End Point Window with Controlled Texture Surface

Abstract

A chemical mechanical polishing pad window having a controlled textured surface containing repeating patterned features, the window resulting in consistent ISRM over the life of the CMP pad. max-min Providing characteristic values ​​improves end point detection and in situ rate monitoring.A chemical mechanical polishing pad having a window in accordance with the present invention is also provided.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63 / 141,368, entitled "ENDPOINT WINDOW WITH CONTROLLED TEXTURE SURFACE," filed January 25, 2021, which is incorporated herein by reference.

[0002] The present disclosure relates generally to chemical mechanical planarization, and more specifically to an endpoint window having a controlled textured surface. [Background technology]

[0003] Integrated circuits are typically formed on a substrate by successively depositing conductive, semiconductive, and / or insulating layers on a silicon wafer. Various fabrication processes require planarization of at least one of these layers on a substrate. For example, for certain applications (e.g., polishing a metal layer to form vias, plugs, and lines in trenches in a patterned layer), the top layer is planarized until the top surface of the patterned layer is exposed. For other applications (e.g., planarizing a dielectric layer for photolithography), the top layer is polished until a desired thickness remains on the bottom layer. Chemical mechanical planarization (CMP), sometimes referred to as chemical mechanical polishing, is one planarization method. This planarization method typically involves a substrate mounted on a carrier head. The exposed surface of the substrate is typically applied to a polishing pad on a rotating platen. The carrier head provides a controllable load (e.g., force) on the substrate to press the substrate against the rotating polishing pad. A polishing liquid, such as a slurry having abrasive particles, may be placed on the surface of the polishing pad during polishing.

[0004] In some cases, the CMP pad may include a window to allow for in-situ monitoring of the polishing process. For example, laser light can be passed through the window and reflected off of the material being removed via CMP, and the intensity of the reflected light can be used to determine when the etching process is complete. As the reflective material (e.g., metal) is removed, the amount of light reflected from the wafer decreases. This decrease can be observed by monitoring the intensity of the laser light returning through the window over time, and used to detect the endpoint of the etching process (i.e., to determine when the reflective material is completely removed from the surface of the wafer). Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure recognizes that reliable CMP endpoint detection requires a window with a finely tuned initial percent laser light transmittance, and that this transmittance should remain as stable as possible throughout the life of the pad. Conventional CMP pad windows do not meet the requirements for accurate and reliable monitoring of the polishing process, resulting in process inefficiencies and reduced yields. Conventional windows in CMP pads are susceptible to significant changes in transmittance during use. For example, diamond conditioners used as part of the CMP workflow can scratch and / or remove the window surface, thereby changing the light transmittance through the window. The present disclosure recognizes that as the window thins after continued use and / or conditioning, the window becomes susceptible to deformation during use, resulting in unwanted measurement variability. This is due to the increased ISRM. max-minThe window characteristics can be quantified by the characteristics (see FIG. 6C and Table 1 and corresponding description below). In some cases, by scanning the surface of the wafer, it can be determined when reflective material has been removed from a particular wafer area. Conventional windows can result in variations in the light intensity measured at different areas of the wafer surface even when no material has been removed (see FIG. 1C and corresponding description below). The present disclosure also provides that not only should the light transmittance be below a threshold level determined based on the characteristics of the detector used for CMP monitoring and endpoint detection, but that the presence of a repeating pattern on the surface of the window reduces the variation in measurements over time, resulting in reduced and more consistent ISRM. max-min It is also recognized that the transmission characteristic provides a characteristic value. If the light transmission is too high, the detector may become saturated and the signal may be unstable and / or unreliable. However, even if the window provides a sufficiently low light transmission, this transmission characteristic itself does not provide a reliable measurement (e.g., a consistent ISRM) over the life of the CMP pad. max-min It is generally not sufficient to provide a [Means for solving the problem]

[0006] The present disclosure provides an improved window for endpoint detection and in-situ rate monitoring. This unique CMP pad window provides a solution to the problems of conventional CMP pad window technology, including those mentioned above. The CMP pad window described in this disclosure has a controlled textured surface with repeating patterned features, e.g., a unique texture on at least one surface of the window. For example, a controlled textured surface with repeating patterned features (e.g., a micropatterned texture) can be provided on the bottom surface of the CMP pad window to diffuse light passing through the CMP pad window. The repeating pattern provides a light diffusing texture. The repeating patterned features can be prepared using injection molding, laser cutting, and / or any other machining or surface patterning techniques. The novel CMP pad window allows for reliable and reproducible removal rate monitoring and endpoint detection. The present disclosure also includes novel methods for preparing surface textures on materials used for the CMP pad window. These methods facilitate more precise tuning of the window texture and transmission of light through the window, both of which are critical to providing reliable and improved performance. The method may involve injection molding, machining (eg, with an end mill bit of suitable diameter, laser machining), and / or any other suitable technique.

[0007] In one embodiment, a window for a chemical mechanical planarization (CMP) pad includes (e.g., is formed from) an optically transparent material. A first side of the window has a repeating patterned texture or feature. The first side may correspond to (e.g., face in the same direction as) a bottom side of the CMP pad, which does not contact a substrate being planarized during a CMP process using the CMP pad.

[0008] ISRM of the window being measured max-min The property value may be below a threshold value (e.g., 1%, 0.5%, or 0.3%). max-min The characteristic value may be the difference between the maximum and minimum percent intensity measured across the surface of the wafer that includes the reflective material. max-minThe characteristic value may change by less than a threshold amount (e.g., 5%, 10%, 25%, or 50%) after using the CMP pad window to chemically mechanically planarize one or more wafers for a predetermined period of time (e.g., at the end of the CMP pad's useful life).

[0009] The repeating patterned features are configured to diffuse light passing through the window. The repeating patterned features may include regularly spaced raised features. The window may have a width and a length that is less than the width. The width and length may characterize, for example, the physical dimensions of the window (whether the window is square, rounded square, oval, or any other shape). As an example, the repeating patterned features may include a first set of regularly spaced raised features parallel to the direction of the width of the window and a second set of regularly spaced raised lines at a predetermined angle (20°-60°) to the first set of regularly spaced raised features. As another example, the repeating patterned features may include a cross-hatch texture having a first set of regularly spaced features in a first plane that make a first angle (e.g., 45°) relative to the direction of the window width and a second set of regularly spaced features in the first plane that make a second angle (e.g., 90°) relative to the first set of lines, where the first angle is different from the second angle.

[0010] In another embodiment, a chemical mechanical planarization (CMP) pad includes a top surface that contacts a substrate to be planarized during a CMP process using the CMP pad, a bottom surface opposite the top surface, and a window that allows light to pass between an upper side associated with the top surface and a bottom side associated with the bottom surface. The window includes an optically transparent material. A first surface of the window has a repeating patterned texture or feature. The first surface may correspond to (face in the same direction as) a bottom surface of the CMP pad that does not contact a substrate to be planarized during a CMP process using the CMP pad.

