Head load / unload station with charge discharge path

Abstract

Embodiments herein generally relate to chemical mechanical polishing (CMP) systems, and in particular, to head clean load / unload (HCLLI) stations used with CMP systems and methods related thereto. The apparatus includes a substrate loading station that includes a cup assembly, and a support assembly concentrically disposed within the cup assembly, including a substrate support including an annular lip configured to engage with a surface of a substrate, at least one contact sensor disposed on the annular lip, the at least one contact sensor configured to contact a substrate, and a grounded resistive path coupled to the at least one contact sensor. In another embodiment, the cup assembly includes a load cup, at least one contact probe disposed on the load cup configured to contact a substrate, and a grounded resistive path coupled to the at least one contact probe.

Description

HEAD LOAD / UNLOAD STATION WITH CHARGE DISCHARGE PATHBACKGROUNDField

[0001] Embodiments herein generally relate to electronic device manufacturing, and in particular, to chemical mechanical polishing (CMP) systems and methods used in a semiconductor device manufacturing process.Description of the Related Art

[0002] In chemical mechanical polishing (CMP), the utilization of a head clean load unload (HCLU) station is used to load and unload substrates onto the polishing head, as well as to cleanse the polishing head between successive polishing cycles. The HCLU station is composed of a load cup to hold the substrate, a cleaning system responsible for the removal of polishing residues from the polishing head, and a transfer system that effects the movement of substrates between the load cup and the polishing head. The load cup supports the substrate during loading and unloading, and while the cleaning system combines chemicals and water to eliminate polishing residues from the polishing head and substrate. The transfer system operates through a robotic arm, facilitating substrate transfer between the load cup and the polishing head.

[0003] During CMP, static charge buildup can occur in substrates due to friction from contact with the rotating polishing pad, separating substrates from the load cup and subsequent transfer, and induction effects arising from charged objects, such as the HCLU station. The static charge buildup on substrates may damage substrates and induce defects, causes metal layers to break down, and attract particles to the surface of the substrate.

[0004] Accordingly, there is a need for improved systems and methods for loading and unloading a substrate from a substrate processing system that reduce static charge buildup.SUMMARY

[0005] Embodiments described herein generally relate to chemical mechanical polishing (CMP) systems, and in particular, to head clean load / unload (HCLU) stations used with CMP systems and methods related thereto.

[0006] In an embodiment, a substrate loading station is provided. The substrate loading station includes a cup assembly, and a support assembly concentrically disposed within the cup assembly, including a substrate support including an annular lip configured to engage with a surface of a substrate, at least one contact sensor disposed on the annular lip, the at least one contact sensor configured to contact a substrate, and a grounded resistive path coupled to the at least one contact sensor.

[0007] In another embodiment, a substrate loading station is provided. The substrate loading station includes a cup assembly, and a support assembly concentrically disposed within the cup assembly, including a substrate support including an annular lip configured to engage with a surface of a substrate, at least one contact pad on the annular lip configured to contact a substrate, and a grounded resistive path coupled to the at least one contact pad.

[0008] In yet another embodiment, a substrate loading station is provided. The substrate loading station includes a cup assembly, including a load cup, at least one contact probe disposed on the load cup configured to contact a substrate, and a grounded resistive path coupled to the at least one contact probe, and a support assembly disposed concentrically within the cup assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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 which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of the disclosure and are therefore not to be considered limiting of its scope, as the disclosure may admit to other equally effective embodiments.

[0010] Figure 1 illustrates a schematic side view of a substrate polishing system, according to certain embodiments.

[0011] Figure 2A is a schematic top down view of a loading station which may be used with the polishing system of Figure 1A, according to certain embodiments.

[0012] Figure 2B is a schematic side view of the loading station shown in Figure 2A taken along line 2B-2B, according to certain embodiments.

[0013] Figure 2C is a schematic electronic diagram of the loading station shown in Figure 2A, according to certain embodiments.

[0014] Figure 3A is a schematic top down view of a loading station which may be used with the polishing system of Figure 1A, according to certain embodiments.

[0015] Figure 3B is a schematic side view of the loading station shown in Figure 3A taken along line 3B-3B, according to certain embodiments

[0016] Figure 4 is a schematic side view of a loading station which may be used with the polishing system of Figure 1A, according to certain embodiments.

[0017] Figure 5 illustrates a block diagram of a method of electrically discharging a substrate after a polishing process, according to certain embodiments.

[0018] 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

[0019] Embodiments herein generally relate to chemical mechanical polishing (CMP) systems, and in particular, to head clean load / unload (HCLLI) stations used with CMP systems and methods related thereto.

