Process control method for pattern wafer index polishing

Abstract

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

Description

[Technical Field]

[0001]

[0001] This disclosure relates to chemical mechanical polishing (CMP), and more specifically to analyzing the endpoints of the CMP process. [Background technology]

[0002]

[0002] Integrated circuits are typically formed on a semiconductor substrate by continuously depositing conductive layers, semiconducting layers, and / or insulating layers onto the substrate. Various manufacturing processes require planarization of the layers on the substrate. For example, one manufacturing process involves depositing a filler layer on a non-planar surface and planarizing this filler layer. In certain applications, the filler layer is planarized until the top surface of a patterned layer is exposed. For example, a metal layer can 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. In another example, a dielectric layer may be deposited on a patterned conductive layer and then planarized to allow for a subsequent photolithography process.

[0003]

[0003] Chemical mechanical polishing (CMP) is a recognized planarization method. This planarization method typically requires a substrate to be placed on a carrier head. The exposed surface of the substrate, i.e., the surface with layer deposition, is usually positioned to contact a rotating polishing pad. The carrier head applies a controllable load to the substrate, pressing it against the polishing pad. Typically, a polishing slurry containing abrasive particles is supplied to the surface of the polishing pad and spreads between the substrate and the polishing pad. The polishing pad and the carrier head each rotate at a constant rotational speed, and the abrasive slurry removes material from one or more layers.

[0004]

[0004] In conventional CMP operations, sensors placed on the polishing platen are used to detect endpoints of the CMP process. However, in conventional designs, the data collected from the sensors changes over time due to different parts of the substrate that pass over the sensors during the polishing process. Due to variations in material thickness and differences in material type commonly found on patterned semiconductor substrates, it is difficult to reliably detect endpoints in conventional CMP processes. For example, one factor affecting the ability of a CMP system to reliably and repeatedly detect endpoints in conventional CMP processes is that in conventional CMP processes, it is not possible to know whether changes in the sensing characteristics of the film being polished are related to the removed material or to artifacts in the patterned semiconductor substrate structure. Therefore, there is a need to improve the endpoint detection process in the art. [Overview of the project]

[0005]

[0005] In one embodiment, a method for processing substrates in a chemical mechanical polishing (CMP) system includes performing a polishing process on a plurality of substrates, each polishing process performed on each substrate includes transferring each of the plurality of substrates to the surface of a first polishing pad, wherein transferring each of the substrates includes using a carrier head oriented in a first orientation to pick up a substrate positioned in a second orientation on a substrate receiving surface in the CMP system, and polishing each surface of the substrates on a first polishing pad connected to a first platen, wherein the first platen includes one or more first sensors configured to detect the properties of material placed on each surface of the substrates, and one of the one or more first sensors is positioned in a third orientation, and a controller controls the process of polishing each surface of the substrates. The process includes polishing each surface of a substrate, configured to position one or more first sensors on the substrate, carrier head, and platen in substantially the same orientation relative to each other at the start; scanning each surface of the substrate with one or more sensors during the polishing process, which includes generating scanning data that includes detection characteristics of materials disposed on each surface of the substrate; determining that the generated scanning data substantially matches library scanning data stored in the controller's memory; determining any differences between some attributes of the generated scanning data and some attributes of the library scanning data; and adjusting the characteristics of the polishing process for each surface of the substrate based on the determined differences between some attributes of the generated scanning data and some attributes of the library scanning data.

[0006]

[0006] In one embodiment, a method for processing substrates in a chemical mechanical polishing (CMP) system includes performing polishing operations on a plurality of substrates, wherein each polishing operation performed on each substrate transfers each of the plurality of substrates to the surface of a first polishing pad. Transferring each of the substrates includes using a carrier head oriented in a first orientation to remove the substrate positioned in a second orientation on a substrate receiving surface in the CMP system. The method further includes polishing the surface of each substrate on a first polishing pad connected to a first platen. The first platen comprises one or more first sensors configured to detect the properties of the material placed on each surface of the substrate. One of the one or more first sensors is positioned in a third orientation. A controller is configured to position the substrates, the carrier head, and one or more first sensors on the first platen in substantially the same orientation relative to each other at the start of the process of polishing each surface of the substrates. The method further includes scanning each surface of a substrate on a first polishing pad with one or more first sensors during the process of polishing each surface of the substrate, wherein scanning each surface of the substrate includes generating first scan data including first detection characteristics of a material placed on each surface of the substrate. The method further includes determining the difference between some attributes of the generated first scan data and some attributes of first library scan data stored in a controller during the process of polishing each surface of the substrate on the first polishing pad. The method further includes adjusting the characteristics of the process of polishing each surface of the substrate on the first polishing pad based on the determined difference between some attributes of the generated first scan data and some attributes of the first library scan data.

[0007]

[0007] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes using a first carrier head to transfer the substrate from a first polishing pad to a second polishing pad. The method further includes 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 initiating a polishing process of the surface of the substrate on the second polishing pad. During the polishing process, the method further includes using an endpoint sensor coupled to the second polishing pad to scan a first portion of the surface of the substrate for a first time to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. During the polishing process, the method further includes using the endpoint sensor to scan a first portion of the surface of the substrate for a second time to generate second orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scan data with the first library to determine that the endpoint of the polishing process has been reached. This method further includes stopping the polishing process when it is determined that the endpoint has been reached.

[0008] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes determining the orientation of the substrate relative to a first carrier head. The method further includes initiating a first polishing process on the 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, during the first polishing process, scanning a first portion of the substrate surface for a first time using a first endpoint sensor coupled to the first polishing pad to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. The method further includes, during the first polishing process, scanning a first portion of the substrate surface for a second time using the first endpoint sensor to generate second orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scan data with a first library to determine that the endpoint of the first polishing process has been reached. This method further includes stopping the first polishing process when it is determined that the endpoint of the first polishing process has been reached.

[0009]

[0008] In one embodiment, a non-temporary computer-readable medium stores instructions, which, when executed by one or more processors, cause a controller to perform a method for processing a substrate in a chemical mechanical polishing (CMP) system, the method including determining the orientation of the substrate relative to a first carrier head. The method further includes initiating a first polishing process of the surface of the substrate engaged with a first polishing pad, the first polishing process including using a first carrier head to rotate the first polishing pad and rotating the substrate relative to the first polishing pad. The method further includes, during the first polishing process, using a first endpoint sensor coupled to the first polishing pad to scan a first portion of the surface of the substrate for a first time to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. The method further includes scanning a first portion of the substrate surface for a second time using a first endpoint sensor during a first polishing process to generate second orientation-dependent scanning data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scanning data with a first library to determine that the endpoint of the first polishing process has been reached. If it is determined that the endpoint of the first polishing process has been reached, the method further includes stopping the first polishing process.

[0010]

[0009] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes determining the orientation of the substrate relative to a first carrier head. The method further includes initiating a polishing process on the surface of the substrate engaged with a polishing pad. During the polishing process, the method further includes repeatedly using at least one endpoint sensor coupled to the polishing pad to scan a first portion of the surface of the substrate and generating orientation-dependent scanning data of the characteristics of the first portion of the surface. The method further includes comparing the orientation-dependent scanning data with a library of orientation-dependent scanning data to determine when the endpoint of the polishing process has been reached.

[0011]

[0010] To enable a detailed understanding of the above-described features of the Disclosure, a more specific description of the Disclosure, which has been briefly summarized above, can be obtained by referring to embodiments. Some of these embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate exemplary embodiments of the Disclosure and should not be considered limiting in scope, and the Disclosure may permit other equally effective embodiments. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic top view of an exemplary chemical mechanical polishing (CMP) system. [Figure 2A] Figure 1 shows a schematic cross-sectional view of an exemplary polishing station of the CMP system according to an embodiment described herein. [Figure 2B] This is a top view of the front of a substrate polished on the polishing station shown in Figure 2A, according to an embodiment described herein. [Figure 3] Figure 2A shows a schematic top view of a carrier head positioned at a scanning location on the polishing pad, relative to the polishing station, according to the embodiment described in this book. [Figure 4] Figure 2A shows a top view of the front surface of the substrate scanned by the orientation sensor of the polishing station according to the embodiment described in this book. [Figure 5] Figure 2A shows a top view of the front of the substrate, illustrating the scanning path of the endpoint sensor of the polishing station according to an embodiment described herein. [Figure 6A] This shows a series of substrate scanning data collected by endpoint sensors on multiple substrates using conventional techniques. [Figure 6B] A series of orientation-dependent scanning data collected by endpoint sensors on multiple substrates using one or more of the processing techniques disclosed herein, according to embodiments described herein, is shown. [Figure 6C]A flowchart of a method for processing a substrate according to an embodiment described herein. [Figure 6D] An example of orientation-dependent scan data collected on a substrate according to an embodiment described herein is shown. [Figure 6E] A graph including a plurality of orientation-dependent scan data collected as a function of scan data (or platen rotation) on a plurality of substrates according to an embodiment described herein is shown. [Figure 6F] An example of substrate surface topography data collected from a model or measured on a substrate according to an embodiment described herein is shown. [Figure 6G] An example of orientation-dependent scan data collected on a substrate according to an embodiment described herein is shown. [Figure 6H] A plot of orientation-dependent scan data collected using each scan path shown in FIG. 6G on a substrate according to an embodiment described herein is shown.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013]

[0025] For ease of understanding, the same reference numbers are used to denote the same elements common to the figures, where possible. Even without further description, the elements and features of one embodiment are intended to be advantageously incorporated into other embodiments.