[0011] ISRM of the window being measured max-minThe property value may be below a threshold value (e.g., 1%, 0.5%, or 0.3%). max-min The characteristic value may be the difference between the maximum and minimum percent intensity measured across a wafer that includes the reflective material. max-min The characteristic value may change by less than a threshold amount (e.g., 5%, 10%, 25%, or 50%) after using the CMP pad window to chemically mechanically planarize one or more wafers for a predetermined period of time (e.g., at the end of the CMP pad's useful life).

[0012] The repeating patterned texture or features are configured to diffuse light passing through the window. The repeating patterned features may include regularly spaced raised features. The window may have a width and a length that is less than the width. The width and length may characterize the physical dimensions of the window (e.g., whether the window is square, rounded square, oval, or any other shape). As an example, the repeating patterned features may include a first set of regularly spaced raised features parallel to the direction of the width of the window and a second set of regularly spaced raised lines at a predetermined angle (20°-60°) to the first set of regularly spaced raised features. As another example, the repeating patterned features may include a cross-hatch texture having a first set of regularly spaced features in a first plane that make a first angle (e.g., 45°) relative to the direction of the window width and a second set of regularly spaced features in the first plane that make a second angle (e.g., 90°) relative to the first set of lines, where the first angle is different from the second angle.

[0013] For an aid in understanding the present disclosure, reference is now made to the following description taken in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0014] [Figure 1A] FIG. 1A is a schematic diagram illustrating an example of a system for chemical mechanical planarization (CMP). [Figure 1B]FIG. 1B is a schematic diagram showing a portion of the system shown in FIG. 1A used for in-situ velocity monitoring and endpoint detection. [Figure 1C] FIG. 1C is an example plot showing detected intensity versus wafer diameter during an example CMP process using different CMP pad windows. [Diagram 2] FIG. 2 shows a schematic diagram of an example CMP pad including a window and a close-up view showing the textured surface of the window. [Figure 3A] 3A, 3B, and 3C are schematic diagrams illustrating example surface textures for a CMP pad window. [Figure 3B] 3A, 3B, and 3C are schematic diagrams illustrating example surface textures for a CMP pad window. [Figure 3C] 3A, 3B, and 3C are schematic diagrams illustrating example surface textures for a CMP pad window. [Figure 3D] FIG. 3D is a cross-sectional schematic diagram showing a randomly textured surface at a higher magnification. [Figure 3E] 3E, 3F, and 3G are schematic diagrams of example cross-sections showing the patterned texture of the CMP window at higher magnification. [Figure 3F] 3E, 3F, and 3G are schematic diagrams of example cross-sections showing the patterned texture of the CMP window at higher magnification. [Figure 3G] 3E, 3F, and 3G are schematic diagrams of example cross-sections showing the patterned texture of the CMP window at higher magnification. [Figure 4] FIG. 4 is a schematic diagram showing the combination of two pieces with textured surfaces to form an example window for a CMP pad. [Diagram 5] 5A and 5B are images showing examples of molds used in injection molding to prepare windows with textured surfaces. [Figure 6A] 6A and 6B are plots showing the percent light transmission at different wavelengths for different windows for CMP pads. [Figure 6B]6A and 6B are plots showing the percent light transmission at different wavelengths for different windows for CMP pads. [Figure 6C] FIG. 6C is a bar graph showing ISRM max-min characteristic values ​​for example CMP windows after CMP pad break-in and at the end of pad life. [Figure 7] 7, 8 and 9 are flow charts illustrating example processes for preparing CMP pad windows and CMP pads containing such windows. [Figure 8] 7, 8 and 9 are flow charts illustrating example processes for preparing CMP pad windows and CMP pads containing such windows. [Figure 9] 7, 8 and 9 are flow charts illustrating example processes for preparing CMP pad windows and CMP pads containing such windows. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] It should be understood at the outset that, although example embodiments of implementations of the present disclosure are described below, the present disclosure may be practiced using any number of techniques, whether currently known or not. The present disclosure is in no way limited to the example embodiments, drawings, and techniques described below. Additionally, the drawings are not necessarily drawn to scale.

[0016] Chemical Mechanical Planarization System with Endpoint Detection FIG. 1 illustrates a system 100 for performing chemical mechanical planarization. The system 100 includes a CMP pad 200 (also referred to as a "polishing pad"; see also FIG. 2 and corresponding description below), which is disposed on or attached to a platen 102. For example, an adhesive layer (not shown) may be used to attach the polishing pad to the platen 102. In some embodiments, the platen 102 may be rotated during chemical mechanical planarization. A wafer 104 (e.g., a silicon wafer with or without the conductive, semiconductive, and / or insulating layers described above) is attached to a rotatable chuck head 106. The wafer 104 may be attached using a vacuum and / or a reversible adhesive (e.g., an adhesive that holds the wafer 104 in place during chemical mechanical planarization, but allows the wafer 104 to be removed from the head 106 after chemical mechanical planarization). As shown in FIG. 1, pressure may be applied to the wafer 104 during chemical mechanical planarization (eg, to facilitate contact between the surface of the wafer 104 and the polishing pad 200).

[0017] An example polishing pad 200 is shown in FIG. 2 and described in detail below. Briefly, polishing pad 200 has a generally circular or nearly circular shape (i.e., with a top surface, a bottom surface, and curved edges). Polishing pad 200 may include polyurethane. Polishing pad 200 includes a window 202. Window 202 may be of any size suitable for a given application. Window 202 may have a specially designed texture on its top and bottom surfaces, as described in detail below in connection with FIGS. 2-4. For example, window 202 may have a first texture on one surface and the same or a different texture on the other surface. In some embodiments, window 202 may have repeating patterned features and / or a roughened texture on one surface and a repeating patterned texture on the other surface (see FIGS. 3A-C and corresponding description). In some embodiments, window 202 has a roughened texture on the top surface and a repeating patterned texture on the bottom surface (see examples in FIGS. 3A and 3B). In some embodiments, window 202 has a crosshatch pattern machined on both its top and bottom surfaces (see example crosshatch pattern shown in FIG. 3C).

[0018] The window 202 is generally positioned within or over an aperture in the CMP pad 200. As shown in the side view of FIG. 2B, light from the laser 112 may be directed through the window 202. A portion of the light reflected from the reflective material 118 on the surface of the wafer 104 being polished passes back through the window 202 and reaches the detector 114. A signal from the detector 114 is provided to a computer 116. The computer is configured to monitor the light intensity over time. The computer 116 may be configured to detect that an endpoint has been reached when the intensity reaches a predetermined value (e.g., or a user may monitor the plot 150 to determine when the CMP process is complete).

