JP2016517185A - Apparatus and method for acoustic monitoring and control of Si through electrode exposure process - Google Patents

Abstract

To detect and automatically react to TSV breakage, the TSV (Si through electrode) exposure process using CMP (Chemical Mechanical Polishing) can be acoustically monitored and controlled. The acoustic emission received by one or more acoustic sensors located proximate to the substrate holder and / or polishing pad of the CMP system can be analyzed to detect TSV breakage during the CMP process. In response to detecting a TSV failure, one or more corrective actions can automatically occur. In some embodiments, the polishing pad platen may have one or more acoustic sensors incorporated into the polishing pad platen that extend into a polishing pad that is mounted on the polishing pad platen. As with other aspects, a method for monitoring and controlling the TSV exposure process is further provided. [Selection] Figure 5

Description

Related Application [0001] This application is entitled “APPARATUS AND METHODS FOR ACOUSTIC MONITORING AND CONTROL OF THROUGH-SILICON-VIA REVEAL PROCESSING” (Attorney Docket No. 20654) filed on May 1, 2013. Priority is claimed from provisional patent application No. 13 / 874,495, which is incorporated herein by reference in its entirety for all purposes.

  [0002] The present invention relates generally to semiconductor device fabrication, and more specifically to backside chemical mechanical polishing of TSVs (Si through electrodes).

  [0003] Chemical mechanical polishing (CMP), also known as chemical mechanical planarization, is a process commonly used in the manufacture of integrated circuits (ICs) on semiconductor substrates. The CMP process can remove morphological features and materials from the partially processed substrate and produce a flat surface for subsequent processing. In a CMP process, an abrasive and / or a chemically active polishing solution may be used on one or more rotating polishing pads that are pressed against the surface of the substrate. The substrate can be held in a substrate holder that rotates the substrate. The substrate holder can further vibrate the substrate back and forth across the surface of the rotating polishing pad.

  [0004] In the manufacture of ICs, 3D packaging can be used to improve circuit function and / or performance in a compact footprint. Three-dimensional packaging may involve interconnecting alternately stacked IC chips using TSVs (Si through electrodes) to electrically connect the stacked IC chips. TSV is a vertical conductor that extends through the substrate. To access the TSV from the backside of the substrate (for the purpose of subsequent electrical connection to another IC below), CMP can be used in a TSV exposure process. The TSV exposure process may include polishing and etching the backside of the substrate to expose the TSV as a stub protruding from the backside surface. A dielectric film can then be deposited on the backside surface. Using CMP, the protruding stubs can be removed and the backside surface can be polished to achieve the desired thickness of the dielectric film, completing the TSV exposure process. However, TSV failure (ie, failure of one or more stubs) may occur, which may destroy the substrate. Therefore, improvement of TSV exposure processing is desired.

  [0005] According to one aspect, a platen for a chemical mechanical polishing (CMP) apparatus is provided. The platen is configured to receive a polishing pad on the surface, has a disk-shaped base having at least one through hole, and is received in the at least one through hole and protrudes from the surface of the disk-shaped base. An acoustic sensor comprising an acoustic sensor configured to be electrically coupled to a controller.

  [0006] According to another aspect, a chemical mechanical polishing (CMP) apparatus configured to perform a CMP process is provided. The CMP apparatus comprises a platen with a polishing pad, a substrate holder configured to hold a substrate to be polished, and the platen or substrate holder is configured to bring the substrate and polishing pad into contact with each other during the CMP process. An acoustic sensor positioned proximate to the polishing pad or substrate and one or more signals electrically coupled to the acoustic sensor and received from the acoustic sensor to detect TSV (Si through electrode) breakage An acoustic processor configured to analyze

  [0007] According to a further aspect, a method for monitoring and controlling a TSV (Si through electrode) exposure process is provided. The method includes processing the substrate using a chemical mechanical polishing (CMP) process, sensing the acoustic emission of the CMP process, and analyzing the acoustic emission to detect TSV failure.

  [0008] Still other aspects, features, and advantages of the present invention can be readily apparent from the following detailed description, including a number of illustrative examples, including the best mode contemplated for carrying out the invention. Various embodiments and implementations are described and illustrated. The invention may further include other embodiments and different embodiments, some of which may be modified in various aspects, all without departing from the scope of the invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not as restrictive. The drawings are not necessarily to scale. The present invention includes all modifications, equivalents, and alternatives falling within the scope of the invention.

