Specimen inspection method

Abstract

To improve particle (eg, electron and x-ray) sensor devices and methods in order to improve the efficiency and accuracy of a SEM system.SOLUTION: A SEM system includes an electron source configured to generate an electron beam and a set of electron-optical systems configured to scan the electron beam across a specimen and focus electrons scattered by the specimen onto one or more imaging planes. The SEM system includes a first detector module disposed at the one or more imaging planes, the first detector module has a multi-pixel solid-state sensor configured to convert scattered particles, e.g., electrons and / or x-rays, from the specimen into an equivalent set of signal charges. The multi-pixel solid-state sensor is coupled to a plurality of application specific integrated circuits (ASICs) configured to process the set of signal charges from one or more pixels.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates generally to the field of scanning electron microscopy, and more specifically to scanning electron microscopy Adaptive Clustering and Distributed Digital Typing with a Multipurpose Sensor Module for Applications Concerning the implementation of the sanitization scheme. [Background technology]

[0002] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application is the subject of a U.S. Provisional Patent Application dated August 28, 2019, filed with the grant of U.S. Provisional Patent Application No. 2006-0103644 filed on August 28, 2019, named Marcel Trimpl as inventor. Priority is claimed from patent application Ser. No. 62 / 892545, the entire contents of which are incorporated herein by reference. Carry over.

[0003] In manufacturing semiconductor devices, such as logic and memory devices, many By processing substrates, such as semiconductor wafers, using a number of manufacturing processes, Various features and multiple levels of the semiconductor device are formed. As the size of semiconductor devices becomes smaller, better semiconductor devices and photomask inspection equipment and lasers are required. It is becoming increasingly important to develop a scanning electron microscope (SEM) system. is one such technology that allows specimens to be inspected and reviewed. SEM systems incorporate particle detectors that allow the detection of primary electrons. Secondary electrons scattered or emitted from the specimen as the beam scans across the specimen, Scattered electrons and X-rays can be detected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 9,767,986 Summary of the Invention [Problem to be solved by the invention]

[0005] To improve the efficiency and accuracy of SEM systems, particle (e.g. electron and x-ray) sensor data Improved devices and methods are desired. [Means for solving the problem]

[0006] A scanning electron microscopy system is disclosed. In one illustrative embodiment, the system includes an electron beam In one illustrative embodiment, the system also includes an electron source configured to generate The electron beam is scanned across the specimen, and the electrons scattered by the specimen are collected on one or more sheets of A set of electron optics configured to focus the light onto an imaging surface. The system of the illustrative embodiment includes a first detector disposed in one or more of the imaging planes. In one illustrative embodiment, the first detector module includes a multi-pixel solid-state image sensor configured to convert scattered particles from a sample into an equivalent set of signal charges; In one exemplary embodiment, the multi-pixel solid-state sensor has a A plurality of use sensors configured to process the set of signal charges from one or more pixels. It is connected to an application specific integrated circuit (ASIC).

[0007] Additional and / or alternative scanning electron microscopy methods are disclosed. The system includes an electron source configured to generate an electron beam. The system scans the electron beam across the sample and captures the electrons scattered by the sample in one or more It has a set of electron optics configured to focus onto multiple imaging planes. The system of an exemplary embodiment also includes a plurality of imaging devices disposed at the imaging plane or planes. In one illustrative embodiment, the first detector module In one exemplary embodiment, the pixel array includes a multi-pixel application specific integrated circuit (ASIC). Each pixel of the multi-pixel ASIC converts particles scattered in the sample into an equivalent electrical signal. Each pixel of the multi-pixel ASIC has a photodiode configured to have an equivalent electrical It has a circuit for processing the signal.

[0008] A method for inspecting a specimen is disclosed. In one illustrative embodiment, the method generates a scan clock signal. Also, in some exemplary embodiments, the method includes generating a first electron beam. In the method of the embodiment, the first electron beam is deflected (redirected) in synchronization with the scan clock signal. In one illustrative embodiment, the method further comprises: scanning an area on the specimen with the A signal generated at the sample in response to the child beam is directed to a cluster having a plurality of pixels. In one exemplary embodiment, the method further comprises: By detecting it in the first period that is synchronized with the inspection clock, generating a first electrical signal corresponding to the collected charges; and converting the first electrical signal into a first digital signal. In addition, in one exemplary embodiment, the method converts the electric charge collected by the cluster into The load is detected in a second period synchronized with the scanning clock, and the data is collected in the second period. generating a second electrical signal corresponding to the transferred charge and converting the second electrical signal into a second digital signal; and converting the second electrical signal, but starting the conversion of the second electrical signal before the conversion of the first electrical signal is completed. In one illustrative embodiment, a method includes analyzing a first digital signal and a second digital signal. This is used to determine whether or not there is a defect.

[0009] Additional and / or alternative methods of specimen testing are disclosed. In certain illustrative embodiments, the methods include In one illustrative embodiment, the method further comprises generating a first electron beam. In one illustrative embodiment, the method further comprises: directing the first electron beam to a first location on the specimen; In one illustrative embodiment, the method further comprises: In one exemplary embodiment, the method directs the signal generated in the image to a pixel. By detecting the charge collected by the pixel, an electric charge corresponding to the charge collected by the pixel is obtained. In one illustrative embodiment, the method further comprises: generating an electrical signal that is a first threshold and a second threshold; The electrical signal is compared with two thresholds, and the electrical signal is greater than the first threshold and less than the second threshold. In such a case, it is determined that the element is present.