[0014]

[0026] Apparatuses and methods for reliably determining the endpoint of a chemical mechanical polishing (CMP) process are disclosed herein. The endpoint detection methods disclosed herein include using computer-generated methods and supporting hardware to improve the determination of the endpoint of a CMP process.

[0015]

[0027] FIG. 1 is a top view showing 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 a silicon wafer with one or more layers deposited thereon, is processed within the CMP system 100 to polish the surface of the substrate 115.

[0016]

[0028] A wet robot 108 is provided to transfer the substrate 115 between the factory interface module 102 and the polishing module 106. The wet robot 108 can also be configured to transfer the substrate 115 between the polishing module 106 and the cleaner 104. The factory interface module 102 includes a dry robot 110 configured to transfer the substrate 115 between one or more cassettes 114, one or more transfer platforms 116, one or more measurement stations 117, and one or more pre - alignment stations 118 of the factory interface 102. The substrate 115 is loaded into the CMP system 100 via the cassette 114. In one embodiment shown in FIG. 1, four substrate storage cassettes 114 are shown. The dry robot 110 within the factory interface 102 has a range of motion sufficient to facilitate transfer between the four cassettes 114 and one or more transfer platforms 116. Optionally, the dry robot 110 can be attached to a rail or track 112 to position the robot 110 laterally within the factory interface module 102. The dry robot 110 is further configured to receive the substrate 115 from the cleaner 104 and return the cleaned and polished substrate to the substrate storage cassette 114.

[0017]

[0029] Figure 1 shows an exemplary polishing module 106 that includes a plurality of polishing stations 124 in which a substrate 115 is polished while being held in a carrier head 210 (e.g., a polishing head). Each polishing station 124 includes a conditioning assembly 132 and a polishing fluid supply module 135. Although polishing module 106 is shown to have three polishing stations 124, polishing module 106 may have more than three polishing stations 124. For example, polishing module 106 may have two pairs of polishing stations 124, with each pair of stations 124 processing the substrate 115 independently of the other pair. The polishing stations 124 are sized to interface with one or more carrier heads 210 to facilitate polishing of the substrate 115. The carrier heads 210 are coupled to carriages (not shown) mounted on overhead tracks 128, shown by dashed lines in Figure 1. The overhead track 128 allows for selective positioning of the carriage around the polishing module 106, thereby facilitating selective positioning of the carrier head 210 above the polishing station 124 and the load cup 122. In the embodiment shown in Figure 1, the overhead track 128 has a circular configuration that allows the carriage holding the carrier head 210 to rotate selectively and independently above and / or away from the load cup 122 and the polishing station 124. In addition, the overhead track 128 facilitates sweeping 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 Figure 2.

[0018]

[0030] Each polishing station 124 includes a polishing pad 204 having a polishing surface (e.g., polishing surface 204A in Figure 2) capable of polishing a substrate 115. Each polishing station 124 includes a conditioning assembly 132 and a polishing fluid supply module 135. In one embodiment, the conditioning assembly 132 may include a pad conditioning assembly 140 that dresses the polishing surface of the polishing pad 204 by removing polishing debris and opening the pores of the polishing pad 204 using a pad conditioning disc 133. In another embodiment, the polishing fluid supply module 135 may include a fluid supply arm 134 for supplying slurry. In one embodiment, each polishing station 124 includes a pad conditioning assembly 132. In one embodiment, the fluid supply arm 134 is configured to supply a fluid flow (e.g., slurry 222 in Figure 2) to the polishing station 124. The polishing pad 204 is supported on a platen (e.g., platen 202 in Figure 2) that rotates the polishing pad 204 during processing. Each polishing station 124 includes a polishing pad 204 fixed to a rotatable platen 202. Different polishing pads 204 may be used in different polishing stations 124 to control material removal from the substrate 115.

[0019]

[0031] At least one load cup 122, such as the two load cups 122 shown in Figure 1, is located near the lower right corner of the polishing module 106 between the polishing stations 124 closest to the wet robot 108. The load cup 122 can perform multiple functions, including cleaning the carrier head 210, receiving the substrate 115 from the wet robot 108, cleaning the substrate 115, and loading the substrate 115 into the carrier head (e.g., the carrier head 210 in Figure 2).

[0020]

[0032] The substrate 115 typically has reference marks such as notches, flat edges, or other types of features that can be used to identify the crystal orientation of the substrate 115 and to note the rotational orientation of the front surface of the substrate 115 relative to the central axis. In certain embodiments, the factory interface module 102 may further include a pre-aligner 118 for positioning the substrate 115 in a known desired rotational orientation. By pre-aligning the substrate 115 in the desired rotational orientation, it becomes possible to then transfer the substrate 115 to the substrate support surface in the load cup 122 and position it thereon in a known position and rotational orientation relative to the components in the CMP system 100. Thus, the carrier head 210 can then pick up the substrate 115 in a known rotational orientation relative to the carrier head 210. For example, the pre-aligner 118 may include a reference mark detection system, such as a light blocker sensor (not shown), to sense when the reference marks are in a particular angular position.

[0021]

[0033] In certain embodiments, the substrate 115 is placed in a measurement station 117 by a dry robot 110 before being placed on the transfer platform 116. For example, the dry robot 110 may transfer the substrate 115 from the pre-aligner 118 to the measurement station 117. The measurement station 117 is used to measure various aspects of the substrate 115. The measurement station 117 may use optical sensors, eddy current sensors, resistance sensors, or other sensors to measure the substrate 115. For example, the measurement station 117 may use eddy current sensors for conductive films and optical sensors for dielectric films to measure the thickness of the upper layer on the patterned surface of the substrate 115. The controller 190 receives the measurements, which can be used to facilitate the processing of the substrate 115 within the CMP system 100. After the substrate 115 has been measured in the measurement station 117, the dry robot 110 may transfer the substrate 115 to the transfer platform 116.

[0022]

[0034] In some embodiments, data collected within the measurement station 117 can be used with the controller 190 to determine and / or form a topographic model of the film placed on the surface of the substrate. An example of a topographic model of a patterned substrate signal is shown in Figure 6F. Thus, as will be further discussed below, by correlating the topographic model of the film information received from the measurement station 117 with a known orientation of reference marks on the substrate, the controller 190 can use the film topographic information and the collected endpoint sensor data (also referring to reference marks on the substrate) to reliably determine whether the polishing process on one or more portions of the substrate surface is directed toward the endpoint.

[0023]

[0035] The wet robot 108 is configured to transfer the substrate 115 from the transfer platform 116 to one of the load cups 122. The rinsed carrier head 210 is moved above the load cup 122 along with the unpolished substrate 115. The unpolished substrate 115 is then chucked onto the carrier head 210, which then moves to a position above the pad 204 of the polishing station 124 to begin the CMP process.

[0024]

[0036] The controller 190 controls aspects of the CMP system 100 during the CMP process (e.g., polishing process, polishing operation, polishing). In certain embodiments, the controller 190 is one or more programmable digital computers running digital control software. The controller 190 may include a CPU (e.g., processor) 191 located near the polishing apparatus, a programmable computer such as a personal computer. The controller may include memory 192 and support circuitry 193. The controller 190 can, for example, adjust the rotation of the polishing pads 204 and the carrier head 210 to perform a desired CMP process and facilitate monitoring of the endpoints of the CMP process. The CMP processing system 100 is powered by a power supply 180 (e.g., a power supply configured to power the components of the CMP processing system 100).

[0025]

[0037] In this document, memory 192 takes the form of a computer-readable storage medium (e.g., non-volatile memory) containing instructions, which, when executed by the CPU, facilitate the operation of the CMP processing system 100. The instructions in memory are in the form of a program product (e.g., a middleware application, an equipment software application, or any other program that implements the method of this disclosure). The program code may conform to any one of many different programming languages. In one embodiment, this disclosure may be implemented as a program product stored in a computer-readable storage medium for use with a computer system. One or more programs in the program product define the functions of the embodiment (including the methods and operations described herein). Exemplary computer-readable storage media include, but are not limited to, (i) non-writable storage media on which information is permanently stored (e.g., read-only memory devices in a computer, such as a CD-ROM disk readable by a CD-ROM drive, flash memory, ROM chip, or any type of solid-state non-volatile semiconductor memory), and (ii) writable storage media on which modifiable information is stored (e.g., floppy disks in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). Such computer-readable storage media are embodiments of the present disclosure when carrying computer-readable instructions that direct the functionality of the methods described herein.

[0026]

[0038] The platen 202 and carrier head 210 each have rotation sensors, such as encoders, to determine their rotational position during CMP operation. As shown in Figure 1, the platen encoder 195, the first head encoder 196, and the second head encoder 197 are communicably connected to the controller 190. The platen encoder 195 is configured to determine the rotational (e.g., angle) direction of the platen 202 and pad 204. The first head encoder 196 is configured to determine the rotational direction of each carrier head 210. The second head encoder 197 is configured to determine the position of each carrier head 210 on the polishing pad 204 (e.g., along the sweep path 302 of the carrier head 210 in Figure 3). Thus, the controller 190 can determine and track the rotational direction of the carrier heads 210 relative to the platen 202 during the CMP process. 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 an encoder and an internal timing element to calculate the rotational speed of the carrier head 210 and / or platen 202 and polishing pad 204.