[0019] FIG. 1C shows an example plot 150 of light intensity information as a function of wafer diameter as the wafer 104 is scanned across the window 202. Advanced micromachining processes may require that the polishing process be monitored as a function of position along the surface of the wafer 104. These surface scanning approaches may be referred to as in-situ rate monitoring (ISRM). For example, different pressures may be applied during polishing of a particular area of ​​the wafer's surface, and the pressures may be determined based on information obtained through in-situ rate monitoring. Reliable performance of such advanced polishing processes requires a consistent and reliable signal as a function of position along the surface of the wafer 104. If the window 202 is functioning properly (e.g., as is particularly facilitated using the inherently textured window 202 described in this disclosure), a uniform intensity profile 152a is initially seen, which decreases to a lower value 156a following completion of the CMP process.

[0020] The difference 154a between the maximum and minimum intensity along the surface of the wafer 104 is a relatively small value for the novel window 202 described in this disclosure. For example, the difference 154a for the novel window 202 described in this disclosure may be below a threshold (in units of percent light transmittance) of about 1%, 0.5%, 0.1%, or less. This difference 154a may be stable throughout the life cycle of the window 202 (see FIG. 6C and Table 1 below). This difference 154a is referred to herein as the in situ velocity monitoring minimum / maximum characteristic value (ISRM). max-minThe intensity profile 152b is also referred to as a characteristic value. This relatively small variation (i.e., based on small differences 154a) facilitates the use of advanced processing techniques to actively control the polishing removal rate in different zones or regions of the wafer surface. In contrast, a conventional window may have an inconsistent intensity profile 152b, which decreases over time during polishing (see profile 156b after polishing is completed for a conventional CMP pad window). The difference 154b between the maximum and minimum intensity along the surface of the wafer 104 is relatively large for a conventional window 202, such that advanced CMP processes cannot be performed reliably.

[0021] Returning to FIG. 1A, polishing pad 200 may have any suitable thickness and any suitable diameter (e.g., to be employed in a CMP system such as system 100 described above). For example, polishing pad 200 may have a thickness of about 0.5 millimeters (mm) or less to more than 5 centimeters (cm). In some embodiments, polishing pad 200 may have a thickness of 1 mm to 5 mm. The polishing pad diameter is generally selected to match or be slightly smaller than the diameter of platen 102 of polishing system 100 with which it is used. Polishing pad 200 generally has a uniform or near uniform thickness (e.g., thickness variation of no more than 50%, 25%, 20%, 10%, 5%, or less across the radial extent of the polishing pad).

[0022] A slurry 108 may be provided on the surface of the polishing pad 200 prior to and / or during chemical mechanical planarization. The slurry 108 may be any slurry suitable for planarization of the type of wafer and / or layer material to be planarized (e.g., to remove a silicon oxide layer from the surface of the wafer 104). The slurry 108 generally includes a fluid and an abrasive and / or chemically reactive particle. Any suitable slurry 108 may be used. For example, the slurry 108 may react with one or more materials to be removed from the surface to be planarized. The conditioner 110 is a device configured to condition the surface of the polishing pad 200. The conditioner 110 generally contacts the surface of the polishing pad 200 and removes a portion of the top layer of the polishing pad 200 to improve its performance during chemical mechanical planarization. For example, the conditioner 110 may roughen the surface of the polishing pad 200.

[0023] As described in more detail below, the uniquely textured window 202 described in this disclosure reduces or eliminates changes in light transmission through the window following contact with the slurry 108, the wafer 104, and / or the conditioner 110. For example, the bottom surface of the window 202 may have repeating patterned features, such as the repeating patterned texture shown in Figures 6E-G and described in more detail below. The repeating patterned features may be used to reduce ISRM throughout the life of the CMP pad 200. max-min For example, as the CMP pad 200 and window 202 thin during use, ISRM can be used to measure the properties of the window 202 without causing any significant change in the properties of the window 202. max-min The property values ​​remain consistent with the novel window 202 of the present disclosure (see also Table 1 and FIG. 6C and corresponding description below). As another example, the texture of the top surface of the window 202 (i.e., the surface exposed during use of the CMP pad 200) may have a texture that mimics that generated by contact with the conditioner 110, the slurry 108, and / or the wafer 104.

[0024] Example of an improved window polishing pad FIG. 2 illustrates an example of a CMP pad 200 in more detail. The CMP pad 200 includes a top surface 204 that contacts material during a CMP process, a bottom surface 206, and a window 202 over or within an aperture in the CMP pad 200. The CMP pad 200 has a generally circular or generally cylindrical shape. The thickness 208 of the CMP pad 200 may be from about 1 mm to about 10 mm or more. The diameter of the CMP pad 200 may be from about 500 mm to about 800 mm. The CMP pad 200 has a generally uniform thickness 208. A uniform thickness is defined as a thickness that varies by no more than 50%, 25%, 20%, 10%, 5%, or less over the radial extent of the pad 200. In other words, the thickness measured near the center of the pad 200 is approximately the same as the thickness near the edge of the pad 200.

[0025] The CMP pad 200 may be formed from a thermosetting material, such as polyurethane, or any other suitable material. The top surface 204 may include grooves, or any other suitable structure or pattern, to facilitate CMP (see close-up 210). For example, the grooves may facilitate transport of polished material and / or any other product of the CMP process from the surface 204 of the CMP pad 200 and the wafer 104 being planarized. The CMP pad 200 includes a window 202 over or within an aperture of the CMP pad 200. The window 202 may be formed from a thermosetting or thermoplastic material, such as polyurethane, polyethylene terephthalate glycol, cyclic olefin copolymer, or any other suitable material (i.e., a material that is suitably optically transparent (FIGS. 6A and 6B) and moldable / machinable to prepare the textured surfaces 220, 222). The window 202 may be located at any suitable location within the CMP pad 200. Window 202 may be of any size suitable for viewing a portion of wafer 104 during the CMP process (see FIGS. 1A and 1B).

[0026] The close-up top view 210 of the window 202 shows the top surface 220 of the window 202. The top surface 220 may have an inherent texture, as described in more detail below with respect to FIGS. 3A and 3C. For example, the top surface 220 may have a roughened texture (see FIGS. 3A and 3D). The roughened texture may be achieved through a random roughening process, such as sanding, conditioning (see FIG. 1A), sandblasting, or the like. The roughened texture may correspond to an average surface roughness of 1-50 micrometers, or in some cases, about 2-10 micrometers. As another example, the top surface 220 may have a repeating patterned texture, such as a cross-hatch patterned texture (see, e.g., FIGS. 3C, F, G), a "wavy" patterned texture (see, e.g., FIG. 3E), or any other suitable texture.