[0010] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only. The accompanying drawings are illustrative and are not intended to limit the scope of the invention as claimed. The following description, taken together with the general description, is incorporated in and constitutes a part of this specification, illustrating embodiments of the present invention. It serves to explain the principles of the invention.

[0011] Those skilled in the art will understand the present invention by referring to the attached drawings. This will enable a better appreciation of the many advantages of this disclosure. [Brief description of the drawings]

[0012] [Figure 1]FIG. 1 depicts a scanning electron microscopy system according to one or more embodiments of the present disclosure. [Figure 2A] FIG. 1 illustrates a multi-pixel detector module configured as a secondary electron detector in accordance with one or more embodiments of the present disclosure. [Figure 2B] FIG. 1 illustrates a multi-pixel detector module configured as a backscattered electron and / or X-ray detector in accordance with one or more embodiments of the present disclosure. [Figure 2C] FIG. 2 illustrates a multi-pixel detector module arranged according to a multi-electron beam configuration in accordance with one or more embodiments of the present disclosure. [Figure 3A] FIG. 1 depicts the combining of clusters distributed by an ASIC to a specified number of channels in accordance with one or more embodiments of the present disclosure. [Figure 3B] FIG. 1 depicts the combining of clusters distributed by an ASIC to a specified number of channels in accordance with one or more embodiments of the present disclosure. [Figure 3C] FIG. 1 depicts the combining of clusters distributed by an ASIC to a specified number of channels in accordance with one or more embodiments of the present disclosure. [Figure 3D] FIG. 1 depicts the combining of clusters distributed by an ASIC to a specified number of channels in accordance with one or more embodiments of the present disclosure. [Figure 4A] FIG. 2 illustrates a block diagram of the sensor-to-ASIC connections and operation within a single readout channel in accordance with one or more embodiments of the present disclosure. [Figure 4B] FIG. 2 depicts a conceptual diagram of a coarse floor plan of a sensor pixel according to one or more embodiments of the present disclosure. [Figure 5A] 1 depicts a physical assembly of a detector module according to one or more embodiments of the present disclosure. [Figure 5B] 1 depicts a physical assembly of a detector module according to one or more embodiments of the present disclosure. [Figure 5C]13A-13D depict a physical assembly of a detector module according to one or more additional and / or alternative embodiments of the present disclosure. [Figure 5D] 13A-13D depict a physical assembly of a detector module according to one or more additional and / or alternative embodiments of the present disclosure. [Figure 6A] FIG. 2 depicts a conceptual timing diagram of a distributed digitization scheme using several ADCs in an ASIC to process a cluster in accordance with one or more embodiments of the present disclosure. [Figure 6B] FIG. 2 illustrates a conceptual diagram of the application of a sample-and-hold circuit to a signal from one or more pixels and subsequent analog-to-digital conversion of that signal, in accordance with one or more embodiments of the present disclosure. [Figure 7] FIG. 2 illustrates a block diagram of an analog-to-digital conversion (ADC) unit provided within a pixel of a readout ASIC in accordance with one or more embodiments of the present disclosure. [Figure 8] FIG. 1 depicts a flow chart illustrating a method for inspecting a specimen according to one or more embodiments of the present disclosure. [Figure 9] FIG. 10 depicts a flow chart illustrating a method for inspecting a specimen according to one or more additional and / or alternative embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be particularly shown and described with reference to certain embodiments and specific features thereof. The embodiments described herein should be understood to be illustrative and not limiting. It should be immediately apparent to those skilled in the art that, from the essence and technical scope of the present disclosure, Various modifications and changes in form and detail may be made without departing from the scope of the present invention. Reference is now made in detail to the subject matter illustrated in the accompanying drawings.

[0014] Embodiments of the present disclosure provide a multi-purpose sensor model suitable for scanning electron microscopy applications. Module and method involving adaptive clustering and distributed digitization schemes - Patents.com It is oriented towards something.

[0015] FIG. 1 illustrates a scanning electron microscope (SEM) system according to one or more embodiments of the present disclosure. 1 illustrates a conceptual diagram of a SEM system 100. The SEM system 100 may be used for inspection and / or In this case, the SEM system 100 can be used as a review tool. Reviewing and / or inspecting the specimen 128 for defects and Alternatively, the SEM system 100 can be used to determine the material composition of the defect. The SEM system can also be configured as an imaging overlay metrology tool. 100 to capture an image of an overlay metrology target disposed on a specimen 128. and using it to determine the overlay error between successive layers of the sample 128. This can be done.

[0016] The SEM system 100 of the embodiment includes an electron source 102. The electron source 102 includes a single Or, it may be any suitable electron source for generating the multiple electron beams 106. The source 102 may include one or more electron emitters 101. For example, the one or more electron emitters 101 may be a single electron emitter. For example, the one or more electron emitters 101 may be composed of a plurality of electron emitters. The one or more electron emitters 101 may include any of the known techniques for electron emission. The electron source 102 may include one or more electron emitters. The device may have a actuator 103.

