Processing control method for pattern wafer indexing polishing

Abstract

In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes determining an orientation of the substrate relative to a first carrier head. The method further includes initiating a polishing process of a surface of the substrate bonded to the polishing pad. The method further includes, during the polishing process, repeatedly scanning a first portion of the surface of the substrate using at least one endpoint sensor coupled to the polishing pad to generate orientation-related scan data of a property of the first portion of the surface. The method further includes comparing the orientation-related scan data to a library of orientation-related scan data to determine when an endpoint of the polishing process has been reached.

Description

background Technical Field

[0001] This disclosure relates to chemical mechanical polishing (CMP); more specifically, this disclosure relates to analyzing the endpoints of CMP treatments.

[0002] Related technical specifications

[0003] Integrated circuits are typically formed on a substrate by sequentially depositing conductive layers, semiconductor layers, and / or insulating layers on a semiconductor substrate. Various manufacturing processes require planarization of the layers on the substrate. For example, one manufacturing process involves depositing a fill layer on a non-planar surface and planarizing the fill layer. For some applications, the fill layer is planarized until the top surface of the patterned layer is exposed. For example, a metal layer may be deposited on a patterned insulating layer to fill trenches and holes in the insulating layer. After planarization, the remaining metal in the trenches and holes of the patterned layer forms vias, plugs, and lines to provide conductive paths between integrated circuits (ICs) on the substrate. As another example, a dielectric layer may be deposited on a patterned conductive layer and then planarized for subsequent photolithography processes.

[0004] Chemical mechanical polishing (CMP) is a widely accepted planarization method. This method typically requires mounting a substrate on a carrier head. The exposed surface of the substrate (i.e., the surface with deposited layers) is usually placed on a rotating polishing pad. The carrier head provides a controlled load on the substrate to push it against the polishing pad. A polishing slurry containing abrasive particles is typically supplied to the surface of the polishing pad and sprayed between the substrate and the polishing pad. The polishing pad and the carrier head each rotate at a constant speed, and the abrasive slurry removes material from one or more layers.

[0005] Conventional CMP operations utilize sensors positioned within the polishing platform to detect the endpoint of the CMP process. However, because the substrate through which the sensor passes during the polishing process, the data collected from the sensor in a conventional design varies over time. Due to the common variations in material thickness and different material types on patterned semiconductor substrates, reliably detecting the endpoint of a conventional CMP process is challenging. For example, one factor affecting the ability of a CMP system to reliably and repeatably detect the endpoint of a conventional CMP process involves the fact that conventional CMP processes cannot determine whether changes in the sensing properties of the film being polished are related to factors such as material that has been removed or artificial defects in the structure of the patterned semiconductor substrate. Therefore, there is a need in the art for improved endpoint detection processes. Summary of the Invention

[0006] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: performing polishing processes on a plurality of substrates, wherein each polishing process performed on each substrate includes: conveying each of the plurality of substrates to the surface of a first polishing pad, wherein the step of conveying each of the plurality of substrates includes the step of: retrieving the substrates positioned in a second orientation by using a carrier head oriented along a first orientation in the CMP system. The system includes a substrate receiving surface; polishing the surface of each of a plurality of substrates on a first polishing pad coupled to a first platform, wherein the first platform includes one or more sensors configured to detect properties of materials disposed on the surfaces of each of the plurality of substrates, one of the one or more sensors being positioned in a third orientation, and a controller being configured to position the substrates, the carrier head, and the one or more sensors on the platform relative to each other in substantially the same orientation at the start of the polishing process of the surfaces of each of the plurality of substrates; scanning the surfaces of each of the plurality of substrates by the one or more sensors during the polishing process, wherein the step of scanning the surfaces of each of the plurality of substrates includes the following steps: generating scan data including the detected properties of materials disposed on the surfaces of each of the substrates; determining that the generated scan data substantially matches library scan data stored in the memory of the controller; determining that there is a difference between the properties of a portion of the generated scan data and the properties of a portion of the library scan data; and adjusting the characteristics of the polishing process of the surfaces of each of the plurality of substrates based on the determined difference between the properties of the portion of the generated scan data and the properties of the portion of the library scan data.

[0007] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: performing polishing processes on a plurality of substrates, wherein each polishing process performed on each substrate includes: transferring each of the plurality of substrates to the surface of a first polishing pad. The step of transferring each of the plurality of substrates includes the step of: retrieving a substrate positioned in a second orientation on a substrate receiving surface within the CMP system using a carrier head oriented in a first orientation. The method further includes the step of: polishing the surface of each of the plurality of substrates on a first polishing pad connected to a first platform. The first platform includes one or more first sensors configured to detect properties of a material disposed on the surface of each of the plurality of substrates. One of the one or more first sensors is positioned in a third orientation. A controller is configured to, at the start of the process of polishing the surface of each of the plurality of substrates, position the substrates, the carrier head, and the one or more first sensors on the first platform relative to each other in substantially the same orientation. The method further includes the following steps: during a process of polishing the surface of each of a plurality of substrates on a first polishing pad, scanning the surface of each of the plurality of substrates by one or more first sensors, wherein the step of scanning the surface of each of the plurality of substrates includes the following steps: generating first scan data, the first scan data including first detected properties of a material disposed on the surface of each of the plurality of substrates. The method further includes the following steps: determining a difference between the properties of a portion of the first scan data generated during the process of polishing the surface of each of the plurality of substrates on the first polishing pad and the properties of a portion of first library scan data stored in a controller. The method further includes the following steps: adjusting the characteristics of the process of polishing the surface of each of the plurality of substrates on the first polishing pad based on the determined difference between the properties of the portion of the generated first scan data and the properties of the portion of the first library scan data.

[0008] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: transferring the substrate from a first polishing pad to a second polishing pad using a first carrier head. The method further includes the step of: determining the orientation of the substrate relative to the first carrier head after transferring the substrate to the second polishing pad. The method further includes the step of: initiating a polishing process on the surface of the substrate on the second polishing pad. The method further includes the step of: during the polishing process, using an endpoint sensor coupled to the second polishing pad, scanning a first portion of the surface of the substrate for the first time to generate first orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the step of: during the polishing process, using an endpoint sensor, scanning the first portion of the surface of the substrate a second time to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the polishing process has been reached. The method further includes the step of: stopping the polishing process once the endpoint has been determined to have been reached.

[0009] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the step of determining the orientation of the substrate relative to a first carrier head. The method further includes the step of initiating a first polishing process on a surface of the substrate engaged with a first polishing pad, the first polishing process including rotating the first polishing pad and rotating the substrate relative to the first polishing pad using the first carrier head. The method further includes the step of: during the first polishing process, using a first endpoint sensor coupled to the first polishing pad to first scan a first portion of the surface of the substrate to generate first orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the step of: during the first polishing process, using the first endpoint sensor to second scan the first portion of the surface of the substrate to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the first polishing process has been reached. The method further includes the step of: once it is determined that the endpoint of the first polishing process has been reached, stopping the first polishing process.

[0010] In one embodiment, a non-transient computer-readable medium includes instructions stored thereon that, when executed by one or more processors, cause a controller to perform a method of processing a substrate in a chemical mechanical polishing (CMP) system. The method includes the steps of: determining the orientation of the substrate relative to a first bearing head. The method further includes the steps of: initiating a first polishing process on a surface of the substrate engaged with a first polishing pad, the first polishing process including rotating the first polishing pad and rotating the substrate relative to the first polishing pad using the first bearing head. The method further includes the steps of: during the first polishing process, firstly scanning a first portion of the surface of the substrate using a first endpoint sensor coupled to the first polishing pad to generate first orientation-related scan data of the properties of the first portion of the substrate. The method further includes the steps of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the steps of: during the first polishing process, secondly scanning the first portion of the surface of the substrate using the first endpoint sensor to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the steps of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the first polishing process has been reached. The method further includes the steps of: stopping the first polishing process once the endpoint of the first polishing process has been determined to have been reached.

[0011] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the step of determining the orientation of the substrate relative to a first bearing head. The method further includes the step of initiating a polishing process on a surface of the substrate bonded to a polishing pad. The method further includes the step of repeatedly scanning a first portion of the substrate surface during a first polishing process using at least one endpoint sensor coupled to the polishing pad to generate orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of comparing the orientation-related scan data with a library of orientation-related scan data to determine when the endpoint of the polishing process has been reached. Attached Figure Description

[0012] To gain a detailed understanding of the features described above, reference can be made to the embodiments for a more specific description of the disclosure briefly summarized above; some of these embodiments are illustrated in the accompanying drawings. However, it should be noted that the drawings are merely illustrative of exemplary embodiments of the disclosure and should not be construed as limiting the scope of the disclosure; other equally effective embodiments are permissible.

[0013] Figure 1 A schematic top view of an exemplary chemical mechanical polishing (CMP) system is depicted.

[0014] Figure 2A The embodiments described herein are illustrated. Figure 1 A schematic cross-sectional view of an exemplary polishing station of a CMP system.

[0015] Figure 2B Based on the embodiments described herein Figure 2A A top view of the front surface of a substrate being polished on a polishing station.

[0016] Figure 3 The embodiments described herein are from Figure 2A A schematic top view of the bearing head positioned at the scanning location on the polishing pad in the polishing station.

[0017] Figure 4 The embodiments described herein are illustrated by Figure 2A A top view of the front surface of the substrate scanned by the orientation sensor of the polishing station.

[0018] Figure 5 A top view of the front surface of a substrate according to an embodiment described herein is depicted, showing... Figure 2A The scanning path of the end sensor at the polishing station.

[0019] Figure 6A This illustrates a series of substrate scan data collected by the endpoint sensor on multiple substrates using conventional techniques.

[0020] Figure 6B This illustrates a series of orientation-correlated scan data collected on multiple substrates by an endpoint sensor using one or more of the processing techniques disclosed herein according to embodiments described herein.