[0027] The close-up bottom view 212 of the window 202 shows the bottom surface 222 of the window 202. The bottom surface 222 may have a controlled texture, including repeating patterned features to diffuse light passing through the window 202. For example, the bottom surface 222 may have a texture (see FIG. 3B) including repeating patterned features and optionally a roughened texture. For example, the bottom surface 222 may have cross-hatch pattern features (see FIG. 3C), a "wavy" patterned texture, or any other suitable controlled texture. Further examples of patterned textures are shown in FIGS. 3D-G and described below. The texture of the top surface 220 may be the same or different from the texture of the bottom surface 222. 2 describes the top surface 220 of the window 202 as corresponding to (facing in the same direction as) the top surface 204 of the CMP pad 200, and the bottom surface 222 of the window 202 as corresponding to (facing in the same direction as) the bottom surface 206 of the CMP pad 200, it will be appreciated that the orientation of the window 202 may be altered. For example, the window 202 may be oriented such that the top surface 202 of the window 202 faces the bottom surface 206 of the CMP pad 200.

[0028] FIG. 3A illustrates an example top surface 220 of window 202. In the example of FIG. 3A, top surface 220 has a roughened texture 302. The roughened texture may have an average surface roughness of about 1-50 micrometers, or in some cases, about 2-10 micrometers. The example top surface 220 of FIG. 3A may be prepared using injection molding (see FIG. 5B), machining, treatment with an abrasive material, or any other suitable process. In some cases, injection molding may be used to improve consistency between different window preparations at a relatively low manufacturing cost. For example, the texture 302 of top surface 220 may be a randomly roughened texture 340 illustrated in FIG. 3D. The roughened texture 340 illustrates a randomly roughened surface, such as a portion of a cross section of top surface 220 of FIG. 3A. The randomly roughened texture 340 includes random features 342 randomly distributed on a surface (e.g., on top surface 220). The size 344a,b of the random features 342 (eg, the width and / or height / depth size shown in FIG. 3D) may be about 1-50 micrometers, or in some cases about 2-10 micrometers.

[0029] FIG. 3B illustrates an example bottom surface 222 of the window 202. In the example of FIG. 3B, the bottom surface 222 may have an area with a controlled texture 304 and an area with a different texture 320. The area with texture 304 may be an area (having a width 316 and a length 318) through which light from the laser 112 passes during in-situ velocity monitoring / endpoint detection (see FIGS. 1A-C and corresponding description above). For example, all or a portion of the area with controlled texture 304 may be aligned to overlie an aperture in the CMP pad 200 such that light passes through the textured area. The texture 304 of the bottom surface 222 may include a repeating pattern configured to diffuse light passing through the window 202. Meanwhile, the remaining surface area with texture 320 may rest on or contact a portion of the pad 200, thereby aiding in the attachment of the window 202 to the pad 220. The length 318 and width 316 of the area having texture 304 may be any value suitable for a given in situ velocity monitoring and endpoint detection application. As a non-limiting example, the length 318 may be approximately 50 millimeters (e.g., 2 inches) and the width 314 may be 13 millimeters (0.5 inches).

[0030] In one embodiment, the texture 304 through which light passes for in-situ velocity monitoring / endpoint detection includes a repeating pattern with regularly spaced features 306 (e.g., the tips of the troughs / cups 352 in FIG. 3E or the rounded ridges 362 in FIGS. 3F,G). The features 306 may be straight, as shown. In some cases, the features 306 may be curved or have any other suitable shape or design. The features 306 may be raised relative to the surface 222 or at a depth below the surface 222. More generally, the average height of the surface 222 may be raised, recessed, or approximately flush with the features 306. For example, the height or depth of the features 306 may be from about 25 micrometers to about 500 micrometers (e.g., from 0.001 inches to about 0.02 inches). The first set of features 306 may be parallel to the direction of the width 316 of the window 202, as shown in the example of FIG. 3B, or may be at any other suitable angle (see FIG. 3C). The width of the features 306 may be from about 25 micrometers to about 500 micrometers (e.g., 0.001 inches to about 0.02 inches). The distance 308 between adjacent features 306 (e.g., the pitch of the repeating patterned features 306) may be from about 120 micrometers to about 750 micrometers (e.g., 0.005 inches to about 0.03 inches).

[0031] FIG. 3E illustrates an example of a controlled texture that includes repeating patterned features 350. The repeating patterned features 350 in FIG. 3E may be referred to as "wavy" features. FIG. 3E illustrates a portion of a cross section of a surface, such as bottom surface 222 in FIG. 3B or 3C, having repeating patterned features 350. For example, the repeating patterned features 350 may be texture 304 in FIG. 3B or texture 322 in FIG. 3C. For example, features 352 may correspond to textures 306, 310 in FIG. 3B or textures 324, 330 in FIG. 3C. The repeating patterned features 350 have regular features 352. These features 352 are troughs or cups formed on the surface (e.g., via machining or any other suitable method). In some embodiments, the repeating patterned features 350 are also roughened, so that they also include roughened features similar to those described with respect to FIG. 3D above (see also FIG. 3G, which illustrates an example of a combination of repeating patterned features and roughened textures). The width 354 of the repeating patterned feature 350 may be any suitable value. By way of example, the width 354 may be between about 0.1 millimeters and about 0.5 millimeters. The depth 356 of the feature 352 may be any suitable value. By way of example, the depth 356 may be between about 2 micrometers and about 100 micrometers.

[0032] 3F and 3G show another example of a controlled texture including repeating patterned features 360 and 370, respectively. The repeating patterned features 360 and 370 in FIG. 3F and 3G may be referred to as rounded ridge-like features. FIG. 3F and 3G show a portion of a cross section of a surface, such as bottom surface 222 in FIG. 3B or 3C, having repeating patterned features 360 and 370. For example, repeating patterned features 360 and 370 may be texture 304 in FIG. 3B or texture 322 in FIG. 3C. For example, feature 362 may correspond to features 306, 310 in FIG. 3B or features 324, 330 in FIG. 3C. Repeating patterned textures 360 and 370 have regular features 362. Regular features 362 are ridges formed on a surface (e.g., via injection molding or any other suitable method). The texture 370 of FIG. 3G may also be randomly roughened (e.g., as or similar to that described with respect to FIG. 3D above). The width 364 of the features 362 may be any suitable value. By way of example, the width 364 may be between about 0.1 millimeters and about 0.5 millimeters. The spacing 366 between adjacent features 362 may be any suitable value. By way of example, the spacing 366 may be between about 0.1 millimeters and about 0.5 millimeters. The spacing 366 may be the same as or different from the width 364. The height 368 of the features 362 may be any suitable value. By way of example, the height 368 may be between about 25 micrometers and about 500 micrometers.

