Adaptive pattern tuning using a paddle assembly

Abstract

An electroplating chamber, system, and method are disclosed. The chamber includes a paddle disposed within a vessel, the paddle having a plurality of apertures arranged as a two-dimensional array extending along first and second lateral directions. The paddle is configured to be translated during electroplating in a third lateral direction that is angularly offset from the first and second lateral directions. In some embodiments, a diffuser is disposed between one or more anodes and the paddle, the diffuser having apertures positioned to overlap the paddle apertures. During electroplating, relative motion between the paddle apertures and patterned regions of a substrate modulates exposure to an electric field. The disclosed configurations may be used in electroplating processes involving substrates having patterned regions.

Description

PATENTAttorney Docket No.: 44026186WO01ADAPTIVE PATTERN TUNING USING A PADDLE ASSEMBLY BACKGROUNDField

[0001] The present disclosure generally relates to methods, components, and apparatuses for semiconductor manufacturing. More specifically, the present disclosure generally relates to electroplating components and other semiconductor processing equipment.Description of the Related Art

[0002] Microelectronic devices, such as semiconductor devices, are fabricated on and / or in wafers or workpieces. A typical wafer plating process involves depositing a metal seed layer onto the surface of the wafer via vapor deposition. A photoresist may be deposited and patterned to expose the seed layer. The wafer is then moved into the vessel of an electroplating processor where electric current is conducted through an electrolyte to the wafer, to apply a blanket layer or patterned layer of a metal or other conductive material onto the seed layer. Examples of conductive materials include permalloy, gold, silver, copper, cobalt, tin, nickel, and alloys of these metals. Subsequent processing steps form components, contacts, and / or conductive lines on the wafer. Many aspects of an electroplating process may impact process uniformity, such as irregularities in the electric field due to pattern variations, mass-transfer rates, as well as other process and component parameters. Even minor discrepancies across a substrate may impact downline finishing processes.

[0003] Conventional electroplating chambers and methods lead to high Total Thickness Variation (TTV) when processing large die patterns that include significant area density variations and also have a pattern perimeter that does not extend to the edge of the wafer. Controlling the TTV using conventional means often requires low plating rates, which results in low throughput. Designs that yield lower TTV enable higher plating rates and therefore higher wafer throughput, which is a desirable factor in producing microelectronic devices.

[0004] Thus, there is a need for improved systems and methods that can be used to produce high quality devices and structures.PATENTAttorney Docket No.: 44026186WO01SUMMARY

[0005] Embodiments of the present disclosure generally relate to a semiconductor processing chamber, and more particularly, an electroplating system and methods of processing wafers that include large die patterns.

[0006] In one aspect, an electroplating chamber is provided. The electroplating chamber comprises a vessel comprising one or more walls; and a paddle disposed within the vessel, the paddle comprising: a first surface; a second surface opposite the first surface; a plurality of ribs extending from the first surface, the plurality of ribs being arranged in a generally parallel relationship; and a plurality of paddle apertures extending through a thickness of the paddle, wherein the paddle apertures are arranged as a two-dimensional array that extends along a first lateral direction and a second lateral direction that is positioned at an angle relative to the first lateral direction; and an actuator configured to translate the paddle in a third lateral direction, wherein the third lateral direction is positioned at an angle relative to each of the first lateral direction and the second lateral direction.

[0007] In some embodiments of the electroplating chamber, the first lateral direction and the second lateral direction are orthogonal to one another. In some embodiments, the two-dimensional array comprises a repeating unit-cell pattern, and the unit-cell pattern includes a first plurality of paddle apertures having a first size or shape and a second plurality of paddle apertures having a second size or shape different from the first size or shape. In some embodiments, the third lateral direction forms an oblique angle relative to each of the first lateral direction and the second lateral direction. In some embodiments, at least some of the paddle apertures have an elongated aperture shape defining a major axis and a minor axis, and the major axis is oriented substantially parallel to the third lateral direction. In some embodiments, at least a subset of the paddle apertures extend through a base portion of the paddle and a rib portion of the paddle. In some embodiments, the paddle comprises one or more raised extension features defining at least one of the paddle apertures, the raised extension features projecting from the first surface and defining an aperture exit plane that is offset from the first surface toward a substrate-facing side of the vessel.PATENTAttorney Docket No.: 44026186WO01

[0008] In another aspect, an electroplating system is provided. The electroplating system comprises a vessel comprising one or more walls; one or more anodes disposed in the vessel; a diffuser disposed in the vessel between the one or more anodes and a substrate position in the vessel, the diffuser comprising a diffuser body defining a plurality of diffuser apertures extending through a thickness of the diffuser body; and a paddle disposed in the vessel between the diffuser and the substrate position, the paddle comprising: a first surface facing the substrate position; a second surface opposite the first surface; a plurality of ribs extending from the first surface, the plurality of ribs being arranged in a generally parallel relationship; and a plurality of paddle apertures extending through a thickness of the paddle; wherein, in a processing configuration, the plurality of paddle apertures are positioned to overlap the plurality of diffuser apertures along a direction between the one or more anodes and the substrate position.