[0009] The drawings described below are for illustrative purposes only. The drawings are in no way intended to limit the scope of the invention.
FIG. 2 shows a continuous cross-sectional view of a semiconductor substrate undergoing a TSV (Si through electrode) exposure process without TSV damage according to the prior art. Fig. 2 shows a TSV without damage according to prior art. FIG. 3 shows a cross-sectional view of a semiconductor substrate having TSV failure with TSV failure according to the prior art. Fig. 2 shows a TSV with breakage according to the prior art. 1 shows a schematic partial side view of a chemical mechanical polishing (CMP) system according to an embodiment. FIG. 4 shows a top view of a platen of a CMP system, according to an embodiment. FIG. 6B illustrates a cross-sectional side view (taken along line 6B-6B in FIG. 6A) of a CMP system platen and polishing pad, according to an embodiment. FIG. 4 shows a flow diagram of a method for monitoring and controlling a TSV exposure process according to an embodiment.

  [0017] Reference will now be made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

  [0018] In one aspect, a TSV (Si through electrode) exposure process using CMP (Chemical Mechanical Polishing) is acoustically monitored and controlled to detect and automatically respond to TSV breakage. May be. In some IC manufacturing processes, TSV failure may occur more frequently during CMP, and the TSV aspect ratio (ie, the height of the exposed TSV stub relative to the TSV diameter) is high (eg, small diameter). TSV). High aspect ratio TSVs may allow ICs to have higher density chip-to-chip interconnects. However, high aspect ratio TSVs may be less rigid and, as a result, are more susceptible to breakage during the CMP process that removes exposed TSV stubs from the backside surface of the substrate.

  [0019] One or more acoustic sensors may be positioned within the CMP system and receive acoustic emissions during the CMP process. The one or more acoustic sensors may be coupled to, for example, a substrate holder and / or a polishing pad platen. In some embodiments, the polishing pad platen may have one or more acoustic sensors that are incorporated therein and extend into the polishing pad that is mounted on the polishing pad platen.

  [0020] In some embodiments, acoustic emissions received by one or more acoustic sensors can be analyzed by a system controller and / or an acoustic processor to detect TSV corruption. The acoustic processor may be part of the CMP system controller, or alternatively, a separate stand-alone component coupled to the CMP system controller. In response to detecting a TSV failure, the system controller and / or the acoustic processor may automatically initiate one or more corrective actions. For example, in some embodiments, the operator can be notified of TSV corruption. Additionally or alternatively, the CMP process can be preprogrammed in the system controller and / or acoustic processor, for example, by reducing the pressing force of the substrate or polishing pad relative to the other by a predetermined amount. May be automatically corrected by reducing the rotational speed of the polishing pad and / or substrate by a predetermined amount, and / or a combination of both. In some embodiments, the CMP process may be automatically stopped and / or transferred to a system controller endpoint routine in response to detecting a TSV failure.

  [0021] In another aspect, a method for monitoring and controlling a TSV exposure process is provided, as described in more detail below in connection with FIGS. 1A-7.

  [0022] FIGS. 1A-1C illustrate a substrate 100 undergoing a TSV exposure process, which may be referred to as a BVR (backside via Reveal) CMP process, according to the prior art. FIG. 1A shows a substrate 100 having a backside surface 102A that has been partially processed by a TSV exposure process. The substrate 100 includes a silicon base layer 104, a metal (eg, copper) layer 105, a plurality of TSVs 108 extending from the metal base layer 106 and projecting beyond the silicon base layer 104, a barrier layer 110 covering the TSV 108 and the metal layer 106, and A dielectric layer 112 covering the back surface 102A may be provided. In some manufacturing processes, the TSV 108 may have a height H above the silicon base layer 104 that can range from about 2 μm to about 4 μm, which can vary from TSV 108 to TSV 108. The substrate 100 having the backside surface 102A may be received in a CMP system for further TSV exposure processing shown in FIGS. 1B and 1C.

