Multi-reflection measurement for measuring etching parameters

Abstract

A system includes a memory and at least one processing device operatively coupled to the memory to facilitate an etch recipe development process by performing a plurality of operations. The operations include: receiving a request to initiate an iteration of an etch process using an etch recipe to etch a plurality of materials, each of the plurality of materials being located at a respective one of a plurality of reflectometry measurement points; obtaining material thickness data for each of the plurality of materials resulting from the iteration of the etch process; and determining one or more etching parameters based on the material thickness data.

Description

Technical Field

[0001] The present disclosure relates generally to electronic device manufacturing and, more particularly, to multi-reflection measurements for measuring etch parameters. Background Art

[0002] Manufacturing systems produce products based on manufacturing parameters. For example, a substrate processing system produces substrates based on a number of parameters of a process recipe. Products have performance data based on what parameters were used during production. Etching process equipment can be used to remove material from an area of ​​a substrate via, for example, chemical reactions and / or physical bombardment. For example, a vacuum etching process can use plasma to produce gas phase reactants. During an etching process, the etch rate refers to the rate at which material is removed, and the etch selectivity refers to the ratio of the etch rates observed in two materials. There may be multiple materials of interest during etching. Such materials include: (1) a target material to be etched; (2) materials beneath the target material; (3) mask materials; and (4) materials adjacent to the target material that may be exposed to the etching process (e.g., process gases). Summary of the invention

[0003] The following is a brief overview of the disclosure, in order to provide a basic understanding of some aspects of the disclosure. This overview is not an extensive review of the disclosure. This overview is neither intended to identify the key or important elements of the disclosure, nor is it intended to describe any scope of the specific embodiments of the disclosure or any scope of the claims. The sole purpose of this overview is to present some concepts of the disclosure in a simplified form, as a preface to a more detailed description presented later.

[0004] In one aspect of the present disclosure, a system includes a memory and a processing device operatively coupled to the memory. The processing device facilitates an etch recipe development process by performing a plurality of operations, the plurality of operations including: receiving a request to initiate an iteration of an etch process using an etch recipe to etch a plurality of materials, the plurality of materials each being located at a respective one of a plurality of reflectometry measurement points; obtaining material thickness data for each of the plurality of materials resulting from the iteration of the etch process; and determining one or more etching parameters based on the material thickness data.

[0005] In another aspect of the present disclosure, a method includes receiving, by at least one processing device, a request to initiate an iteration of an etching process using an etching recipe to etch a plurality of materials, each of the plurality of materials being located at a respective one of a plurality of reflectometry measurement points. The etching process is associated with an etching recipe development process. The method further includes obtaining, by the at least one processing device, material thickness data for each of the plurality of materials generated by the iteration of the etching process; and determining, by the processing device, one or more etching parameters based on the material thickness data.

[0006] In another aspect of the present disclosure, a system includes a sensor head including a plurality of collimators corresponding to a plurality of collection cylinders located above a plurality of reflectometry measurement points. The plurality of reflectometry measurement points correspond to locations of a plurality of materials. The system further includes an optical detector; a switching device operatively coupled to the sensor head and the optical detector to enable selective measurement of the plurality of reflectometry measurement points with the optical detector; and a processing device operatively coupled to the optical detector and the switching device to facilitate an etch recipe development process using selective measurements of the plurality of reflectometry measurement points. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like reference numerals denote similar elements. It should be noted that different references to "one" or "an" embodiment in the present disclosure do not necessarily refer to the same embodiment, and such references mean at least one.

[0008] Figure 1 is a high-level overview diagram of a multiple interferometric endpoint (MIEP) system implementing multi-reflection metrology for measuring etch parameters according to some embodiments.

[0009] Figure 2 According to some embodiments, Figure 1 Top view of the carrier wafer device used in the MIEP system.

[0010] Figure 3 is a cross-sectional view of a collimator assembly according to some embodiments.

[0011] Figure 4 is a schematic diagram of an etch recipe development subsystem according to some embodiments.

[0012] Figure 5is a graph showing the observed thickness change over time for etch recipes applied to a plurality of samples, according to some embodiments.

[0013] Figure 6 is a flow chart of a method of implementing multi-reflection measurement for measuring etching parameters according to some embodiments.

[0014] Figure 7 is a block diagram illustrating a computer system according to certain embodiments. DETAILED DESCRIPTION

[0015] Embodiments described herein relate to multi-reflection measurement methods for measuring etching parameters. When an etching process recipe is developed to achieve a desired etch pattern, methods for obtaining feedback are limited. For example, methods for obtaining feedback include: (1) external metrology with a wafer; (2) external metrology with a specimen; (3) single-point in-situ reflectometry; and (4) ellipsometry.

[0016] To perform external metrology with wafers, a wafer with a film of the material of interest can be pre-measured with ellipsometer or other external metrology. The wafer can be etched with the proposed etch process and then re-measured with external metrology. Etch selectivity can then be determined by comparing wafers with films of different materials.

[0017] To perform external metrology with samples, similar to external metrology with wafers, samples with films of the material of interest are placed on a carrier wafer. The film thickness of each sample can be baselined using ellipsometer or other external metrology. Selectivity can be determined by comparing the etch rates of each material.