[0033] Any second set of features 310 may be at an angle 314 (e.g., 20°-90°) relative to the first set of features 306. The second set of features 310 may be straight, curved, or any other suitable shape or design, such as those described with respect to Figures 3E-G above. For example, the angle 314 may be about 60°, or any suitable angle. The repeating patterned features 310 may have the same or different height / depth, width, and pitch 312 as described above with respect to features 306.

[0034] Still referring to FIG. 3B, the texture 320 may be any texture. For example, the texture 320 may be the same or similar roughened texture as described above with respect to FIG. 3A. In some cases, the texture 304 may include both repeating patterned features 306, 310 and a roughened texture (see, e.g., FIG. 3G). The example bottom surface 222 of FIG. 3B may be prepared using injection molding (see FIG. 5A), machining, and / or any other suitable process.

[0035] FIG. 3C illustrates another example of a controlled texture for the top surface 220 and / or bottom surface 222 of the window 202. The example surfaces 220, 222 include a controlled texture 322. The controlled texture 322 includes a cross-hatch pattern of repeating features 324 and 330. The features 324 and 330 may be the same as or similar to the features 306 and 310 described above (e.g., any of the example features described above shown in the patterned texture of FIGS. 3E-G). The features 324 and 330 may be straight or curved. The features 324, 330 may be machined into the surfaces 220, 222 and / or prepared using injection molding. The features 324 and 330 may have any suitable depth and / or height. By way of example, the depth / height of the features 324 and 330 may be from about 25 micrometers to about 500 micrometers (e.g., from about 0.001 inches to about 0.02 inches). The features 324 and 330 may have any suitable width. By way of example, the width of the features 324 and 330 may be between about 120 micrometers and about 750 micrometers (e.g., 0.005 inches and about 0.03 inches). The distance 326, 332 between adjacent features 324, 330 may be any suitable value. By way of example, the distance 326, 332 between adjacent features 324, 330 may be between about 120 micrometers and about 750 micrometers (e.g., 0.005 inches and about 0.03 inches). The first set of features 324 may be at an angle 328 (e.g., 45°) relative to the direction of the width of the window 202. The second channel set of features 330 may be at an angle 334 (about 90°) relative to the first set of features 324. The example surfaces 220, 222 of FIG. 3C may be prepared by machining (eg, CNC milling with ends of appropriate diameter, laser machining, or the like).

[0036] The patterned features shown in Figures 3A-G are merely examples. The window 202 may generally include any combination of the surfaces 220, 222 and / or textures 302, 304, 320, 322, 340, 350, 360, 370 described above with respect to Figures 3A-G. For example, the top surface 220 may have the roughened texture 302 of Figure 3A and / or the repeating patterned texture 322 of Figure 3C. Meanwhile, the bottom surface 222 may include the patterned texture 304 of Figure 3B or the patterned texture 322 of Figure 3C. The present disclosure contemplates the use of any other patterned features and textures suitable for facilitating reliable preparation of the window 202 with consistent light transmission properties and long lifespan for monitoring the CMP process. For example, the bottom surface 222 may include one or more of a wavy texture or the like.

[0037] The depth of the machined and / or injection molded features (see Figures 3B, 3C, 3E, 3F, and 3G) may be adjusted to improve optical transmission properties for improved monitoring of the CMP process (e.g., for end-point detection). For example, the machining cut depth to obtain the cross-hatch feature of Figure 3C may be adjusted to obtain a desired optical transmission at a given wavelength and / or to obtain a desired ISRM as described in connection with Figure 1C above. max-min The depth / height of the features may be adjusted to provide a characteristic value. In some embodiments, the depth / height of the features is selected such that the light transmission characteristics of the window 202 remain relatively constant even if a portion of the surface of the window 202 is removed during the CMP process and / or the window 202 is deformed or moved during the CMP process. For example, it may be beneficial for the cut depth used during machining to be greater than 120 micrometers (e.g., about 0.005 inches). In some embodiments, the cut depth used during machining (or the feature depth prepared using injection molding) may be between about 25 micrometers and about 75 micrometers (e.g., 0.001 inches to 0.003 inches). In some cases, the cut depth along the machined surfaces 220, 222 allows for further control of the light transmission through the window 202.

[0038] In some embodiments, separate pieces may be prepared such that one piece includes the top surface 220 and another piece includes the bottom surface 222. FIG. 4 illustrates an embodiment in which a first piece 402 including the top surface 220 is placed on a second piece 404 including the bottom surface 222 to form the window 202. Pieces 402 and 404 may be attached using an adhesive (e.g., a pressure sensitive adhesive). In some cases, the window 202 may be formed by chemically bonding pieces 402 and 404 together (e.g., in the presence of heat and / or an appropriate adhesion promoter). The window 202 may be placed in or over an aperture in the pad 200 with or without an adhesive such that light passing through the aperture also passes through the window 202. In some embodiments, the window 202 is chemically bonded to the CMP pad 200.

[0039] Example of a mold for an injection molded window 5A and 5B show example molds 502 and 510 used in an injection molding apparatus 500 to prepare surfaces 222 and 220, respectively. Mold 502 for preparing bottom surface 222 includes inverse representations of textures 304, 320 described above in conjunction with FIG. 3B. Region 504 of mold 502 corresponds to the region of bottom surface 222 in FIG. 3B having texture 304. Region 506 corresponds to the region of bottom surface 222 in FIG. 3B having texture 320. Mold 502 may include ejector pins to aid in removal of the formed piece from apparatus 500. Mold 510 for preparing top surface 220 of window 202 includes inverse representations of surface 220 described above in conjunction with FIG. 3A. Mold 510 may be bead blasted to obtain an appropriate roughened texture (e.g., random roughened texture 340 of FIG. 3D for texture 320, or repeating patterned textures 350, 360, 370 of FIGS. 3E-G for texture 304). During injection molding, a single piece may be formed, with both a top and bottom surface on opposite sides of the piece, or separate pieces may be prepared and combined as described above in connection with FIG. 4 and below in connection with FIG. 8.