  [0023] FIG. 1B shows a substrate 100 having a further processed backside surface 102B, where the dielectric layer 112 and the barrier layer 110 may have been removed from the top surface 109 of the TSV 108 by a CMP process. The CMP process removes material from the backside surface 102B of the substrate 100 and / or removes the backside surface 102B of the substrate 100 until the backside surface 102C of FIG. Polishing may continue. As shown in FIG. 1C, the TSV 108 may be flush with the surface 113 of the dielectric layer 112, or, in some manufacturing processes, until the desired thickness of the dielectric layer 112 is obtained. May be slightly lower. As shown, several copper dishings 111 can occur on the end face of the TSV 108. A final soft buff may be provided, which controls the surface finish and removes small scratches and defects on the surface. If TSV damage has not occurred, the final surface condition of the substrate 100 may appear as shown in FIG. 1C when the TSV exposure process is complete.

  [0024] FIG. 2 shows a photomicrograph of a substrate 200 having a TSV 208 and surrounding backside substrate surface 202 when the TSV exposure process is complete without TSV failure.

  [0025] FIG. 3 shows a substrate 300 having a treated backside surface 302 with TSV failure, according to the prior art. TSV failure may result in non-reworkable scratches and / or scratches across the surface of the substrate, which can adversely affect IC chip yield and reliability. The substrate 300 may include a silicon base layer 304, a metal (eg, copper) layer 306, TSVs 308a and 308b, a barrier layer 110, and a dielectric layer 312. The TSV 308b may have broken during the CMP process. This damage may cause oxide gouging 315 that may expose the silicon base layer 304 to metal contamination during processing. In some embodiments, the TSV 308b may be formed of copper, which is a relatively soft material, for example. Copper contamination on the silicon base layer 304 caused by TSV failure may potentially affect IC quality and / or reliability during post-packaging electrical testing.

  [0026] FIG. 4 shows a photomicrograph of a substrate 400 having TSV 408 and surrounding backside substrate surface 402 after TSV failure has occurred. As shown, substantial scratches and flaws on the surface may occur after TSV 408 failure during the CMP process. In addition, metal particles that may have been pulled due to TSV failure may cause, for example, metal pad 414 (ie, the top surface of TSV 408) to fail to meet one or more specifications required for further processing. This may further affect IC yield and / or reliability.

  [0027] FIG. 5 illustrates a chemical mechanical polishing (CMP) system 500 according to one or more embodiments. The CMP system 500 may be configured to hold the substrate 501 in contact with the polishing pad 516 and may be used to perform a CMP process on the substrate 501 as part of the TSV exposure process. Substrate 501 may be a silicon-containing wafer, such as a patterned wafer including partially or fully formed transistors and a plurality of TSVs formed therein. The substrate 501 may be attached (eg, via an adhesive) to a second carrier wafer or other suitable backing so that the TSV exposure process can be performed on the substrate 501. The polishing pad 516 may be mounted on a platen 518, which may be disk-shaped and is rotated by a suitable motor (not shown) coupled to the platen 518 by a shaft 520. The platen 518 may rotate between about 10-200 rpm. Other rotational speeds may be used.

  [0028] The substrate 501 may be held in a substrate holder 522. The substrate holder can further be referred to as a retainer or carrier head. In some embodiments, the substrate 501 may be held on the substrate holder 522 via a vacuum. Other suitable substrate holding techniques may be used. In some embodiments, the substrate holder 522 may be configured to move the substrate 501 in contact with and away from the polishing pad 516 (ie, up and down as shown). Good. The substrate holder 522 may be rotated and, in some embodiments, oscillated back and forth across the surface of the polishing pad 516 as the polishing pad 516 rotates in contact with the backside surface of the substrate 501. In some embodiments, the vibration speed of the substrate holder 522 may be between about 0.1 mm / second and 5 mm / second. Other vibration rates may be used. In some embodiments, the substrate holder 522 may be rotated between about 10-200 rpm. Other rotational speeds may be used. The vibration may occur between the central portion of the polishing pad 516 and the radial side. In some embodiments, the substrate holder 522 is manufactured by Applied Materials, Inc. of Santa Clara, California. It is also possible to use a 5-zone pressure head with a contour shape, which can be obtained from (Contour, 5-zone pressure head).