[0017] The SEM system 100 of the embodiment includes an electron optical system 111. In the optical system 111, a set of electron optical systems is arranged in the form of an electron optical column. The optical system 111 includes one or more focusing optics that focus the electron beam 106 onto the specimen 128. The electron optical system 111 guides the sample 128 through a beam. The system may include one or more deflection optics configured to scan across the optical axis 106. The focusing and deflection optical system provided in the electron optical system 111 can be a scanning electron microscope. The focusing and deflecting optics may be any of those known in the art. For example, one or more of The focusing optics may include, but is not limited to, one or more condenser lenses. The optical system may include a lens 107 and one or more objective lenses 110. The deflection optical system may include, but is not limited to, one or more deflectors ( For example, the electron optical system 111 may include one or more A plurality of deflectors 105 and one or a plurality of lower deflectors 109. In operation, the electron source 102 generates an electron beam 106. The child beam 106 is guided through a plurality of focusing and deflection optics 105 in the electron optical system 111. , 107, 109, 110, a specimen 128 disposed on a movable stage 130 In some embodiments, the electron source 102 may include multiple beams. It is also possible to generate beams and focus and deflect them onto the specimen 128. In particular, the electron source 102 and the electron optical column 111 are arranged in a single beam configuration. As a configuration, a multi-beam configuration with multiple electron sources / columns is also available. It can also be used in the form of a 'on'.

[0018] In the embodiment, the system 100 includes one or more designated locations within the electron-optical system 111. The one or more detector modules are arranged in a Each detector module includes one or more multi-pixel solid-state sensors. Each of the detector modules 122a, 122b and / or 122c may be configured as one or more solid-state For example, the first multi-pixel detector module 122 may include a sensor. a is placed away from the sample 128, and one of the detector modules 122a is provided with Or, the light scattered by the sample is reflected by the electrode 121 on the detector plane of a plurality of multi-pixel solid-state sensors. The secondary electrons 129 collected and accelerated by the electron beam can be collected. The detector modules 122b and / or 122c are positioned near the specimen 128 and are limited thereto. Although the specimen 128 is not a target for analysis, backscattered electrons, X-rays, and / or Auger electrons, etc. emitted by the specimen 128 so that particles (e.g. particles emanating from the sample at a very high solid angle) are concentrated there. As shown in FIG. 1, one or more of the detector modules 122a to 122c may be It is noted that the present invention provides a method for detecting the presence of a plurality of electrons in a single electron optical column. The scope of the present disclosure is not limited to the locations or number of detector modules shown in FIG. Instead, how many multi-pixel detector modules and how many positions are provided in the system 100? It is also possible.

[0019] In an embodiment, the detector modules 122a, 122b and / or 122c include multi-element One or more of the elemental solid state sensors are connected to a number of logic elements. For example, One or more of these multi-pixel solid-state sensors are integrated into a number of application-specific integrated circuits (ASICs). In an embodiment, the plurality of logic elements may be connected to a given multi-pixel solid state. It is configured to process a set of signal charges from a group of pixels of the sensor. The logic elements utilized in the detector module or modules then process the signals from the pixel groups. The signal charges may be processed by any logic element known in the art, but for simplicity's sake, For our purposes, we will describe the detector module in the context of an ASIC. This configuration should not be interpreted as limiting the technical scope of the present disclosure.

[0020] 2A-2C show a block diagram of a system 100 according to one or more embodiments of the present disclosure. Various configurations of multi-pixel detector modules suitable for use in the present invention are depicted. The multi-pixel detector module of the described configuration is suitable for use as a secondary electron detector. The multi-pixel detector module in the configuration depicted in FIG. 2B detects backscattered electrons and / or X-rays. A multi-pixel detector module having the configuration depicted in FIG. 2C is suitable for use as a detector. is for a multi-electron beam system, and the deflection signal originating from any electron beam is detected by the multi-pixel detector. The signals are simultaneously detected by the detector module.

[0021] In the embodiment shown in FIG. 2A, the multi-pixel detector module 122 includes a substrate carrier 201. For example, the substrate carrier 201 may be made of ceramic material, and the ASIC A multi-pixel solid-state sensor can be mounted thereon, which is read by the substrate carrier 2. 01 has a set of conductive contacts 203 for driving and controlling voltages, and the module Area 202 provides a data path that allows data collection by one ASIC. In the example shown in FIG. 2B, area 202 represents the area covered by the ASI The area covered by one C is 4mm x 4mm in size, making a 16 x 1 It is noted that the present invention is The technical scope of the disclosure is the number, size or location of ASIC clustering of pixel groups. The examples shown in A are not intended to be limiting. Rather, it is to be noted that Based on these differences, different ASIC clustering configurations can be implemented. Table 1 shows the cluster sizes and the resulting cluster conversion speeds.

[0022] [Table 1]

[0023] This example shows a sensor pixel of 250 μm, with a total of 16 × 16 read targets per ASIC. The sensor pixels and the data converters with a conversion speed of 3 MHz are built into each readout pixel. This is based on the data.