[0021] Figure 6C This is a flowchart of a method for processing a substrate according to an embodiment described herein.

[0022] Figure 6D An example of orientation-related scan data collected on a substrate according to embodiments described herein is shown.

[0023] Figure 6E A graph is shown according to an embodiment described herein; the graph includes multiple orientation-related scan data collected that vary across multiple substrates (or platform rotation).

[0024] Figure 6F Examples of substrate surface topography data collected from a model or measured on a substrate according to embodiments described herein are shown.

[0025] Figure 6G An example of orientation-related scan data collected on a substrate according to an embodiment described herein is shown.

[0026] Figure 6HThe use of the embodiments described herein is illustrated. Figure 6G The diagram shows the orientation-related scan data collected on the substrate by the corresponding scan path.

[0027] For ease of understanding, the same reference numerals have been used to denote common elements in the figures where possible. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0028] This document discloses an apparatus and method for reliably determining the endpoint of a chemical mechanical polishing (CMP) process. The endpoint detection method disclosed herein includes the following steps: using computer-generated methods and supporting hardware to improve the determination of the endpoint of the CMP process.

[0029] Figure 1 This is a top plan view illustrating one embodiment of a CMP system 100. The CMP system 100 includes a factory interface module 102, a cleaner 104, a polishing module 106, and a controller 190. A substrate 115, such as having one or more silicon wafers deposited thereon, is processed within the CMP system 100 to polish the surface of the substrate 115.

[0030] A wetting robot 108 is configured to transfer substrate 115 between the factory interface module 102 and the polishing module 106. The wetting robot 108 may also be configured to transfer substrate 115 between the polishing module 106 and the cleaner 104. The factory interface module 102 includes a drying robot 110 configured to transfer substrate 115 between one or more wafer carriers 114, one or more transfer platforms 116, one or more metering stations 117, and one or more pre-aligner stations 118 of the factory interface 102. The substrate 115 is loaded into the CMP system 100 via the wafer carrier 114. Figure 1 In one embodiment illustrated, four substrate memory wafer carriers 114 are shown. A drying robot 110 within the factory interface 102 has sufficient range of motion to facilitate transfer between the four wafer carriers 114 and one or more transfer platforms 116. Optionally, the drying robot 110 may be mounted on a track or rail 112 to laterally position the robot 110 within the factory interface module 102. The drying robot 110 is additionally configured to receive substrates 115 from a cleaner 104 and return the cleaned and polished substrates to the substrate memory wafer carriers 114.

[0031] Figure 1An exemplary polishing module 106 is shown; the exemplary polishing module 106 includes a plurality of polishing stations 124 on which a substrate 115 is polished and simultaneously held in a carrier head 210 (e.g., a polishing head). Each polishing station 124 includes a trimming assembly 132 and a polishing fluid delivery module 135. Although the polishing module 106 is shown as having three pairs of polishing stations 124, the polishing module 106 may have more than three polishing stations 124. For example, the polishing module 106 may have two pairs of polishing stations 124, each pair of polishing stations 124 processing the substrate 115 independently of the other pair of polishing stations. The polishing stations 124 are sized to mate with one or more carrier heads 210 to facilitate polishing of the substrate 115. The carrier head 210 is coupled to a carrier (not shown); the carrier is mounted on Figure 1 The dotted line indicates the overhead track 128. The overhead track 128 allows the carrier box to be selectively positioned around the polishing module 106, which facilitates the selective positioning of the carrier head 210 on the polishing station 124 and the loading shroud 122. Figure 1 In the illustrated embodiment, the overhead track 128 has a ring configuration, which allows the carrier cassette to selectively and independently rotate and / or exit the loading shroud 122 and polishing station 124 above and from the loading shroud 122 and polishing station 124. Furthermore, the overhead track 128 facilitates the carrier cassette sweeping over the rotating carrier head 210 relative to the polishing station 124 during polishing. The polishing station 124 will be described in more detail with reference to FIG. 2.

[0032] Each polishing station 124 includes a polishing pad 204 having a polishing surface (e.g., polishing surface 204A in FIG. 2) capable of polishing a substrate 115. Each polishing station 124 includes a trimming assembly 132 and a polishing fluid delivery module 135. In one embodiment, the trimming assembly 132 may include a pad trimming assembly 140 that trims the polishing surface of the polishing pad 204 by removing polishing debris and opening holes in the polishing pad 204 using a pad trimming disc 133. In another embodiment, the polishing fluid delivery module 135 may include a fluid delivery arm 134 to deliver slurry. In one embodiment, each polishing station 124 includes a pad trimming assembly 132. In one embodiment, the fluid delivery arm 134 is configured to deliver a fluid flow (e.g., slurry 222 in FIG. 2) to the polishing station 124. The polishing pad 204 is supported on a platform (e.g., platform 202 in FIG. 2) that rotates the polishing pad 204 during processing. Each polishing station 124 includes a polishing pad 204 fixed to a rotatable platform 202. Different polishing pads 204 can be used at different polishing stations 124 to control the removal of material from the substrate 115.

[0033] At least one loading cover 122 (e.g.) Figure 1The two loading covers 122 shown are located near the lower right corner of the polishing module 106 between the polishing stations 124 closest to the wetting robot 108. The loading covers 122 can be used for a variety of functions, including cleaning the carrier head 210, receiving the substrate 115 from the wetting robot 108, cleaning the substrate 115, and loading the substrate 115 into the carrier head (e.g., the carrier head 210 in FIG. 2).

[0034] Substrate 115 typically has reference markings, such as notches, flat edges, or other types of features that can be used to identify the crystal orientation of substrate 115 and record the rotational orientation of the front surface of substrate 115 relative to a central axis. In some embodiments, the factory interface module 102 may also include a pre-aligner 118 to position substrate 115 in a known and desired rotational orientation. Pre-aligning substrate 115 to the desired rotational direction allows substrate 115 to then be conveyed to a substrate support surface within loading shroud 122 and positioned thereon with a known position and rotational orientation relative to components in the CMP system. Thus, carrier head 210 can then retrieve substrate 115 with a known rotational orientation relative to carrier head 210. For example, pre-aligner 118 may include a reference marking detection system, such as a light-blocking sensor (not shown), to sense when a reference marking is at a specific angular position.

[0035] In some embodiments, the substrate 115 is placed in a metering station 117 by a drying robot 110 before being placed on the transfer platform 116. For example, the drying robot 110 may transfer the substrate 115 from a pre-aligner 118 to the metering station 117. The metering station 117 is used to measure various aspects of the substrate 115. The metering station 117 may use optical, eddy current, resistive, or other sensors to measure the substrate 115. For example, the metering station 117 may measure the thickness of the upper layer on the patterned surface of the substrate 115 by using an eddy current sensor for conductive films and an optical sensor for dielectric films. The controller 190 receives measurements that can be used to facilitate the processing of the substrate 115 within the CMP system 100. After measuring the substrate 115 in the metering station 117, the drying robot 110 may transfer the substrate 115 to the transfer platform 116.

[0036] In some embodiments, the data collected within the metering station 117 can be used to determine and / or form a model of the morphology of a film configured on a substrate surface using the controller 190. Figure 6FAn example of the morphology of a patterned substrate signal is shown. Therefore, as further discussed below, by associating the morphology of the film information received from metrology station 117 with the known orientation of a reference mark on the substrate, controller 190 can use the film morphology information and the collected endpoint sensor data (also referred to as the reference mark on the substrate) to reliably understand how the polishing process in one or more portions of the substrate surface is progressing toward the endpoint and whether the CMP endpoint has been reached.

[0037] A wetting robot 108 is configured to transfer a substrate 115 from a transfer platform 116 to one of the loading hoods 122. A rinsed carrier head 210 is moved over the loading hood 122 containing the unpolished substrate 115. The unpolished substrate 115 is thus clamped to the carrier head 210; the carrier head 210 then moves to a position above the pad 204 of the polishing station 124 to begin CMP processing.

[0038] Controller 190 controls various aspects of CMP system 100 during CMP processes (e.g., polishing process, polishing operation, polishing). In some embodiments, controller 190 is one or more programmable digital computers executing digital control software. Controller 190 may include a CPU (e.g., processor) 191 located near the polishing equipment, such as a programmable computer, like a personal computer. Controller may include memory 192 and support circuitry 193. Controller 190 may, for example, coordinate the rotation of polishing pad 204 and carrier head 210 to perform the desired CMP process and help monitor the endpoint of the CMP process. CMP processing system 100 is powered by power source 180, such as a power source configured to provide electrical power to components of CMP processing system 100.

[0039] Here, memory 192 is in the form of a computer-readable storage medium (e.g., non-volatile memory) containing instructions that, when executed by the CPU, facilitate the operation of CMP processing system 100. The instructions in memory are in the form of a disclosed program product (e.g., a program implementing the methods of this disclosure), such as a middleware, device software application, etc. The program code may conform to any of a variety of different programming languages. In one example, this disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) of the program product define the functionality of the embodiments (including the methods and operations described herein). Exemplary computer-readable storage media include, but are not limited to: (i) non-writable storage media that permanently stores information thereon (e.g., a read-only memory device within a computer, such as a CD-ROM disc readable by a CD-ROM disk drive, flash memory, ROM chip, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media that stores changeable information thereon (e.g., a disk drive or disk drive within a hard disk, or any type of solid-state random access semiconductor memory). Such a computer-readable storage medium is an embodiment of this disclosure when it carries computer-readable instructions that guide the functions described herein.