[0009] In some embodiments of the electroplating system, the plurality of diffuser apertures comprise a first set of diffuser apertures having a first cross-sectional area and a second set of diffuser apertures having a second cross-sectional area different from the first cross-sectional area. In some embodiments, the first set of diffuser apertures and the second set of diffuser apertures are distributed in a pattern across the diffuser body, and the pattern comprises a laterally spaced two-dimensional array of diffuser apertures. In some embodiments, the diffuser comprises one or more extension features projecting from the diffuser body toward the substrate position, and at least one diffuser aperture extends through an extension feature to define an aperture exit plane that is offset from a main surface of the diffuser body toward the substrate position. In some embodiments, the paddle apertures comprise enlarged openings in a direction of paddle translation sized to accommodate relative motion between the paddle and the diffuser while maintaining the overlap between the paddle apertures and the diffuser apertures for at least a portion of a translation stroke. In some embodiments, the electroplating system further comprises an actuator configured to translate the paddle laterally relative to the diffuser during electrodeposition. In some embodiments, the electroplating system further comprises a thief electrode disposed in the vessel adjacent a perimeter region of the substrate position.PATENTAttorney Docket No.: 44026186WO01

[0010] In yet another aspect, a method of electroplating a substrate is provided. The method comprises positioning a substrate within a vessel of an electroplating system; applying an electrical bias between one or more anodes and the substrate to initiate electrodeposition; translating a paddle disposed between the one or more anodes and the substrate during electrodeposition, wherein the paddle comprises a plurality of paddle apertures arranged as a two-dimensional array extending along a first lateral direction and a second lateral direction that is positioned at an angle relative to the first lateral direction; and translating the paddle in a third lateral direction that is positioned at an angle relative to each of the first lateral direction and the second lateral direction, such that, during translation, the paddle apertures move relative to patterned regions of the substrate.

[0011] In some embodiments of the method, the first lateral direction and the second lateral direction are orthogonal to one another. In some embodiments, translating the paddle comprises oscillating the paddle laterally in the third lateral direction with a stroke length that is less than or equal to a pitch of ribs formed on the paddle. In some embodiments, the paddle apertures include elongated apertures defining a major axis oriented substantially parallel to the third lateral direction. In some embodiments, the method further comprises positioning a diffuser between the one or more anodes and the paddle, the diffuser comprising a plurality of diffuser apertures, and translating the paddle comprises moving the paddle such that, for at least a portion of a translation cycle, the paddle apertures overlap the diffuser apertures along a direction between the anodes and the substrate. In some embodiments, the method further comprises rotating the substrate relative to the paddle during electrodeposition.

[0012] In another aspect, a non-transitory computer readable medium has stored thereon instructions, which, when executed by a processor, causes the process to perform operations of the above apparatus and / or method.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of whichPATENTAttorney Docket No.: 44026186WO01are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0014] FIG. 1A is a plan view of a wafer that includes multiple large die patterns that include area density variations.

[0015] FIG. 1B is a close-up plan view of a one of the multiple large die patterns that includes a plurality of area density variations.

[0016] FIG. 2A is an isometric view of an electroplating chamber, according to one or more embodiments of the present disclosure.

[0017] FIG. 2B is an isometric view of a portion of the electroplating chamber illustrated in FIG. 2A, according to one or more embodiments of the present disclosure.

[0018] FIG. 3 is a partial schematic side cross-sectional view of a first configuration of the electroplating chamber shown in FIGS. 2A-2B, according to one or more embodiments of the present disclosure.

[0019] FIGS. 4A, 4B and 4D are schematic partial isometric views of lower portions of the electroplating chamber shown in FIGS. 2A-2B, according to one or more embodiments of the present disclosure.

[0020] FIG. 4C includes a plan view of an example of a diffuser design with a representative die pattern overlaid on a portion of the diffuser design, according to one or more embodiments of the present disclosure.

[0021] FIGS. 5A and 5B are plan views of an upper portion of the electroplating chamber, according to one or more embodiments of the present disclosure.

[0022] FIG. 6A includes partial schematic side cross-sectional views of a diffuser and a paddle disposed in different orientations within the upper portion of the electroplating chamber, according to one or more embodiments of the present disclosure.PATENTAttorney Docket No.: 44026186WO01

[0023] FIG. 6B is a partial schematic side cross-sectional views of a configuration of a diffuser and a paddle disposed within the upper portion of the electroplating chamber, according to one or more embodiments of the present disclosure.

[0024] FIG. 6C includes a plan view and isometric view of an example of the diffuser design illustrated in FIG. 6B, according to one or more embodiments of the present disclosure.

[0025] FIGS. 6D-6E each include a plan view and an isometric view of other examples of a diffuser design, according to one or more embodiments of the present disclosure.

[0026] FIG. 7 is a partial schematic side cross-sectional view of a second configuration of the electroplating chamber shown in FIGS. 2A-2B, according to one or more embodiments of the present disclosure.

[0027] FIG. 8A is a plan view of a first paddle design with a representative die pattern overlaid on a portion of first paddle design, according to one or more embodiments of the present disclosure.

[0028] FIG. 8B is a partial schematic side cross-sectional view of the paddle design shown in FIGS. 8A, according to one or more embodiments of the present disclosure.

[0029] FIG. 9 is a plan view of a second paddle design with a representative die pattern overlaid on a portion of second paddle design, according to one or more embodiments of the present disclosure.

[0030] FIG. 10 is an isometric view of a third paddle design with a representative die pattern overlaid on a portion of third paddle design, according to one or more embodiments of the present disclosure.

[0031] FIG. 11 is a plan view of a fourth paddle design with a representative die pattern overlaid on a portion of fourth paddle design, according to one or more embodiments of the present disclosure.PATENTAttorney Docket No.: 44026186WO01

[0032] FIG. 12 is a plan view of a fifth paddle design with a representative die pattern overlaid on a portion of the diffuser and paddle designs, according to one or more embodiments.

[0033] FIG. 13 is a flow diagram illustrating a method of electroplating a substrate according to one or more embodiments of the present disclosure.