[0024] In the example of Figure 2A, a cluster of 8x8 pixels is created, and the total number of pixels per ASIC is A total of four clusters are generated. This configuration is particularly useful for secondary electron detectors. In this configuration, the conversion speed per cluster is about 200 MHz. The clusters generated by the IC are reprocessed downstream on the data path, and the detector subchannels are It is noted that the example depicted in FIG. 2B In this example, five channels are generated by the module.

[0025] According to the embodiment shown in FIG. 2B, multiple detector modules can be provided. In the example shown in FIG. 2B, a plurality of detector modules 122 (e.g., 2, 3, 4, 5, 6 , N detector modules) are arranged around the primary beam 106, thereby A passage opening 205 is formed near the wafer plane so that backscattered electrons and / or can collect other particles, such as X-rays and Auger electrons, at high solid angles. In some embodiments, each detector module 122 may be configured differently depending on its detection purpose. In the example shown in FIG. 2B, three detector modules are arranged with a cluster size of 2×2. One of the detector modules (upper right) is It is configured to detect X-rays emitted by the specimen. The columns, numbers and cluster sizes are not limited to those mentioned above. Rather, it is noted that In the set of detector modules shown in FIG. 2B, how many modules 122 are arranged in what pattern? The modules may be arranged according to the line to form the openings 205. It is noted that a 4×4 size cluster is used. This allows for cluster conversion speeds approaching 50MHz. Detector modules may be individually configured to operate at a low conversion rate, such as, but not limited to, 3 MHz. It may be configured to read pixels (e.g. 1x1 clusters) individually.

[0026] In some embodiments, one or more of the detector modules 122 may include a screen 20. 4 may be provided on top of one or more modules 122. 4 can be inserted. The screen can be made of a thin material with a low atomic number. For example, the screen 204 can be formed to a thickness of 50 to 150 μm, but is not limited to this. For example, the screen can be made of a thin beryllium screen of 100 For example, the screen may be a 100 μm thick beryllium screen. It may consist of a layer of material formed directly on the sensor module 122. For example, The screen may be directly deposited on the sensor module 122, including but not limited to: The substrate may have a layer of boron, carbon or aluminum coated thereon. The screen 204 absorbs electrons scattered by the specimen during scanning, while The screen allows most of the X-rays generated by the specimen to pass through, allowing for more efficient detection. 204 may be added to one or more of the detector modules and may be permanently attached. The configuration of the module 122 can be changed by inserting and removing the module 122. It should be noted that the screen 204 can be used in the configuration shown in FIG. The present invention is not limited to the above configuration, and may be configured to include one or more screens 204 together with any number of detection modules 122. , and may be utilized in any sequence.

[0027] In the embodiment shown in FIG. 2C, the ASICs of the detector module 122 are clustered in a 4×4 order. It should be noted that if such detector modules are used in multiple If the module were installed in the SEM system 100 in a modular configuration, With this system, a total of 400 scattered beams may be detected at rates approaching 50 MHz.

[0028] 3A-3D show a block diagram of a microcomputer that is configured to operate in accordance with one or more embodiments of the present disclosure. A combination of clusters distributed across a number of channels is depicted. The formation of multiple channels is adjusted as shown in FIG. 3A to FIG. 3D, and the SEM system 1 is 00 for various applications. For example, FIG. 3A shows one center chuck. The optical fiber 100 has a first channel 301 and four side channels 302a, 302b, 302c, and 302d. The combination of clusters can be performed dynamically during the scan, and Thus, within that module 122 the shape and size of the channels can be varied. These features allow the scattered beam 129 to change during scanning, e.g., the primary beam 106 This allows for the handling of changes in focus / defocus and wandering of the scattered beam 129. By implementing the cluster configuration of 3B, the scattered electron beam 129 wanders or drifts and The present invention can handle situations where a module moves from a central position to a non-central position.

[0029] Also, for example, by implementing the cluster configuration in Figure 3C, a larger center channel is required. For example, by implementing the cluster configuration shown in FIG. 3D, This allows for situations where a smaller center channel is needed. The separate clusters can be combined into a single center channel.

[0030] FIG. 4A illustrates a sensor-to-ASIC connection and A block diagram of the operation within a single read channel is depicted.

[0031] In an embodiment, a sensor 401 is provided with at least one connection per pixel. In one configuration, the sensor pixels 403 are attached to a plurality of ASICs 402. Floating diffusion node (FD) - for example, a floating diffusion capacitor that can be used to connect the gate of an amplifier stage This allows the charge generated within the pixel to be collected within the volume connected to the According to this example, the amplifier stages are biased by a common voltage VOD (voltage drain). The output (OS) of the amplifier stage can be fed to individual readout pixels 40 of the ASIC. 4 for further processing. In some embodiments, By connecting the amplifier appropriately, its source potential is biased at a constant voltage and its drain The signal can be read by the

[0032] In an embodiment, the voltage of the floating diffusion node is controlled by a reset stage. According to the present invention, the reset stage is provided with a simple reset transistor, The drain of the reset transistor can be connected to a global reset voltage (RD). can be controlled through the reset gate (RG).

[0033] In some embodiments, a global signal common to all pixels of the sensor array is provided as the reset signal. The input voltage can be supplied by a gate.

[0034] In some embodiments, the reset gate of the pixel of the sensor layer and each pixel of the ASIC Additional per-pixel contacts may be provided between the reset circuit units within the pixel array.