[0040] Platform 202 and carrier head 210 each have a rotation sensor, such as an encoder, to determine their rotational position during CMP operation. Figure 1 As shown, platform encoder 195, first head encoder 196, and second head encoder 197 are communicatively coupled to controller 190. Platform encoder 195 is configured to determine the rotational (e.g., angular) orientation of platform 202 and pad 204. First head encoder 196 is configured to determine the rotational orientation of each carrier head 210. Second head encoder 197 is configured to determine the position of each carrier head 210 above polishing pad 204 (e.g., along...). Figure 3 The sweep path 302 of the carrier head 210. Therefore, the controller 190 is able to determine and track the rotational orientation of the carrier head 210 relative to the platform 202 during CMP processing. In some embodiments, each carrier head 210 has its own dedicated first head encoder 196 and second head encoder 197. In a further embodiment, the controller 190 may use encoders and internal timing elements to determine the rotational rate of the carrier head 210 and / or the platform 202 and the polishing pad 204.

[0041] The substrate 115 can be polished in one or more polishing stations 124. For example, the carrier head 210 can retrieve the unpolished substrate 115 from a substrate support surface (not shown) in the loading shroud 122. The physical position of the substrate relative to the platform 202 and the carrier head 210 is known during CMP processing based on known orientation and rotational position data received from the first encoder 196 and data received from the second encoder 197. The carrier head 210 and the substrate 115 held thereon are then moved to a first polishing station 124, such as the polishing station 124 located in the upper right corner of the polishing module 106 closest to the cleaner 104. The substrate 115 then undergoes a CMP polishing operation in the first polishing station 124, such as removing a first layer formed on the substrate 115. Once the substrate 115 has been polished in the first polishing station 124, the carrier head 210 moves the substrate 115 to a second polishing station 124 (e.g., the polishing station 124 in the upper left corner of the polishing module 106) for additional CMP polishing. For example, the second polishing station 124 can polish the surface of the substrate 115 to form trench lines of a desired height. In some embodiments, the carrier head 210 and the substrate 115 may optionally be transferred from the second polishing station 124 to a third polishing station 124 (e.g., the polishing station 124 in the lower left corner of the polishing module 106) to subject the substrate 115 to additional polishing.

[0042] After polishing, the carrier head 210 moves the polished substrate 115, which is held thereon, over the loading shroud 122, whereby the polished substrate 115 is then placed into the substrate support surface of the loading shroud 122. The wetting robot 108 transfers the polished substrate 115 from the substrate support surface of the loading shroud 122 to the cleaning chamber in the cleaner 104, where slurry residue and other contaminants accumulated on the surface of the substrate 115 during polishing are removed. Figure 1 In the illustrated embodiment, the cleaner 104 includes two pre-cleaning modules 144, two mega-frequency ultrasonic cleaner modules 146, two brush cassette modules 148, two spray modules 150, and two dryers 152. The drying robot 110 then removes the substrate 115 from the cleaner 104. In some embodiments, the drying robot 110 conveys the substrate 105 to a metering station 117 for re-measuring. In some embodiments, post-polishing measurements can be used to adjust subsequent substrate polishing parameters. Finally, the drying robot 110 returns the substrate 115 to one of the wafer carriers 114.

[0043] Figure 2A It shows Figure 1A schematic cross-sectional view of the polishing station 124 of the CMP system 100. As shown, the polishing station 124 further includes a plurality of endpoint detection sensors 224 and an optional orientation sensor 250. A substrate 115 disposed in the carrier head 210 is shown as engaging with the polishing surface 204A of the pad 204 coupled to the platform 202.

[0044] Figure 2B This is a top view of substrate 115, showing the front surface 230 of substrate 115 bonded to polishing pad 204 during polishing. Front surface 230 includes patterned portions 232 and unpatterned portions 234. Patterned portions 232 (e.g., patterned surfaces) are portions of substrate 115 in which multiple semiconductor devices are formed within semiconductor dies during one or more prior processes. As shown, patterned portions 232 are divided into multiple complete dies 233 arranged in a grid pattern. Each die 233 includes multiple semiconductor devices formed on substrate 115. For example, the semiconductor devices include one or more layers formed by one or more processes such as physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD).

[0045] The unpatterned portion 234 is the portion of the front surface 230 surrounding the patterned portion 232. The semiconductor device is not formed on the unpatterned surface 234. The unpatterned portion 234 may be exposed to the same processing environment in which the patterned portion 232 is formed. A material such as a barrier metal may be deposited on the unpatterned surface 234 while the semiconductor device is formed on the patterned portion 232. In some embodiments, the unpatterned portion 234 may be a partially patterned portion, comprising only a portion of the die, rather than the entire die. The surface area of ​​the unpatterned portion 234 may be non-uniform around the patterned portion 232. Figure 2B As shown, depending on the shape of the patterned portion 232, the surface area of ​​the unpatterned surface 234 varies around the patterned portion 232. Therefore, portions of the unpatterned surface 234 have a larger surface area than other portions.

[0046] The substrate 115 includes a reference mark 236 (e.g., a wafer notch) located at the edge of the substrate 115 and therefore at the edge of the unpatterned portion 234. Depending on the doping type and crystal orientation of the substrate 115, the reference mark 236 is a fixed feature formed on the substrate 115. Although the reference mark 236 is shown as being formed on... Figure 2B The reference mark 236 may be a V-shaped notch on the edge of the substrate 115, but it may be another feature. For example, the reference mark 236 may be one or more flat edges of the substrate 115.

[0047] The substrate 115 has a first line of symmetry 235 passing through the center of the reference mark 236. The unpatterned surface 234 is generally symmetrical about the first line of symmetry 235. Therefore, a first region 237 on either side of the line of symmetry 235 adjacent to the reference mark 236 has a substantially identical surface area. Additionally, a similar pair of second regions 238 with similar surface areas to the first regions 237 exist on opposite edges of the substrate 115 about the reference mark 236. Although the unpatterned surface 234 is generally symmetrical about the first line of symmetry 235, the circuitry formed in the respective dies 233 of the patterned surface 232 may be symmetrical or asymmetrical about this first line of symmetry 235.

[0048] Return to reference Figure 2A For example, an adhesive (such as a pressure-sensitive adhesive (PSA) layer (not shown)) disposed between the polishing pad 204 and the platform 202 is used to fix the polishing pad 204 to the platform 202. The carrier head 210 facing (the polishing pad 204 is mounted on the platform 202) includes a flexible diaphragm 212 configured to apply varying pressures to the back surface of a substrate 115 disposed between the carrier head 210 and the polishing pad 204. This flexible diaphragm 212 is also configured to clamp the substrate 115 to the carrier head 210 to allow the carrier head 210 to move the substrate 115 around the polishing module 106. The carrier head 210 includes a carrier ring 218 surrounding the substrate 115, which holds the substrate 115 within the head 210 during polishing. The carrier head 210 rotates about a carrier head axis 216 while the flexible diaphragm 212 holds the front surface 230 of the substrate 115 ( Figure 2B The bearing ring 218 is pressed against the polishing surface 204A of the polishing pad 204. During polishing, the downward pressure on the bearing ring 218 pushes the bearing ring 218 against the polishing pad 204 to improve the uniformity of the polishing process and prevent the substrate 115 from sliding out from under the bearing head 210. In some embodiments, the bearing head 210 includes a shaft 211 having an axis collinear with the bearing head shaft 216. In a further embodiment, each of the platform 202 and the bearing head 210 has a mechanism or motor (not shown) for driving its rotation.

[0049] In some embodiments, both the platform 202 and the polishing pad 204 rotate about a common platform axis 205. In some embodiments, the polishing pad 204 rotates in the same direction of rotation as the carrier head 210. For example, both the polishing pad 204 and the carrier head 210 rotate counterclockwise. During the polishing operation, the polishing pad 204 and the carrier head 210 may rotate at the same or different speeds. Figure 2AAs shown, the polishing pad 204 has a surface area larger than the front surface 230 of the substrate 115. However, in a further embodiment, the polishing pad 204 has a surface area smaller than the front surface 230 of the substrate 115.

[0050] Figure 2A An exemplary embodiment of one of the endpoint detection sensors 224 is also shown. Each endpoint detection sensor 224 is radially positioned from the platform axis 205. The endpoint detection sensor 224 is disposed in a platform opening 226 formed in the platform 202 and below the endpoint detection feature 227 (e.g., an optically clear window) of the polishing pad 204. The endpoint detection sensor 224 guides light through the platform opening 226 and the endpoint detection feature 227 at the front surface 230 of the substrate 115 to detect the properties of the front surface 230 during polishing as the endpoint sensor 224 passes below the substrate 115. The controller 190 uses the data collected by the endpoint detection sensor 224 to determine when the endpoint of the CMP process has been reached. The endpoint may be, for example, when the desired thickness of the layer formed on the patterned surface 232 is reached. For example, the endpoint may be reached when the metal in the plurality of trench lines formed on the patterned portion 232 reaches the desired thickness.

[0051] Although the endpoint detection sensor 224 is shown as an optical sensor, it can be any other suitable sensor capable of monitoring changes in the patterned portion 232 during CMP processing. For example, the endpoint sensor 224 could be an eddy current sensor or an induced current sensor. Eddy current sensors and induced current sensors can be embedded in platform 202 and / or pad 204, and the endpoint detection feature 227 (e.g., an optically transparent window) and opening 226 can be omitted or replaced by an electromagnetically transparent window. Although the polishing station 124 is shown as having three endpoint detection sensors 224 (e.g., optically transparent windows) arranged around an optional orientation sensor 250, Figure 1 (as demonstrated by the three endpoint detection features 227 in the text), but polishing station 124 may include fewer or more than three endpoint sensors 224.

[0052] Each endpoint detection sensor 224 is positioned at a fixed distance from the rotation center of platform 202 (e.g., platform axis 205). Platform encoder 195 tracks the rotational position of platform 202 and pad 204. Controller 190 is able to determine the position of endpoint sensor 224 as platform 202 rotates based on the fixed position of endpoint sensor 224 and the rotational information obtained from platform encoder 195.