[0034] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0035] The present disclosure generally relates to a substrate processing chamber, and more particularly, an electroplating chamber assembly that includes a chamber geometry configured to improve an electroplating deposition uniformity within the processing chamber, and related methods. Embodiments of the present disclosure more particularly relate to an electroplating system and methods of processing wafers that are adapted to deposit a layer on multiple large die patterns. The terms wafer, substrate, or work piece, as used herein, can include any type of semiconductor substrate, packaging substrate, substrate carrier, interposer substrate, bridge substrate, printed circuit board (PCB), or other type of substrate that includes die patterns disposed on a surface of the substrate. In some embodiments, the die pattern containing substrate can include an advanced packaging substrate that may include a material such as glass, silicon, ceramic, or organic or polymeric (e.g., FR4, BT, polyimide (PI), polyester, etc.) containing materials. The advanced packaging substrates can include one or more redistribution layers (RDL). The substrates can also be square, rectangular, or circular in shape. In one example, a square 310mm x 310mm or 600mm x 600mm panel is used. In some cases where a non-circular substrate is used, the non-circular substrate can be mounted to a circular shaped carrier substrate during processing.

[0036] FIG. 1 A is a plan view of a wafer 100 that includes multiple large die patterns that include area density variations within regions of each die pattern. As shown inPATENTAttorney Docket No.: 44026186WO01FIG. 1A, the wafer includes eight die patterns D1-D8 that are positioned, oriented and exposed on a surface of a wafer. In some configurations, the dark colored regions of the die patterns include one or more exposed features that include one or more metal layers that have a varying pattern density, while the white or uncolored regions will typically include an unpatterned photoresist or dielectric material.

[0037] FIGS. 1 B is a close-up plan view of a first die pattern D1 of the plurality of die patterns that includes a plurality of area density variations. In one example, the first die pattern D1 includes multiple regions that can be characterized as falling within one of three different average area densities R1 -R3. In the examples provided herein, it is assumed that each of die patterns D1-D8 include two or more regions that have different area densities, such as one or more regions that include a first area density R1 , one or more regions that include a second area density R2, and one or more regions that include a third area density R3, wherein the first area density R1 is less than the second area density R2, which is less than the third area density R3. Due to the variation in area density, the plating rate and thus TTV within the different area density regions during a plating process will have significant variations across the die patterns.

[0038] Some embodiments of the present disclosure overcome the challenges experienced in the industry when trying to plate metals within die patterns similar to the first die pattern D1 by incorporating components that selectively shield various regions of a wafer and die patterns from the electric field produced during electroplating operations. For example, some embodiments of the present disclosure may utilize a shielding assembly that includes a paddle, or a paddle and a diffuser that each include shield areas that correspond with and shield sparse regions of a die pattern from the electric field and include open areas that enable the electric field to pass through to dense regions of the substrate that are to be plated during an electroplating process. The use of such a shielding assembly may enable plating rates within dense regions and sparse regions to be more uniform. Some embodiments may utilize a paddle, or a paddle and a diffuser, that include apertures aligned with dense regions that enable the electric field to pass through to the dense regions of the substrate, while a solid face or smaller aperture within the paddle is used to shieldPATENTAttorney Docket No.: 44026186WO01sparse regions from the electric field. Some embodiments may improve the Total Thickness Variation (TTV) and co-planarity of the deposited layer. Accordingly, embodiments of the present disclosure may produce improved TTV and co-planarity of substrates during electroplating operations.

[0039] FIGS. 2A-2B illustrate an exemplary electroplating system 210 for electroplating a wafer according to embodiments of the present technology. FIG. 3 is a partial schematic side cross-sectional view of a first configuration of the electroplating chamber 300 shown in FIGS. 2A-2B, according to one or more embodiments. The electroplating system 210 may include a head 214 supported on a head lifter 216 and a vessel 301. A single electroplating system 210 may be used as a standalone unit. Alternatively, multiple electroplating systems 210 may be provided in arrays within an enclosure, with wafers or workpieces loaded and unloaded into and out of the processors by one or more robots. Head lifter 216 may lift and / or invert the head 214 to load and unload a wafer. Head lifter 216 may also lower the head 214 into engagement with one or more components of the vessel 301 for processing of the wafer. A membrane 240 (FIG. 3) may be included to divide the vessel 301 into a lower chamber 309 containing one or more anodes A1-A3, and a first liquid electrolyte, below the membrane 240, and an upper chamber 310 containing a second liquid electrolyte (e.g., catholyte). Alternatively, the membrane 240 may be omitted with the vessel 301 having a single chamber holding a single electrolyte. The one or more anodes A1 -A3 may each be coupled with a power supply 360a-c. In other embodiments the one or more anodes A1-A3 may be coupled with a common power supply.

[0040] The contact ring (not shown) is disposed on the head 214, which is provided to hold the wafer and may have a plurality of contact fingers for making electrical contact with a conductive layer, such as a metal seed layer, formed on the surface of the wafer that includes the die pattern regions D1-D8. Referring to FIG. 3, the wafer is positioned in a face-down orientation so that the die pattern regions D1-D8 are positioned to contact an electrolyte that flows from the upper chamber 310, through the shielding assembly 316, into a plating region 311, and then to the lower facing surface of the wafer. The head 214 may include a rotor (not shown) for rotating thePATENTAttorney Docket No.: 44026186WO01wafer and contact ring during processing. The head 214 may be movable to position the substrate holder into a processing position in the vessel, where the metal layers within the die pattern regions are in contact with electrolyte in the vessel 301. A rinse assembly 212 having tiered drain rings may be provided above and / or about the vessel 301.

[0041] A paddle 330 is provided at a fixed vertical position within the vessel 301 adjacent to the wafer. In some embodiments, the paddle 330 may be a generally circular plate of dielectric material having a plurality of parallel ribs or blades spaced apart by slots and / or other openings. A paddle actuator 350 may move the paddle 330 horizontally in a flat plane, parallel to the wafer, within the vessel 301 to agitate the electrolyte. The paddle 330 and the paddle actuator 350 may be supported on a base plate 220 (FIG. 2B) attached to the vessel 301. The wafer may be rotating or stationary during an electroplating operation. However, in some embodiments provided herein the wafer is stationary for a first period of time in a first position and then rotated an angle relative to a vertical axis to a second position for a second period of time. In one example, the angle of rotation is 180 degrees. The slots and / or other openings on the paddle 330 may enable allow ionic current to pass through the paddle 330.