[0027]

[0039] The substrate 115 may be polished at one or more of the polishing stations 124. For example, the carrier head 210 can remove the unpolished substrate 115 from the substrate support surface (not shown) in the load cup 122. Based on known orientation and rotational position data received from the first head encoder 196, and the physical position from data received from the second head encoder 197, the position of the substrate relative to the platen 202 and the carrier head 210 during the CMP process is known. The carrier head 210 and the substrate 115 chucked therein are then moved to the first polishing station 124 (for example, the polishing station 124 in the upper right corner of the polishing module 106 closest to the cleaner 104). A CMP polishing operation is then performed on the first polishing station 124, such as removing the first layer formed on the substrate 115. Once the substrate 115 has completed polishing in the first polishing station 124, the carrier head 210 moves the substrate 115 to a second polishing station 124 (e.g., a 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 moved from the second polishing station 124 to a third polishing station 124 (e.g., a polishing station 124 in the lower left corner of the polishing module 106) for additional polishing of the substrate 115.

[0028]

[0040] After polishing, the carrier head 210 moves the polished substrate 115, which is chucked in the carrier head 210, onto the load cup 122, and the polished substrate 115 is then placed within the substrate support surface of the load cup 122. The wet robot 108 transports the polished substrate 115 from the substrate support surface of the load cup 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. In the embodiment shown in Figure 1, the cleaner 104 includes two pre-cleaning modules 144, two megasonic cleaner modules 146, two brush box modules 148, two spray jet modules 150, and two dryers 152. The dry robot 110 then removes the substrate 115 from the cleaner 104. In some embodiments, the dry robot 110 transports the substrate 115 to the measurement station 117 for further measurement. In certain embodiments, the post-polishing measurements can be used to adjust the polishing parameters for subsequent substrates. Finally, the dry robot 110 returns the substrate 115 to one of the cassettes 114.

[0029]

[0041] Figure 2A shows a schematic cross-sectional view of the polishing station 124 of the CMP system 100 of Figure 1. As shown, the polishing station 124 further includes a plurality of endpoint detection sensors 224 and optionally an orientation sensor 250. A substrate 115 positioned within the carrier head 210 is shown engaged with the polishing surface 204A of a pad 204 connected to a platen 202.

[0030]

[0042] Figure 2B is a top view of the substrate 115 showing the front surface 230 of the substrate 115 as it engages with the polishing pad 204 during polishing. The front surface 230 includes a patterned portion 232 and an unpatterned portion 234. The patterned portion 232 (e.g., a patterned surface) is a portion of the substrate 115 in which multiple semiconductor devices are formed within a semiconductor die during one or more preceding processes. As shown, the patterned portion 232 is divided into multiple full dies 233 arranged in a grid pattern. Each die 233 contains multiple semiconductor devices formed on the 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).

[0031]

[0043] 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 that forms the patterned portion 232. While the semiconductor device is being formed on the patterned portion 232, materials such as barrier metal may be deposited on the unpatterned surface 234. In some embodiments, the unpatterned portion 234 may be a partially patterned portion, which is incomplete and contains only a partial die. The surface area of ​​the unpatterned portion 234 may not be uniform around the patterned portion 232. As shown in Figure 2B, the surface area of ​​the unpatterned surface 234 varies around the patterned portion 232 depending on the shape of the patterned portion 232. Thus, the unpatterned surface 234 has portions with a larger surface area than other portions.

[0032]

[0044] The substrate 115 includes reference marks 236 (e.g., wafer notches) on the edges of the substrate 115, and therefore on the edges of the unpatterned portions 234. The reference marks 236 are fixed features formed on the substrate 115, depending on the doping type and crystal orientation of the substrate 115. In Figure 2B, the reference marks 236 are shown as V-shaped notches formed on the edges of the substrate 115, but the reference marks 236 may be other features. For example, the reference marks 236 may be one or more flat edges of the substrate 115.

[0033]

[0045] The substrate 115 has a first symmetry line 235 that passes through the center of a reference mark 236. The unpatterned surface 234 is generally symmetric with respect to this first symmetry line 235. Thus, there are first regions 237 on both sides of the symmetry line 235 adjacent to the reference mark 236, having substantially the same surface area. Furthermore, a second region 238, similar to the reference mark 236 and having a similar surface area to the first region 237, exists at the opposite end of the substrate 115. While the unpatterned surface 234 may be generally symmetric with respect to the first symmetry line 235, the circuits formed on the individual dies 233 of the patterned surface 232 may or may not be symmetric with respect to this first symmetry line 235.

[0034]

[0046] Returning to Figure 2A, the polishing pad 204 is fixed to the platen 202, for example, by using an adhesive such as a pressure-sensitive adhesive (PSA) layer (not shown) placed between the polishing pad 204 and the platen 202. The carrier head 210 facing the platen 202 and the polishing pad 204 mounted thereon includes a flexible diaphragm 212 configured to apply different pressures to the back surface of the substrate 115, which is positioned between the carrier head 210 and the polishing pad 204. The flexible diaphragm 212 is also configured to chuck the substrate 115 to the carrier head 210 in order 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. While the carrier head 210 rotates around the carrier head axis 216, the flexible diaphragm 212 presses the front surface 230 (Figure 2B) of the substrate 115 against the polishing surface 204A of the polishing pad 204. During polishing, a downward force on the carrier ring 218 presses the carrier ring 218 against the polishing pad 204, improving the uniformity of the polishing process and preventing the substrate 115 from sliding off from under the carrier head 210. In certain embodiments, the carrier head 210 includes a shaft 211 having an axis collinear with the carrier head axis 216. In further embodiments, the platen 202 and the carrier head 210 each have a mechanism or motor (not shown) that drives their rotation.

[0035]

[0047] In some embodiments, both the platen 202 and the polishing pad 204 rotate around a common platen axis 205. In some embodiments, the polishing pad 204 rotates in the same direction as the carrier head 210. For example, both the polishing pad 204 and the carrier head 210 rotate counterclockwise. The polishing pad 204 and the carrier head 210 may rotate at the same speed or at different speeds during the polishing operation. As shown in Figure 2A, the polishing pad 204 has a larger surface area than the front surface area 230 of the substrate 115. However, in further embodiments, the polishing pad 204 has a smaller surface area than the front surface area 230 of the substrate 115.

[0036]

[0048] Figure 2A also shows one exemplary embodiment of the endpoint detection sensors 224. Each endpoint detection sensor 224 is positioned radially from the platen axis 205. The endpoint sensors 224 are positioned within a platen opening 226 formed in the platen 202, below the endpoint detection feature portion 227 (e.g., an optically transparent window) of the polishing pad 204. The endpoint detection sensors 224 direct light through the platen opening 226 and the endpoint detection feature 227 of the front surface 230 of the substrate 115 to detect the characteristics of the front surface 230 as the endpoint sensor 224 passes below the substrate 115 during polishing. The controller 190 uses the data collected by the endpoint detection sensors 224 to determine when an endpoint of the CMP process has been reached. An endpoint may be, for example, when a desired thickness of the layer formed on the patterned surface 232 is reached. For example, an endpoint may be reached when the metal in a plurality of trench lines formed on the patterned portion 232 reaches a desired thickness.

[0037]

[0049] Although the endpoint detection sensor 224 is shown as an optical sensor, the endpoint sensor 224 may be any other suitable sensor capable of monitoring changes in the patterned portion 232 during the CMP process. For example, the endpoint sensor 224 may be an eddy current sensor or an inductive current sensor. The eddy current sensor and the inductive current sensor may be embedded in the platen 202 and / or pad 204, and the endpoint detection feature 227 (e.g., an optically transparent window) and the opening 226 may omit or replace the electromagnetic field transparent window. Although the polishing station 124 is shown to have three endpoint detection sensors 224 arranged around an optional orientation sensor 250, as demonstrated by the three endpoint detection features 227 in Figure 1, the polishing station 124 may include fewer than three or more than three endpoint sensors 224.

[0038]

[0050] Each endpoint detection sensor 224 is positioned at a fixed distance from the rotation center of the platen 202 (e.g., the platen axis 205). The platen encoder 195 tracks the rotational position of the platen 202 and the pad 204. The controller 190 can determine the position of the endpoint sensors 224 as the platen 202 rotates, based on the fixed position of the endpoint sensors 224 and the rotational information obtained from the platen encoder 195.

[0039] Circuit board orientation information

[0051] As described above, by using the pre-positioning device 118, robot 108, and controller 190, the substrate can be positioned on the substrate support surface of the load cup 122 in a known orientation, thereby allowing the orientation of the substrate 115 relative to the orientation of the carrier head 210, as well as the orientations of the platen 202 and pad 204, to be known in advance and monitored and controlled during processing in the CMP system 100. However, in some processing methods, it may be desirable to confirm and / or determine the orientation of the substrate 115 relative to the orientation of the carrier head 210, and the orientations of the platen 202 and pad 204. The orientation of the substrate 115 relative to the orientation of the carrier head 210, and the orientations of the platen 202 and pad 204 can optionally be determined after performing a polishing process on a separate platen 202 and pad 204, and the subsequent polishing process is performed using the orientation sensor 250 and controller 190. In one embodiment, the controller 190, carrier head 210, and orientation sensor 250 are used to verify and / or determine the orientation of the substrate 115 after it has been processed in a first polishing station 124 (e.g., the polishing station 124 in the upper right of Figure 1) and before it is processed on the platen 202 and pad 204 in a second polishing station 124 (e.g., the intermediate polishing station 124 in Figure 1).