[0053] Substrate orientation information

[0054] As described above, by using the pre-aligner 118, robot 108, and controller 190, the substrate can be positioned on the substrate support surface of the loading cover 122 with a known orientation, such that the orientation of the substrate 115 relative to the carrier head 210 and the orientation of the platform 202 and pad 204 are known and can be monitored and controlled during processing within the CMP system 100. However, in some processing methods, it is desirable to confirm and / or determine the orientation of the substrate 115 relative to the carrier head 210 and the orientation of the platform 202 and pad 204. Optionally, after polishing is performed on different platforms 202 and pad 204, the orientation of the substrate 115 relative to the carrier head 210 and the orientation of the platform 202 and pad 204 can be determined from the location where subsequent polishing will be performed by the orientation sensor 250 and controller 190. In one example, at the first polishing station 124 (e.g., Figure 1 After the substrate is processed in the upper right polishing station 124, the controller 190, the carrier head 210, and the orientation sensor 250 are used to confirm and / or determine the second polishing station 124 (e.g., Figure 1 Orientation of substrate 115 on platform 202 and pad 204 in intermediate polishing station 124 before processing substrate.

[0055] Figure 2A The orientation sensor 250 is also shown. (As will be related to...) Figure 3 and Figure 4 As discussed, the orientation sensor 250 is optionally used to position the reference mark 236 in situ, allowing the controller 190 to determine the rotational orientation of the substrate 115 relative to the carrier head 210 and the pad 204. The controller 190 is able to associate the determined position of the reference mark 236 with the rotational orientation of the carrier head 210 because the substrate 115 rotates together with the carrier head 210. The orientation sensor 250 is used to determine and / or confirm the rotational orientation of the substrate 115 after it has been transferred from one polishing station 124 to another. In other words, the substrate 115 does not need to be removed from the polishing module 106, pass through the cleaner 124, and be placed in the pre-aligner 118 or metering station 117 to determine the rotational orientation of the substrate 115 before polishing it on the second or third polishing station 124.

[0056] Knowing the rotational orientation of the substrate 115 and the carrier head 210 during polishing, as well as the position of each endpoint sensor 224, allows the controller 190 to determine which portion of the front surface 230 of the substrate 115 a particular endpoint sensor 224 is scanning. In other words, the controller 190 can correlate the position and orientation of the substrate 115 with the position of each endpoint sensor 224 during the polishing process.

[0057] Orientation sensor 250 is located at the center of rotation of platform 202, such that the rotation axis of sensor 250 is collinear with platform axis 205. Endpoint sensor 224 is arranged around orientation sensor 250 and rotates about platform axis 205 as platform 202 rotates. To locate reference mark 236, the carrier head 210 is moved to... Figure 2A The scan position shown (see also) Figure 3 The substrate 115 is positioned above the orientation sensor 250. This allows the orientation sensor 250 to scan the edge of the substrate 115 to locate the reference mark 236. In some embodiments, the orientation sensor 250 scans the edge of the substrate 115 to locate the reference mark 236 as the carrier head 210 completes one or more full rotations about the carrier head axis 216. In other embodiments, the reference mark 236 is located only after a partial rotation of the carrier head 210.

[0058] In some embodiments, and such as Figure 2A As shown, the orientation sensor 250 is an isotropic electromagnetic sensor. In some embodiments, the orientation sensor 250 is an eddy current sensor, an optical sensor, or other sensor capable of detecting the reference mark 236. As shown, the orientation sensor 250 is partially embedded in the platform 202 and the pad 204. In some embodiments, the orientation sensor 250 is only embedded in the platform 202 and is covered by the pad 204.

[0059] In some embodiments, a material layer formed on the surface of the substrate partially or completely covers the front surface 230; both the patterned portion 232 and the unpatterned portion 234 are completely or partially covered by the layer. This layer can be deposited to form another layer or feature on the die 233 of the patterned portion 232, which will be polished in a CMP system. Even though layers are deposited on both the patterned portion 232 and the unpatterned portion 234, the orientation sensor 250 is still able to scan the edge of the substrate 115 to locate the reference mark 236. For example, the orientation sensor 250 can obtain data showing whether the portion of the layer scanned by the orientation sensor 250 is located above the underlying patterned portion 232 or the unpatterned portion 234. In other words, even if both the patterned portion 232 and the unpatterned portion 234 are partially blocked by the same layer, the controller 190 can still distinguish between the patterned portion 232 and the unpatterned portion 234. In addition, even if the layer completely or partially covers the front surface 230, the data obtained by the orientation sensor 250 can still show changes in the material being scanned, such as changes in the area of ​​the unpatterned portion 234.

[0060] Figure 3A schematic top plan view of the polishing station 124 is shown to illustrate the carrier head 210 in a scanning position to locate reference mark 236. Trimming assembly 132 and polishing fluid delivery module 135 are omitted. The head 210 is movable relative to the pad 204 along a sweep path 302 to sweep the substrate 115 along the polishing surface 204A during the polishing process. As the platform 202 rotates, the endpoint sensor 224 passes through the sweep path 302. The endpoint sensor 224 passes beneath the substrate 115 as the carrier head 210 places the substrate 115 at one or more locations along the sweep path 302, which is located in the path of travel of the endpoint sensor 224 as the platform 202 rotates.

[0061] The carrier head 210 is shown in the scanning position, with the edge of the front surface 230 at least partially positioned above the orientation sensor 250. The carrier head 210 is rotated relative to the orientation sensor 250 and the platform 202 while the orientation sensor 250 scans the edge of the substrate 115 to locate the reference mark 236. After the substrate 115 has been transferred from one polishing station 124 to another in the polishing module 106, the carrier head 210 is moved to the scanning position to allow scanning 310 (see...). Figure 4 The front surface 230 is used to determine the rotational orientation of the substrate 115.

[0062] Figure 4 A scan 310 of the orientation sensor 250 on a region of the front surface 230 of the substrate 115 is shown. Scan 310 (i.e., shown by dashed lines) illustrates the path of the orientation sensor 250 through the edge region of the front surface 230 of the substrate to collect data as the carrier head 210 rotates the substrate 115 relative to the orientation sensor 250. Scan 310 is performed close enough to the edge of the substrate 115 that it passes through a portion of the reference mark 236. In some embodiments, the orientation sensor 250 performs scan 310 only below the unpatterned surface 234 when the carrier head 210 is in the scan position. Alternatively, the orientation sensor 250 may perform scan 310 along the edge of the substrate 115 that passes through both the patterned surface 232 and the unpatterned surface 234.

[0063] Orientation sensor 250 collects data about front surface 230 along scan 310. This data is sent to controller 190 for analysis to determine the position of reference mark 236. First encoder 196 simultaneously records the rotational position of carrier head 210 while orientation sensor 250 collects data along scan 310. Controller 190 correlates the data obtained from orientation sensor 250 with the rotational position of carrier head 210. In other words, controller 190 is able to match the data obtained from orientation sensor 250 with the rotational position of carrier head 210. This allows controller 190 to analyze the data to determine the position of reference mark 236 associated with the rotational position of carrier head 210. Once the position of reference mark 236 associated with carrier head 210 is known, the rotational orientation of substrate 115 is determined.

[0064] In some embodiments, the carrier head 210 rotates only one revolution around the carrier head axis 216 to allow the orientation sensor 250 to collect sufficient data along the scan 310 to determine the position of the reference mark 236. In some embodiments, the carrier head 210 rotates more than one revolution to collect sufficient data along the scan 310 to determine the position of the reference mark 236.

[0065] In some embodiments, both platform 202 and carrier head 210 rotate as orientation sensor 250 scans substrate 115. In other embodiments, platform 202 remains stationary while carrier head 210 rotates to allow orientation sensor 250 to scan substrate 115. Once the rotational orientation of substrate 115 is determined, controller 190 can cause platform 202 to begin rotating to initiate CMP processing.

[0066] During CMP processing, controller 190 uses information collected from platform encoder 195, first head encoder 196, and second head encoder 197 to determine and track the position of carrier head 210 relative to platform 202. In other words, controller 190 knows the position of carrier head 210 above rotating platform 202 at any given time, including knowing the rotational orientation of carrier head 210 relative to platform 202. Once controller 190 determines the rotational position of substrate 115 relative to carrier head 210, controller 190 similarly knows the rotational orientation and position of substrate 115 relative to rotating platform 202 and end sensor 224 at any given time during the polishing process.

[0067] The controller 190 uses the positional information of the substrate 115 and the platform 202 to determine which portions of the front surface 230 each endpoint sensor 224 scans during endpoint analysis. In other words, since the position and rotational orientation of the substrate 115 relative to the head 210 and the platform 202 are known, the controller 190 is able to correlate the data collected by the endpoint sensors 224 with known positions on the front surface 230. The sweep position of the head 210 relative to the platform 202 and the rotation of both the head 210 and the platform 202 can be coordinated so that each endpoint sensor 224 traverses the same scan path multiple times during CMP processing to scan the same area (e.g., the same region) of the front surface 230. Repeatedly acquiring data from the same area of ​​the substrate improves the signal-to-noise ratio of the data acquired from the endpoint sensors 224, because the endpoint sensors 224 will obtain a consistent signal at each scan reflecting the progress of the polishing process over time. Improved signal-to-noise ratio improves endpoint analysis, allowing for more accurate determination of when the endpoint is reached to generate the desired and uniform polish on the patterned surface 232.