[0040] Optical transmittance through different windows for CMP pads. 6A and 6B show plots 600 and 610 of the transmittance of various wavelengths of light through different windows. These windows include various control windows employing the prior art (Controls 1-4 and Controls A-B), samples with a single randomly textured surface (Single Textures 1-6 and Single Textures A-C), and the novel technology disclosed herein having a controlled texture including repeating patterned features on at least the bottom surface (Samples 1-4 and Samples A-E). Percent transmittance was measured using a Thermo-Fisher Genesys 10s UV-Vis spectrophotometer at 633 nm. As noted above, the present disclosure recognizes that the transmittance of light through the window 202 should fall within a threshold range 602 that ensures that the signal reaching the detector 114 (see FIG. 1B) is suitable for reliable monitoring of the CMP process. The threshold range 602 may be less than 20%. In some cases, the threshold range may be between 5% and 15% at about 630 nm. For different applications, different threshold ranges may be selected (e.g., depending on the characteristics of the detector 114 (see FIG. 1A) used for in-situ speed monitoring / endpoint detection) and the textures of the top surface 220 and bottom surface 222 may be adjusted accordingly.

[0041] As also recognized herein, a consistently low characteristic ISRM that does not change significantly over the life of the CMP pad. max-min It is important to have a consistent ISRM of 0.1% over the life of the CMP pad. This cannot be achieved by simply reaching the target transmittance range, but also requires further improved properties of the CMP window. For example, at least some of the control windows shown in Figures 6A and 6B exhibit optical transmittance at the target transmittance. However, these control windows employing prior art techniques exhibit consistently low ISRM over the life of the CMP pad, as further explained in connection with Figure 6C and Table 1 below. max-min Attribute values ​​cannot be provided.

[0042] FIG. 6C shows the ISRM of conventionally available CMP windows (Control 1 and 2) and two CMP windows with repeating patterned textures of the present disclosure (New Windows 1 and 2). max-min After CMP pad break-in (e.g., after conditioning as described above in connection with FIG. 1A), the novel window has a lower ISRM than the control window. max-min At or near the end of pad life (e.g., after the CMP pad is no longer usable for the CMP process, e.g., after the top layer of the pad has been completely removed and / or after about 0.5 millimeters of the top surface of the CMP pad and / or CMP window have been removed), the control window exhibits a significantly increased ISRM. max-min The end of pad life can be defined as when the pad wear is such that 20% of the initial groove depth remains. max-min The characteristic value increases by about 190% (i.e., from 0.75 to 1.105). max-min The characteristic value increases by about 160% (i.e., from 0.75 to 1.955). In contrast, the ISRM of the new window max-min The characteristic value does not increase significantly from the break-in period to the end of pad life. New Window 1 ISRM max-min The characteristic value increases by about 5% (i.e., from 0.275 to 0.29). ISRM of new window 1 max-min The characteristic value increases by about 90% (i.e., from 0.15 to 0.21). max-min The property values ​​also remain within a target range of less than 0.5% (or less) throughout the life of the pad.

[0043] The novel window samples with controlled texture described in this disclosure (samples 1-4 and A-D in Figures 6A and 6B, and novel windows 1 and 2 in Figure 6C) not only have percent transmission values ​​within this threshold range 602, but also have repeating patterned features (see, e.g., Figures 3A-G and corresponding description above). These samples exhibit more reliable and reproducible transmission characteristics and ISRM than can be achieved using conventional techniques. max-minThus, the novel window samples described in this disclosure perform better than conventional windows for CMP pads and can be prepared using a more reliable and cost-effective process (see Figures 7-9).

[0044] Method for preparing textured surfaces and textured windows for CMP pads FIG. 7 illustrates a process 700 for preparing a window 202. The process 700 generally facilitates the preparation of a window 202 having improved light transmission properties and a longer life span. The process 700 may begin at step 702. In step 702, a first textured surface 220 is prepared. The first textured surface 220 may be prepared using injection molding and / or any suitable machining process (e.g., CNC machining with an end mill, laser machining, or the like). For example, an uncured thermosetting material may be introduced into an injection molding machine and contacted with a mold (e.g., mold 510 of FIG. 5B) to prepare the first textured surface 220. In some embodiments, a piece may be obtained (e.g., a commercially available transparent piece may be obtained), and one side of the piece may be machined or treated with an adhesive to prepare the first textured surface 220.

[0045] In step 704, second surface 222 is prepared on the opposite side of the piece from step 702. If injection molding was used to prepare first textured surface 220 in step 702, second textured surface 222 may be prepared during the same injection molding process (e.g., using mold 502 of FIG. 5A as a mold for second textured surface 222). As another example, second textured surface 222 may be prepared using any suitable machining process.

[0046] In step 706, the window 202 from step 704 is placed in or over an aperture in the CMP pad 200 such that light passing through the aperture also passes through the window 202. The window 202 may be attached to the CMP pad 200 using an adhesive (e.g., a pressure sensitive adhesive) or without an adhesive (e.g., using ultrasonic welding or any other suitable technique). For example, the window 202 may be attached to a top pad portion or a subpad portion of the CMP pad 200 using an adhesive or via welding. In some embodiments, the window 202 is chemically bonded to the CMP pad 200 (e.g., in the presence of heat and / or a suitable adhesion promoter).

[0047] As an example of the attachment of a window of the present invention to a polishing pad, the following procedure may be used: A recess or pocket may be formed in the top pad using CNC or similar methods. The dimensions of the recess will match the dimensions of the window to be assembled. The dimensions of the recess are thus variable, but the recess does not extend the entire thickness of the top pad. In other words, the recess does not form an aperture through the top pad. A subpad is then laminated or glued to the top pad. A hole is then drilled through the top pad and subpad at the recess, such that the dimensions of the hole are such that a ledge is formed by the remaining top pad material and the underlying subpad material. A window is then assembled into the recess on top of the hole, forming an optical detection port, or window, in the pad. This shows one embodiment of assembling a window according to the present invention into a polishing pad.

[0048] FIG. 8 illustrates an example process 800 for preparing a window 202 by combining a first piece (e.g., piece 402 of FIG. 4) having a first textured surface 220 with a second piece (e.g., piece 404 of FIG. 4) having a second textured surface 222. The process 800 generally facilitates the preparation of a window 202 having improved light transmission properties and a longer lifespan. The process 800 may begin at step 802, in which a first window piece (e.g., piece 402 of FIG. 4) having a first textured surface 220 is prepared. The first piece may be prepared using injection molding and / or any suitable machining (e.g., CNC machining with an end mill). For example, an uncured thermosetting material may be introduced into an injection molding machine and contacted with a mold (e.g., mold 510 of FIG. 5B) to prepare the first piece using injection molding. The piece may be further machined to create any additional desired texture features. The first piece may be prepared using injection molding and / or machining using method 900, described below in relation to Figure 9. In some embodiments, a piece may be obtained (e.g., a commercially available transparent piece may be obtained) and the first textured surface 220 may be prepared by machining the piece.