[0035] The upper sensor stage 401 of the assembly is referred to as "Scanning Electron Microscope and Specimen Inspection and Review". -Scanning electron microscope and methods of inspecting and reviewing sa A patent issued on September 19, 2017 by Brown et al. entitled "Multiples" The sensor layer can be made using the floating diffusion technology and resistive gate described in Reference 1. No. 6,399,433, filed on Oct. 23, 2007, and is hereby incorporated by reference in its entirety.

[0036] In some embodiments, instead of using a sensor layer 401 attached to a readout ASIC, A detector diode is provided in each pixel of the ASIC to detect polarized particles from the specimen 128 during scanning. The photodiode can be used with high voltage (HV) power rails above 10V. ) process.

[0037] In an embodiment, a pixel 404 of the readout ASIC receives signals from the sensor pixels at an input stage. Keeping parasitic impedance between the amplifier output and its input stage to a minimum By using this, the maximum processing speed can be achieved with a given power consumption. A cluster summation circuit sums the signal from the pixel in the cluster with the signals from the adjacent pixels. Figure 4A shows the connections from the center pixel to its two immediate neighbors. The cluster is shown with additional input from other pixels in the vicinity. A realistic size for a pixel should be in the range of 1 to 10 pixels; however, a pixel cluster of 1 pixel should be used. A star is one where summation is disabled and each pixel is processed individually (e.g. (See the example in Table 1.) This cluster signal is then processed through digitization and additional The digitization step involves standard analog processing. The log-digital transformation is performed using the equidistant quantization steps and the multi-threshold chemical element sampling method detailed in Fig. 7. For applications where individual event detection is essential, Record the arrival of an event with the scan clock and assign the event to a scan location on the sample. It is noted that one part of this post-processing is the time stamp unit. The part includes the data stream hardware required to take the data from each pixel out of each ASIC. The sum of pixel values ​​is processed after digitization in a post-processing unit. It may be performed within

[0038] According to an embodiment, the reset circuit is triggered by the digitization unit. By controlling the voltage of the reset gate of the sensor pixel, the reset gate voltage of the sensor pixel can be controlled. The reset circuit uses high voltage process components, which makes it suitable for the reset stage. It can be operated by supplying a voltage (e.g. 10 to 30V). The control can be in the form of resetting the floating diffusion by a reset pulse. The set allows the dynamic range of the sensor pixels to be infinitely expanded and the sensor Such a reset pulse can be used to accommodate variations in particle flux between pixels in the sensor. By synchronizing all pixels of the sensor, the function of a global reset can be simulated. A much smaller capacitance is driven than the global reset that is routed throughout the array. Therefore, the use of per-pixel reset allows for very fast reset at lower power. By supplying an analog voltage from the reset circuit, the floating diffusion can be closed. A loop feedback control is formed to counter pixel-to-pixel transistor variations and thermal drift. It can also enhance immunity to

[0039] FIG. 4B illustrates a coarse floorplan of a sensor pixel according to one or more embodiments of the present disclosure. The conceptual structure of the sensor pixel coarse floor plan shown in FIG. 4B is The output signal (RG) and output signal (OS) are connected to the bias points of the readout ASIC and other devices. The reset drain (RD) and voltage drain (VOD) of the sensor pixel are In some embodiments, the signal is routed as a global signal across the entire sensor array. In the case where a reset gate (RG) is not provided for each pixel of the ASIC, The reset gate (RG) is pulled low on the sensor, as are the input and voltage drain signals. It can be routed either per or globally.

[0040] 5A and 5B each show a detector according to one or more embodiments of the present disclosure. The physical assembly of the module 122 is depicted.

[0041] FIG. 5A shows a rear view of a multi-pixel detector module according to an embodiment. The ASIC507 is connected to the sensor. This view shows the back of the ASIC. FIG. 5B shows a multi-pixel solid-state sensor 502 with a backside treatment 501. A side view of the detector module 122 is shown. In some embodiments, its rear surface is In an embodiment, the sensor layer is connected to the sensor via a solder bump. It is connected to the Through Silicon Via Interposer (TSI) 504. A direct-bond-interconnect (DBI) technology may be used. A fine pitch (10μm to 20μm) can be used for the 0μm thick TSI. Through silicon vias 505 electrically connect the front side of the TSI to its back side. The pitch of the TSVs in the TSI is the pixel pitch in the sensor or ASIC. On the back side of the TSI, multiple (e.g., 4 or more) A multi-metal redistribution layer (RDL) with metal layer 506 is used to reduce the amount of Routing the pixel output to the input of the ASIC507 and For example, a pixel of 250 μm×250 μm size on the sensor layer can be This can be matched with the pixel size of about 180 μm × 180 μm in the ASIC. cormorant.

[0042] According to the embodiment shown in FIG. 5B, the ASIC can embody TSVs. The input and output of the ASIC are connected to the conductive connections on the mechanical board 509 on the back side of the ASIC. If each ASIC covers 16x16 pixels, Due to the pixel size difference between the ASIC and the sensor, an assembly margin of approximately 1 mm space can be left.