[0068] In a conventional CMP process, the orientation of the substrate 115 is unknown after it is transferred to the second polishing station 124. Therefore, the controller does not know which parts of the substrate were scanned during the endpoint analysis because the collected data cannot be correlated with known locations on the substrate surface. Figure 6A An example of collecting substrate scan data from a series of substrates using conventional techniques is shown. Figure 6A Containing multiple measurements, referred to herein as substrate scan data 605, substrate scan data 605 has been collected for multiple substrates 602. Each substrate 602 is a substrate 115. Each of the collected substrate scan data 605 is created as a path traversed by the endpoint sensor 224 across the substrate surface, including film property information detected by the endpoint sensor 224 and illustrated by curve 606. In this example, the multiple substrates 602 comprise a number M of substrates, where M varies from 1 to M, and M is at least greater than 1 (e.g., Figure 6A (where M is greater than 3). Furthermore, as... Figure 6A As shown, during processing, each substrate 602 is scanned multiple times. The number of scans 601 may include N scans, each scan providing substrate scan data 605, where N varies from 1 to N, and N is at least greater than 1 (e.g., in...). Figure 6A In the case of N being greater than 3), due to a lack of knowledge regarding the orientation of the substrate 602 relative to the carrier head 210 and the orientation of the platform 202 and pad 204, the film property information detected in each collected substrate scan data 605 will differ from the path taken by the endpoint sensor 224 through different and unknown portions of the surface of the substrate 602. Figure 6AAs shown, each of the curves 606 in each of the collected substrate scan data 605 is relative to each consecutive scan 6011, 6012, 6013... and 601... N And relative to each consecutive substrate 6021, 6022, 6023...602 M They are different. Therefore, endpoint analysis in conventional CMP processing is based on random portions of substrate 602 scanned by an endpoint sensor. It has been found that the methods disclosed herein, and in... Figure 6B - Figure 6H The endpoint detection process shown improves the controller 190's ability to detect the endpoint of the CMP process.

[0069] Figure 5 It shows Figure 2B The top view of the substrate 115 shown illustrates exemplary first endpoint scan paths 501, 502, and 503 passing through the front surface 230. Each endpoint scan path 501, 502, and 503 is associated with... Figure 3 The corresponding endpoint sensor 224 (see window 227) of the polishing station 124 shown corresponds to the path passing beneath the front surface 230 of the substrate 115. As the scan path of the endpoint sensor crosses the front surface 230 of the substrate 115, the endpoint sensor 224 generates a curve, such as curve 606 provided within the substrate scan data 605. As shown, each endpoint scan path is arc-shaped due to the movement of the carrier head 210 and the platform 202 during polishing. Each endpoint sensor 224 scans the outer surface multiple times along the corresponding endpoint scan paths 501, 502, and 503 during the CMP process (i.e., scans 6011, 6012, 6013… and 601…). N To facilitate endpoint analysis.

[0070] Improved endpoint treatment equipment and methods

[0071] In some embodiments, by using the devices and methods disclosed herein, during endpoint analysis, improved substrate scan data 655 is created using data obtained by endpoint sensor 224 along a known scan path through the substrate surface. The improved substrate scan data 655 is used to better determine when the endpoint of the polishing process has been reached. Figure 6C A flowchart of an exemplary method 630 for processing a substrate using improved substrate scan data 655 collected on one or more substrates is shown. For clarity and ease of discussion, the improved substrate scan data 655 is generally referred to herein as orientation-related scan data 655 or ODS data 655 to avoid confusion with substrate scan data 605 collected using conventional configurations that do not monitor or utilize substrate orientation information during processing.

[0072] As discussed further below, for substrates with similar processing or patterning in one or more batches, the ability to start with a known orientation of the substrate relative to the carrier head 210, platform 202, and pad 204 allows for the prior collection of data from previously processed substrates, which can be used to more accurately determine the polishing process endpoint. Furthermore, the controller 190 is able to use the position and orientation of the substrate 115 to correlate the data acquired by the endpoint sensor 224 with each specific die 233 along the scan path of the endpoint sensor 224. Therefore, the endpoint of the CMP process can be evaluated based on one or more specific dies 233. In some embodiments, the controller 190 can use the known orientation of the substrate 115 to coordinate the carrier head 210 and platform 202 such that the endpoint detection sensor 224 traverses the same scan path multiple times during the polishing of each substrate 115. In other words, the same portion of each substrate 115 can be repeatedly scanned by the endpoint sensor 224.

[0073] In some embodiments, the carrier head 210 and the substrate 115 may be positioned relative to each other with the same orientation before the polishing process begins. In other words, before the polishing operation of the substrate 115 begins, each substrate 115 and the carrier head 210 may be positioned in the same starting position (e.g., initial orientation) relative to the end point sensor 224 of the polishing pad 204. For example, when each substrate 115 positioned in a second orientation is retrieved from a substrate retrieval surface within the CMP system 100 (e.g., from a pre-aligner 118), the carrier head 210 may be positioned in a first orientation. The carrier head 210 then engages the substrate 115 at the starting point on the polishing pad 204 using the end point sensor 224 positioned in a third orientation. For substrates with similar processing or patterning in one or more batches of substrates, the ability to start with the substrate in the same orientation relative to the carrier head 210, platform 202, and pad 204 allows for more accurate determination of the polishing process end point using data previously collected from previously processed substrates.

[0074] Figure 6B Multiple ODS data 655 collected on multiple substrates 652 are shown. Each substrate 652 is a substrate 115. The orientation of each substrate 652 relative to the carrier head 210 is known. Each of the collected ODS data 655 includes film property information detected by the endpoint sensor 224. Curve 656 within the ODS data 655 illustrates an example of film property information. In this example, the multiple substrates include a number of substrates M, where M varies from 1 to M, and M is at least greater than 1 (e.g., Figure 6B (where M is greater than 3). Additionally, as... Figure 6BAs shown, during processing, each substrate 652 is scanned multiple times. The number of scans 651 may include N scans, each scan providing ODS data 655, where N varies from 1 to N, and N is at least greater than 1 (e.g., in...). Figure 6B (where N is greater than 3). Due to the known orientation of the substrate 652 relative to the carrier head 210, platform 202, and pad 204, the detected film property information in each collection segment of the ODS data 655 will typically include small or minute variations in the shape of the curve 656 as the endpoint sensor 224 traverses the same portion of the surface of each substrate 652. Figure 6B The diagram shows that for each scan of each consecutive substrate, 6511, 6512, 6513...651... N (such as each of the first scan 6511 of each substrate, each of the second scan 6512 of each substrate, each of the third scan 6513 of each substrate, and the Nth scan 651 of each substrate) N As shown in curve 656, which are essentially the same shape in each of the collected ODS data 655, each of the curves in curve 656 is essentially similar.

[0075] Figure 6C A method 630 is described for processing a substrate using improved substrate scan data 655 collected on one or more substrates. Method 630 begins with operation 632, in which the orientation of a substrate 652 (e.g., substrate 115) is determined by one or more methods described herein. In one example, the orientation of substrate 652 is determined using a pre-aligner 118 and a controller 190. After the orientation of substrate 652 is determined, substrate 652 is conveyed to a loading shroud 122 with a known orientation using the controller 190, and finally to a carrier head 210; carrier head 210 is additionally oriented with a known position and orientation due to the use of a first head encoder 196 and a second head encoder 197, respectively.

[0076] In an alternative example, the substrate 652 is conveyed to the loading shroud 122 and the carrier head 210 using a controller 190, the carrier head 210 being oriented with a known position and orientation. Then, as described above, the orientation of the substrate 652 relative to the carrier head 210, as well as the orientation of the platform 202 and the pad 204, is determined using an orientation sensor 250. When the substrate 652 is conveyed to a subsequent polishing station, such as after the substrate 652 has been conveyed from a first polishing station to a second polishing station, the orientation sensor 250 can also be used to determine the orientation of the substrate 652 relative to the carrier head 210. During the orientation determination process performed by the orientation sensor 250, it is expected that no material or trace amounts of material will be removed from the surface of the substrate 652 before the orientation of the substrate 652 relative to the carrier head 210, the platform 202, and the pad 204 is determined, to ensure that the substrate 6521 to 652M Each of them will have a similar polishing starting point. In some cases, it may be expected that the controller 190 will begin CMP processing after the substrate 652, the carrier head 210, and / or the platform 202 are all aligned and oriented relative to each other with a known or identical starting position and orientation, to ensure that the scan path across the substrate surface of each consecutive substrate 652 is substantially the same.

[0077] Next, at operation 634, substrate 652 is polished on pad 204 of platform 202 coupled to polishing station 124 (such as a first polishing station). The polishing process includes pressing the front surface 230 of substrate 652 against the surface of pad 204 while simultaneously providing slurry and / or other chemicals to the substrate surface. During the polishing process, a diaphragm 212 within carrier head 210 presses substrate 652 against the surface of pad 204. The carrier head 212 and platform 202 can be coordinated such that at least one desired portion (such as a desired scan path) of the front surface of substrate 652 is repeatedly scanned by endpoint sensor 224.

[0078] Next, at operation 636, one or more endpoint sensors 224 generate ODS data 655 by detecting film property information as the endpoint sensors 224 traverse the path across the substrate surface. Due to the known orientation of the substrate 652 relative to the orientation of the carrier head 210, platform 202, and pad 204, the film property information detected in each segment of collected ODS data 655 generated by the one or more endpoint sensors 224 will typically include small or minute variations in the shape of curve 656. However, due to differences in substrate size, such as the location where the scan path crosses the substrate surface, it may vary slightly from substrate to substrate. This will result in slight variations in curve 656 in each collected ODS data 655 across a series of substrate-to-substrate scans. Errors or variations in the ODS data 655 collected from each successive scan can therefore cause the scan path on the substrate to drift over time, which can be addressed by one or more of the techniques described below.

[0079] Next, at operation 637, the generated ODS data 655 is analyzed to determine whether the polishing process has reached its endpoint. Operation 637 includes operation 638, which compares the generated ODS data 655 with information stored in the memory of the controller 190. The information stored in the memory may include a library of ODS data 655 collected from previous polishing runs on previously processed substrates (e.g., the first substrate in a batch), calibration substrate data collected from specially processed substrates (these data are used to determine the required sequence of ODS data 655 to achieve the endpoint of the polishing process), or modeling data generated based on known information about the polishing process and the substrate to be processed.