[0040]

[0052] Figure 2A also shows the orientation sensor 250. As will be explained in relation to Figures 3 and 4, the orientation sensor 250 is optionally used to locate a reference mark 236 in place so that the controller 190 can determine the rotational orientation of the substrate 115 relative to the carrier head 210 and pads 204. The controller 190 can correlate the confirmed position of the reference mark 236 with the rotational orientation of the carrier head 210, since the substrate 115 rotates with the carrier head 210. The orientation sensor 250 is used to confirm and / or confirm the rotational orientation of the substrate 115 after the substrate 115 has been transferred from one polishing station 124 to another. In other words, it is not necessary to remove the substrate 115 from the polishing module 106, pass it through the cleaner 104, and place it in the pre-positioning unit 118 or measurement station 117 to confirm the rotational orientation of the substrate 115 before polishing the substrate 115 on the second or third polishing station 124.

[0041]

[0053] By knowing the rotational orientation of the substrate 115 and the carrier head 210, as well as the position of each endpoint sensor 224 during polishing, the controller 190 can determine which portion of the front surface 230 of the substrate 115 is being scanned by a particular endpoint sensor 224. 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.

[0042]

[0054] The orientation sensor 250 is positioned at the center of rotation of the platen 202 such that the axis of rotation of the sensor 250 is collinear with the platen axis 205. The endpoint sensor 224 is positioned around the orientation sensor 250 and orbits the platen axis 205 as the platen 202 rotates. To locate the reference mark 236, the carrier head 210 is moved to a scanning position as shown in Figure 2A (see also Figure 3) so that the edge of the substrate 115 is positioned over 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 as the carrier head 210 makes one or more full rotations around the carrier head axis 216 to locate the reference mark 236. In other embodiments, the reference mark 236 is located only after a partial rotation of the carrier head 210.

[0043]

[0055] In some embodiments, the orientation sensor 250 is an isotropic electromagnetic sensor, as shown in Figure 2A. In some embodiments, the orientation sensor 250 is an eddy current sensor, an optical sensor, or another sensor capable of detecting the reference mark 236. As shown, the orientation sensor 250 is partially embedded in both the platen 202 and the pad 204. In some embodiments, the orientation sensor 250 is embedded only in the platen 202 and covered by the pad 204.

[0044]

[0056] In some embodiments, a layer of material formed on the surface of the substrate partially or completely covers the front surface 230, so that both the patterned portion 232 and the unpatterned portion 234 are completely or partially covered by the layer. This layer may be deposited to form another layer or feature on the die 233 of the patterned portion 232, which is polished in a CMP system. The orientation sensor 250 can scan the edge of the substrate 115 to locate the reference mark 236 even if layers are deposited on both the patterned portion 232 and the unpatterned portion 234. For example, the orientation sensor 250 can obtain data indicating that a portion of the layer scanned by the orientation sensor 250 was on the underlying patterned portion 232 or unpatterned portion 234. In other words, the controller 190 can distinguish between the patterned portion 232 and the unpatterned portion 234 even if both are at least partially hidden by the same layer. In addition, the data acquired by the orientation sensor 250 can show variations in the scanned material (e.g., variations in the unpatterned area 234) even if the layer completely or partially covers the front surface 230.

[0045]

[0057] Figure 3 shows a schematic top view of the polishing station 124, indicating the carrier head 210 to a scanning position to locate the reference mark 236. The conditioning assembly 132 and polishing fluid supply module 135 are omitted. The head 210 is movable relative to the pad 204 along the sweep path 302 to sweep the substrate 115 along the polishing surface 204A during the polishing process. The endpoint sensor 224 traverses the sweep path 302 as the platen 202 rotates. The endpoint sensor 224 passes below the substrate 115 when the carrier head 210 positions the substrate 115 at one or more positions along the sweep path 302 within the travel path of the endpoint sensor 224 as the platen 202 rotates.

[0046]

[0058] The carrier head 210 is shown in the scanning position, with the edge of the front surface 230 positioned at least partially above the orientation sensor 250. The carrier head 210 rotates relative to the orientation sensor 250 and the platen 202, while the orientation sensor 250 scans the edge of the substrate 115 to locate the reference mark 236. After the substrate 115 is transferred from one polishing station 124 to another within the polishing module 106, the carrier head 210 moves to the scanning position, allowing it to perform a scan 310 (see Figure 4) of the front surface 230 to confirm the rotational orientation of the substrate 115.

[0047]

[0059] Figure 4 shows the scanning 310 of a region of the front surface 230 of the substrate 115 by the orientation sensor 250. The scanning 310 (i.e., shown by the dashed line) shows the path by which the orientation sensor 250 passes across the edge region of the front surface 230 of the substrate and collects data as the carrier head 210 rotates the substrate 115 relative to the orientation sensor 250. The scanning 310 is performed near the edge of the front surface 230. The scanning 310 is brought close enough to the edge of the substrate 115 so that the scanning 310 passes over a portion of the reference mark 236. In some embodiments, the orientation sensor 250 performs the scanning 310 only under the unpatterned surface 234 when the carrier head 210 is in the scanning position. Alternatively, the orientation sensor 250 can complete the scanning 310 along the edge of the substrate 115, passing over both the patterned surface 232 and the unpatterned surface 234.

[0048]

[0060] The orientation sensor 250 collects data about the front surface 230 along the scan 310. This data is sent to the controller 190 for analysis to determine the position of the reference mark 236. The first head encoder 196 simultaneously records the rotational position of the carrier head 210 while the orientation sensor 250 collects data along the scan 310. The controller 190 associates the data acquired from the orientation sensor 250 with the rotational position of the carrier head 210 from which the data was acquired. In other words, the controller 190 can match the data acquired from the orientation sensor 250 with the rotational position of the carrier head 210. This allows the controller 190 to analyze the data and determine the position of the reference mark 236 relative to the rotational orientation of the carrier head 210. Once the position of the reference mark 236 relative to the carrier head 210 is known, the rotational orientation of the substrate 115 can be determined.

[0049]

[0061] In some embodiments, the carrier head 210 rotates only once around the carrier head axis 216 for the orientation sensor 250 to collect sufficient data along the scan 310 to determine the position of the reference mark 236. In other embodiments, the carrier head 210 rotates more than one time to collect sufficient data along the scan 310 and determine the position of the reference mark 236.

[0050]

[0062] In some embodiments, both the platen 202 and the carrier head 210 rotate as the orientation sensor 250 scans the substrate 115. In other embodiments, the platen 202 remains stationary while the carrier head 210 rotates, allowing the orientation sensor 250 to scan the substrate 115. Once the rotational orientation of the substrate 115 is confirmed, the controller 190 can start rotating the platen 202 to initiate the CMP process.

[0051]

[0063] During the CMP process, the controller 190 uses information collected from the platen encoder 195, the first head encoder 196, and the second head encoder 197 to determine and track the position of the carrier head 210 relative to the platen 202. In other words, the controller 190 knows where the carrier head 210 is on the rotating platen 202 at any given time point, including knowing the rotational orientation of the carrier head 210 relative to the platen 202. Once the controller 190 has determined the rotational orientation of the substrate 115 relative to the carrier head 210, the controller 190 also knows the rotational orientation and position of the substrate 115 relative to the rotating platen 202 and the endpoint sensor 224 at any given time point in the polishing process.

[0052]

[0064] The controller 190 uses the positional information of the substrate 115 and the platen 202 to determine which portion of the front surface 230 is scanned by each endpoint sensor 224 during endpoint analysis. In other words, since the position and rotational orientation of the substrate 115 relative to the head 210 and the platen 202 are known, the controller 190 can correlate the data collected by the endpoint sensors 224 to known positions on the front surface 230. The sweep position of the head 210 relative to the platen 202, and the rotation of both the carrier head 210 and the platen 202, can be adjusted so that each endpoint sensor 224 scans the same area (e.g., the same region) of the front surface 230 by traversing the same scan path multiple times during the CMP process. By acquiring data from the same area on the substrate, the endpoint sensors 224 acquire a constant signal in each scan that reflects the progress of the polishing process over time, thus repeatedly improving the signal-to-noise ratio of the data acquired by the endpoint sensors 224. By improving the signal-to-noise ratio, endpoint analysis is enhanced, allowing for more accurate determination of when the endpoint is reached, and resulting in the desired uniform polishing across the patterned surface 232.