[0020] In CMP, a head clean load unload (HCLLI) station is used to load and unload substrates onto the polishing head, as well as to cleanse the polishing head between successive polishing cycles. The HCLLI station is composed of a load cup to hold thesubstrate, a cleaning system responsible for the removal of polishing residues from the polishing head, and a transfer system that effects the movement of substrates between the load cup and the polishing head. The load cup, supports the substrate during loading and unloading, while the cleaning system combines chemicals and water to eliminate polishing residues from the polishing head and substrate. In some embodiments the load cup includes a vacuum chuck. In other embodiments, the load cup is a passive mechanical support. The transfer system operates through a robotic arm, facilitating substrate transfer between the load cup and the polishing head.

[0021] The HCLLI station is typically used in CMP by initially loading a substrate into the HCLLI station's load cup, transferring the substrate to the polishing head, lowering the polishing head and substrate toward the polishing pad to initiate the polishing process, followed by raising the polishing head and returning the substrate to the HCLLI station for cleaning.

[0022] In the context of CMP, static charge buildup in substrates can be attributed to various factors, including friction-induced generation of static electricity during contact with the rotating polishing pad, the separation of substrates from the load cup and subsequent transfer, and induction effects arising from charged objects within the CMP environment, such as the polishing head or the HCLLI station. Further, charge buildup may be caused by a cleaning step where high flow or pressure deionized water generates a high charge on the substrate surface. The repercussions of static charge accumulation on substrates are multifaceted and encompass electrostatic discharge (ESD), which may damage substrates and induce defects, substrate charging-induced metal breakdown (WCIMB), where static charge causes metal layers to break down, and substrate charging-induced particle adhesion (WCIPA), which entails the attraction of particles to the substrate's surface.

[0023] The present disclosure provides for improved systems and methods that grounds a substrate at a HCLLI station and safely discharges the static charge buildup in the substrate through a ground connection within the HCLLI station. The present disclosure then reduces substrate charge buildup and minimizes charge-induced damage to the substrate.

[0024] Figure 1 is a schematic side view of an exemplary polishing system 100 which may be used to perform the methods set forth herein. Here, the polishing system 100 includes a base 101 , a plurality of polishing stations 102 (one shown), a loading station 104, a carrier transport system 106, a plurality of carrier assemblies 108, and a system controller 110.

[0025] The loading station 104 is used to receive substrates from a substrate handler 112, e.g., a robot having an end effector 114, and return substrates back thereto and to load and unload substrates to and from individual ones of the carrier assemblies 108. The carrier transport system 106 may comprise any suitable system for supporting the plurality of carrier assemblies 108 and to moving the carrier assemblies 108 between the loading station 104 and one or more of the plurality of polishing stations 102 for substrate processing thereon. As shown in Figure 1 , the carrier transport system 106 may be a pivot module which moves the plurality of carrier assemblies 108 between the polishing station 102 and the loading station 104 by pivoting a support arm 107 about an axis A. While shown as a pivot module, other carrier transport system are contemplated.

[0026] The polishing station 102 includes a platen 116 having a polishing pad 118 mounted thereon, a fluid delivery arm 120, and a pad conditioner assembly 122. The platen 116 is rotatable about an axis B using an actuator 128 coupled thereto. The fluid delivery arm 120 is positioned over the platen 116 and is used to deliver a polishing fluid, such as a polishing slurry having abrasives suspended therein, to a surface of the polishing pad 118. Typically, the polishing fluid contains a pH adjuster and other chemically active components, such as an oxidizing agent, to enable chemical mechanical polishing of the material surface of the substrate. The pad conditioner assembly 122 is used urge a fixed abrasive conditioning disk 124 against the polishing pad 118 before, after, or during polishing of a substrate in order to abrade, rejuvenate, and remove polish byproducts from, the surface of the polishing pad 118.

[0027] The carrier assemblies 108 are used to transport substrates to and from individual ones of the plurality of polishing stations 102 and therebetween and to urge the substrates against the rotating polishing pads in the presence of the polishing fluid.Here, each of the carrier assemblies 108 includes a carrier head 130, a carrier shaft 132 coupled to the carrier head 130, and one or more actuators 136 coupled to the carrier shaft 132. The one or more actuators 136 are used to rotate the carrier head 130 about a carrier axis C, and to sweep the carrier head 130 between an inner radius and an outer radius of the polishing pad 118 while the carrier head 130 simultaneously exerts a force against a backside or non-active surface of a substrate 138 disposed therein.

[0028] Figure 2A is a schematic top down view of a loading station 200, according to one embodiment, which may be used in place of the loading station 104 of Figure 1 . Figure 2B is a schematic sectional view of the loading station 200 taken along line 2B-2B of Figure 2A. The loading station 200 may be a head clean load / unload (HCLLI) station.