[0080] In some embodiments, during operation 638, the controller 190 searches for a basic match between curve 656 in the recently generated ODS data 655 and information stored in memory (e.g., previously stored curve 656 data). In some cases, the matching process may include comparing a portion of curve 656 in the recently generated ODS data 655 with the same portion of each curve 656 stored in memory to determine if a match exists between the curves. In some embodiments, by monitoring the current time, number of scans, or number of rotations of the platform 202, the number of curves that need to be analyzed to determine if a match exists can be reduced to only a few curves stored before and after the current time when the recently generated ODS data 655 was measured in the current CMP process.

[0081] Operation 637 further includes operation 640, which compares the properties of a portion of curve 656 of the recently generated ODS data 655 with the properties of a portion of substantially matching stored information (e.g., previously stored curve 656 data) to determine the current state of the polishing process performed on substrate 115. In one example, to determine the state of the CMP process, the comparison may include: using inter-peak variation information found in the matching information stored in memory (such as with the thirtieth scan 651 of the previously processed substrate). 30 (Related peak variation information) is used to determine the peak variation information within a portion of curve 656 in the most recently generated ODS data 655, such as the thirtieth scan 651 of the substrate. 30 . Figure 6D The measured inter-peak variation "P" within the desired portion of curve 656, representing the generated ODS data 655, can be compared with information stored in the memory of controller 190 (such as the same portion of curve 656 stored in memory). Therefore, by comparing the properties of a portion of curve 656 with the same properties of a portion of substantially matching stored information, deviations in the compared properties (e.g., the height difference of the inter-peak variation "P") can be used in subsequent operations to adjust one or more CMP processing parameters (e.g., time, pressure, and (multiple) rotational speeds, etc.) to reach the endpoint of the CMP processing.

[0082] Figure 6E The diagram illustrates the relative peak variation "P" of one or more previously processed substrates 652 as a function of the number (or number of scans) performed on the current substrate (X-axis) dependent on the number of scans of data stored in memory (Y-axis), which has been determined by further analysis or testing to have reached an endpoint for a certain substrate type at point 625. Reference Figure 6EIn one example, after performing 28 scans on the currently processed substrate 652, it is determined that the measured properties of the generated ODS data 655 match the properties of the curve 656 data stored in memory. A similar result is achieved after performing 30 scans (e.g., point 622). In this case, the polishing process performed on the currently processed substrate 652 is further than the nominal polishing process, which is located in a comparison database stored in the memory of the controller 190. When the data stored in memory for the nominal polishing process precisely matches the scan data generated by the currently processed substrate, the slope of the peak variation data will be equal to a 1:1 slope, as shown by the linear curve 620.

[0083] In some embodiments, the comparison of the ODS databases may be station-specific. For example, controller 190 may have a first ODS database for a first polishing station, a second ODS database for a second polishing station, and a third ODS database for a third polishing station. Differences in the databases may be due to differences in the polishing processes performed on the workstations.

[0084] Next, at operation 642, based on a comparison of the measured properties of the current substrate 652 and the measured properties of a matching memory substrate, controller 190 determines whether the endpoint has been reached. Therefore, the endpoint is determined by determining that the properties measured on the current substrate 652 similarly match the properties of a substrate that has achieved the desired endpoint. For example, controller 190 may determine that the ODS data 655 acquired during the scan substantially matches the ODS data stored in controller 190 (e.g., in a library) corresponding to the endpoint of the polishing process. If it is determined that the endpoint has been reached, the method then proceeds to operation 646, where the CMP process is stopped, and in some cases, the final scan data (i.e., curve 656) is stored in memory for use by controller 190 in a subsequent endpoint detection step. If it is determined that the endpoint has not been reached, method 630 then proceeds to operation 644.

[0085] If the endpoint has not been reached as determined in operation 642, operation 644 is executed, in which controller 190 then adjusts one or more of the CMP processing parameters (e.g., time, pressure, rotational speed(s) of platform 202 or carrier head 210, etc.) to drive the current polishing process to the expected endpoint. The amount of adjustment to one or more CMP processing parameters may be based on deviations in comparative properties. In one example, because the current CMP process removes polish faster than expected after the 28th scan, the CMP process needs to be changed to slow down the process to achieve the expected endpoint. For example, the rotational speed of carrier head 210 may be adjusted to increase or decrease the polishing rate. Method 630 then returns to operations 636-637, which are then repeated again. Operations 636-644 are typically repeated multiple times during the CMP polishing process until the endpoint is detected during operation 642. Method 630 may be repeated at each polishing station 124 within the CMP system 100. In other words, method 630 can be used to determine when the end of the polishing operation that occurred at a particular polishing station 124 has been reached.

[0086] Figure 6F An example of substrate surface signal topography data collected from a model or measured on substrate 652 according to embodiments described herein is illustrated. Controller 190 may use the film topography information to determine what ODS data 655 should include for substrate 652, such that the determined ODS data 655 can be stored in memory and used as library data during operation 637. In one embodiment, topography data may be received from a scan of a reference substrate in metrology station 117, or received by scanning data of the substrate using endpoint sensor 224 before the start of CMP processing (i.e., before the substrate is pushed onto the polishing pad surface and / or before slurry is applied). In one example, topography data may be generated by modeling techniques based on prior knowledge of the topography of the substrate or a batch of substrates.

[0087] Figure 6G Examples of multiple alternative scan paths created for a substrate due to variations in substrate properties, according to embodiments described herein, are illustrated. Variations in substrate properties can alter the scan path of the endpoint sensor 224 across the substrate, resulting in variations in the measured ODS data 655. Differences in substrate properties may include substrate dimensions; for example, substrate dimensions can cause slight variations in the position of the scan path across the substrate from one substrate to the next, resulting in slight variations in the curve 656 in each ODS data 655 collected in a series of scans from substrate to substrate. Errors or variations in the ODS data 655 collected from each successive scan can also cause drift of the scan path over time during processing. Figure 6H The use of the embodiments described herein is illustrated. Figure 6GA diagram showing the substrate scan data collected along the corresponding scan path. (See diagram.) Figure 6H As shown, curve 656 for each different scan path "i" is... Figure 6G The value changes from "i+5" to "i-6". If it is determined that the scan path deviates from the expected scan path (i.e., the i-th scan path), the position of the carrier head 210 or the rotation speed of the carrier head 210 can be modified in the next few scans to adjust the scan path position based on the pre-stored scan profile generated by theoretical modeling or experimentally collected profiles.

[0088] Additionally, controller 190 can analyze data acquired at the intersections of the scan paths of two or more endpoint sensors 224 to evaluate the endpoint of the CMP process. For example, controller 190 can analyze data acquired at point 511, the intersection of the first scan path 501 and the third scan path 503, to analyze the endpoint of the CMP process. This data can be used to plot the trajectory of the CMP process. Furthermore, controller 190 can analyze data acquired at point 512, the intersection of the second scan path 502 and the third scan path 503, and at point 513, the intersection of the first scan path 501 and the second scan path 502, to evaluate the endpoint of the CMP process. Data acquired at each point 511, 512, and 513 can be used to plot a separate trajectory of the endpoint process during endpoint analysis. In some embodiments, controller 190 can also compare data acquired at the intersections of the scan paths of two or more endpoint sensors 224 to confirm that the data acquired from each endpoint sensor 224 is consistent.

[0089] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: performing polishing processes on a plurality of substrates, wherein each polishing process performed on each substrate includes: conveying each of the plurality of substrates to the surface of a first polishing pad, wherein the step of conveying each substrate includes the steps of: retrieving a substrate positioned in a second orientation on a substrate receiving surface within the CMP system using a carrier head oriented in a first orientation; polishing the surface of each of the plurality of substrates on a first polishing pad coupled to a first platform, wherein the first platform includes one or more sensors configured to detect properties of a material disposed on the surface of each of the plurality of substrates, wherein one of the one or more sensors is oriented in a third orientation, and a controller is configured to, during the polishing of the surface of each of the plurality of substrates... At the start of the process, the substrate, the carrier head, and one or more sensors on the platform are positioned relative to each other in substantially the same orientation. During the process of polishing the surface of each of the plurality of substrates, the surface of each of the plurality of substrates is scanned by one or more sensors, wherein the step of scanning the surface of each of the plurality of substrates includes the following steps: generating scan data including the properties of the material disposed on the surface of each of the plurality of substrates; determining that the generated scan data substantially matches a library scan data stored in the memory of the controller; determining that there is a difference between the properties of a portion of the generated scan data and the properties of a portion of the library scan data, and adjusting the processing characteristics of polishing the surface of each of the plurality of substrates based on the determined difference between the properties of the portion of the generated scan data and the properties of the portion of the library scan data.

[0090] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: performing polishing processes on a plurality of substrates, wherein each polishing process performed on each substrate includes: transferring each of the plurality of substrates to the surface of a first polishing pad. The step of transferring each of the plurality of substrates includes the step of: retrieving a substrate positioned in a second orientation on a substrate receiving surface within the CMP system using a carrier head oriented in a first orientation. The method further includes the step of: polishing the surface of each of the plurality of substrates on a first polishing pad coupled to a first platform. The first platform includes one or more first sensors configured to detect the properties of a material disposed on the surface of each of the plurality of substrates. One of the one or more first sensors is oriented in a third orientation. A controller is configured to, at the start of the process of polishing the surface of each of the plurality of substrates, position the substrates, the carrier head, and the one or more first sensors on the first platform relative to each other in substantially the same orientation. The method further includes the following steps: during the process of polishing the surface of each of a plurality of substrates on a first polishing pad, scanning the surface of each of the plurality of substrates by one or more first sensors, wherein the step of scanning the surface of each substrate includes the following steps: generating first scan data, the first scan data including first detected properties of materials disposed on the surface of each of the plurality of substrates. The method further includes the following steps: determining a difference between the properties of a portion of the generated first scan data and the properties of a portion of first library scan data stored in a controller. The method further includes the following steps: adjusting the polishing characteristics of the surface of each of the plurality of substrates on the first polishing pad based on the determined difference between the properties of the portion of the generated first scan data and the properties of the portion of the first library scan data.