  [0029] In other embodiments, the positions of the polishing pad 516 / platen 518 and the substrate 501 / substrate holder 522 may be reversed. That is, the polishing pad 516 and platen 518 may be part of or attached to an overhead assembly or polishing head. The overhead assembly or polishing head is configured to move the polishing pad 516 upward and away from the backside surface of the substrate 501 held in the substrate holder 522.

  [0030] A slurry 524 (chemical polishing liquid) may be applied to the polishing pad 516 and inserted between the polishing pad 516 and the substrate 501 by the distributor 526. Distributor 526 may be coupled to slurry feeder 528 via one or more suitable conduits. A pump 530, a valve 532, or other liquid transport and transfer mechanism can supply a metered amount of slurry 524 to the surface of the polishing pad 516. In some embodiments, distributor 526 may apply slurry 524 onto the surface of polishing pad 516 in front of substrate 501 so that slurry 524 can be received in front of substrate 501; The polishing pad 516 can be pulled between the polishing pad 516 and the substrate 501 by the rotation of the polishing pad 516.

  [0031] In some embodiments, one or more components of the CMP system 500 are manufactured by Applied Materials, Inc. of Santa Clara, California. It may be equivalent to or based on the Reflexion® GT ™ CMP system.

  [0032] The CMP system 500 may further include one or more acoustic sensors 534a and / or 534b operable to sense acoustic emissions that occur during a CMP process performed on the substrate 501. In some embodiments, the CMP system 500 may include only one of the acoustic sensors 534a or 534b. In other embodiments, the CMP system 500 may include both acoustic sensors 534a and 534b. In yet other embodiments, the CMP system 500 may include more than one acoustic sensor and may be positioned at locations other than those shown for the acoustic sensors 534a and 534b.

  [0033] The acoustic sensors 534a and / or 534b may be positioned proximate to the polishing pad 516 and / or the substrate 501 during the CMP process. In some embodiments, the acoustic sensor 534a may be physically coupled to the platen 518 (or overhead polishing head) in any suitable manner. For example, the acoustic sensor 534a may be mounted in a bracket that is mechanically fastened to the platen 518. In some embodiments, the platen 518 may be an assembly that includes an upper platen and a lower platen (not shown) attached together. The upper platen may have a polishing pad 516 mounted thereon, and the acoustic sensor 534a may be incorporated into or attached to the upper platen, for example via a bracket or other suitable mechanism. Alternatively, it may be incorporated into or attached to the outer end of the lower platen, for example. In some embodiments, the bracket or other suitable mechanism may include a spring loaded mechanism that ensures that the acoustic sensor 534a always maintains contact with the polishing pad. In some embodiments, the bracket or other suitable mechanism may include a buffer pad, thereby reducing signal attenuation or degradation. The power and signal cables (which can be represented at least in part by the signal connection 536a) are, in some embodiments, routed through the platen 518 (or the lower platen of the platen assembly described above) to a high frequency (eg, about 1 MHz). ) May be connected to sensor 534a via an 8-terminal slip ring. In some embodiments, the acoustic sensor 534b may be physically coupled to the substrate holder 522 in any suitable manner in addition to or instead of the acoustic sensor 534a. For example, the acoustic sensor 534b may be mounted in a bracket that is mechanically fastened to the substrate holder 522. The acoustic sensors 534a and / or 534b may alternatively be located at other suitable locations relative to the substrate 501 and polishing pad 516. In some embodiments, the acoustic sensors 534a and / or 534b may include a platen 516, a substrate holder 522, and / or any other suitable component of the CMP system 500 (eg, described below in connection with FIGS. 6A and 6B). Platen 616) may be directly built into or incorporated.

  [0034] The acoustic sensors 534a and / or 534b are configured to detect TSV breakage based on acoustic emissions from the CMP process via wireless or wired signal connections 536a and / or 536b, respectively. It may be configured to be electrically coupled to the acoustic processor 538 and / or the system controller 540.

  [0035] The acoustic processor 538 may be part of the system controller 540 as shown, or a separate stand-alone component that may be electrically coupled to the system controller 540. The system controller 540 may include a processor 542 that can control the operation of the CMP system 500 including one or more CMP processes used for TSV exposure processing. In some embodiments, the system controller 540 may not be coupled to the acoustic processor 538 and / or may not include the acoustic processor 538; instead, the processor 542 may have the functionality of the acoustic processor 538 described herein. There is a case where it is further executed.