[0029] The loading station 200 includes a cup assembly 202, a support assembly 204 concentrically disposed within in the cup assembly 202, and a fluid delivery assembly 206. The cup assembly 202 includes a load cup 212 disposed on a first shaft 214 and an actuator 216 coupled to the first shaft 214 which is used to move the load cup 212 in the Z-direction, i.e. , towards and away from a carrier head positioned thereover (not shown). The load cup 212 includes an annular upper portion 218 and a lower housing 220 which collectively define a basin 222 for collecting fluids used during the carrier and substrate cleaning methods set forth herein. Fluids are drained from the basin 222 using a drain 224 fluidly coupled thereto.

[0030] The upper portion 218 includes one or more carrier alignment features, here an annular lip 226, extending upwardly from an upward facing surface of the upper portion 218 and located proximate to the peripheral edge thereof. During transfer of a substrate 138 (shown in phantom in Figure 2B) to and from a carrier head (not shown), the load cup 212 is moved in the Z-direction to a raised position (not shown) so that the annular lip 226 surrounds a portion of the outwardly facing surface of the carrier head to facilitate alignment between the carrier head and the load cup 212.

[0031] The support assembly 204 includes a substrate support 228 disposed on a second shaft 230 and an actuator 232 coupled to the second shaft 230 which is used to move the pedestal in the Z-direction. In some embodiments, the support assembly 204 is a loadcup. The substrate support 228 has a generally circular shape when viewed from top down and an annular lip 238 disposed proximate to the circumferential edge of the substrate support 228 and extending upwardly therefrom. The annular lip 238 is sized and positioned to engage with the radially outermost portions of the active surface of the substrate 138, thus supporting the substrate 138 away from a recessed surface 240 of the substrate support 228 in order to minimize contact with, and to avoid the related scratching of, devices manufactured thereon.

[0032] The substrate support 228 is movable in the Z-direction relative to the load cup 212 and may be extended upwardly therefrom and retracted thereinto to provide access to an end effector 114 (Figure 1 ) of a substrate handler 112 and to facilitate substrate loading and unloading from the carrier head positioned thereabove. Here, the substrate support 228 has a plurality of openings 242 disposed therethrough and a plurality of cutouts 244a disposed about a peripheral edge thereof. The upper portion 218 of the load cup 212 features a corresponding plurality of cutouts 244b formed in the radially inward facing surface thereof which are aligned with the plurality of cutouts 244a formed in the edge of the substrate support 228. The pluralities of openings 242 and cutouts 244a, b enable the fluid delivery assembly 206 disposed therebeneath to direct fluids towards desired surfaces of a carrier head (or a vacuum chucked substrate) positioned over the loading station 200 and aligned therewith.

[0033] The fluid delivery assembly 206 is fixedly coupled to the load cup 212 and includes a one or more first nozzles 250a (three shown), one or more second nozzles 250b (three shown), and a plurality of third nozzles 250c. The one or more first nozzles 250a and the one or more second nozzles 250b are aligned with the openings formed by the cutouts 244a, b when viewed form top down. In some embodiments, the one or more first nozzles 250a and one or more second nozzles 250b are used to direct cleaning fluids towards an annular gap disposed between a flexible membrane and the retaining ring of a rotating carrier head to remove polishing byproducts therefrom.

[0034] The support assembly 204 includes at least one contact pad 252 coupled to the controller 110 (Figure 1 ). The at least one contact pad 252 physically touches the substrate 138 to detect its presence within support assembly 204. The at least one contact pad 252 includes a conductive contact surface 254 that contacts the substrate 138 when the substrate 138 is placed into the substrate station 200. The at least one contact pad 252 is disposed within the substrate station 200, e.g., on the annular lip 238, such that the outer edges of the substrate 138 rests on the at least one contact pad 252 and the conductive contact surface 254. This placement allows the load cup 212 to clean the substrate 138 as intended without obstruction by the at least one contact pad 252, maintaining the efficiency of the load cup 212. The at least one contact pad 252 may be a plurality of contact pads, such as 2, 3, 4, or more sensors each with a conductive contact surface 254. For example, the at least one contact pad 252 may include a first contact pad 252a with a first conductive contact surface 254a and a second contact pad 252b with a second conductive contact surface 254b that are symmetrically separated or placed along the annular lip 238. The first contact pad 252a and the second contact pad 252b may be placed on opposing ends of the annular lip 238. The at least one contact pad 252 is disposed on the annular lip 238 such that the outer edges of the substrate 138 rests on the at least one contact pad 252. This placement allows the load cup 212 to clean the substrate 138 as intended without obstruction by the at least one contact pad 252, maintaining the efficiency of the load cup 212. Preferably, the at least one contact pad 252 should extend 3 mm or less into the diameter of the substrate 138, such as about 2 mm, such as about 1 mm.

[0035] The conductive contact surface 254 of the at least one contact pad 252 is electrically coupled, e.g., via a conductive wire, to a grounded resistive path 256. The conductive contact surface 254 of the at least one contact pad 252 is the first point of contact for the substrate 138 within the load cup 212 to facilitate proper charge dissipation.