[0043] In some embodiments, the ASIC may not incorporate TSVs. In that case, FIG. 5D. In this embodiment, the sensor side By shifting one ASIC row 511 in the middle, wire bonds can be used for connection to the board. The AS sensor area is exposed and accessible. The transfer of drive signals and data between ICs is through additional solder connections to the TSI. The same can be achieved, and they can be routed to other ASICs within the RDL of the TSI. It will be censored.

[0044] It is noted that in the detector module 122, one or more intra-ASIC TSVs In the embodiment utilized, the module is , one can construct detector modules that are infinitely scalable.

[0045] The assembly shown in FIG. 5D can be fabricated using the following procedure.

[0046] Create TSI504 to have the specified thickness (e.g., about 100 μm) and 0 μm) and provide an unthinned sensor 502. First, the handle wafer (not shown) is attached to the front side of the sensor 502 (as shown in FIG. 5D). Then, by thinning the back side of the sensor 502, After thinning, the backside of the sensor 502 can be treated. For example, the backside of the sensor 502 can be treated with boron. Then, the boron implantation process is performed to form a boron implantation layer 501. A wafer (not shown) is attached to the backside of the sensor 502 (or the topside of the sensor 502 as shown in FIG. 5D). The handle wafer is then removed from the front side of the sensor 502. Then, the front side of the sensor 502 may be bonded (e.g., by solder bump or direct bonding (DBI) technology). Thus, a conductive connection may be made to the front side of the TSI via one or more connection mechanisms 503. In addition, the ASIC 507 may be conductively connected to the backside of the TSI 504 by a redistribution layer 506. The handle wafer is then removed from the backside of the sensor 502 and the sensor / TSI The sensor / ASIC assembly can then be attached to the substrate 509. The TSI / ASIC assembly may be removed after being mounted on the substrate 509 .

[0047] It is noted that the procedure for manufacturing the assembly shown in FIG. 5B is also the same as that for manufacturing the assembly shown in FIG. The procedure for the assembly can be similar to that of FIG. When manufacturing the assembly, a TSV (through silicon via) is attached to the ASIC, and the hand ASIC 507 is thinned using a wafer and mounted on a substrate 509 with solder bumps 513. An additional step may be performed to make a conductive connection to the pad.

[0048] FIG. 6A illustrates a block diagram of a multi-ASIC ADC in accordance with one or more embodiments of the present disclosure. Conceptual framework for timing of distributed digitization schemes using cluster processing It should be noted that this distributed digitization method does not Although not all ADCs are required, any number of ADCs can be used, such as 256. A sample and hold circuit for signals from one or more pixels and a subsequent A conceptual diagram 610 of the analog-to-digital conversion of the signal is shown. Each digitizer uses a high-speed S&H circuit to generate analog values ​​at the rate of the sample scan clock t1. Hold the specimen at the same speed as the electron beam is rastered. Then, each ADC can hold the conversion for a period t2, which is much slower than t1. The analog value can be converted to a digital value in the conversion period t2. and the number of pixels (and therefore ADCs) that are combined to form a single cluster. ,Consistent. For example, we can combine 8x8 pixels of the sensor to form a single class. In this example, 3 ADCs could be used to convert the cluster. A single conversion frequency of 1.5 MHz supports a wafer scan clock of 192 MHz. It is possible.

[0049] FIG. 7 shows a block diagram of a readout ASIC in accordance with one or more embodiments of the present disclosure. 7 illustrates an analog-to-digital conversion (ADC) unit 700. The captured signal from the detector is stored in the S&H unit at the head for each clock cycle of the sample scan. Then, the ADC700 is used to perform the SAR (Successive Approximation Register) ADC. In "ADC mode", it is possible to perform classical analog-to-digital conversion. A binary sigma-based digital-to-analog converter (DSA) provides equidistant digitization. A lookup table that is a standard conversion table with standard conversion steps based on the A look-up table (LUT) is provided.

[0050] According to an embodiment, the DAC may be made of, for example, silicon, aluminum, copper, titanium, or other , the upper and lower thresholds (which define the energy window) of chemical elements that may appear during a sample scan, etc. It can also be driven by a look-up table (LUT) that contains useful reference levels. The comparison of each signal with its energy window results in the presence or absence of a particular chemical element. This mode can be called "element ID mode." According to an embodiment, AD The C unit 700 can be switched between ADC mode and element ID mode. To switch between ADC mode and element ID mode, the only thing required is the The only difference is that the lookup table in the ADC unit is configured differently. and for the upper and lower thresholds that define an energy window for each particular element to be detected. A number of comparators may be provided, including one for each of the first and second comparators.

[0051] FIG. 8 is a flow diagram of a method 800 for inspecting a specimen according to one or more embodiments of the present disclosure. As noted herein, the steps of method 800 are implemented by a system 100. However, it is further recognized that The method 800 is not limited to the system 100 and may be implemented in additional or alternative systems. All or some of the steps of method 800 may be performed in a level embodiment.

[0052] In step 802 of the method, a scan clock signal is generated. In step 804 of the method, In step 806 of the method, a first electron beam is generated. The first electron beam is deflected in a direction perpendicular to the sample surface so as to scan an area on the sample. The chip 808 detects the signal generated in the sample in response to the electron beam by a plurality of pixels. In step 810 of the method, the collected data is directed to the cluster. The charge is detected in the first period synchronized with the scan clock. generating a first electrical signal corresponding to the charges collected in a first period by the In step 812 of the method, the cluster is converted into a first digital signal. The collected charge is detected in a second period synchronized with the scanning clock. generating a second electrical signal corresponding to the charge collected between the first and second digital inputs; a digital signal, the conversion of the second electrical signal being completed before the conversion of the first electrical signal is completed. In step 814 of the method, a first digital signal and a second digital signal are The presence or absence of defects is determined by analyzing the number.