[0091] In one or more embodiments of the method for performing the polishing process, the properties of a portion of the generated first scan data and a portion of the first library data include: the variation between the peak values ​​of the generated first scan data and the first library scan data.

[0092] In one or more embodiments of the method for performing a polishing process, the step of characteristically polishing the surface of each of a plurality of substrates includes the steps of: adjusting at least one of the magnitude of the force applied to the substrate by the bearing head, the rotational speed of the bearing head and the substrate, and the rotational speed of the first platform.

[0093] In one or more embodiments of the method for performing the polishing process, the first library scan data includes: scan data generated from a previously polished substrate polished on a first polishing pad, scan data generated from material property measurements performed on the substrate, or scan data generated using a computer-generated model.

[0094] In one or more embodiments of the method for performing the polishing process, one or more first sensors include eddy current sensors.

[0095] In one or more embodiments, the method of performing the polishing process further includes the step of determining that the generated first scan data substantially matches the endpoint of the first library scan data. The method further includes the step of stopping polishing of each substrate on the first polishing pad once it is determined that the generated first scan data substantially matches the endpoint of the first library scan data.

[0096] In one or more embodiments, the method of performing the polishing process further includes the steps of: conveying each substrate from a first polishing pad to a second polishing pad coupled to a second platform using a carrier head. The method further includes the step of: moving the carrier head to a scanning position above an orientation sensor coupled to the second platform. The method further includes the step of: determining the orientation of the substrate relative to the carrier head using the orientation sensor.

[0097] In one or more embodiments, the method of performing the polishing process further includes the step of polishing each substrate on a second polishing pad. The method further includes the step of scanning the surface of each of the plurality of substrates by means of one or more second sensors coupled to a second platform during the process of polishing the surface of each of the plurality of substrates on the second polishing pad, wherein the step of scanning the surface of each of the plurality of substrates includes the step of generating second scan data, the second scan data including a second detected property of the material disposed on the surface of each of the plurality of substrates. The method further includes the step of determining a difference between the properties of a portion of the generated second scan data and the properties of a portion of second library scan data stored in a controller during the process of polishing the surface of each of the plurality of substrates. The method further includes the step of adjusting the characteristics of the process of polishing the surface of each of the plurality of substrates on the second polishing pad based on the difference between the determined properties of the first portion of generated scan data and the properties of the portion of second library scan data.

[0098] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the steps of: conveying the substrate from a first polishing pad to a second polishing pad using a first carrier head. The method further includes the step of: after conveying the substrate to the second polishing pad, determining the orientation of the substrate relative to the first carrier head. The method further includes the step of: initiating a polishing process on the surface of the substrate on the second polishing pad. The method further includes the step of: during the polishing process, using an endpoint sensor coupled to the second polishing pad to first scan a first portion of the surface of the substrate to generate first orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the step of: during the polishing process, using an endpoint sensor to second scan the first portion of the surface of the substrate to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the polishing process has been reached. The method further includes the step of: stopping the polishing process once the endpoint has been determined to have been reached.

[0099] In one or more embodiments of the method, the step of comparing the first orientation-related scan data with a first library includes the following steps: determining that there are differences between the properties of a portion of the first orientation-related scan data and the properties of a portion of the first library.

[0100] In one or more embodiments of the method, the properties of a portion of the scan data and a portion of the first library include: the variation between peaks in the first directional correlation scan data and the first library.

[0101] In one or more embodiments of the method, the method further includes the step of: adjusting the polishing characteristics of the polishing process based on the difference between the properties of a portion of the determined first orientation-related scan data and the properties of a portion of the first library before a second scan of a first portion of the surface of the substrate using an endpoint sensor.

[0102] In one or more embodiments of the method, the step of adjusting the polishing characteristics of the polishing process includes the following steps: adjusting at least one of the magnitude of the force applied to the substrate by the first bearing head, the rotational speed of the first bearing head, and the rotational speed of the second polishing pad.

[0103] In one or more embodiments of the method, the method further includes the step of placing a first carrier head and a first substrate at a starting position relative to a second polishing pad before starting the polishing process.

[0104] In one or more embodiments of the method, the method further includes the step of: during a polishing process prior to a second scan of the substrate, scanning a portion of the substrate surface using an endpoint sensor to generate third orientation-related scan data of the properties of the surface portion. The method further includes the step of: determining that the portion of the substrate surface scanned by the endpoint sensor during a third scan of the substrate is not a first portion of the substrate. The method further includes the step of: adjusting the position of a first bearing head and / or the rotational speed of the first bearing head such that the endpoint sensor will pass beneath the first portion of the surface during subsequent scans.

[0105] In one embodiment, a method of processing a substrate in a chemical mechanical polishing (CMP) system includes the step of determining the orientation of the substrate relative to a first carrier head. The method further includes the step of initiating a first polishing process on a surface of the substrate engaged with a first polishing pad; the first polishing process includes rotating the first polishing pad and rotating the substrate relative to the first polishing pad using the first carrier head. The method further includes the step of: during the first polishing process, using a first endpoint sensor coupled to the first polishing pad to first scan a first portion of the substrate surface to generate first orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the step of: during the first polishing process, using the first endpoint sensor to second scan the first portion of the substrate surface to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the first polishing process has been reached. The method further includes the step of: once it is determined that the endpoint of the first polishing process has been reached, stopping the first polishing process.

[0106] In one or more embodiments, the method further includes the step of placing a first carrier head and a first substrate at a starting position relative to a first endpoint sensor before starting a first polishing process.

[0107] In one or more embodiments, the method further includes the step of: during a first polishing process prior to a second substrate scan, scanning a portion of the substrate surface using a first endpoint sensor to generate third orientation-related scan data of the properties of the substrate surface portion. The method further includes the step of: determining that the portion of the substrate surface scanned by the first endpoint sensor during substrate scanning is not a first portion of the substrate. The method further includes the step of: adjusting the position of a first bearing head and / or the rotational speed of the first bearing head such that the first endpoint sensor will pass beneath a first portion of the surface during subsequent scans.

[0108] In one or more embodiments, the method further includes the step of: transferring a substrate from a first polishing pad to a second polishing pad. The method further includes the step of: determining the orientation of the substrate relative to a first carrier head after transferring the substrate to the second polishing pad. The method further includes the step of: initiating a second polishing process on the surface of the substrate engaged with the second polishing pad, the second polishing process including rotating the second polishing pad and rotating the substrate relative to the second polishing pad using the first carrier head. The method further includes the step of: during the second polishing process, using a second endpoint sensor coupled to the second polishing pad to first scan a first portion of the substrate surface to generate third orientation-related scan data of the properties of the first portion of the substrate surface. The method further includes the step of: comparing the third orientation-related scan data with a second library of orientation-related scan data. The method further includes the step of: during the second polishing process, using the second endpoint sensor to second scan the first portion of the substrate surface to generate fourth orientation-related scan data of the first portion of the surface. The method further includes the step of: comparing the fourth orientation-related scan data with the second library and determining that the endpoint of the second polishing process has been reached. The method further includes the step of: stopping the second polishing process once it is determined that the endpoint of the second polishing process has been reached.

[0109] In one or more embodiments of this method, determining the orientation of the substrate relative to the first carrier head includes aligning the substrate in a pre-aligner station.

[0110] In one embodiment, a non-transient computer-readable medium includes instructions stored thereon that, when executed by one or more processors, cause a controller to perform a method of processing a substrate in a chemical mechanical polishing (CMP) system. The method includes the step of determining the orientation of the substrate relative to a first carrier head. The method further includes the step of initiating a first polishing process on a surface of the substrate engaged with a first polishing pad, the first polishing process including rotating the first polishing pad and rotating the substrate relative to the first polishing pad using the first carrier head. The method further includes the step of: during the first polishing process, firstly scanning a first portion of the substrate surface using a first endpoint sensor coupled to the first polishing pad to generate first orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the first orientation-related scan data with a first library of orientation-related scan data. The method further includes the step of: during the first polishing process, secondly scanning the first portion of the substrate surface using the first endpoint sensor to generate second orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the second orientation-related scan data with the first library and determining that the endpoint of the first polishing process has been reached. The method further includes the step of: stopping the first polishing process once the endpoint of the first polishing process has been determined to have been reached.

[0111] In one or more embodiments of the medium, the method further includes the step of placing a first carrier head and a first substrate at a starting position relative to a first endpoint sensor before starting a first polishing process.

[0112] In one or more embodiments of the medium, the method further includes the step of: during a first polishing process prior to a second scan of the substrate, scanning a portion of the substrate surface using a first endpoint sensor to generate third orientation-related scan data of the properties of the substrate surface portion. The method further includes the step of: determining that the portion of the substrate surface scanned by the first endpoint sensor during substrate scanning is not a first portion of the substrate. The method further includes the step of: adjusting the position of a first bearing head and / or the rotational speed of the first bearing head such that the first endpoint sensor will pass beneath a first portion of the surface during subsequent scans.