[0049] In step 804, a second window piece (e.g., piece 404 of FIG. 4) is prepared having a second textured surface 222. The second window piece having the second textured surface 222 may be prepared using the same or similar approach as described above with respect to preparing the first window piece having the first textured surface 220 in step 802. The second piece may be prepared using injection molding and / or any suitable machining (e.g., CNC machining with an end mill). For example, an uncured thermosetting material may be introduced into an injection molding machine and contacted with a mold (e.g., mold 502 of FIG. 5A) to prepare the second piece using injection molding. The second piece may be further machined to create any additional desired texture features on the second textured surface 222. The second piece may be prepared using injection molding and / or machining using a method 900 described below in connection with FIG. 9. In some embodiments, a piece may be obtained (eg, a commercially available transparent piece may be obtained) and the second textured surface 222 may be prepared by machining the piece.

[0050] In step 806, a first piece having a first textured surface 220 is placed over (e.g., attached to) a second piece having a second textured surface 222. The two pieces are generally assembled such that the first side 220 is exposed and faces a first direction (e.g., toward the top of the window 202) and the second side 222 is exposed and faces a second direction opposite the first direction (e.g., toward the bottom of the window 202). The first and second pieces may be attached with or without an adhesive (e.g., a pressure sensitive adhesive) to form the window 202. In some cases, the window 202 may be formed by chemically bonding the first and second pieces (e.g., in the presence of heat and / or an appropriate adhesion promoter).

[0051] In step 808, the window 202 from step 806 is placed in or over an aperture in the CMP pad 200 such that light passing through the aperture also passes through the window 202. The window 202 may be attached to the CMP pad 200 using an adhesive (e.g., a pressure sensitive adhesive) or without an adhesive (e.g., using ultrasonic welding or any other suitable technique). For example, the window 202 may be attached to a top pad portion or a subpad portion of the CMP pad 200 using an adhesive or via welding. In some embodiments, the window 202 is chemically bonded to the CMP pad 200 (e.g., in the presence of heat and / or a suitable adhesion promoter).

[0052] FIG. 9 illustrates an example of a method 900 for preparing a controlled textured surface (e.g., surface 220, 222). Method 900 may begin at step 902. In step 902, a piece having a textured surface 220, 222 (e.g., piece 402, 404 in FIG. 4) may be prepared by performing injection molding. For example, an uncured thermosetting material may be introduced into an injection molding machine and contacted with a mold (e.g., mold 502, 510 in FIG. 5A, 5B) to prepare a piece using injection molding. In step 904, it is determined whether the textured surface 220, 222 of the piece should have additional texture features, such as one of the patterned features shown in FIG. 3A, 3B, 3C, or the like. If no additional features are required, process 900 is complete. On the other hand, if additional features are required, the additional features are machined (e.g., using CNC machining with an end mill) in step 906. EXAMPLES

[0053] Working Example This example demonstrates the performance of a window according to the present invention compared to a window that does not have a controlled texture containing repeating patterned features (repeating patterned texture).

[0054] The performance of the four different windows was measured after a break-in period and again at the end of the pad life.max-min The pad life was evaluated using the change in the characteristic value. The end of pad life was defined as the wear of the pad such that 20% of the initial groove depth remained. The four windows were A) IC1010 pad with a window that is a hard thermosetting polyurethane with a hardness of about 70 Shore D commercially available from Rohm and Haas Electronic Materials, B) E6088 pad with a soft thermoplastic polyurethane with a hardness of about 55 Shore D commercially available from CMC Materials Inc., C) E6088 pad with a window according to the present invention with a controlled repeating pattern texture formed from CNC machining, which is a thermoplastic polyurethane with a hardness of about 75 Shore D, and D) E6088 pad with a window according to the present invention with a controlled repeating pattern texture formed from injection molding, which is a thermoplastic polyurethane with a hardness of about 75 Shore D. Windows A) and B) did not have a controlled textured surface with repeating patterned features.

[0055] All of the pads were given the same break-in period, which included conditioning with deionized water for 30 minutes using a 3M A2813 conditioner at 5 lbs down force. After the break-in period, the ISRM was polished under the same conditions for each of the windows while polishing a copper wafer using copper CMP polishing slurry at 2.5 psi down force and 80 rpm platen speed. max-min The characteristic values ​​were measured. Endpoint detection began approximately 20 seconds after the start of polishing, and the recording consisted of approximately 60 traces. ISRM for the four windows. max-min The characteristic values ​​were calculated and are shown in the table below. Second ISRM at the end of pad life max-min The properties were measured on the same pad. ISRM max-min The properties were recalculated and are shown in Table 1 below. [Table 1]

[0056] As can be seen in the table above, ISRM from the break-in period to the end of pad lifemax-min The change in was significantly different for the windows according to the invention compared to the commercial pad windows.

[0057] Modifications, additions, or omissions may be made to the systems, devices, and methods described herein. System and device components may be integrated or separated. Furthermore, system and device operations may be performed by more, fewer, or other components. Methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. Additionally, system and device operations may be implemented using any suitable logic. As used herein, "each" means each member of a set, or each member of a subset of a set.

[0058] As used herein, "or" is inclusive and not exclusive, unless expressly indicated otherwise or the context indicates otherwise. Thus, as used herein, "A or B" means "A, B, or both," unless expressly indicated otherwise or the context indicates otherwise. Furthermore, "and" is jointly and severally, unless expressly indicated otherwise or the context indicates otherwise. Thus, as used herein, "A and B" means "A and B, jointly or severally."

[0059] The scope of the present disclosure includes all changes, substitutions, changes, modifications, and alterations to the embodiments described and illustrated herein that are apparent to one of ordinary skill in the art. The scope of the present disclosure is not limited to the embodiments described or illustrated herein. Furthermore, although the present disclosure describes and illustrates each embodiment herein as including specific components, elements, features, functions, operations, or steps, any of these embodiments may include any combination or substitution apparent to one of ordinary skill in the art of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein. Furthermore, in the appended claims, references to an apparatus or system, or a component part of an apparatus or system, being configured, arranged, capable, formed, enabled, operable, or operates to perform a particular function include the apparatus, system, or component, so long as the apparatus, system, or component is so configured, arranged, capable, formed, enabled, operable, or operates, regardless of whether the apparatus, system, component, or its particular function is activated, turned on, or unlocked. In addition, although the present disclosure may describe or illustrate particular embodiments as providing certain advantages, a particular embodiment may provide none, some, or all of these advantages.