[0053]

[0065] In conventional CMP processes, the orientation of the substrate 115 after transfer to the second polishing station 124 is unknown. As a result, the controller cannot correlate the collected data with known locations on the substrate surface and therefore does not know which part of the substrate is being scanned during endpoint analysis. An example of substrate scanning data collected for a series of substrates using conventional techniques is shown in Figure 6A. Figure 6A includes multiple measurements collected for a plurality of substrates 602, referred to herein as substrate scanning data 605. Each of the substrates 602 is substrate 115. Each of the collected substrate scanning data 605, created so that the endpoint sensor 224 traverses a path across the substrate surface, contains film characteristic information detected by the endpoint sensor 224 and indicated by a curve 606. In this example, the plurality of substrates 602 includes M substrates, where M varies from 1 to M and M is at least greater than 1 (for example, in Figure 6A, M is greater than 3). Also, as shown in Figure 6A, each substrate 602 is scanned multiple times during processing. The scan count 601 may include N scans, each providing substrate scan data 605, where N varies from 1 to N and is at least greater than 1 (for example, in Figure 6A, N is greater than 3). Due to a lack of knowledge regarding the orientation of the substrate 602 relative to the orientation of the carrier head 210, and the orientation of the platen 202 and pads 204, the detected film characteristic information in each collected substrate scan data 605 differs as the endpoint sensor 224 traverses its path across various unknown portions of the surface of the substrate 602. As shown in Figure 6A, each of the curves 606 in each of the collected substrate scan data 605 corresponds to each consecutive scan 6011, 6012, 6013...601 N In this, and in each continuous substrate 6021, 6022, 6023...602 M In this respect, they differ from each other. Therefore, endpoint analysis in conventional CMP processes is based on random portions of the substrate 602 scanned by the endpoint sensor. The endpoint detection process disclosed herein and shown in Figures 6B to 6H has been shown to improve the controller 190's ability to detect endpoints in the CMP process.

[0054]

[0066] Figure 5 shows a top view of the substrate 115 shown in Figure 2B, illustrating an exemplary first endpoint scanning path 501, an exemplary second endpoint scanning path 502, and an exemplary third endpoint scanning path 503 across the front surface 230. Each endpoint scanning path 501, 502, and 503 corresponds to the path taken by each endpoint sensor 224 (see window 227) of the polishing station 124 shown in Figure 3 as it passes under the front surface 230 of the substrate 115. The endpoint sensor 224 generates curves such as curve 606 provided in the substrate scanning data 605 as the scanning path of the endpoint sensor crosses the front surface 230 of the substrate 115. As shown, each endpoint scanning path is arc-shaped due to the movement of the carrier head 210 and platen 202 during polishing. Each endpoint sensor 224 scans the outer surface multiple times along each endpoint scanning path 501, 502, and 503 during the CMP process (i.e., scans 6011, 6012, 601 3... 601 N (Scans the endpoints) to facilitate endpoint analysis.

[0055] Improved endpoint processing device and method

[0067] In some embodiments, by using the apparatus and methods disclosed herein, data obtained by the endpoint sensor 224 along a known scanning path across the surface of the substrate is used during endpoint analysis to generate improved substrate scanning data 655, which is used to better determine when the endpoint of the polishing process has been reached. Figure 6C shows a flowchart of an exemplary method 630 for processing a substrate using the improved substrate scanning data 655 collected on one or more substrates. For ease of clarity and explanation, the improved scanning data 655 is often referred to herein as orientation-dependent scanning data 655, or ODS data 655, to avoid confusion with substrate scanning data 605 collected by using conventionally configured systems and methods that do not monitor or use substrate orientation information during processing.

[0056]

[0068] As will be further explained below, for substrates processed or patterned similarly in a batch or batch of substrates, the ability to start from a known orientation of the substrate relative to the carrier head 210, platen 202, and pad 204 allows for more accurate determination of the polishing endpoint using data previously collected from previously processed substrates. Furthermore, the controller 190 can use the position and orientation of the substrate 115 to correlate the data obtained by the endpoint sensor 224 with each specific die 233 along the scanning path of the endpoint sensor 224. Thus, 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 adjust the carrier head 210 and platen 202 so that the endpoint sensor 224 traverses the same scanning path multiple times during the polishing of each substrate 115. In other words, the same portion of all substrates 115 can be repeatedly scanned by the endpoint sensor 224.

[0057]

[0069] In some embodiments, the carrier head 210 and the substrate 115 may be positioned in the same orientation relative to each other 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., starting direction) relative to the endpoint sensor 224 of the polishing pad 204. For example, the carrier head 210 may be positioned in a first orientation when each substrate 115, positioned in a second orientation, is removed from the substrate removal surface in the CMP system 100, for example, from the pre-positioning unit 118. The carrier head 210 then engages with the substrate 115 at the starting point on the polishing pad 204, and the endpoint sensor 224 is positioned in a third orientation. The ability to start with substrates oriented in the same orientation relative to the carrier head 210, platen 202, and pad 204 for substrates that have been similarly processed or patterned in a batch or batch of substrates allows for more accurate determination of the polishing process endpoint using data previously collected from previously processed substrates.

[0058]

[0070] Figure 6B shows multiple ODS data 655 collected on multiple substrates 652. Each substrate 652 is 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 characteristic information detected by the endpoint sensor 224. An example of film characteristic information is shown by the curve 656 in the ODS data 655. In this example, the multiple substrates include M substrates, where M varies from 1 to M and M is at least greater than 1 (for example, in Figure 6B, M is greater than 3). Also, as shown in Figure 6B, each substrate 652 is scanned multiple times during processing. The number of scans 651 may include N scans, each providing ODS data 655, where N varies from 1 to N and N is at least greater than 1 (for example, in Figure 6B, N is greater than 3). Due to the known orientation of the substrate 652 relative to the orientation of the carrier head 210, platen 202, and pad 204, the film characteristic information detected in each ODS data 655 collected typically includes small variations in the shape of the curve 656 as the endpoint sensor 224 traverses the path across the same portion of each surface of the substrate 652. As shown in Figure 6B, each of the first scans 6511 of each substrate, each of the second scans 6512 of each substrate, each of the third scans 6513 of each substrate, and the Nth scan 651 of each substrate N In each of these, each curve 656 of each collected ODS data 655 is shown by a curve 656 of substantially the same shape, and each of the curves 656 of each consecutive substrate scan 6511, 6512, 6513...651 N In this respect, they are substantially similar to each other.

[0059]

[0071] Figure 6C shows a method 630 for processing a substrate using improved substrate scanning data 655 collected on one or more substrates. Method 630 begins with operation 632, in which the orientation of the substrate 652 (e.g., substrate 115) is determined by one or more methods described herein. In one embodiment, the orientation of the substrate 652 is determined by using a pre-aligner 118 and a controller 190. After determining the orientation of the substrate 652, the substrate 652 is transported to a load cup 122 by using the controller 190 which is in a known orientation, and finally to a carrier head 210 which is additionally oriented to a known position and orientation by using a first head encoder 196 and a second head encoder 197, respectively.

[0060]

[0072] In an alternative example, the substrate 652 is transferred to the load cup 122 and carrier head 210, which are oriented at a known position and orientation, using the controller 190. The orientation of the substrate 652 relative to the orientation of the carrier head 210, as well as the orientation of the platen 202 and pads 204, is then determined using the orientation sensor 250 described above. The orientation sensor 250 may also be used to determine the orientation of the substrate 652 relative to the carrier head 210 when the substrate 652 is transferred to a subsequent polishing station, such as after the substrate 652 has been transferred from a first polishing station to a second polishing station. During the orientation determination process performed by the orientation sensor 250, the substrates 6521-652 M To ensure that each of them has a similar starting point for the polishing process, it may be desirable that no material is removed from the surface of the substrate 652, or only a small amount, before the orientation of the substrate 652 is determined relative to the carrier head 210, platen 202, and pad 204. In some cases, it may be desirable that the controller 190 initiate the CMP process after the substrate 652, carrier head 210, and / or platen 202 are all aligned and oriented to each other at known or the same starting position and orientation, so as to ensure that the scanning path across the substrate surface of each consecutive substrate 652 is substantially the same.

[0061]

[0073] In the next operation 634, the substrate 652 is polished on a pad 204 connected to a platen 202 of a polishing station 124, such as a first polishing station. The polishing process involves pressing the front surface 230 of the substrate 652 against the surface of the pad 204 while a slurry and / or other chemical is supplied to the substrate surface. During the polishing process, a diaphragm 212 in the carrier head 210 biases the substrate 652 against the surface of the pad 204. The carrier head 210 and the platen 202 can be aligned so that at least one desired portion of the front surface of the substrate 652, for example, a desired scanning path, is repeatedly scanned by the endpoint sensor 224.

[0062]

[0074] Next, in operation 636, one or more endpoint sensors 224 generate ODS data 655 by detecting film property information as the endpoint sensors 224 traverse a path across the surface of the substrate. Due to the known orientation of the substrate 652 relative to the orientation of the carrier head 210, platen 202, and pad 204, the detected film property information in each collected ODS data 655 generated by one or more endpoint sensors 224 typically includes small or small variations in the shape of the curve 656. However, due to differences in substrate size, for example, the position of the scanning path across the substrate surface may vary slightly from one substrate to the next, resulting in slight variations in the curve 656 in each of the collected ODS data 655 during a series of scans between substrates. Therefore, errors or variations in the collected ODS data 655 from each consecutive scan can cause drift of the scanning path over time across the substrate, which can be resolved by one or more of the techniques described below.

[0063]

[0075] Next, in 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 memory may include a library of ODS data 655 collected from previous polishing process runs on previously processed substrates (e.g., the first substrate in a batch), calibration substrate data collected from specially processed substrates used to determine the desired ODS data 655 sequence to achieve the polishing process endpoint, or modeling data generated based on known information about the polishing process and the substrate being processed.