[0042] In some embodiments, the paddle 330 itself is used as an electric field shield. In typical operation, the paddle 330 may move with an oscillation (which may be between or about 6-10 Hz in some embodiments), and with a stroke that is about a half (1 / 2) to one (1) times the paddle rib pitch P1 (FIG. 3). A secondary low frequency oscillation may be used to shift the rib reversal points to avoid imprinting either an electric field or mass transfer signature on the wafer (i.e., stripes on a stationary substrate, and rings on a rotating substrate). This secondary oscillation is referred to as the stagger motion. The stagger motion envelope may be roughly equal to the rib pitch P1. During processing, the paddle actuator 350 moves the paddle 330 to agitate the electrolyte (e.g., sometimes referred to as the catholyte) disposed within the plating region 311 the contained in the vessel 301. For example, the paddle 330 may move back and forth within a paddle travel dimension, with an oscillating motion. For some applications, the paddle 330 may use other movements, such as start / stop, stagger, etc.PATENTAttorney Docket No.: 44026186WO01

[0043] In some embodiments, additional components may be integrated into an electroplating system to improve the co-planarity of the plated substrate. In one example, as shown in FIG. 3, some electroplating systems 210 include a shielding assembly 316 that includes a paddle 330 and a diffuser 320 that are used in combination to selectively shield portions of the substrate from the electric field produced by the anodes during the plating operation to reduce electrodeposition variations within selected regions of the wafer, such as the sparse regions, such as regions with smaller average area densities (e.g., average area densities R1), while enabling the electrodeposition within higher area density regions, such as the regions having average area densities R3. This may help improve the co-planarity across the substrate.

[0044] In some embodiments, the shielding assembly 316 includes a diffuser 320 that is mounted on and sealed to a wall 302 of the vessel 301. The diffuser 320 includes a plurality of apertures 321 that are formed through a diffuser body 322. The apertures 321 are formed in a pattern, such as an array, through which the electrolyte flowing from the upper chamber 310 (i.e., electrolyte flow 315) passes through as it flows through the apertures 331 in the paddle 330 and into the plating region 311 and to the surface of the wafer.

[0045] In some embodiments, a thief electrode 340 is provided within a portion of the vessel 301 to adjust the plating uniformity across the surface of the wafer due to the application of a bias applied by a thief power supply (not shown), which “thieves” some of the plating current from the wafer.

[0046] FIGS. 4A, 4B and 4D are isometric views of successive portions of the lower region of the vessel 301. FIG. 4A illustrates a portion of the lower region of the vessel 301 that includes three anodes A1-A3 disposed within three anode regions.

[0047] FIG. 4B illustrates a portion of the lower region of the vessel 301 that includes a diffuser 320 that is disposed over the anodes A1-A3 disposed within the three anode regions. The diffuser 320 includes a plurality of apertures 321 , such as a plurality of first apertures 321 A, a plurality of second apertures 321 B, and a plurality of third apertures 321 C that are formed through the diffuser body 322 and are sizedPATENTAttorney Docket No.: 44026186WO01and distributed in a pattern (e.g., array) that is configured to align with desired regions of each of the die pattern regions (e.g., die pattern regions D1-D8) formed on a surface of the wafer. The array of apertures 321 can include a two-dimensional laterally spaced array, such as an array that includes the apertures 321 being positioned within a square, a rectangular or a hexagonal array of apertures, for example. The diffuser body 322 includes a dielectric material, such as a plastic material (e.g., PVDF, PPO, PEEK, NPP, PTFE, etc.) or ceramic material (e.g., alumina) that includes the plurality of apertures.

[0048] FIG. 4C is a plan view of an example of a diffuser 320 design that includes a representative die pattern overlaid over the aperture pattern formed in the diffuser 320. The configuration illustrated in FIG. 4C illustrates an exemplary configuration and stationary orientation of the wafer and die pattern relative to the diffuser 320 during an electroplating operation. As shown in FIG. 4C, the diffuser 320 includes an aperture pattern that includes first apertures 321 A, second apertures 321 B, and third apertures 321 C. The first apertures 321 A are formed and aligned with the regions of the die pattern formed on the wafer that include a high area density, such as the average area densities R3 (FIG. 1B). The second apertures 321 B are formed and aligned with regions of the die pattern formed on the wafer that include a medium area density, such as the average area densities R2 (FIG. 1 B). The third apertures 321 C are formed and aligned with regions of the die pattern formed on the wafer that include a low area density, such as the average area densities R1 (FIG. 1B). Since the high-density regions have a high average area density the apertures 321A have a cross-sectional area (e.g., hole size) that is larger than the other apertures 321 B and 321 C formed in the aperture pattern. Similarly, since the medium density regions have a higher average area density than the lower density regions, the apertures 321 B will have a cross-sectional area (e.g., hole size) that is larger than the apertures 321 C.

[0049] FIG. 4D illustrates a portion of the lower region of the vessel 301 that includes a paddle 330 that is disposed over the diffuser 320 and the anodes A1-A3. The paddle 330 includes a base 334, a plurality of ribs 335 extending from the base 334, and the plurality of apertures 331. The base 334 and plurality of ribs 335 of the paddle 330 may include a dielectric material, such as a plastic material (e.g., PVDF,PATENTAttorney Docket No.: 44026186WO01PPO, PEEK, NPP, PTFE, etc.) or ceramic material (e.g., alumina) that includes the plurality of apertures 331.