  [0036] The acoustic processor 538 may be configured to receive one or more signals representing acoustic emissions transmitted by the acoustic sensors 534a and / or 534b. The acoustic processor 538 may be configured to detect TSV corruption by analyzing one or more signals received from the acoustic sensors 534a and / or 534b. One or more signals received from the acoustic sensors 534a and / or 534b may have an amplitude that may vary over time (eg, representing acoustic emission intensity). The acoustic processor 538 may be configured to receive a time-varying signal and its amplitude may be compared against one or more thresholds and / or threshold bands. Signal amplitudes that exceed those thresholds or that are outside their threshold bands may indicate TSV corruption. In some embodiments, processing the received signal may include comparing a particular aspect or region of the received signal waveform to a preset threshold. The acoustic processor 538 may include appropriate signal filtering, amplification, conversion (eg, A / D conversion), and component processing, and may be configured to store data and one or more analytical values. A different memory may be included. Data and analysis values may be stored, for example, in any suitable storage medium (eg, RAM, ROM, or other memory) of the acoustic processor 538 and / or the system controller 540. One or more stored analysis values and data may be used to monitor and control one or more CMP processes associated with TSV failure detection.

  [0037] In some embodiments, frequency-based analysis may be used to process acoustic data. Using stationary signal analysis such as fast Fourier transform (FFT) or non-stationary signal analysis such as wavelet packet transform (WPT) by acquiring acoustic signals from acoustic sensors 534a and / or 534b at a high sampling rate It may be possible. WPT has received acoustic signals in two parts: a low frequency component that can generate an approximation of signal identity, and a high frequency component that can generate signal details. It may be decomposed. This decomposition may be repeated by successively decomposing successive approximations.

  [0038] In other embodiments, time-based analysis may be used to process acoustic data. For example, a simple square of an acoustic signal received from, for example, acoustic sensors 534a and / or 534b under the condition that the TSV corruption event possesses a sufficiently large signal spike with respect to the signal-to-noise ratio. The average square root (rms) may be monitored.

  [0039] The following setup procedure may be used in some embodiments to associate the received acoustic signal with a TSV corruption event. The first setting substrate having no protruding TSV stub can be subjected to a CMP process to generate basic acoustic signal data for normalization. A second setting substrate with a very high protruding TSV stub (eg, 15 μm long with 5 μm diameter) may undergo a CMP process. The second setting substrate may be inspected after processing of TSV breakage using, for example, optical inspection or scanning electron microscope. A comparison of the magnitudes of the recorded signals from the first setting board and the second setting board can be made. Any signal spikes that are visible with acoustic activity over the base signal during the steady state CMP process may be classified as a failure signal, which may then be used to correlate TSV failure events. .

  [0040] The acoustic processor 538 may automatically react to detection of TSV failure by initiating one or more corrective actions. Corrective actions may include notifying the operator, for example, by triggering an alarm, or displaying a warning or other type of message on a display device coupled to the system controller 540. Corrective action may additionally or alternatively include automatically stopping the CMP process in response to detecting TSV corruption. Corrective action may additionally or alternatively include automatically modifying one or more parameters of the CMP process in response to detection of TSV failure. For example, the acoustic processor 538 may automatically reduce the down force applied by the substrate holder 522 to the polishing pad 516 (or vice versa) and / or for TSV failure. Responsive to detection, to automatically reduce the rotational speed of the substrate holder 522, the platen 518, or both, according to one or more programmed routines executed by the acoustic processor 538 or system controller 540. It may be configured. This may allow the CMP system 500 to continue to automatically process subsequent substrates using the modified processing parameters.

  [0041] FIGS. 6A and 6B illustrate an assembly 600 of polishing pad 616 and platen 618 that can be used in a CMP apparatus, such as, for example, CMP system 500, according to one or more embodiments. The platen 618 may include a disk shaped base 644 configured to receive a polishing pad 616 on a surface 617 of the disk shaped base 644. The disc-shaped base 644 may have one or more through holes 633a, 633b, and 633c. That is, in some embodiments, the disk-shaped base 644 has only one of the through holes 633a, 633b, and 633c, or only two or three of the through holes 633a, 633b, and 633c. The through holes 633a, 633b, and 633c described above may be provided.