[0064]

[0076] In some embodiments, during operation 638, the controller 190 is used to find a substantial 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 involve comparing a portion of curve 656 in the recently generated ODS data 655 with each of the corresponding portions of curve 656 stored in memory to determine if there is a match between the curves. In some embodiments, by monitoring the current time, number of scans, or rotations of the platen 202, the number of curves that need to be analyzed to determine whether they match can be reduced to only a few curves stored around the current time during the current CMP process in which the recently generated ODS data 655 was measured.

[0065]

[0077] Operation 637 also includes Operation 640, which compares some attributes of the curve 656 in the recently generated ODS data 655 with some attributes of substantially matching stored information (e.g., previously stored data of the curve 656) in order to determine the current state of the polishing process being performed on the substrate 115. In one embodiment, to determine the status of the CMP process, the comparison is made using peak-to-peak variation information within a portion of the curve 656 in the recently generated ODS data 655 (e.g., the 30th scan of the substrate 651 30) is determined to be the peak-to-peak variation information (e.g., the 30th scan 651 of the previously processed substrate) found in the consistency information stored in the memory 30 including the peak-to-peak variation information associated with 30 . FIG. 6D shows the measured peak-to-peak variation "P" within the desired portion of the curve 656 of the generated ODS data 655, and this peak-to-peak variation "P" can be compared with the information stored in the memory of the controller 190 (e.g., the portion where the curve 656 is stored in the memory). Therefore, by comparing some attributes of the curve 656 with the same attributes of some of the stored information that substantially matches, in order to achieve the endpoint of the CMP process, one or more of the CMP process parameters (e.g., time, pressure, rotational speed, etc.) can be adjusted, and the deviation of the compared attributes (e.g., the peak-to-peak variation "P") can be used in subsequent operations.

[0066]

[0078] FIG. 6E shows a plot of the relatively measured peak-to-peak variation "P" for one or more previously processed substrates 652 as a function of the number (or time) of scans performed on the current substrate and the number of scans of the data stored in the memory (Y-axis), where it is determined by further analysis or testing that the endpoint of a particular substrate type has been reached at point 625. Referring to FIG. 6E, in one embodiment, after 28 scans have been performed on the currently processed substrate 652, the measured attributes of the generated ODS data 655 are determined to match the attributes of the curve 656 data stored in the memory that achieved similar results after 30 scans were performed (e.g., point 622). In this case, the polishing process being performed on the currently processed substrate 652 is further from the nominal polishing process within the library of comparison data stored in the memory of the controller 190. If the data stored in the memory for the nominal polishing process exactly matches the scan data being generated on the currently processed substrate, the slope of the peak-to-peak variation data will be equal to a 1:1 slope, as shown by the linear curve 620.

[0067]

[0079] In some embodiments, the comparative ODS data library may be specific to the polishing station. For example, the controller 190 may have a first library of ODS data for a first polishing station, a second library of ODS data for a second polishing station, and a third library of ODS data for a third polishing station. The differences in libraries may be due to differences in the polishing processes performed at the stations.

[0068]

[0080] Next, in operation 642, the controller 190 determines whether an endpoint has been reached based on a comparison of the measured attributes of the current substrate 652 with a matching stored substrate. Thus, an endpoint is determined by determining that the attributes measured on the current substrate 652 match those of a substrate that has reached a desired endpoint. For example, the controller 190 may determine that the ODS data 655 acquired during scanning substantially matches the ODS data stored in the controller 190 (e.g., a library) corresponding to an endpoint in the polishing process. If it is determined that an endpoint has been reached, the method then proceeds to operation 646, in which the CMP process is stopped, and possibly the final scan data (i.e., curve 656) is stored in memory for use by the controller 190 in a subsequent endpoint detection step. If it is determined that an endpoint has not been reached, the method then proceeds to operation 644.

[0069]

[0081] If the endpoint has not been achieved, as determined in operation 642, then operation 644 is performed, and the controller 190 then adjusts one or more of the CMP processing parameters (e.g., time, pressure, rotation speed of the platen 202 or carrier head 210) to drive the current polishing process to the desired endpoint. The amount of adjustment of one or more CMP processing parameters may be based on the deviation of the comparison attribute. In one embodiment, in the current CMP process after the 28th scan, the removal of the polishing process is faster than expected, so the CMP process needs to be modified to slow down the process to achieve the desired endpoint. For example, the rotation speed of the carrier head 210 may be adjusted to increase or decrease the polishing speed. 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 before an endpoint is detected during operation 642. Method 630 can be repeated at each polishing station 124 in the CMP system 100. In other words, method 630 can be used to determine when the endpoint of a polishing operation performed at a particular polishing station 124 has been reached.

[0070]

[0082] Figure 6F shows an example of substrate surface signal topography data collected from a model or measured on a substrate 652 according to an embodiment described herein. The controller 190 can use film topography information to determine what the ODS data 655 should include for the substrate 652 so that the determined ODS data 655 can be stored in memory and used as library data during operation 637. In one embodiment, the topography data can be received using endpoint sensor 224 data collected from scanning a reference substrate in a measurement station 117 or by scanning the substrate before initiating the CMP process (i.e., before pressing the substrate onto the polishing pad surface and / or before providing slurry). In one embodiment, the topography data can be generated by a modeling technique based on prior knowledge of a batch of substrates or substrate topography.

[0071]

[0083] Figure 6G shows examples of multiple alternative scanning paths created for a substrate due to variations in substrate characteristics, according to embodiments described herein. Variations in substrate characteristics can change the scanning path of the endpoint sensor 224 across the substrate, resulting in variations in the measured ODS data 655. Differences in substrate characteristics may include, for example, substrate size, which can slightly vary the position of the scanning path across the substrate surface from one substrate to the next, resulting in slight variations in the curve 656 in each of the collected ODS data 655 over a series of scans between substrates. Errors or variations in the ODS data 655 collected from each consecutive scan can also cause drift in the scanning path over time during processing. Figure 6H shows a plot of substrate scanning data collected using each of the scanning paths shown in Figure 6G, according to embodiments described herein. As shown in Figure 6H, the curve 656 for each of the various scanning paths "i" in Figure 6G varies from "i+5" to "i-6". If it is determined that the scan path deviates from the expected scan path (i.e., has a scan path), then, for example, the position of the carrier head 210 or the rotational speed of the carrier head 210 can be corrected over the next few scans to adjust the scan path position according to a pre-saved scan profile generated by theoretical modeling or an experimentally collected profile.

[0072]

[0084] In addition, the controller 190 may analyze data acquired at points where the scan paths of two or more endpoint sensors 224 intersect to evaluate the endpoints of the CMP process. For example, the controller 190 may analyze data acquired at point 511 where the first scan path 501 and the third scan path 503 intersect to analyze the endpoints of the CMP process. This data can be used to plot a trace of the CMP process. In addition, the controller 190 may analyze data acquired at point 512 where the second scan path 502 and the third scan path 503 intersect, and at point 513 where the first scan path 501 and the second scan path 502 intersect, to evaluate the endpoints of the CMP process. The data acquired at each of the points 511, 512, and 513 can be used to plot another trace of the endpoint processing during endpoint analysis. In some embodiments, the controller 190 may also compare data acquired at points where the scan paths of two or more endpoint sensors 224 intersect to verify that the data acquired from each endpoint sensor 224 is consistent.

[0073]

[0085] In one embodiment, a method for processing substrates in a chemical mechanical polishing (CMP) system includes performing a polishing process on a plurality of substrates, each polishing process performed on each substrate comprising: transferring each of the plurality of substrates to the surface of a first polishing pad, wherein the transfer of each substrate includes using a carrier head oriented in a first orientation to pick up a substrate positioned in a second orientation on a substrate receiving surface in the CMP system; and polishing each of the substrates on a first polishing pad connected to a first platen, wherein the first platen includes one or more first sensors configured to detect the properties of material placed on each of the substrates, and one of the one or more first sensors is positioned in a third orientation, and a controller opens the process of polishing each of the substrates. The process includes polishing each surface of a substrate, configured to position one or more first sensors on the substrate, carrier head, and platen in substantially the same orientation relative to each other at the start; scanning each surface of the substrate with one or more sensors during the polishing process, which includes generating scanning data that includes detection characteristics of materials disposed on each surface of the substrate; determining that the generated scanning data substantially matches library scanning data stored in the controller's memory; determining any differences between some attributes of the generated scanning data and some attributes of the library scanning data; and adjusting the characteristics of the polishing process for each surface of the substrate based on the determined differences between some attributes of the generated scanning data and some attributes of the library scanning data.

[0074]

[0086] In one embodiment, a method for processing substrates in a chemical mechanical polishing (CMP) system includes performing polishing operations on a plurality of substrates, wherein each polishing operation performed on each substrate transfers each of the plurality of substrates to the surface of a first polishing pad. Transferring each substrate includes using a carrier head oriented in a first orientation to remove a substrate positioned in a second orientation on a substrate receiving surface in the CMP system. The method further includes polishing the surface of each substrate on a first polishing pad connected to a first platen. The first platen comprises one or more first sensors configured to detect the properties of the material placed on each surface of the substrate. One of the one or more first sensors is positioned in a third orientation. A controller is configured to position the substrates, the carrier head, and one or more first sensors on the first platen in substantially the same orientation relative to each other at the start of the process of polishing each surface of the substrates. The method further includes scanning each surface of a substrate on a first polishing pad with one or more first sensors during the process of polishing each surface of the substrate, wherein scanning each surface of the substrate includes generating first scan data including first detection characteristics of a material placed on each surface of the substrate. The method further includes determining the difference between some attributes of the generated first scan data and some attributes of first library scan data stored in a controller during the process of polishing each surface of the substrate on the first polishing pad. The method further includes adjusting the characteristics of the process of polishing each surface of the substrate on the first polishing pad based on the determined difference between some attributes of the generated first scan data and some attributes of the first library scan data.