[0050] FIGS. 5A and 5B illustrate examples of aperture 331 configurations in two different paddle 330 designs that are disposed over a diffuser 320 that has a plurality of apertures 321 formed therein. As shown in FIGS. 5A and 5B, the paddle 330, which is disposed over a diffuser 320, includes an aperture pattern that includes a plurality of apertures 331 that have differing shapes and sizes. The plurality of apertures 331 are configured to be aligned with the plurality of apertures 321 formed in the diffuser 320 during processing. Due to the first oscillation and / or second oscillation motions of the paddle 330 during an electroplating process, the shape of the apertures 331 formed in the paddle 330 in the direction of motion (e.g., translation direction 510) of the paddle 330 are elongated versus a direction that is transverse to the direction of motion. The shape of the apertures 331 are configured so that the apertures 331 formed in the paddle 330 do not block, or only minimally block as a percentage of processing time, the apertures 321 formed in the diffuser 320 during the movement of the paddle 330 during processing.

[0051] FIG. 6A includes a partial schematic side cross-sectional view of a shielding assembly 316 including a diffuser 320 and a paddle 330 disposed in different relative orientations to each other within the upper portion of the vessel 301. The three different partial side cross-sectional views illustrate different positions that the paddle 330 and diffuser 320 may be positioned in relative to the wafer during processing. As illustrated in FIG. 6A, the design of the electroplating system 210 can include adjusting one or more of the dimensional variables used to form one or more of the components or features within the shielding assembly 316. In one example, the dimensional variables can include a chamber-wall-to-wafer-spacing C1-C3, a paddle-rib-height PH1-PH3, a paddle-rib-to-wafer-spacing PW1-PW3, a paddle-base-to-rib-height PB1-PB3 (e.g., base 324 thickness), paddle-to-diffuser-gap PD1-PD3, a diffuser thickness DT1-DT3, diffuser aperture 321 sizes and array orientations relative to the die pattern, and paddle aperture 331 sizes and array orientations relative to the die pattern. The illustrated configurations and / or provided dimension examples are not intended to be limiting as to the scope of the disclosure provided herein and are provided to describePATENTAttorney Docket No.: 44026186WO01one of many different process variables that can be used to adjust a plating process’s TTV and other related deposition parameter results on the die patterns formed on the wafer.

[0052] FIG. 6B includes partial schematic side cross-sectional view of a diffuser 320 design that includes an extension feature 625 that protrudes through an aperture 331 of the paddle 330. The extension feature 625 of the aperture 321 includes an opening at a first end 626 that is positioned a distance S1 from the surface of the wafer. The extension feature 625 is configured to reduce the spread of the electric field generated between the anode(s) and the cathodically biased die pattern formed on the substrate due to a reduced vertical spacing between the exit region of apertures 321 in the diffuser 320 and the wafer. The direction of motion (e.g., translation direction 610) is shown.

[0053] FIG. 6C includes a plan view and isometric view of an example of the diffuser 320 design illustrated in FIG. 6B, according to one or more embodiments. The extension features 625 illustrated in the FIG. 6C include various different external shapes that are configured to be positioned within the apertures 331 of a paddle 330 and sized so that external surfaces of the extension features 625 will not interfere with the edges of the apertures 331 of the paddle 330 when the first oscillation and / or second oscillation motions of the paddle 330 are performed during an electroplating process.

[0054] FIG. 6D includes a plan view and isometric view of an example of a diffuser 320 design, according to one or more embodiments. FIG. 6E includes a plan view and isometric view of another example of a diffuser 320 design, according to one or more embodiments. The diffuser 320 design in FIG. 6D illustrates one possible configuration of apertures 321 and the diffuser 320 design in FIG. 6E illustrates an alternate configuration of apertures 321.

[0055] FIG. 7 is a partial schematic side cross-sectional view of a second configuration of the electroplating chamber 300 shown in FIGS. 2A-2B, according to one or more embodiments. In this configuration, the shielding assembly 316 only includes a paddle 330 which is provided at a fixed vertical position within the vesselPATENTAttorney Docket No.: 44026186WO01301 adjacent to the wafer. In some embodiments, the paddle 330 may be a generally circular plate of dielectric material having a plurality of parallel ribs or blades spaced apart by slots and / or other openings. The paddle actuator 350 is configured to move the paddle 330 horizontally within the vessel 301 to agitate the electrolyte. The paddle 330 and the paddle actuator 350 may be supported on a base plate 20 (FIG. 2B) attached to the vessel 301 of the electroplating chamber 300. The wafer may be rotating or stationary during an electroplating operation. The slots and / or other openings on the paddle 330 allow an ionic current to pass through the apertures 331 in the paddle 330.

[0056] As used herein, “lateral" directions” refer to directions that lie within a plane generally parallel to a major surface of the substrate during processing (e.g., parallel to the substrate surface during electroplating). In some embodiments, apertures formed through a paddle are arranged as a two-dimensional array, meaning that the apertures are distributed in a repeating pattern that extends in at least two non-collinear lateral directions within the plane of the paddle.

[0057] In some embodiments, the two-dimensional array extends along a first lateral direction and along a second lateral direction that is positioned at an angle relative to the first lateral direction. In one example, the first and second lateral directions are orthogonal to one another (e.g., corresponding to X-direction and Y-direction axes within the plane of the paddle), although other angular relationships are contemplated.

[0058] FIG. 8A is a plan view of a first paddle design 800 with a representative die pattern D1 overlaid on a portion of the first paddle design 800, according to one or more embodiments. FIG. 8B is a partial schematic side cross-sectional view of the first paddle design 800 shown in FIG. 8A, according to one or more embodiments. FIGS. 8A and 8B illustrate one example of a paddle design in which a plurality of apertures are arranged as a two-dimensional array within the paddle. As shown in FIG. 8A, paddle apertures 631 and paddle apertures 632 are distributed in a repeating pattern that extends in a first lateral direction and in a second lateral direction that is positioned at an angle relative to the first lateral direction. In the illustratedPATENTAttorney Docket No.: 44026186WO01embodiment, the first and second lateral directions are orthogonal to one another and lie within a plane generally parallel to the surface of the substrate.

