational motion and/or a linear motion, separately from the CMP head.

The conditioner assemblymay be used to condition (for example, clean and/or regenerate) the polishing padand may perform a process of polishing the surface of the polishing pad. The process of conditioning the polishing padmay be performed between polishing processes of the target substrate S using the CMP assembly, or may be performed simultaneously with the polishing process of the target substrate S.

The conditioner assemblymay include a conditioner disk, a disk headcoupled to the conditioner disk, and a conditioner spindle portionfor transmitting rotational force to the conditioner disk.

The disk headmay be coupled to the conditioner disk. The polishing padmay be conditioned by horizontally rotating the conditioner diskon the polishing padin a state in which the conditioner diskcoupled to the disk headis in contact with the polishing pad.

The disk headwill be described in more detail later with reference to drawings.

The conditioner diskmay be mounted on the lower surface of the disk head. The conditioner diskmay include at least one pad, among various pads that may condition the polishing pad.

The conditioner diskmay include abrasive elements, for example, abrasive diamond particles fixed on the conditioner disk. The conditioner diskmay also include at least one composition, among other abrasive compositions in addition to or instated of diamond particles. For example, silicon carbide particles may be used instead of or in addition to the abrasive diamond particles. In an example embodiment, the conditioner diskmay also include a fixed brush formed of a polymer resin.

The conditioner spindle portionmay be connected to the conditioner arm, and the conditioner armmay be connected to the outer spindle. For example, one end of the conditioner armmay be connected to the conditioner spindle portion, and the other end of the conditioner armmay be connected to the outer spindle.

The conditioner armand the outer spindlemay move the disk headand the conditioner diskto an appropriate location on the polishing pad. While the polishing padperforms a rotational motion and/or a linear motion, the outer spindlemay be used to sweep the conditioner armaround an outer rotation axisto vibrate the conditioner diskbetween the inner and outer sides of the upper surface of the polishing pad.

The conditioner spindle portionmay be connected to a lower portion of the conditioner arm. An upper end of the conditioner spindle assemblymay be connected to a lower portion of the conditioner arm, and a lower end of the conditioner spindle portionmay be connected to the disk head.

A drive motor, not illustrated, that may provide rotational force to the disk headthrough the conditioner spindle portionmay be connected to the conditioner spindle portion. The drive motor may rotate the conditioner spindle portionand the conditioner diskaround a conditioner rotation axisAlthough not illustrated, the drive motor may be installed inside the conditioner arm.

A fluid supply devicemay be provided within the polishing apparatusto supply a polishing fluid, containing polishing particles for polishing the target surface of the target substrate S, to the polishing pad.

The polishing fluid may be provided as a slurry composition including polishing particles and a solvent. The size, type, and/or concentration of the polishing particles used in the polishing process may be selected depending on a state of an object to be removed of the target substrate S (for example, a size of an initial step, a thickness of a layer, and/or a material of the layer). The polishing particles may include at least one of, for example, diamond, silicon carbide (SiC), cubic boron nitride (CBN), silicon dioxide (SiO), cerium oxide (CeO), or aluminum oxide (AlO).

The fluid supply devicemay include a supply pipefor supplying the polishing fluid and a fluid supply nozzleprovided on one end of the supply pipeto spray the polishing fluid onto the polishing pad.

In an example embodiment, the fluid supply nozzlemay supply the polishing fluid to a certain fixed location of the polishing padon the platen. In an example embodiment, the fluid supply nozzleis movable on the polishing padon the platen. The movable fluid supply nozzlemay supply the polishing fluid to any location of the polishing padon the platen. The fluid supply nozzlemay be moved in synchronization with the CMP head, and thus the polishing fluid may be efficiently supplied between the target substrate S and the polishing pad.

Although not illustrated, the polishing apparatusmay further include a cleaning solution supply device supplying a cleaning solution for cleaning the target substrate S and the polishing padafter the polishing process. The cleaning solution may be supplied to the target substrate S and the polishing padby the cleaning solution supply device to remove polishing particles remaining on the target surface of the target substrate S and the polishing padand processing products generated by the polishing process. Deionized water (DI water) may be used as a cleaning solution. In addition to the DI water, a chemical may be appropriately supplied as the cleaning solution depending on the type of polishing particles. The cleaning solution supply device may include a cleaning solution nozzle for supplying the cleaning solution to a predetermined location on the polishing pad. The cleaning solution nozzle may be moved in a manner, similar to the fluid supply nozzle and may supply the cleaning solution to any location on the polishing pad.

In an example embodiment, the polishing apparatusmay include a controller. The controllermay control various driving devices of the polishing apparatusand the opening and closing of a valves of each nozzleto control the operation of the polishing apparatus. For example, the controllermay include a central processing unit (CPU) processing various types of data, a memory storing various types of data, or the like. The controllermay be communicatively connected to the platen, the CMP assembly, the fluid supply device, and the conditioner assembly, and may transmit command signals to control the platen, the CMP assembly, the fluid supply device, and the conditioner assembly. For example, the controllermay drive the conditioner assemblyby instructing values of rotational speed and/or rotational torque of the conditioner rotation axisto the conditioner assembly. In addition, for example, the controllermay drive the platenby instructing the values of the rotational speed and rotational torque of the driving motor to the platen.

The polishing apparatushaving the above-described structure may polish the target substrate S by supplying a polishing fluid, containing polishing particles, to the polishing padwhile rotating the platenand/or the CMP head. The polishing padand the platenmay rotate around a rotation axisof the driving spindle. The target substrate S may be pressed against the polishing padby the CMP headand the CMP headmay be moved within the plane of the platen, so that the target substrate S may be polished.

In the polishing apparatushaving the described structure, while rotating each of the platenand the disk head, the conditioner diskmay be placed on the polishing padby the disk headand then pressed, and the disk headmay be moved within the upper surface of the platento perform a conditioning process of the polishing pad.

For example, the disk headmay vertically lower the conditioner disktoward the polishing padsuch that a conditioning surface of the conditioner diskmay be brought into contact with the polishing surface of the polishing pad. The disk headmay rotate around the conditioner rotation axisof the conditioner spindle portion. The conditioner armmay rotate around the rotation axisof the outer spindlesuch that the disk headmay sweep over a polishing surface of the polishing padin a reciprocal motion. Through the rotational motion of the conditioner diskand the reciprocal motion of the disk head, contaminants on the conditioning surface of the conditioner diskmay be removed, and the polishing surface may be polished to be retextured. Thus, the conditioning process of the polishing padmay be performed.

The conditioning process may be performed in the polishing process of the target substrate S, or may be performed after the polishing process of the target substrate S and before a polishing process of a next target substrate S. As a result, a surface condition of the polishing padmay be maintained during the polishing process, and the polishing process may be stabilized.