[0075]

[0087] In one or more embodiments of the method for performing the polishing process, some attributes of the generated first scan data and some attributes of the first library data include peak-to-peak variations in the generated first scan data and the first library scan data.

[0076]

[0088] In one or more embodiments of the method for performing the polishing process, the characteristics of the process for polishing the surface of each substrate include adjusting at least one of the amount of force applied to the substrate by the carrier head, the rotational speed of the carrier head and the substrate, and the rotational speed of the first platen.

[0077]

[0089] 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.

[0078]

[0090] In one or more embodiments of the method for performing the polishing process, one or more first sensors include eddy current sensors.

[0079]

[0091] In one or more embodiments, a method for performing a polishing process further includes determining that the generated first scan data substantially matches the endpoint of the first library scan data. If it is determined that the generated first scan data substantially matches the endpoint of the first library scan data, the method further includes stopping the polishing of each substrate on the first polishing pad.

[0080]

[0092] In one or more embodiments, a method for performing a polishing process further includes using a carrier head to transfer each substrate from a first polishing pad to a second polishing pad connected as a second platen. The method further includes moving the carrier head to a scanning position above an orientation sensor connected to the second platen. The method further includes using the orientation sensor to determine the orientation of the substrate relative to the carrier head.

[0081]

[0093] In one or more embodiments, a method for performing a polishing process further includes polishing each substrate on a second polishing pad. The method further includes scanning the surface of each substrate with one or more second sensors connected to a second platen during the process of polishing the surface of each substrate on the second polishing pad, wherein scanning the surface of each substrate includes generating second scan data, which includes second detection characteristics of the material placed on the surface of each substrate. The method further includes determining the difference between some attributes of the generated second scan data and some attributes of second library scan data stored in a controller during the process of polishing each surface of the substrate on the second polishing pad. The method further includes adjusting the characteristics of the process of polishing each surface of the substrate on the second polishing pad based on the determined difference between some attributes of the generated first scan data and some attributes of the second library scan data.

[0082]

[0094] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes transferring the substrate from a first polishing pad to a second polishing pad using a first carrier head. The method further includes 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 initiating a polishing process of the substrate surface on the second polishing pad. During the polishing process, the method further includes scanning a first portion of the substrate surface for a first time using an endpoint sensor coupled to the second polishing pad to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. During the polishing process, the method further includes scanning a first portion of the substrate surface for a second time using the endpoint sensor to generate second orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scan data with the first library to determine that the endpoint of the polishing process has been reached. When it is determined that the endpoint has been reached, the method further includes stopping the polishing process.

[0083]

[0095] In one or more embodiments of this method, comparing first orientation-dependent scan data with a first library includes determining whether there is a difference between some attributes of the first orientation-dependent scan data and some attributes of the first library.

[0084]

[0096] In one or more embodiments of this method, some attributes of the scan data and some attributes of the first library include peak-to-peak variations in the first orientation-dependent scan data and the first library.

[0085]

[0097] In one or more embodiments of the Method, the Method further includes adjusting the polishing characteristics of the polishing process based on a difference determined between some attributes of first orientation-dependent scan data and some attributes of a first library, before scanning a first portion of the substrate surface at a second time using an endpoint sensor.

[0086]

[0098] In one or more embodiments of the present method, adjusting the polishing characteristics of the polishing process includes adjusting at least one of the amount of force applied to the substrate by the first carrier head, the rotational speed of the first carrier head, and the rotational speed of the second polishing pad.

[0087]

[0099] In one or more embodiments of the present method, the method further includes positioning the first carrier head and the first substrate in a starting position relative to the second polishing pad before initiating the polishing process.

[0088]

[0100] In one or more embodiments of the Method, the Method further includes scanning a portion of the substrate surface using an endpoint sensor during a polishing process prior to a second scan of the substrate, thereby generating third orientation-dependent scanning data of the characteristics of the portion of the surface. The Method further includes determining that the portion of the substrate surface scanned by the endpoint sensor during the third scan of the substrate is not a first portion of the substrate. The Method further includes adjusting the position and / or rotational speed of the first carrier head so that the endpoint sensor passes beneath the first portion of the surface during subsequent scans.

[0089]

[0101] In one embodiment, a method for processing a substrate in a chemical mechanical polishing (CMP) system includes determining the orientation of the substrate relative to a first carrier head. The method further includes initiating a first polishing process on the 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, during the first polishing process, scanning a first portion of the substrate surface for a first time using a first endpoint sensor coupled to the first polishing pad to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. The method further includes, during the first polishing process, scanning a first portion of the substrate surface for a second time using the first endpoint sensor to generate second orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scan data with a first library to determine that the endpoint of the first polishing process has been reached. This method further includes stopping the first polishing process when it is determined that the endpoint of the first polishing process has been reached.

[0090]

[0102] In one or more embodiments, the method further includes positioning the first carrier head and the first substrate at a starting position relative to the first endpoint sensor before initiating the first polishing process.

[0091]

[0103] In one or more embodiments, the method further includes scanning a portion of the substrate surface using a first endpoint sensor during a first polishing process prior to scanning the substrate at a second time, thereby generating third orientation-dependent scanning data of the characteristics of the portion of the substrate surface. The method further includes determining that the portion of the substrate surface scanned by the first endpoint sensor during scanning of the substrate is not a first portion of the substrate. The method further includes adjusting the position and / or rotational speed of the first carrier head so that the first endpoint sensor passes beneath the first portion of the surface during subsequent scanning.

[0092]

[0104] In one or more embodiments, the method further includes transferring a substrate from a first polishing pad to a second polishing pad. After transferring the substrate to the second polishing pad, the method further includes determining the orientation of the substrate relative to the first carrier head. The method further includes initiating a second polishing process of the surface of the substrate engaged with the second polishing pad, the second polishing process including using the first carrier head to rotate the second polishing pad and rotate the substrate relative to the second polishing pad. During the second polishing process, the method further includes scanning a first portion of the surface of the substrate for a first time using a second endpoint sensor coupled to the second polishing pad to generate third orientation-dependent scanning data of the characteristics of the first portion of the surface. The method further includes comparing the third orientation-dependent scanning data with a second library of orientation-dependent scanning data. During the second polishing process, the method further includes scanning a first portion of the surface of the substrate for a second time using a second endpoint sensor to generate fourth orientation-dependent scanning data of the first portion of the surface. The method further includes comparing a fourth orientation-dependent scan data with a second library to determine if the endpoint of the second polishing process has been reached. If it is determined that the endpoint of the second polishing process has been reached, the method further includes stopping the second polishing process.

[0093]

[0105] In one or more embodiments of this method, determining the orientation of the substrate with respect to the first carrier head includes aligning the substrate in a pre-alignment station.

[0094]

[0106] In one embodiment, a non-temporary computer-readable medium stores instructions, which, when executed by one or more processors, cause a controller to perform a method for processing a substrate in a chemical mechanical polishing (CMP) system, the method including determining the orientation of the substrate relative to a first carrier head. The method further includes initiating a first polishing process of the surface of the substrate engaged with a first polishing pad, the first polishing process including using a first carrier head to rotate the first polishing pad and rotating the substrate relative to the first polishing pad. During the first polishing process, the method further includes scanning a first portion of the surface of the substrate for a first time using a first endpoint sensor coupled to the first polishing pad to generate first orientation-dependent scan data of the characteristics of the first portion of the surface. The method further includes comparing the first orientation-dependent scan data with a first library of orientation-dependent scan data. The method further includes scanning a first portion of the substrate surface for a second time using a first endpoint sensor during a first polishing process to generate second orientation-dependent scanning data of the characteristics of the first portion of the surface. The method further includes comparing the second orientation-dependent scanning data with a first library to determine that the endpoint of the first polishing process has been reached. If it is determined that the endpoint of the first polishing process has been reached, the method further includes stopping the first polishing process.

[0095]

[0107] In one or more embodiments of the medium, the method further includes positioning the first carrier head and the first substrate at a starting position relative to the first endpoint sensor before initiating the first polishing process.

[0096]

[0108] In one or more embodiments of the medium, the method further includes scanning a portion of the substrate surface using a first endpoint sensor during a first polishing process prior to scanning the substrate at a second time, thereby generating third orientation-dependent scanning data of the characteristics of the portion of the substrate surface. The method further includes determining that the portion of the substrate surface scanned by the first endpoint sensor during scanning of the substrate is not a first portion of the substrate. The method further includes adjusting the position and / or rotational speed of the first carrier head so that the first endpoint sensor passes beneath the first portion of the surface during subsequent scanning.