[0059] In some embodiments, the two-dimensional array comprises a repeating unit-cell pattern that includes a plurality of apertures having different sizes and / or shapes. For example, each unit cell may include one or more apertures 631 and one or more apertures 632, and the unit cell may be repeated across the paddle in both the first lateral direction and the second lateral direction. The apertures within a given unit cell may be identical to one another or may differ in size, shape, or spacing, depending on the desired alignment with patterned regions of the substrate.

[0060] During processing, the paddle is translated in a third lateral direction that is different from and not parallel to either the first lateral direction or the second lateral direction of the two-dimensional array. In some embodiments, the third lateral direction is oriented at an oblique angle relative to each of the first and second lateral directions. By translating the paddle in a direction that is angularly offset from the array directions, the apertures within the two-dimensional array sweep across patterned regions of the substrate in a time varying manner, which can increase the effective exposure time of selected regions to the electric field and improve deposition uniformity.

[0061] Accordingly, in various embodiments described herein, the paddle includes a two-dimensional array of apertures extending along first and second lateral directions within the plane of the paddle, while the paddle is translated during processing along a third lateral direction that is angularly offset from the first and second lateral directions.

[0062] As shown in FIG. 8A, the orientation of the die pattern D1 on a wafer is oriented at an angle relative to a translation direction 820 of the paddle 330. In some embodiments, the array of apertures 631 formed in the paddle 330 are formed in a two-dimensional array and are configured to be aligned over desired portions of a die pattern formed on the wafer. In other words, the apertures 631 are positioned within an array that is aligned with and adjacent to the regions of the die pattern D1 that have a known average area density, such as one or more of the average area densities R1-R3. It has been found that by orienting die patterns that have a certain shape, suchPATENTAttorney Docket No.: 44026186WO01as a square or rectangular shaped die pattern, and / or a die pattern that contains square, diamond, or rectangular shaped area density regions (e.g., regions 801 , 802) within the die pattern, the time that the apertures 631 within the paddle 330 are positioned over the desired regions of the die pattern can be maximized as the paddle 330 is oscillated in the translation direction 820 during processing. By maximizing the time that the apertures 631 are positioned over desired regions of the die pattern D1 , the final plating uniformity across each die pattern and across the wafer can be greatly improved. In some embodiments, as shown in FIGS. 8A and 8B, the apertures 631 can extend through the base 334 and through portions of the ribs 335.

[0063] FIG. 9 is a plan view of a second paddle design 900 with a representative die pattern D1 overlaid on a portion of the second paddle design 900, according to one or more embodiments. As shown in FIG. 9, the apertures 631 formed in the paddle 330 can include non-circular shapes, such as slots or rectangles. In this example, the major dimension (e.g., long direction) of apertures 631 in the die pattern D1 are oriented in a perpendicular orientation to the translation direction 920 of the paddle 330.

[0064] FIG. 10 is an isometric view of a third paddle design 1000 with a representative die pattern D1 overlaid on a portion of the third paddle design 1000, according to one or more embodiments. As shown in FIG. 10, the orientation of the die pattern D1 on a wafer is oriented at an angle relative to the translation direction 1020 of the paddle 330. Also as shown in FIG. 10, the third paddle design 1000 includes extension features 1025 that protrude above the base 334 of the paddle 330. The apertures 331 A, 331 B that extend above the base 334 each include an opening at a first end 1026 that is positioned a distance from the surface of the wafer. The extension features 1025 are configured to reduce the spread of the electric field generated between the hole exits and the cathodically biased die pattern regions formed on the wafer due to the reduced vertical spacing between the exit region of apertures 331 and the wafer. As illustrated in FIG. 10, the external shape of the extension features 1025 and aperture opening sizes (e.g., apertures 331A, 331 B) formed therethrough can be adjusted to match the position of the desired area density regions within the die pattern.PATENTAttorney Docket No.: 44026186WO01

[0065] FIG. 11 is a plan view of a fourth paddle design 1100 with a representative die pattern D1 overlaid on a portion of the fourth paddle design 1100, according to one or more embodiments. As shown in FIG. 11 , the orientation of the die pattern D1 on a wafer is oriented at an angle relative to the translation direction of the paddle 330. Also as shown in FIG. 11, the fourth paddle design 1100 includes apertures 331 that extend through the ribs 335 of the paddle 330.

[0066] FIG. 12 is a plan view of a fifth paddle design 1200 with a representative die pattern D1 overlaid on a portion of the fifth paddle design 1200, according to one or more embodiments. As shown in FIG. 12, the apertures 331 within the paddle 330 are formed within the base 334, and the spacing of the ribs 335 in the paddle 330 are adjusted to allow the apertures 331 within the paddle 330 to be disposed between the ribs 335. In this case, the rib 335 pitch and orientation of the apertures 331 are selected to provide the best aperture 331 layout with respect to the wafer pattern. In some embodiments, the distance between the aperture 331 exit, which is positioned at the upper end (e.g., first end 626 of an extension feature 625) closest to the wafer, and the wafer can be varied by either placing the apertures 331 in either the base 334 of the paddle 330 or through the ribs 335 of the paddle 330. The technique shown in Fig. 10 can also be used to vary the hole exit distance to the wafer. Hole diameter is another variable that can be adjusted. However, if the holes are too small, the electrical resistance of the path through the paddle 330 increases and plating current may want to leak around the outer edge of the paddle 330. Minimizing the resistance to current flowing through the apertures 331 in the paddle 330 and use of the thief electrode 340 along the perimeter can help compensate for the formation of current leaks that form around the paddle 330.