[0036] Figure 2C is a schematic electronic diagram of the loading station shown in Figure 2A, according to certain embodiments.

[0037] The grounded resistive path 256 is a grounded pathway for charge to leave the substrate 138 in a controlled operation. For example, the grounded resistive path 256 may have a first point within a conductive material of the first contact pad 252a and have a second point at a ground. By controlling the resistivity of the grounded resistive path 256, the rate of discharge from the substrate can be controlled, and thus avoid damage due to rapid electrical discharging from the substrate.

[0038] Where the at least one contact pad 252 includes a plurality of contact pads, each of the conductive contact surfaces 254 are coupled to the grounded resistive path 256. For example, the second conductive contact surface 254b of the second contact pad 252b and a third conductive contact surface 254c of a respective third contact pad 252c are all electrically coupled to a common the grounded resistive path 256. Alternatively, the first conductive contact surface 254a and the second conductive contact surface 254b may be electrically coupled to separate grounded resistive paths 256, each of the separate grounded resistive paths 256 having the same electrical characteristics, e.g., ohmic values. The grounded resistive path 256 includes a resistance that safely discharges the substrate over time. The resistance may come from a resistor 258 or be ohmic resistance from the conductive wire itself. The resistance may have an ohmic value of between about 0.1 ohms to about 1011ohms, preferably between about 105ohms to about 109ohms. Grounding the substrate 138 by using the at least one contact pad electrically coupled to the grounded resistive path 256 prevents the substrate from having uncontrolled charge dissipation or arcing when the substrate is being transferred by a robot, preventing damage to the substrate.

[0039] The grounded resistive path 256 enables the substrate 138 to discharge voltage and / or current from the substrate 138 to the ground in a controlled environment. The controller 110 monitors the grounded resistive path 256 and determines if any charge is still present in the substrate 138. The controller 110 may monitor one or more of a voltage or a current through the grounded resistive path 256. The controller 110 may include a voltage sensor or current sensor that detects voltage or current within or travelling along the grounded resistive path 256. The controller 110 determines based on a detected voltage, a detected change in voltage, a detectedcurrent, a detected change in current, a polarity, or a combination thereof whether the substrate 138 has been discharged.

[0040] In some embodiments, the substrate station 200 includes a probe (not shown) that enables electrostatic charge monitoring that monitors voltage levels of substrate 138 independently of controller 110 and the contact pad 252.

[0041] Figure 3A is a schematic top down view of a loading station 300, according to another embodiment, which may be used in place of the loading station 104 of Figure 1 . Figure 3B is a schematic sectional view of the loading station 300 taken along line 3B-3B of Figure 3A.

[0042] The loading station 300 includes a cup assembly 302, a support assembly 304 concentrically disposed within the cup assembly 302, and a fluid delivery assembly 306. The cup assembly 302 includes a load cup 312 disposed on a first shaft 314 and an actuator 316 coupled to the first shaft 314 which is used to move the load cup 312 in the Z-direction, i.e. , towards and away from a carrier head positioned thereover (not shown). The load cup 312 includes an annular upper portion 318 and a lower housing 320 which collectively define a basin 322 for collecting fluids used during the carrier and substrate cleaning methods set forth herein. Fluids are drained from the basin 322 using a drain 324 fluidly coupled thereto.

[0043] The upper portion 318 includes one or more carrier alignment features, here an annular lip 326, extending upwardly from an upward facing surface of the upper portion 318 and located proximate to the peripheral edge thereof. During transfer of a substrate 138 (shown in phantom in Figure 3) to and from a carrier head (not shown), the load cup 312 is in a raised position (not shown) and the annular lip 326 surrounds a portion of the outwardly facing surface of the carrier head to facilitate alignment between the carrier head and the load cup 312.

[0044] The support assembly 304 includes a substrate support 328 disposed on a second shaft 330 and an actuator 332 coupled to the second shaft 330 which is used to move the substrate support 328 in the Z-direction. The substrate support 328 has a generally circular shape when viewed from top down and an annular lip 338 disposed proximate to the circumferential edge of the substrate support 328 and extendingupwardly therefrom. The annular lip 338 is sized and positioned to engage with the radially outermost portions of the active surface of a substrate 138, thus supporting the substrate 138 away from a recessed surface 340 of the substrate support 328 in order to minimize contact with, and to avoid the related scratching of, devices manufactured thereon.