[0097]

[0109] In one or more embodiments of the medium, the method further includes transferring a substrate from a first polishing pad to a second polishing pad. The method further includes 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 initiating a second polishing process of the surface of the substrate engaged with the second polishing pad, the second polishing process including using the first carrier head to rotate the second polishing pad and rotate the substrate relative to the second polishing pad. During the second polishing process, the method further includes scanning a first portion of the surface of the substrate for a first time using a second endpoint sensor coupled to the second polishing pad to generate third orientation-dependent scanning data of the characteristics of the first portion of the surface. The method further includes comparing the third orientation-dependent scanning data with a second library of orientation-dependent scanning data. During the second polishing process, the method further includes scanning a first portion of the surface of the substrate for a second time using a second endpoint sensor to generate fourth orientation-dependent scanning data of the first portion of the surface. The method further includes comparing a fourth orientation-dependent scan data with a second library to determine if the endpoint of the second polishing process has been reached. If it is determined that the endpoint of the second polishing process has been reached, the method further includes stopping the second polishing process.

[0098]

[0110] In one or more embodiments of the medium, determining the orientation of the substrate with respect to the first carrier head includes aligning the substrate in a pre-alignment station.

[0099]

[0111] The above description applies to embodiments of the present disclosure, but other embodiments and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the following claims.

Claims

1. A method for processing substrates in a chemical mechanical polishing (CMP) system, comprising performing a polishing process on multiple substrates, wherein each polishing process performed on each substrate is Transferring each of the plurality of substrates to the surface of the first polishing pad, wherein transferring each of the substrates is This includes using a carrier head oriented in a first orientation to remove a substrate positioned in a second orientation on a substrate receiving surface within the CMP system, Transferring each of the aforementioned substrates to the surface of the first polishing pad Polishing each surface of the substrate on the first polishing pad connected to the first platen, The first platen includes one or more first sensors configured to detect the properties of the material disposed on each of the surfaces of the substrate, One of the one or more first sensors is positioned in a third orientation. The controller is configured to position the substrate, the carrier head, and the one or more first sensors on the first platen in substantially the same orientation relative to each other at the start of the process of polishing each of the surfaces of the substrate. Polishing each surface of the aforementioned substrate, Scanning each of the surfaces of the substrate during the process of polishing each of the surfaces of the substrate on the first polishing pad, including scanning each of the surfaces of the substrate with one or more first sensors, and generating first scanning data including first detection characteristics of the material disposed on each of the surfaces of the substrate, During the process of polishing each of the surfaces of the substrate on the first polishing pad, the difference between the attributes of a portion of the generated first scan data and the attributes of a portion of the first library scan data stored in the controller is determined. Based on the determined difference between the attributes of the portion of the generated first scan data and the attributes of the portion of the first library scan data, the characteristics of the process for polishing each of the surfaces of the substrate on the first polishing pad are adjusted. Methods that include...

2. The method according to 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 peak-to-peak fluctuations in the generated first scan data and the first library scan data.

3. The method according to claim 1, wherein the characteristics of the process for polishing each of the surfaces of the substrate include adjusting at least one of the amount of force applied to the substrate by the carrier head, the rotational speed of the carrier head and the substrate, and the rotational speed of the first platen.

4. The method according to claim 1, wherein 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.

5. The method according to claim 1, wherein the one or more first sensors include an eddy current sensor.

6. It is determined that the generated first scan data substantially matches the endpoint of the first library scan data. When 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. The method according to claim 1, further comprising:

7. Using the carrier head, each substrate is transferred from the first polishing pad to the second polishing pad connected as a second platen. Moving the carrier head to a scanning position above the orientation sensor connected to the second platen, Using the orientation sensor, the orientation of the substrate relative to the carrier head is determined. The method according to claim 6, further comprising:

8. Polishing each substrate on the second polishing pad, Scanning each of the surfaces of the substrate during the process of polishing each of the surfaces of the substrate on the second polishing pad, by scanning each of the surfaces of the substrate with one or more second sensors connected to the second platen, and including generating second scanning data including second detection characteristics of the material disposed on each of the surfaces of the substrate, During the process of polishing each of the surfaces of the substrate on the second polishing pad, the difference between some of the attributes of the generated second scan data and some of the attributes of the second library scan data stored in the controller is determined. The method according to claim 7, further comprising adjusting the characteristics of the process for polishing each of the surfaces of the substrate on the second polishing pad based on a determined difference between the attributes of the portion of the generated first scan data and the attributes of the portion of the second library scan data.

9. A method for processing a substrate in a chemical mechanical polishing (CMP) system, Using a first carrier head, the substrate is transferred from the first polishing pad to the second polishing pad, After transferring the substrate to the second polishing pad, the orientation of the substrate relative to the first carrier head is determined. The polishing process of the surface of the substrate on the second polishing pad is initiated, During the polishing process, an endpoint sensor connected to the second polishing pad is used to scan the first portion of the surface of the substrate for a first time to generate first orientation-dependent scanning data of the characteristics of the first portion of the surface. The first orientation-dependent scanning data is compared with a first library of orientation-dependent scanning data. During the polishing process, the endpoint sensor is used to scan the first portion of the surface of the substrate for a second time to generate second orientation-dependent scanning data of the characteristics of the first portion of the surface. The second orientation-dependent scanning data is compared with the first library to determine that the endpoint of the polishing process has been reached. If it is determined that the aforementioned endpoint has been reached, the polishing process will be stopped. A method that includes this.

10. The method according to claim 9, wherein comparing the first orientation-dependent scanning data with the first library determines that there is a difference between some attributes of the first orientation-dependent scanning data and some attributes of the first library.

11. The method according to claim 10, wherein the attributes of the portion of the scan data and the attributes of the portion of the first library include peak-to-peak fluctuations in the first orientation-dependent scan data and the first library.

12. The method of claim 10, further comprising adjusting the polishing characteristics of the polishing process based on a difference determined between the attributes of the portion of the first orientation-dependent scan data and the attributes of the portion of the first library, before scanning the first portion of the surface of the substrate at a second time using the endpoint sensor.

13. The method according to claim 12, wherein adjusting the polishing characteristics of the polishing process includes adjusting at least one of the amount of force applied to the substrate by the first carrier head, the rotational speed of the first carrier head, and the rotational speed of the second polishing pad.

14. The method according to claim 9, further comprising positioning the first carrier head and the first substrate at a starting position relative to the second polishing pad before initiating the polishing process.

15. During the polishing process before scanning the substrate for a second time, the endpoint sensor is used to scan a portion of the surface of the substrate to generate third orientation-dependent scanning data of the characteristics 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. The position of the first carrier head and / or the rotational speed of the first carrier head are adjusted so that the endpoint sensor passes under the first portion of the surface during subsequent scanning. The method according to claim 9, further comprising:

16. A non-temporary computer-readable medium on which instructions are stored, wherein, when executed by one or more processors, the instructions cause a controller to execute a method for processing a substrate in a chemical mechanical polishing (CMP) system, and the method is Determining the orientation of the substrate relative to the first carrier head, Initiating a first polishing process on the surface of the substrate engaged with a first polishing pad, wherein the first polishing process includes rotating the first polishing pad using the first carrier head and rotating the substrate relative to the first polishing pad. During the first polishing process, a first endpoint sensor connected to the first polishing pad is used to scan a first portion of the surface of the substrate for a first time to generate first orientation-dependent scanning data of the characteristics of the first portion of the surface. The first orientation-dependent scanning data is compared with a first library of orientation-dependent scanning data. During the first polishing process, the first endpoint sensor is used to scan the first portion of the surface of the substrate for a second time to generate second orientation-dependent scanning data of the characteristics of the first portion of the surface. The second orientation-dependent scanning data is compared with the first library to determine that the endpoint of the first polishing process has been reached. When it is determined that the endpoint of the first polishing process has been reached, the first polishing process is stopped. Non-temporary computer-readable media, including [specific examples of such media].

17. The medium according to claim 16, further comprising positioning the first carrier head and the first substrate at a starting position relative to the first endpoint sensor before initiating the first polishing process.

18. The method described above is During the first polishing process, prior to scanning the substrate for the second time, the first endpoint sensor is used to scan a portion of the surface of the substrate to generate third orientation-dependent scanning data of the characteristics 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. Adjusting the position and / or rotational speed of the first carrier head so that the first endpoint sensor passes under the first portion of the surface during subsequent scanning. The medium according to claim 16, further comprising:

19. The method described above is Transferring the substrate from the first polishing pad to the second polishing pad, After transferring the substrate to the second polishing pad, the orientation of the substrate relative to the first carrier head is determined. Initiating a second polishing process of the surface of the substrate engaged with the second polishing pad, wherein the second polishing process includes rotating the second polishing pad using the first carrier head and rotating the substrate relative to the second polishing pad. During the second polishing process, a second endpoint sensor connected to the second polishing pad is used to scan the first portion of the surface of the substrate for a first time to generate third orientation-dependent scanning data of the characteristics of the first portion of the surface. The third orientation-dependent scanning data is compared with the second library of orientation-dependent scanning data. During the second polishing process, the second endpoint sensor is used to scan the first portion of the surface of the substrate for a second time to generate fourth orientation-dependent scanning data of the first portion of the surface. The fourth orientation-dependent scanning data is compared with the second library to determine that the endpoint of the second polishing process has been reached. When it is determined that the endpoint of the second polishing process has been reached, the second polishing process is stopped. The medium according to claim 16, further comprising:

20. The medium according to claim 16, wherein determining the orientation of the substrate with respect to the first carrier head includes aligning the substrate in a pre-alignment station.

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