[0113] In one or more embodiments of the medium, the method further includes the step of: transferring a substrate from a first polishing pad to a second polishing pad. The method further includes the step of: after transferring the substrate to the second polishing pad, determining the orientation of the substrate relative to a first carrier head. The method further includes the step of: initiating a second polishing process on the surface of the substrate engaged with the second polishing pad; the second polishing process includes rotating the second polishing pad and rotating the substrate relative to the second polishing pad using the first carrier head. The method further includes the step of: during the second polishing process, using a second endpoint sensor coupled to the second polishing pad to first scan a first portion of the substrate surface to generate third orientation-related scan data of the properties of the first portion of the surface. The method further includes the step of: comparing the third orientation-related scan data with a second library of orientation-related scan data. The method further includes the step of: during the second polishing process, using the second endpoint sensor to second scan the first portion of the substrate surface to generate fourth orientation-related scan data of the first portion of the surface. The method further includes the step of: comparing the fourth orientation-related scan data with the second library and determining that the endpoint of the second polishing process has been reached. The method further includes the step of: once it is determined that the endpoint of the second polishing process has been reached, stopping the second polishing process.

[0114] In one or more embodiments of the medium, the step of determining the orientation of the substrate relative to the first carrier head includes the step of aligning the substrate in a pre-aligner station.

[0115] While the foregoing describes embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A method for processing a substrate in a chemical mechanical polishing (CMP) system, comprising the following steps: Polishing processes are performed on multiple substrates, wherein each polishing process performed on each substrate includes the following steps: Each of the plurality of substrates is transferred to the surface of a first polishing pad, wherein the step of transferring each of the substrates includes the following steps: A substrate positioned in a second orientation on a substrate receiving surface within the CMP system is retrieved by using a carrier head oriented in a first orientation. On the first polishing pad coupled to the first platform, the surface of each of the substrates is polished, wherein: The first platform includes one or more first sensors configured to detect properties of a material disposed on the surface of each of the substrates. One of the one or more first sensors is positioned in a third orientation, and A controller configured to, at the start of the process of polishing the surface of each of the substrates, position the substrates, the carrier head, and the one or more first sensors on the first platform relative to each other in substantially the same orientation. During the process of polishing the surface of each of the substrates on the first polishing pad, the surface of each of the substrates is scanned by the one or more first sensors, wherein scanning the surface of each of the substrates includes the step of generating first scan data, the first scan data including a first detection property of the material disposed on the surface of each of the substrates; During the process of polishing the surface of each of the substrates on the first polishing pad, it is determined that there is a difference between the properties of a portion of the first scan data generated and the properties of a portion of the first library scan data stored in the controller; and The characteristics of the process of polishing the surface of each of the substrates on the first polishing pad are adjusted based on the determined differences between the properties of the portion of the generated first scan data and the properties of the portion of the first library scan data.

2. The method of claim 1, wherein the attributes of the portion of the generated first scan data and the attributes of the portion of the first library data include: The variation between the peak values ​​in the generated first scan data and the first library scan data.

3. The method of claim 1, wherein the characteristic of the process of polishing the surface of each of the substrates includes: Adjust at least one of the force applied by the bearing head to the substrate, the rotational speed of the bearing head and the substrate, and the rotational speed of the first platform.

4. The method of claim 1, wherein the first library scan data comprises: Scan data generated from a previously polished substrate polished on the first polishing pad, scan data generated from material property measurements performed on the substrate, or scan data generated using a computer-generated model.

5. The method of claim 1, wherein the one or more first sensors include eddy current sensors.

6. The method of claim 1, further comprising the following steps: It is determined that the generated first scan data substantially matches the endpoint of the first library scan data; and Once it is determined that the generated first scan data substantially matches the endpoint of the first library scan data, the polishing of each substrate on the first polishing pad is stopped.

7. The method of claim 6, further comprising the following steps: The carrier head is used to transfer each substrate from the first polishing pad to a second polishing pad coupled as a second platform; Move the carrier head to a scanning position above the orientation sensor coupled to the second platform; as well as The orientation sensor is used to determine the orientation of the substrate relative to the carrier head.

8. The method of claim 7, further comprising the following steps: Polish each substrate on the second polishing pad; During the process of polishing the surface of each of the substrates on the second polishing pad, the surface of each of the substrates is scanned by one or more second sensors coupled to the second platform, wherein the step of scanning the surface of each of the substrates includes the step of generating second scan data, the second scan data including a second detection property of the material disposed on the surface of each of the substrates; During the process of polishing the surface of each of the substrates on the second polishing pad, it is determined that there is a difference between the properties of a portion of the generated second scan data and the properties of a portion of the second library scan data stored in the controller; and The characteristics of the process for polishing the surface of each of the substrates on the second polishing pad are adjusted based on the determined differences between the properties of the portion of the generated first scan data and the properties of the portion of the second library scan data.

9. A method for processing a substrate in a chemical mechanical polishing (CMP) system, comprising the following steps: A first carrier head is used to transfer a substrate from a first polishing pad to a second polishing pad; After the substrate is transferred to the second polishing pad, the orientation of the substrate relative to the first carrier head is determined; Begin polishing the surface of the substrate on the second polishing pad; During the polishing process, an endpoint sensor coupled to the second polishing pad is used to scan a first portion of the surface of the substrate for the first time to generate first orientation-related scan data of the properties of the first portion of the surface; Compare the first orientation-related scan data with the first library of orientation-related scan data; During the polishing process, the endpoint sensor is used to scan the first portion of the surface of the substrate a second time to generate second orientation-related scan data of the properties of the first portion of the surface; The second directional correlation scan data is compared with the first library to determine that the endpoint of the polishing process has been reached; as well as Once the endpoint is determined to have been reached, the polishing process is stopped.

10. The method of claim 9, wherein the step of comparing the first orientation-related scan data with the first library includes the following steps: It is determined that there is a difference between the attributes of a portion of the first orientation-related scan data and the attributes of a portion of the first library.

11. The method of claim 10, wherein the attributes of the portion of the scan data and the portion of the first library include: The variation between the first directional correlation scan data and the peak values ​​in the first library.

12. The method of claim 10, further comprising the following steps: Before using the endpoint sensor to scan the first portion of the surface of the substrate for the second time, the polishing characteristics of the polishing process are adjusted based on the determined differences between the properties of the portion of the first orientation-related scan data and the properties of the portion of the first library.

13. The method of claim 12, wherein the step of adjusting the polishing characteristics of the polishing process comprises the following steps: Adjust at least one of the force applied to the substrate by the first bearing head, the rotational speed of the first bearing head, and the rotational speed of the second polishing pad.

14. The method of claim 9, further comprising the following steps: Before starting the polishing process, the first carrier head and the first substrate are placed at the starting position relative to the second polishing pad.

15. The method of claim 9, further comprising the following steps: During the polishing process prior to the second scan of the substrate, the endpoint sensor is used to scan a portion of the surface of the substrate to generate third orientation-related scan data of the properties of the portion of the surface; It is determined that the portion of the surface of the substrate scanned by the endpoint sensor during the third scan of the substrate is not the first portion of the substrate; as well as Adjust the position of the first carrier head and / or the rotation speed of the first carrier head so that the endpoint sensor will pass under the first portion of the surface during subsequent scanning.

16. A non-transient computer-readable medium comprising instructions stored thereon, which, when executed by one or more processors, cause the processors to perform a method of processing a substrate in a chemical mechanical polishing (CMP) system, the method comprising the steps of: Determine the orientation of the substrate relative to the first bearing head; A first polishing process is initiated on the surface of the substrate that is engaged with the first polishing pad. The first polishing process includes: rotating the first polishing pad and rotating the substrate relative to the first polishing pad using the first carrier head. During the first polishing process, a first end point sensor coupled to the first polishing pad is used to scan a first portion of the surface of the substrate for the first time to generate first orientation-related scan data of the properties of the first portion of the surface; Compare the first orientation-related scan data with the first library of orientation-related scan data; During the first polishing process, the first portion of the surface of the substrate is scanned a second time using the first endpoint sensor to generate second orientation-related scan data of the properties of the first portion of the surface; The second directional correlation scan data is compared with the first library to determine that the endpoint of the first polishing process has been reached; and Once it is determined that the endpoint of the first polishing process has been reached, the first polishing process is stopped.

17. The medium of claim 16, wherein the method further comprises the following steps: Before starting the first polishing process, the first carrier head and the first substrate are placed at the starting position relative to the first endpoint sensor.

18. The medium of claim 16, wherein the method further comprises the following steps: During the first polishing process prior to the second scan of the substrate, the first endpoint sensor is used to scan a portion of the surface of the substrate to generate third orientation-related scan data of the properties of the portion of the surface of the substrate; It is determined that the portion of the surface of the substrate scanned by the first endpoint sensor during the scanning of the substrate is not the first portion of the substrate; as well as Adjust the position of the first carrier head and / or the rotation speed of the first carrier head so that the first endpoint sensor will pass under the first portion of the surface during subsequent scanning.

19. The medium of claim 16, wherein the method further comprises the following steps: The substrate is transferred from the first polishing pad to the second polishing pad; After the substrate is transferred to the second polishing pad, the orientation of the substrate relative to the first carrier head is determined; A second polishing process is initiated on the surface of the substrate that is engaged with the second polishing pad. The second polishing process includes: rotating the second polishing pad and rotating the substrate relative to the second polishing pad using the first carrier head. During the second polishing process, a second endpoint sensor coupled to the second polishing pad is used to scan a first portion of the surface of the substrate for the first time to generate third orientation-related scan data of the properties of the first portion of the surface; The third orientation-related scan data is compared with the second library of orientation-related scan data; During the second polishing process, the first portion of the surface of the substrate is scanned a second time using the second endpoint sensor to generate fourth orientation-related scan data of the first portion of the surface; The fourth orientation-related scan data is compared with the second library to determine that the endpoint of the second polishing process has been reached; and Once it is determined that the endpoint of the second polishing process has been reached, the second polishing process is stopped.

20. The medium of claim 16, wherein the step of determining the orientation of the substrate relative to the first carrier head includes the following steps: The substrate is aligned in the pre-aligner station.

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