[0053] FIG. 9 illustrates a sample test in accordance with one or more additional and / or alternative embodiments of the present disclosure. 9 illustrates a flow chart of a method 900 for detecting a cellular component. The steps may be performed in whole or in part by the system 100. It is further recognized that the method 900 is not limited to the system 100, but may be implemented in various other ways. 900 in a system or alternative system level embodiment. It can also be performed.

[0054] In step 902 of the method, a scan clock signal is generated. In step 904 of the method, In step 906 of the method, the first electron beam is directed to the sample. In step 908 of the method, the first electron beam is deflected toward a first location on the substrate. The signal generated at that sample is directed to a pixel. In step 910 of the method, By detecting the charge collected by the pixel, an electrical signal corresponding to the charge collected by that pixel is generated. In step 912 of the method, the electrical signal is compared to a first threshold and a second threshold. In comparison, when the electrical signal is greater than the first threshold and the electrical signal is smaller than the second threshold, , and determine whether the element is present.

[0055] Referring back to FIG. 1, the system 100 according to the embodiment includes a controller 140. The controller 140 is used to control the electron source 102, the electron optical column 111, and / or the detector. One or more control signals C can be supplied to the detector assemblies 122a to 122c. In this way, the controller 140 can control all aspects of the SEM system 100. In an embodiment, the controller 140 is provided in the specimen 128. Indicates one or more features (e.g., defects, pattern features, metrology targets, etc.) that are The detector assembly receives one or more image data signals ID1 and ID2 including the image data. The controller 140 can receive the information from the storage medium. one or more processors configured to execute program instructions stored therein; In this case, the controller 140 may include one or more The processor performs any of the various process steps described throughout this disclosure. can also be performed.

[0056] In any of the methods described herein, the results of one or more steps of the method embodiments may be The results may be stored in memory, including any of the results described herein. The results may be stored in the memory in any manner known in the art. may be any memory described herein or any other suitable storage device known in the art. After the results are stored, the results can be accessed in the memory, Using the results in any of the method or system embodiments described herein, displaying the results to a user, formatting for display, for use in another software module, method or system Furthermore, result storage can be "permanent", "semi-permanent" or "temporary". For example, the memory may be a random access memory. The result may be in RAM, but it does not necessarily remain in that memory permanently. good.

[0057] By further consideration, each of the above-described method embodiments may be combined with any other method described herein. Any other step(s) of the method described above may also be incorporated. Each of the embodiments may be performed by any of the systems described herein.

[0058] As will be understood by those skilled in the art, the components, operations, devices, and objects described herein may be used in various ways. The structures and accompanying discussion are used as examples to aid in conceptual clarity and to illustrate the various Therefore, according to the usage in this application, the specific The intent of the exemplars and the accompanying discussion is to be representative of these more general classes. In general, the intent of the use of any particular example is to be representative of its class. Therefore, without limitation, specific components, actions, devices and objects are not included. This should not be taken as a given.

[0059] Directional terms used in this application, such as "top," "bottom," "upper," "lower," "upper The terms "upward," "downward," "downward" and "downward" are used relative positions for descriptive purposes. The purpose of this document is to present the position of the coordinate system, not to specify an absolute coordinate system. It will be apparent to those skilled in the art that the present invention may be embodied in any form as defined herein. The general principles may be applied to other embodiments.

[0060] With respect to the use of almost all plural and / or singular terms in this application, those of ordinary skill in the art will recognize that , from plural to singular and / or from singular to plural as appropriate to the context and / or usage. For the sake of clarity, the various singular / plural permutations may be used herein. is not explicitly explained.

[0061] The subject matter described herein is a method for manufacturing a device in which various components are embedded within or connected to other components. As you can see, these illustrated architectures are just This is an example, and in fact many other architectures can be implemented to achieve the same functionality. Conceptually, any arrangement of parts that achieves the same function will achieve that desired function. Therefore, any two components in this application are effectively "linked" to perform a specific function. The things that are combined to achieve a desired function "link" with each other to achieve that function. It can be considered that the architecture and intervening materials are the same. Whatever two components are connected in this way, they are "connected" to each other to achieve the desired function. It can also be seen as "connected" or "joined" and any two parts can be viewed as being "connected" or "joined" together. Such things that can be linked together can also be considered to be "combinable" with each other to achieve the desired function. Examples of "connectable" include, but are not limited to, components that are physically connected to each other. The components may be mated and / or physically interact with each other and / or may communicate wirelessly with each other. The components are capable of interacting with each other and / or interacting wirelessly and / or are logically linked to each other. may be capable of interacting and / or logically interacting with one another.