[0060] The use of the terms "a," "an," and "the," and similar referents in the context of describing the present invention (particularly in the context of the claims below) should be construed to cover both the singular and the plural, unless otherwise indicated or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each separate value contained within the range, unless otherwise indicated, and each separate value is incorporated herein as if it were individually set forth herein. Any and all examples provided herein, or the use of example language (e.g., "such as"), are merely intended to better illustrate the present invention and do not limit the scope of the claims. The present invention can be embodied in the following manner. (Appendix 1) 1. A window for a chemical mechanical planarization (CMP) pad, the window comprising an optically transparent material, and a first side of the window having a controlled texture surface including repeating patterned features. (Appendix 2) 2. The window of claim 1, wherein the first surface corresponds to a bottom surface of the CMP pad that does not contact a substrate being planarized during a CMP process using the CMP pad. (Appendix 3) 2. The window of claim 1, wherein the repeating patterned features are configured to diffuse light passing through the window. (Appendix 4) 2. The window of claim 1, wherein the repeating patterned features include regularly spaced raised features. (Appendix 5) 5. The window of claim 4, wherein the repeating patterned feature comprises a crosshatch pattern. (Appendix 6) 5. The window of claim 4, wherein the repeating patterned features comprise rounded ridges. (Appendix 7) 7. The window of claim 6, wherein the rounded ridges are randomly roughened. (Appendix 8) 3. The window of claim 2, wherein a second surface opposite the first surface corresponds to a top surface, the top surface being capable of contacting a substrate to be planarized during a CMP process using the CMP pad, the top surface having a roughened texture corresponding to an average surface roughness of about 1 to about 50 micrometers. (Appendix 9) the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced raised features parallel to the width of the window; a second set of regularly spaced raised lines that are at a predetermined angle to the first set of regularly spaced raised features; and Including, A window as described in Appendix 1. (Appendix 10) the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced features in the first plane that are at a first angle relative to a width direction of the window; a second set of regularly spaced features in the first plane that are at a second angle to the first set of lines; and wherein the first angle is different from the second angle. A window as described in Appendix 1. (Appendix 11) 1. A chemical mechanical planarization (CMP) pad, comprising: an upper surface that contacts a substrate to be planarized during a CMP process using said CMP pad; a bottom surface opposite to the top surface; a window that allows light to pass between an upper side of a CMP pad associated with the top surface and a bottom side of the CMP pad associated with the bottom surface, the window comprising an optically transparent material, and a first side of the window having repeating patterned features; A chemical mechanical planarization (CMP) pad. (Appendix 12) 12. The CMP pad of claim 11, wherein a first side of the window faces in the same direction as a bottom side of the CMP pad, which does not contact a substrate being planarized during a CMP process using the CMP pad. (Appendix 13) 12. The CMP pad of claim 11, wherein the repeating patterned features are formed to diffuse light passing through the window. (Appendix 14) 12. The CMP pad of claim 11, wherein the repeating patterned features include regularly spaced raised features. (Appendix 15) 12. The CMP pad of claim 11, wherein the repeating patterned features comprise a crosshatch pattern. (Appendix 16) 12. The CMP pad of claim 11, wherein the repeating patterned features include rounded ridges. (Appendix 17) 17. The CMP pad of claim 16, wherein the rounded ridges are randomly roughened. (Appendix 18) 12. The CMP pad of claim 11, wherein a second surface opposite the first surface corresponds to a top surface, the top surface being capable of contacting a substrate to be planarized during a CMP process using the CMP pad, the top surface having a roughened texture corresponding to an average surface roughness of about 1 to about 50 micrometers. (Appendix 19) the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced raised features parallel to the width of the window; a second set of regularly spaced raised lines that are at a predetermined angle to the first set of regularly spaced raised features; and Including, 12. The CMP pad of claim 11. (Appendix 20) the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced features in the first plane that are at a first angle relative to a width direction of the window; a second set of regularly spaced features in the first plane that are at a second angle to the first set of lines; and wherein the first angle is different from the second angle. 12. The CMP pad of claim 11.

Claims

1. 1. A window for a chemical mechanical planarization (CMP) pad, the window comprising an optically transparent material, a first side of the window having a controlled texture surface comprising repeating patterned features, the repeating patterned features comprising rounded ridges, the rounded ridges being randomly roughened.

2. The window of claim 1 , wherein the first surface corresponds to a bottom surface of the CMP pad that does not contact a substrate being planarized during a CMP process using the CMP pad.

3. The window of claim 1 , wherein the repeating patterned features are configured to diffuse light passing through the window.

4. The window of claim 1 , wherein the repeating patterned features comprise regularly spaced raised features.

5. The window of claim 4 , wherein the repeating patterned features comprise a crosshatch pattern.

6. 3. The window of claim 2, wherein a second side opposite the first side corresponds to a top surface, the top surface capable of contacting a substrate to be planarized during a CMP process using the CMP pad, the top surface having a roughened texture corresponding to an average surface roughness of about 1 to about 50 micrometers.

7. the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced raised features parallel to the width of the window; a second set of regularly spaced raised lines that are at a predetermined angle to the first set of regularly spaced raised features; and Including, The window of claim 1 .

8. the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced features in the first plane that are at a first angle relative to a direction of the window width; a second set of regularly spaced features in the first plane that are at a second angle to the first set of lines; and wherein the first angle is different from the second angle. The window of claim 1 .

9. 1. A chemical mechanical planarization (CMP) pad, comprising: an upper surface that contacts a substrate to be planarized during a CMP process using said CMP pad; a bottom surface opposite the top surface; a window that allows light to pass between an upper side of a CMP pad associated with the top surface and a bottom side of the CMP pad associated with the bottom surface, the window comprising an optically transparent material, and a first surface of the window having repeating patterned features; Including, A chemical mechanical planarization (CMP) pad, wherein the repeating patterned features include rounded ridges, the rounded ridges being randomly roughened.

10. 10. The CMP pad of claim 9, wherein a first side of the window faces in the same direction as a bottom side of the CMP pad that does not contact a substrate being planarized during a CMP process using the CMP pad.

11. The CMP pad of claim 9 , wherein the repeating patterned features are formed to diffuse light passing through the window.

12. The CMP pad of claim 9 , wherein the repeating patterned features include regularly spaced raised features.

13. The CMP pad of claim 9 , wherein the repeating patterned features comprise a cross-hatch pattern.

14. 10. The CMP pad of claim 9, wherein a second surface opposite the first surface corresponds to a top surface, the top surface being capable of contacting a substrate to be planarized during a CMP process using the CMP pad, the top surface having a roughened texture corresponding to an average surface roughness of about 1 to about 50 micrometers.

15. the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced raised features parallel to the width of the window; a second set of regularly spaced raised lines that are at a predetermined angle to the first set of regularly spaced raised features; and Including, 10. The CMP pad of claim 9.

16. the window has a width and a length that is less than the width, the width and length characterizing physical dimensions of the window; and The repeating patterned features include: a first set of regularly spaced features in the first plane that are at a first angle relative to a direction of the window width; a second set of regularly spaced features in the first plane that are at a second angle to the first set of lines; and wherein the first angle is different from the second angle.

10. The CMP pad of claim 9.

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