[0045] The substrate support 328 is movable in the Z-direction relative to the load cup 312 and may be extended upwardly therefrom and retracted thereinto to provide access to an end effector 114 (Figure 1 ) of a substrate handler 112 and to facilitate substrate loading and unloading from the carrier head positioned thereabove. Here, the substrate support 328 has a plurality of openings 342 disposed therethrough and a plurality of cutouts 344a disposed about a peripheral edge thereof. The upper portion 318 of the load cup 312 features a corresponding plurality of cutouts 344b formed in the radially inward facing surface thereof which are aligned with the plurality of cutouts 344a formed in the edge of the substrate support 328. The pluralities of openings 342 and cutouts 344a, b enable the fluid delivery assembly 306 disposed therebeneath to direct fluids towards desired surfaces of a carrier head (or a vacuum chucked substrate) positioned over the loading station 300 and aligned therewith.

[0046] The fluid delivery assembly 306 is fixedly coupled to the load cup 312 and includes a one or more first nozzles 350a (three shown), one or more second nozzles 350b (three shown), and a plurality of third nozzles 350c. The one or more first nozzles 350a and the one or more second nozzles 350b are aligned with the openings formed by the cutouts 344a, b when viewed form top down. In some embodiments, the one or more first nozzles 350a and one or more second nozzles 350b are used to direct cleaning fluids towards an annular gap disposed between a flexible membrane and the retaining ring of a rotating carrier head to remove polishing byproducts therefrom.

[0047] The support assembly 304 includes at least one contact pad 352 coupled to the controller 110. The electronic diagram illustrated in Figure 2C is similar to the configuration of the contact pad 352 of the support assembly 304. In Figure 3B, the at least one contact pad 352 of the support assembly 304 is similar to the at least one contact pad 252 of the support assembly 204. For example, the at least one contact pad 352 of the support assembly 304 includes the same components and / or functionsas the least one contact pad 252 of the support assembly 204. The at least one contact pad 352 physically touches the substrate 138 when it is placed within the support assembly 304. For example, the contact sensor 352 may be a plurality of contact sensors, such as 2, 3, 4, or more sensors each with a conductive contact surface 354. For example, the at least one contact pad 252 may include a first contact sensor 352a with a first conductive contact surface 354a and a second contact sensor 352b with a second conductive contact surface 354b that are symmetrically disposed around the support assembly 304.

[0048] The at least one contact pad 352 may be a continuous annular pad or may be a plurality of arced, planar pads, such as 2, 3, 4, or more arced pads. For example, the at least one contact pad 352 may include a first contact pad 352a and a second contact pad 352b that are symmetrically separated or placed along the annular lip 338. The first contact pad 352a and the second contact pad 352b may be placed on opposing ends of the annular lip 338. The at least one contact pad 352 is disposed on the annular lip 338 such that the outer edges of the substrate 138 rests on the at least one contact pad 352. This placement allows the load cup 312 to clean the substrate 138 as intended without obstruction by the at least one contact pad 352, maintaining the efficiency of the load cup 312. Preferably, the at least one contact pad 352 should extend 3 mm or less into the diameter of the substrate 138, such as about 2 mm, such as about 1 mm.

[0049] The at least one contact pad 352 is electrically coupled, e.g., via a conductive wire, to a grounded resistive path 356. Where the at least one contact pad 352 includes a plurality of arced pads, each of the arced pads are coupled to the grounded resistive path 356. The grounded resistive path 356 enables the substrate 138 to discharge voltage and / or current from the substrate 138 to the ground in a controlled environment. For example, the first contact pad 352a and the second contact pad 352b are electrically coupled to the same grounded resistive path 356. Alternatively, the first contact pad 352a and the second contact pad 352b may be electrically coupled to separate grounded resistive paths 356, each of the separate grounded resistive paths 356 having the same electrical characteristics, e.g., ohmic values. The grounded resistive path 356 includes a resistance that safely dischargesthe substrate over time. The resistance may come from a resistor 358 or be ohmic resistance from the conductive wire itself. The resistance may have an ohmic value of between about 0.1 ohms to about 1011ohms, preferably between about 105ohms to about 109ohms. The at least one contact pad 352 is configured to be the first point of contact for the substrate 138 within the load cup 312 to facilitate proper charge dissipation. Grounding the substrate by using the at least one contact pad 352 electrically coupled to the grounded resistive path 356 prevents the substrate from having uncontrolled charge dissipation or arcing when the substrate is being transferred by a robot, preventing damage to the substrate.

[0050] Figure 4 is a schematic sectional view of a loading station 400, according to another embodiment, which may be used in place of the loading station 104 of Figure 1. The loading station 400 includes a cup assembly 402, a support assembly 404 concentrically disposed within the cup assembly 402, and a fluid delivery assembly 406. The cup assembly 402 includes a load cup 412 disposed on a first shaft 414 and an actuator 416 coupled to the first shaft 414 which is used to move the load cup 412 in the Z-direction, i.e., towards and away from a carrier head positioned thereover (not shown). The load cup 412 includes an annular upper portion 418 and a lower housing 420 which collectively define a basin 422 for collecting fluids used during the carrier and substrate cleaning methods set forth herein. Fluids are drained from the basin 422 using a drain 424 fluidly coupled thereto.