[0062] It will be further understood that the invention is defined by the following claims. As will be appreciated by those skilled in the art, the scope of the present application, particularly the scope of the claims (e.g., The words used in the claims are generally intended to be "open" words (e.g. The word "including" means "including but not limited to" and the word "having" means "Having at least...", the word "including..." should be interpreted as "including but not limited to...", etc. It should be understood that a specific number of pieces may be used. If the incorporation of the above into a claim is intended, that intention will be clearly stated in the claim. If such requirements are not stated, then there is no intention to do so. For example, the following appended claims may contain the introductory phrases "at least one" and "one or more." However, some claims incorporate the introduction of claim elements through the use of the indefinite title. The inclusion of a claim-introducing requirement by the word "a" or "an" includes that claim-introducing requirement. There is an implication that all individual claims are limited to inventions containing only one of their constituent elements. The use of such phrases should not be construed as if they were indicative of the invention, and the very phrases introductory to the claims should not be construed as if they were indicative of the invention. "One or more" or "at least one" combined with an indefinite article, e.g. "a" or "an" should not be interpreted as such even when used in a ", "which should be interpreted as meaning "at least one" or "one or more"); and The same holds true with respect to the introduction of claim features by the use of definite articles. Even if a specific number of elements is specified in a claim, it is difficult for a person skilled in the art to As can be understood, the quantity description is usually interpreted to mean at least that explicit number. (e.g., the bare expression "two constituent elements" without other modifiers is usually (It means at least two requirements or more than two requirements.) Furthermore, "A, B and C In cases where a rule similar to "at least one of, etc." is used, the so-called Such a syntax is intended to conform to the way businesses would understand the terms (e.g., "A The "system having at least one of B, C" is not limited to this. However, only A, only B, only C, both A and B, both A and C, both B and C, and / or A. (This would include systems that have three elements: A, B, and C, etc.) In cases where a rule similar to "at least one, etc." is used, it is generally considered that a person skilled in the art would Such a construction is intended to be consistent with the sense in which one would understand the conventions of "A system having at least one of A and C" includes, but is not limited to, A only B, only C, both A and B, both A and C, both B and C, and / or all three (This would include systems having a person having the ability to read, write, and read the data, etc.) In order to obtain a clearer understanding of the concept, almost all sentences are composed of separating conjunctions and / or separating conjunctions that present two or more alternative words. Regardless of whether it appears in the specification, claims, or drawings, It should be understood that the term "common" or "commonly used" is intended to encompass the term "commonly used" or "commonly used" or both. For example, the phrase "A or B" includes the possibilities of "A" or "B" or "A and B." Let it be understood.

[0063] The present disclosure and many of its attendant advantages can be understood from the above description. without departing from the disclosed subject matter or detracting from all of its major advantages. It will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention. The illustrated embodiments are merely illustrative and the appended claims are intended to cover such modifications. The invention is further defined by the following claims. do.

Claims

1. 1. A method of inspecting a specimen, comprising: generating a scan clock signal; generating a first electron beam; deflecting the first electron beam in synchronization with the scan clock signal to scan an area on the specimen; directing a signal generated at the specimen in response to the electron beam to a cluster having two or more pixels; detecting the charges collected by the cluster during a first time period synchronized with the scan clock to generate a first electrical signal corresponding to the charges collected by the cluster during the first time period, and converting the first electrical signal into a first digital signal; detecting the charges collected by the clusters during a second time period synchronized to the scan clock to generate a second electrical signal corresponding to the charges collected during the second time period and converting the second electrical signal into a second digital signal, where the conversion of the second electrical signal begins before the conversion of the first electrical signal is completed; and The method further comprises analyzing the first digital signal and the second digital signal to determine whether a defect exists.

2. 2. The method of claim 1, wherein said charge detection comprises summing charges from two or more pixels.

3. 3. The method of claim 2, wherein said summing includes summing one of a voltage domain and a current domain.

4. 1. A method of inspecting a specimen, comprising: generating a scan clock signal; generating a first electron beam; deflecting the first electron beam toward a first location on the specimen; directing signals generated at the specimen in response to the first electron beam to pixels; detecting the charge collected by the pixel to generate an electrical signal corresponding to the charge collected by the pixel; and The method includes comparing the electrical signal with a first threshold and a second threshold, and determining that an element is present when the electrical signal is greater than the first threshold and the electrical signal is less than the second threshold.

5. 5. The method of claim 4, wherein the first threshold is less than an electrical signal corresponding to a characteristic energy of the element, and the second threshold is greater than the electrical signal corresponding to a characteristic energy of the element.

6. 5. The method of claim 4, wherein the elements include at least one of silicon, aluminum, copper, tungsten, and titanium.

7. The method of claim 4, further comprising: deflecting the first electron beam toward a second location on the specimen; directing a second signal generated at the specimen in response to the first electron beam to a pixel; detecting a second charge collected by the pixel to generate a second electrical signal corresponding to the second charge collected by the pixel; comparing the second electrical signal with the first threshold and the second threshold, and determining that the element is present when the second electrical signal is greater than the first threshold and the second electrical signal is less than the second threshold; and A method for generating a map of where said elements are present on said specimen.

8. 8. The method of claim 7, further comprising: comparing the first and second electrical signals with a third threshold and a fourth threshold, and determining that a second element is present when the second electrical signal is greater than the third threshold and the second electrical signal is less than the fourth threshold; and A method for generating a map of the presence of at least one of the first or second elements on the specimen.

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