  [0042] The platen 618 may further include one or more acoustic sensors 634a, 634b, and / or 634c that are received in the through holes 633a, 633b, and 633c, respectively. In some embodiments, the acoustic sensors 634a, 634b, and / or 634c may be friction fitted in the through holes 633a, 633b, and 633c, respectively. In other embodiments, the acoustic sensors 634a, 634b, and / or 634c may be physically coupled to the disc-shaped base 644 or integrally with the disc-shaped base 644 in any suitable manner. It may be formed. In some embodiments, the platen 618 may include through holes 633a, 633b, and 633c that do not have an acoustic sensor received therein.

  [0043] In some embodiments, the acoustic sensors 634a, 634b, and / or 634c can protrude from the surface 617 of the disc-shaped base 644 by a distance D1. The distance D1 may be selected to reduce acoustic signal attenuation. Acoustic signal attenuation may occur in some embodiments of the polishing pad 616, for example, in the polyurethane soft SUBA ™ portion. In some embodiments, the distance D1 may be about 50 mils (about 1.27 mm). This ensures that one or more of the acoustic sensors 634a, 634b, and / or 634c can be in close proximity to the polishing surface 621 of the polishing pad 616 while not being damaged during polishing.

  [0044] In some embodiments, the acoustic sensor 634a may be positioned approximately in the center of the platen 618. This center position ensures that the distance of the acoustic sensor 634a to the substrate being processed remains constant. The acoustic sensor 634b may be arranged at a distance D2 away from the center of the platen 618 in the radial direction, and the acoustic sensor 634c may be arranged at a distance D3 away from the center of the platen 618 in the radial direction. Good. In one or more embodiments, the distance D2 may be about 5 inches (about 12.7 centimeters) radially outward from the center of the platen 618 and the distance D3 is about radially outward from the center of the platen 618. It may be 10 inches (about 25.4 centimeters). In some embodiments, the distance D3 of about 10 inches (about 25.4 centimeters) is positioned so that the acoustic sensor 634c is closest to the substrate on each rotation path. In some embodiments, the received acoustic data is filtered out as the substrate leaves the acoustic sensor 634c during the CMP process. The distances D2 and / or D3 may alternatively have other suitable lengths.

  [0045] The acoustic sensors 634a, 634b, and / or 634c may be electrically coupled to a controller or acoustic processor, respectively, via a wired or wireless connection. In some embodiments, the acoustic sensors 634a, 634b, and / or 634c may include electrical connectors 646a, 646b, and / or 646c that are accessible under the platen 618 (ie, opposite the surface 617), respectively. Good.

  [0046] Referring to FIG. 6B, the polishing pad 616 may be mounted on a disk-shaped base 644 and includes one or more non-through holes 635a, 635b, and a base-side surface 619 of the polishing pad 616, and 635c may be included. The non-through holes 635a, 635b, and 635c may have a depth as much as the distance D1, and receive a protruding portion of each of the one or more acoustic sensors 634a, 634b, and / or 634c therein. It may be configured to. The number and position of the non-through holes 635a, 635b, and 635c may correspond to the number and position of the through holes 633a, 633b, and 633c of the platen 618, respectively. The polishing pad 616 is, for example, the same as or similar to the IC1000 ™ polishing pad comprising a SUBA ™ IV subpad in which one or more non-through holes 635a, 635b, and 635c are formed. May be.

  [0047] In some embodiments, any one or more acoustic sensors 534a, 534b, 634a, 634b, and / or 634c may be piezoelectric, transducer, and / or accelerometer type sensors. Well, each may have a high signal to noise ratio. The acoustic sensors 534a, 534b, 634a, 634b, and / or 634c may include a flat frequency response over a region of about 100-500 kHz in some embodiments. In some embodiments, any one or more acoustic sensors 534a, 534b, 634a, 634b, and / or 634c can amplify the acoustic signal with a gain of about 40-60 dB. The acoustic sensors 534a, 534b, 634a, 634b, and / or 634c may have a high pass filter having a region between about 50 Hz and 100 Hz in some embodiments. Any suitable acoustic sensor may be used for sensors 534a, 534b, 634a, 634b, and / or 634c.