[0051] The upper portion 418 includes one or more carrier alignment features, here an annular lip 426, extending upwardly from an upward facing surface of the upper portion 418 and located proximate to the peripheral edge thereof. During transfer of a substrate 138 (shown in phantom in Figure 4) to and from a carrier head (not shown), the load cup 412 is in a raised position (not shown) and the annular lip 426 surrounds a portion of the outwardly facing surface of the carrier head to facilitate alignment between the carrier head and the load cup 412.

[0052] The support assembly 404 includes a substrate support 428 disposed on a second shaft 430 and an actuator 432 coupled to the second shaft 430 which is used to move the substrate support 428 in the Z-direction. The substrate support 428 has a generally circular shape when viewed from top down and an annular lip 438 disposedproximate to the circumferential edge of the substrate support 428 and extending upwardly therefrom. The annular lip 438 is sized and positioned to engage with the radially outermost portions of the active surface of a substrate 138, thus supporting the substrate 138 away from a recessed surface 440 of the substrate support 428 in order to minimize contact with, and to avoid the related scratching of, devices manufactured thereon.

[0053] The pedestal is movable in the Z-direction relative to the load cup 412 and may be extended upwardly therefrom and retracted thereinto to provide access to an end effector 114 (Figure 1 ) of a substrate handler 112 and to facilitate substrate loading and unloading from the carrier head positioned thereabove. Here, the substrate support 428 has a plurality of openings 442 disposed therethrough. The pluralities of openings 442 enable the fluid delivery assembly 406 disposed therebeneath to direct fluids towards desired surfaces of a carrier head (or a vacuum chucked substrate) positioned over the loading station 400 and aligned therewith.

[0054] The fluid delivery assembly 406 is fixedly coupled to the load cup 412 and includes a one or more first nozzles 450a (three shown), one or more second nozzles 450b (three shown), and a plurality of third nozzles 450c. In some embodiments, the one or more first nozzles 450a and one or more second nozzles 450b are used to direct cleaning fluids towards an annular gap disposed between a flexible membrane and the retaining ring of a rotating carrier head to remove polishing byproducts therefrom.

[0055] The load cup 412 includes at least one contact probe 452 coupled to the controller 110. The at least one contact probe 452 physically touches the substrate 138 to detect its presence within the load cup 412. The at least one contact probe 452 is coupled to an actuator 454 disposed on the load cup 412. The actuator 454 allows the at least one contact probe 452 to displace vertically, e.g., up through the 440, to contact the substrate and down away from the substrate to allow the substrate to contact the 428. The actuator 454 may actuate the at least one contact probe 452 to contact the substrate 138 while the substrate 138 is chucked to the substrate carrier or after the substrate has been unloaded to the substrate loading station 400. The actuator 454 may include piezoelectric actuators, linear motors, ball screw actuators,lead screw actuators, belt-driven actuators, pneumatic actuators, or any suitable actuator that provides linear motion of the at least one contact probe 452. In some embodiments, the at least one contact probe 452 is disposed within the loading station 400 such that the outer edges of the substrate 138 contact on the at least one contact probe 452 when the at least one contact probe 452 is actuated. This placement allows the load cup 412 to clean the substrate 138 as intended without obstruction by the at least one contact probe 452, maintaining the efficiency of the load cup 412. Preferably, the at least one contact probe 452 should extend 3 mm or less into the diameter of the substrate 138, such as about 2 mm, such as about 1 mm.

[0056] The at least one contact probe 452 is electrically coupled, e.g., via a conductive wire, to a grounded resistive path 456. The grounded resistive path 456 shall be continuously electrically coupled to the at least one contact probe 452 even with actuation by the actuator 454. The grounded resistive path 456 includes a resistance that safely discharges the substrate over time. The resistance may come from a resistor 458 or be ohmic resistance from the conductive wire itself. The resistance may have an ohmic value of between about 0.1 ohms to about 1011ohms, preferably between about 105ohms to about 109ohms. The at least one contact probe 452 is the first point of contact for the substrate 138 within the load cup 412 to facilitate proper charge dissipation. Grounding the substrate by using the at least one contact probe 452 electrically coupled to the grounded resistive path 456 prevents the substrate from having uncontrolled charge dissipation or arcing when the substrate is being transferred by a robot, preventing damage to the substrate. The contact probe 452 is similar to the one contact pad 252 and the conductive contact surface 254 illustrated in Figure 2C. for example, the grounded resistive path 256 from the substrate 138, through the conductive contact surface 254, the at least one contact pad 252 to the ground is similar to the grounded resistive path 456 from the substrate 138 through the contact probe 452 to the ground. The resistor 258 is similar to the resistor 458.