[0067] FIG. 13 is a flow diagram illustrating a method 1300 of electroplating a substrate according to embodiments of the present disclosure. The method 1300 relates generally to dynamically modulating an electric field applied to a substrate during electrodeposition in order to control deposition uniformity across patterned regions of the substrate. The method 1300 may be practiced using any suitable electroplating system capable of performing the operations described herein and is not limited to a particular chamber configuration unless otherwise specified.PATENTAttorney Docket No.: 44026186WO01

[0068] At operation 1302, a substrate is positioned within an electroplating environment. In some embodiments, the substrate includes a plurality of patterned regions, such as die patterns, formed on a surface of the substrate, as illustrated in FIGS. 1A-1B. The patterned regions may include regions having differing pattern densities across the substrate surface. In some embodiments, positioning the substrate includes securing the substrate to a substrate support or head 14 of an electroplating chamber 300, such that the substrate is disposed within a vessel 301.

[0069] At operation 1304, an electrolyte is introduced into the electroplating environment to contact the substrate. In some embodiments, the electrolyte is introduced into the vessel 301 and flows toward the substrate from a region containing one or more anodes A1-A3. The electrolyte may include any electrolyte suitable for electrodeposition of a conductive material on the substrate. For example, the electrolyte may include an aqueous solution containing metal ions such as copper, cobalt, nickel, tin, silver, gold, or alloys thereof. In some embodiments, the electrolyte may include copper sulfate-based electrolytes, copper methanesulfonate-based electrolytes, or other electrolytes commonly used in semiconductor and advanced packaging electroplating processes. The electrolyte may further include one or more additives, such as levelers, suppressors, accelerators, or grain refiners. However, the present disclosure is not limited to any particular electrolyte composition. The electrolyte may be circulated within the vessel 301 during electroplating to maintain desired processing conditions.

[0070] At operation 1308, an electrical bias is applied to the substrate to initiate electrodeposition of a conductive material on the substrate surface. In some embodiments, the substrate is biased cathodically relative to the anodes A1-A3, thereby establishing an electric field through the electrolyte within the vessel 301.

[0071] At operation 1310, a shielding element is introduced between the anode and the substrate and is translated relative to the substrate during electrodeposition. In some embodiments, the shielding element is implemented as a paddle 330 disposed between the anodes A1-A3 and the substrate. The paddle 330 may be positioned at a fixed vertical location within the vessel 301 and may be translated laterally relative to the substrate using a paddle actuator 350. Translation of the paddle 330 mayPATENTAttorney Docket No.: 44026186WO01include oscillatory motion in a direction generally parallel to the substrate surface and may be continuous or intermittent during electrodeposition.

[0072] At operation 1312, regions of the substrate are selectively shielded from the electric field for different amounts of time as the shielding element is translated. In some embodiments, apertures 331 formed through the paddle 330 move relative to patterned regions of the substrate, such as the die patterns illustrated in FIGS. 1A-1 B, as the paddle is translated. As a result, regions of the substrate corresponding to different pattern densities shown in FIGS. 1A-1B experience different degrees of electric-field exposure over time, depending on the relative position of the apertures 331 and ribs 335 of the paddle with respect to the patterned regions.

[0073] At operation 1314, deposition rate across patterned regions of the substrate is controlled through selective modulation of the electric field. In this manner, thickness variation across the substrate may be reduced and co-planarity of the deposited conductive material may be improved.

[0074] In some embodiments, the operations of the method 1300 illustrated in FIG.13 may be performed using the electroplating chambers and paddle assemblies described with respect to FIGS. 2-12. In other embodiments, the method 1300 may further include flowing the electrolyte through a diffuser positioned between the anodes A1-A3 and the paddle 330 prior to the electrolyte reaching the substrate. The diffuser may include apertures arranged to correspond to patterned regions of the substrate and may cooperate with the paddle 330 to further modulate the electric field during electrodeposition. However, use of the diffuser is optional, and in other embodiments the method 1300 is performed without a diffuser.

[0075] The operations illustrated in FIG. 13 are provided by way of example and are not intended to limit the scope of the present disclosure. The operations may be performed in any suitable order, and one or more operations may be omitted, repeated, or performed concurrently in some embodiments.

[0076] The previously described embodiments of the present disclosure have many advantages. The disclosed electroplating chambers, systems, and methods provide improved control over electric field distribution during electrodeposition byPATENTAttorney Docket No.: 44026186WO01structurally decoupling paddle aperture geometry from paddle translation direction. By arranging paddle apertures as a two-dimensional array extending along first and second lateral directions and translating the paddle in a third lateral direction that is angularly offset from the array directions, exposure of patterned regions of a substrate to the electric field is varied over time in a controlled manner. In embodiments including a diffuser, cooperative alignment between diffuser apertures and paddle apertures further shapes the electric field without requiring changes to electrolyte chemistry or plating current. These configurations enable greater flexibility in accommodating substrates with patterned regions of differing feature densities and support scalable electroplating processes using purely mechanical and geometric design features. However, the present disclosure does not necessitate that all the advantageous features and all the advantages need to be incorporated into every embodiment of the present disclosure.

[0077] In the Summary and in the Detailed Description, and the Claims, and in the accompanying drawings, reference is made to particular features (including method operations) of the present disclosure. It is to be understood that the disclosure in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect, embodiment, implementation, or example of the present disclosure, or a particular claim, that feature can also be used, to the extent possible in combination with and / or in the context of other particular aspects and embodiments of the present disclosure, and in the present disclosure generally.

[0078] Embodiments and all the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. Embodiments described herein can be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine-readable storage device, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.PATENTAttorney Docket No.: 44026186WO01

[0079] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0080] The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0081] Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0082] The term “comprising,” “including” and “having” and grammatical equivalents thereof are used herein to mean that other components, ingredients, operations, are optionally present. For example, an article “comprising” (or “which comprises”) components A, B, and C can consist of (i.e. , contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. In addition, whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising” or grammatical equivalents thereof, it is understood that it is contemplated that the same composition or group of elements may be preceded with transitional phrases “consisting essentially of,”PATENTAttorney Docket No.: 44026186WO01“consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0083] Where reference is made herein to a method comprising two or more defined operations, the defined operations can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other operations which are carried out before any of the defined operations, between two of the defined operations, or after all of the defined operations (except where the context excludes that possibility).