  [0048] FIG. 7 illustrates a method 700 for monitoring and controlling a TSV exposure process, according to one or more embodiments. At process block 702, the method 700 may include processing the substrate using a CMP process. The CMP process may be part of the TSV exposure process. For example, referring to FIGS. 1A-1C and FIG. 5, a substrate 100 having a backside surface 102A may be received in a CMP system 500. As illustrated and described in connection with backside surfaces 102B and 102C, or 302, substrate 100 may be attached or attached to substrate holder 522 for CMP process and against polishing pad 516. And may be pressed.

  [0049] At process block 704, sensing the acoustic emission of the CMP process may occur. Referring to FIGS. 5, 6A, 6B, sensing of acoustic emission may be performed by any one or more of acoustic sensors 534a, 534b, 634a, 634b, and / or 634c. Acoustic emission is processed, for example, with a substrate such as substrate 100 having backside surface 102A of FIG. 1A or substrate 501 of FIG. 5 with a polishing pad 516 of FIG. 5 or a polishing pad such as polishing pad 616 of FIGS. 6A and 6B. Or from a CMP process. The acoustic sensors 534a, 534b, 634a, 634b, and / or 634c can sense acoustic emissions resulting from the processing of the substrate 100 or 501, and can represent electrical signals representing those acoustic emissions, for example, the system controller 540 and And / or to a controller, such as an acoustic processor 538, and / or an acoustic processor.

  [0050] At process block 706, the method 700 may include analyzing acoustic emissions to detect TSV failure. The acoustic emission analysis may include comparing one or more parameters (eg, amplitude) of the one or more received signals to one or more thresholds and / or threshold ranges. The one or more received signals may represent acoustic emission from the CMP process, and the one or more thresholds and / or threshold ranges may indicate whether TSV corruption has occurred during the CMP process. . The one or more thresholds and / or threshold ranges are the one or more baseline CMPs that are performed on the first setting board where the TSV is broken and the second setting board where the TSV is not broken. It may be predetermined during the process.

  [0051] If TSV corruption is detected at decision block 708, method 700 may proceed to process block 710. For example, in some embodiments, a high spike in the received acoustic signal may cause the method 700 to proceed to process block 710 according to a predefined algorithm. This algorithm may be part of a program running on the acoustic processor 538, or part of endpoint software running on the system controller 540, for example. If no TSV corruption is detected, the method 700 may proceed to decision block 712.

  [0052] At process block 710, the method 700 may include automatically responding to detection of TSV corruption. In some embodiments, this may include automatically notifying an operator who may be able to rework the currently processed substrate. In some embodiments, the method 700 includes, by way of example, automatically modifying the CMP process, additionally or alternatively, by reducing the push force, reducing the rotational speed, or both. , May respond to detection of TSV breakage. The method 700 may additionally or alternatively respond to detection of TSV corruption by automatically stopping the CMP process. This may occur by going directly to terminal block 714 (path shown with a dashed line) or, in some embodiments, going to decision block 712. A YES response may be triggered automatically, and as a result, the CMP process is effectively stopped. In other situations, the method 700 may proceed to decision block 712.

  [0053] At decision block 712, the method 700 may include determining whether an endpoint of the CMP process has been detected. Endpoint detection may be performed by a system controller of a CMP system, such as system controller 540 of CMP system 500, for example. In some embodiments, endpoint detection for the TSV exposure process detects that the TSV is planarized flush with the dielectric oxide surface, as shown in FIGS. 1C and 2. May be included. This endpoint detection may be determined by, for example, acoustic analysis and / or motor torque feedback of motor drive (eg, rotation of the polishing pad). Both acoustic analysis and motor torque feedback may be based on friction changes that can occur as the material being processed changes. For example, as the CMP process changes from primarily removing / polishing metal material on the substrate surface to mainly removing / polishing oxide material on the substrate surface, the substrate surface and polishing pad There may be frictional changes between them. This friction change can be indicated in one or more received acoustic signals and / or in received motor torque feedback. Additionally or alternatively, endpoint detection for the TSV exposure process may be determined based on a white light spectrograph indicating the thickness of a particular oxide. If an endpoint is detected at decision block 712, method 700 may proceed to end block 714. Otherwise, the method 700 can return to process block 704.