[0057] The controller 110 determines if the substrate 138 has been discharged. In some embodiments, the controller 110 measures one or more of a voltage or a current along and / or within the grounded resistive path 256 of Figure 2C, the groundedresistive path 356 of Figure 3B, or the grounded resistive path 456 of Figure 4. The resistor 258 of Figure 2C, the resistor 358 of Figure 3B, or resistor 458 of Figure 4 reduces the risk of arc due to rapid discharge from the substrate 138.

[0058] Figure 5 illustrates a block diagram of a method of electrically discharging a substrate after a polishing process, with loading station 200 as reference. In operation 502, a substrate is polished using a substrate polishing process, such as chemical mechanical polishing.

[0059] In operation 504, the substrate 138 is dechucked from pad 118. urn chuck or robotic arm receives the substrate 138 from the carrier head 130.

[0060] For example, the substrate 138 is polished, then de-chucked from the pad 118 (Figure 1 ), and then transferred to the loading station 200. After a polish operation, the substrate 138 needs to be pulled away from the polishing pad 118 by the carrier head 130.

[0061] The substrate 138 is pulled off the pad 118 by the carrier head 130. Conventionally, dechucking the substrate 138 from the pad 118 is performed by the carrier head 130. The carrier head 130 de-chucks the substrate 138 from the pad 118 using suction generated via a membrane within the carrier head 130. De-chucking the substrate 138 from the pad 118 is done while the substrate 138 and the carrier head 130 are coupled and spinning on the pad 118. The carrier head 130 performs a number of steps to introduce vacuum into one or more membrane chambers within the carrier head 130 (not shown) to act form a suction cup type grip on the substrate 138. The carrier head 130 pulls the substrate 138 off the polishing pad 118 once the suction cup grip is formed.

[0062] Once the carrier head 130 has a suction grip on the substrate 138, the carrier head 130 translates the substrate 138 over the particular loading station 200 (HCLLI). The carrier head 130 release the suction grip to unload substrate 138, to release and transfer the substrate 138, to the HCLLI.

[0063] In some embodiments, the carrier assemblies 108 grip the substrate 138 via channels directly applying suction substrate without a membrane in the carrier head130. This vacuum acts as a force to pull the substrate 138 off the polishing pad 118 for ‘de-chucking’ the substrate 138 from the polishing pad 118.

[0064] In operation 506, the substrate 138 is dechucked from the pad 118 placed onto the loading station 200, e.g., loading station 200, loading station 300, or loading station 400. The substrate placement onto the loading station 200 is achieved through the use of a carrier head 130. The load cup 212 is moved in the Z-direction to a raised position so that alignment features, e.g., the annular lip 226, receive and align the substrate 138. Following this placement, the substrate 138 is secured to the loading station 200 through the application of vacuum or other clamping mechanisms. The selection of the specific placement technique is contingent upon the particular loading station 200 type and the nature of the substrate undergoing processing.

[0065] In operation 508, the substrate 138 is then cleaned. The substrate 138 may be cleaned by a rinse provided by the load cup assembly 202 of the loading station 200. In the load cup assembly 202, a substrate undergoes cleaning through the application of a combination of high-frequency sound waves and chemicals. Under the influence of these sound waves, cavitation bubbles are generated within the cleaning solution, subsequently imploding and generating shockwaves that serve to dislodge contaminants from the substrate's surface. Concurrently, chemicals are used to facilitate the dissolution of these contaminants and their subsequent removal from the cleaning solution.

[0066] For example, a cleaning solution may be introduced into the load cup assembly 202, where high-frequency sound waves are generated to initiate the cleaning process. The substrate 138 is subjected to cleaning for a predetermined duration, following which the cleaning solution is drained from the load cup assembly 202. A rinsing step, utilizing water, is then performed to remove residual cleaning agents, and finally, the substrate 138 is subjected to a drying procedure.

[0067] The composition of the cleaning solution may include a blend of water and chemicals, including acids, bases, and surfactants. The specific chemical constituents utilized are determined by the nature of the contaminants necessitating removal from the surface of the substrate 138.

[0068] In operation 510, the substrate 138 is then grounded using a load cup assembly, for example, the load cup assembly 202. The load cup assembly 202 includes at least one conductive contact surface 254 that contacts the surface of the substrate 138 when the substrate 138 is loaded onto the load cup 212. The at least one conductive contact surface 254 is electrically coupled to a ground via a grounded resistive path 256. The grounded resistive path 256 includes a resistance that safely discharges the substrate 138 over time. The resistance may come from a resistor 258 or be ohmic resistance from the conductive wire itself. The resistance may have an ohmic value of between about 103ohms to about 1011ohms, preferably between about 105ohms to about 109ohms. The ground may be at a bottom portion of the loading station 200 or other suitable, electrically-conductive portion of the substrate polishing system. The operation 510 may also be completed using the features of the loading station 300 (Figures 3A-3B) or loading station 400 (Figure 4). For example, the substrate 138 may be grounded using the at least one contact pad 352 of the loading station 300 or the substrate 138 may be grounded using the contact probe 452 of the loading station 400, or a combination thereof.