[0084] When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

[0085] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0086] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

PATENTAttorney Docket No.: 44026186WO01What is claimed is:

1. An electroplating chamber, comprising:a vessel comprising one or more walls; anda paddle disposed within the vessel, the paddle comprising:a first surface;a second surface opposite the first surface;a plurality of ribs extending from the first surface, the plurality of ribs being arranged in a generally parallel relationship; anda plurality of paddle apertures extending through a thickness of the paddle,wherein the paddle apertures are arranged as a two-dimensional array that extends along a first lateral direction and a second lateral direction that is positioned at an angle relative to the first lateral direction; andan actuator configured to translate the paddle in a third lateral direction, wherein the third lateral direction is positioned at an angle relative to each of the first lateral direction and the second lateral direction.

2. The electroplating chamber of claim 1 , wherein the first lateral direction and the second lateral direction are orthogonal to one another.

3. The electroplating chamber of claim 1, wherein the two-dimensional array comprises a repeating unit-cell pattern, and wherein the unit-cell pattern includes a first plurality of paddle apertures having a first size or shape and a second plurality of paddle apertures having a second size or shape different from the first size or shape.

4. The electroplating chamber of claim 1 , wherein the third lateral direction forms an oblique angle relative to each of the first lateral direction and the second lateral direction.PATENTAttorney Docket No.: 44026186WO015. The electroplating chamber of claim 1, wherein at least some of the paddle apertures have an elongated aperture shape defining a major axis and a minor axis, and wherein the major axis is oriented substantially parallel to the third lateral direction.

6. The electroplating chamber of claim 1 , wherein at least a subset of the paddle apertures extend through a base portion of the paddle and a rib portion of the paddle.

7. The electroplating chamber of claim 1 , wherein the paddle comprises one or more raised extension features defining at least one of the paddle apertures, the raised extension features projecting from the first surface and defining an aperture exit plane that is offset from the first surface toward a substrate-facing side of the vessel.

8. An electroplating system, comprising:a vessel comprising one or more walls;one or more anodes disposed in the vessel;a diffuser disposed in the vessel between the one or more anodes and a substrate position in the vessel, the diffuser comprising a diffuser body defining a plurality of diffuser apertures extending through a thickness of the diffuser body; and a paddle disposed in the vessel between the diffuser and the substrate position, the paddle comprising:a first surface facing the substrate position;a second surface opposite the first surface;a plurality of ribs extending from the first surface, the plurality of ribs being arranged in a generally parallel relationship; anda plurality of paddle apertures extending through a thickness of the paddle;wherein, in a processing configuration, the plurality of paddle apertures are positioned to overlap the plurality of diffuser apertures along a direction between the one or more anodes and the substrate position.

9. The electroplating system of claim 8, wherein the plurality of diffuser apertures comprise a first set of diffuser apertures having a first cross-sectional area and aPATENTAttorney Docket No.: 44026186WO01second set of diffuser apertures having a second cross-sectional area different from the first cross-sectional area.

10. The electroplating system of claim 9, wherein the first set of diffuser apertures and the second set of diffuser apertures are distributed in a pattern across the diffuser body, and wherein the pattern comprises a laterally spaced two-dimensional array of diffuser apertures.

11. The electroplating system of claim 8, wherein the diffuser comprises one or more extension features projecting from the diffuser body toward the substrate position, and wherein at least one diffuser aperture extends through an extension feature to define an aperture exit plane that is offset from a main surface of the diffuser body toward the substrate position.

12. The electroplating system of claim 11 , wherein the paddle apertures comprise enlarged openings in a direction of paddle translation sized to accommodate relative motion between the paddle and the diffuser while maintaining the overlap between the paddle apertures and the diffuser apertures for at least a portion of a translation stroke.

13. The electroplating system of claim 8, further comprising an actuator configured to translate the paddle laterally relative to the diffuser during electrodeposition.

14. The electroplating system of claim 8, further comprising a thief electrode disposed in the vessel adjacent a perimeter region of the substrate position.

15. A method of electroplating a substrate, comprising:applying an electrical bias between one or more anodes and a substrate to initiate electrodeposition, the substrate positioned within a vessel of an electroplating system;translating a paddle disposed between the one or more anodes and the substrate during electrodeposition,PATENTAttorney Docket No.: 44026186WO01wherein the paddle comprises a plurality of paddle apertures arranged as a two-dimensional array extending along a first lateral direction and a second lateral direction that is positioned at an angle relative to the first lateral direction; andtranslating the paddle in a third lateral direction that is positioned at an angle relative to each of the first lateral direction and the second lateral direction, such that, during translation, the paddle apertures move relative to patterned regions of the substrate.

16. The method of claim 15, wherein the first lateral direction and the second lateral direction are orthogonal to one another.

17. The method of claim 15, wherein translating the paddle comprises oscillating the paddle laterally in the third lateral direction with a stroke length that is less than or equal to a pitch of ribs formed on the paddle.

18. The method of claim 15, wherein the paddle apertures include elongated apertures defining a major axis oriented substantially parallel to the third lateral direction.

19. The method of claim 15, further comprising positioning a diffuser between the one or more anodes and the paddle, the diffuser comprising a plurality of diffuser apertures, and wherein translating the paddle comprises moving the paddle such that, for at least a portion of a translation cycle, the paddle apertures overlap the diffuser apertures along a direction between the anodes and the substrate.

20. The method of claim 15, further comprising rotating the substrate relative to the paddle during electrodeposition.

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