  [0054] In an end block 714, processing of the substrate using the method 700 as well as the CMP process may end.

  [0055] The decision blocks of the above process and method 700 may be performed or performed in an order and sequence that is not limited to the order and sequence shown and described. For example, in some embodiments, process block 704 may be executed concurrently with process blocks 706 and / or 710 and / or decision blocks 708 and / or 712.

  [0056] Those skilled in the art should readily appreciate that the invention described herein is capable of a wide range of practical uses and applications. Many embodiments and adaptations of the invention other than those described herein, as well as many variations, modifications, and equivalent arrangements may be made without departing from the substance or scope of the invention. From the above description, it is obvious or reasonably suggested. Thus, while this invention has been described in detail with reference to specific embodiments, this disclosure is illustrative only and provides examples of the invention, which are a complete and possible disclosure of the invention. It should be understood that it has only been created to provide This disclosure is not intended to limit the invention to the particular apparatus, devices, assemblies, systems, or methods disclosed, and conversely, all modifications and equivalents that are within the scope of the invention. And intended to cover alternatives.

Claims (15)

A disk-shaped base configured to receive a polishing pad on a surface thereof, the disk-shaped base having at least one through-hole, and received in the at least one through-hole, and the disk A plate for a chemical mechanical polishing (CMP) apparatus comprising an acoustic sensor protruding from the surface of a shaped base and configured to be electrically coupled to a controller.   The polishing pad of claim 1, further comprising a polishing pad attached to the disk-shaped base, the polishing pad having a non-through hole on the base-side surface configured to receive an acoustic sensor therein. Platen.   The at least one through hole is approximately in the center of the disk-shaped base, or about 5 inches (about 12.7 cm) radially outward from the center, or about 10 inches (about 25.4 cm) in the radial direction from the center. The platen of claim 1, positioned on the outside.   The platen of claim 1, wherein the acoustic sensor protrudes about 50 mils from the surface of the disk-shaped base. A CMP apparatus configured to perform a chemical mechanical polishing (CMP) process comprising:
A platen with a polishing pad,
A substrate holder configured to hold a substrate to be polished;
An acoustic sensor positioned in proximity to the polishing pad or the substrate during the CMP process, and electrically coupled to the acoustic sensor, from the acoustic sensor to detect TSV (Si through electrode) breakage A CMP apparatus comprising an acoustic processor configured to analyze one or more received signals, wherein the platen or the substrate holder is configured to bring the substrate and the polishing pad into contact with each other.   6. The CMP apparatus of claim 5, wherein the acoustic processor is further configured to automatically notify an operator in response to detection of TSV failure.   The acoustic processor automatically performs the CMP process in response to detecting TSV failure by reducing push force, decreasing rotational speed, or both in response to detecting TSV failure. The CMP apparatus of claim 5, further configured to stop or modify.   The CMP apparatus of claim 5, wherein the acoustic sensor comprises a high pass filter having a flat frequency response over a region of about 100-500 kHz and having a region of about 50-100 Hz.   The CMP apparatus according to claim 5, wherein the acoustic sensor amplifies an acoustic signal with a gain of about 40 to 60 dB.   The CMP apparatus according to claim 5, wherein the acoustic sensor is incorporated into the platen such that the acoustic sensor protrudes from a surface of the platen to a polishing pad.   The acoustic sensor is located approximately at the center of the platen or about 5 inches (about 12.7 centimeters) radially outward from the center or about 10 inches (about 25.4 centimeters) radially outward from the center. The CMP apparatus according to claim 5, which is incorporated in the apparatus. A method of monitoring and controlling a Si through electrode (TSV) exposure process,
Processing the substrate using a chemical mechanical polishing (CMP) process;
Sensing the acoustic emission of the CMP process and analyzing the acoustic emission to detect TSV failure.   13. The method of claim 12, further comprising automatically notifying an operator in response to detecting TSV failure.   The method of claim 12, further comprising automatically stopping or correcting the CMP process in response to detecting TSV failure.   The automatically modifying includes automatically modifying the CMP process by reducing push force, reducing rotational speed, or both in response to detecting TSV breakage. The method according to claim 14.