[0069] Optionally, the substrate 138 may be grounded using the load cup assembly 202 after any unloading into the loading station 200, e.g., after substrate dechucking and unloading to the loading station 200 in operation 506 but before substrate cleaning in operation 508. Further, the substrate 138 may be grounded using the load cup assembly 202 multiple times during method 500, such as between operation 506 and 508 then again in operation 510.

[0070] In operation 512, the substrate 138 is removed from the loading station 200 for further processing, using at least one robot arm, e.g., the substrate handler 112.

[0071] The present disclosure provides for improved substrate station assemblies, including improved load cups, and methods that ground substrates during a CMP process. The load cups include a contact, such as a conductive contact surface, a contact pad, or a contact probe, that is electrically coupled to a grounded resistive path that allows the safe dissipation of charge that builds up in the substrate during CMP processing. This dissipation prevents uncontrolled discharge or arcing which, in turn, minimizes damage to the substrate during CMP processing.

[0072] When introducing elements of the present disclosure or exemplary aspects or embodiments thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

[0073] The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0074] The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B and object B touches object C, the objects A and C may still be considered coupled to one another — even if objects A and C do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly in physical contact with the second object.

[0075] 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

What is claimed is:1 . A substrate loading station, comprising: a cup assembly; and a support assembly concentrically disposed within the cup assembly, comprising: a support comprising an annular lip configured to engage with a surface of a substrate; at least one contact sensor disposed on the annular lip, the at least one contact sensor configured to contact a substrate; and a grounded resistive path coupled to the at least one contact sensor.

2. The substrate loading station of claim 1 , wherein the at least one contact sensor comprises a conductive contact surface, the conductive contact surface configured to contact a substrate.

3. The substrate loading station of claim 2, wherein the grounded resistive path is coupled to the conductive contact surface.

4. The substrate loading station of claim 2, wherein the at least one contact sensor comprises a first contact sensor with a first conductive contact surface and a second contact sensor with a second conductive surface, the first conductive contact surface and the second conductive surface coupled to the same grounded resistive path.

5. The substrate loading station of claim 3, wherein the grounded resistive path comprises an ohmic value of between about 0.1 ohms to about 1011ohms.

6. The substrate loading station of claim 2, wherein the conductive contact surface is configured to be a first point of contact for a substrate.

7. The substrate loading station of claim 2, wherein the conductive contact surface is configured to extend 3 mm or less into a diameter of a substrate when contacting the substrate.

8. A substrate loading station, comprising: a cup assembly; and a support assembly concentrically disposed within the cup assembly, comprising: a substrate support comprising an annular lip configured to engage with a surface of a substrate; at least one contact pad on the annular lip configured to contact a substrate; and a grounded resistive path coupled to the at least one contact pad.

9. The substrate loading station of claim 8, wherein the at least one contact pad comprises a first contact pad and a second contact pad on opposing ends of the annular lip.

10. The substrate loading station of claim 9, wherein the first contact pad and the second contact pad are coupled to the same grounded resistive path.11 . The substrate loading station of claim 8, wherein the grounded resistive path comprises an ohmic value of between about 0.1 ohms to about 1011ohms.

12. The substrate loading station of claim 8, wherein the at least one contact pad is configured to be a first point of contact for a substrate.

13. The substrate loading station of claim 8, wherein the at least one contact pad is configured to extend 3 mm or less into a diameter of a substrate when contacting the substrate.

14. A substrate loading station, comprising: a cup assembly, comprising: a load cup; at least one contact probe disposed on the load cup configured to contact a substrate; and a grounded resistive path coupled to the at least one contact probe; and. a support assembly disposed concentrically within the cup assembly.

15. The substrate loading station of claim 14, wherein the at least one contact probe is coupled to an actuator, the actuator configured to provide linear motion to the contact probe.

16. The substrate loading station of claim 14, wherein the at least one contact probe is configured to contact a substrate chucked on a substrate carrier.

17. The substrate loading station of claim 14, wherein the at least one contact probe is configured to contact a substrate unloaded into the substrate loading station.

18. The substrate loading station of claim 14, wherein the grounded resistive path comprises an ohmic value of between about 0.1 ohms to about 1011ohms.

19. The substrate loading station of claim 14, wherein the at least one contact probe is configured to be a first point of contact for a substrate.

20. The substrate loading station of claim 14, wherein the at least one contact probe is configured to extend 3 mm or less into a diameter of a substrate when contacting the substrate.

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