[0018] To perform single-point in-situ reflectometry, a wafer or sample on a carrier is measured in-situ with single-point reflectometry, which is used to monitor the etch rate during the etching process. The etch selectivity can then be determined by measuring each sample / wafer individually. This method may require one wafer or one sample on a carrier wafer and one process for each material.

[0019] With respect to ellipsometry, an in-situ ellipsometer can be added to the etch chamber to measure points adjacent to those measured by reflectometry. However, ellipsometers can be bulky and difficult to align, chamber modifications may be required, and the measurement method is different and must be calibrated. Accordingly, ellipsometry may be practically limited to allowing only one additional measurement point.

[0020] Embodiments described herein may allow for in-situ etching parameter (e.g., etching rate and / or selectivity) measurements to be performed adjacent to each other for multiple reflectometry measurement points. For example, four reflectometry measurement points may be presented, but the number of reflectometry measurement points may depend on the specific application (e.g., at least seven reflectometry measurement points may fit into one window port). More particularly, multiple samples (e.g., at least four samples) with different films may be placed on a carrier wafer below the sensor head. The sensor head may include multiple collimators (e.g., four collimators). The sample may be placed at a position relative to the wafer notch. Because the sample of the wafer is positioned relative to the wafer notch is part of the measurement setup, a fixture or other suitable device may be used to accurately place the sample on the carrier wafer. At least one lamp may be used to generate light reflected from the surface of the carrier wafer to perform reflectometry. A switching device such as an optical multiplexer ("multiplexer") may be used to switch between each of the multiple reflectometry measurement points, thereby enabling a single optical detector to measure multiple reflectometry measurement points. Alternatively, multiple optical detectors may be used instead of the switching device. The switching device may also be used to switch between each of the optical channels connected to the at least one lamp.

[0021] In some embodiments, the system comprises a single lamp and a single optical detector. In some embodiments, the system comprises multiple lamps and a single spectrometer. In some embodiments, the system comprises a single lamp and multiple spectrometers. In some embodiments, the system comprises multiple lamps and multiple spectrometers.

[0022] In addition, the embodiments described herein provide for etching process recipe development and / or optimization using multi-reflection measurement. Illustratively, an individual (e.g., a process engineer) can identify several materials of interest to determine etching parameters (e.g., etching selectivity and / or etching rate). For example, the number of materials of interest can be at least four. Examples of materials of interest include, but are not limited to, oxides, photoresists, nitrides, polysilicon, etc. For each material of interest, it is determined how much area is expected for each sample to match the "load" of those materials of interest in the simulated process. The sample can be cut and placed on a carrier wafer (e.g., using a fixture for accurate sample placement) so that each measurement position has a material of interest. Additional samples can be added to simulate appropriate material loads and / or different sample sizes. The carrier wafer can then be placed in a cladding (e.g., a front opening unified pod (FOUP)), and the carrier wafer can be loaded into the chamber using a robot. Data collection can then be started to measure film thickness, and the first iteration of the etching process can be performed. The film thickness can be measured in real time using multi-reflection measurement. As the etching process recipe is completed, one or more etching parameters (e.g., etching rate and / or etching selectivity) that vary over time can be determined. Based on this result, one or more parameters (e.g., gas type, gas concentration, pressure, radio frequency (RF) power, RF pulse) of the etching process recipe can be manually modified (e.g., modified by a process engineer) or automatically modified to achieve the desired etching rate and / or etching selectivity. Automatic modification can use multivariate design of experiment (DoE) methods and / or machine learning techniques.

[0023] Embodiments described herein advantageously overcome limitations of other measurement techniques by implementing a multi-reflection measurement technique for measuring etching parameters. Embodiments described herein can achieve an etching process with chemical and process equipment parameters that provide good removal rates for target etched material while limiting the removal rates of other materials (e.g., underlying and adjacent materials).

[0024] Figure 11 is a high-level overview diagram of a multiple interferometric endpoint (MIEP) system ("system") 100 that implements a multi-reflection measurement method for measuring etching parameters. More particularly, as will be described in further detail below, the system 100 can analyze a plasma etching process performed in an etching chamber using an etching recipe, and the results of the analysis can be used to develop and / or optimize the etching recipe. As shown, the system 100 includes a carrier wafer 110, a sensor head 120, and an etching recipe development subsystem ("subsystem") 130. The carrier wafer 110 can be placed on an electrostatic chuck or other suitable device (not shown) to secure the carrier wafer 110.

[0025] The carrier wafer 110 and the sensor head 120 are contained within the etching chamber. Figure 2 As further described in detail, a plurality of coupons may be placed on the carrier wafer 110, and a material sample ("sample") may be placed on each coupon. In some embodiments, four coupons are placed on the carrier wafer, each of the four coupons corresponding to a particular sample. However, the number of coupons should not be considered limiting. Each sample may include a different material of interest for measuring one or more etching parameters (e.g., etching rate and / or etching selectivity). For example, each sample may be a thin film.

[0026] The sensor head 120 accommodates a plurality of collimators (not shown) arranged in parallel. In some embodiments, the sensor head 120 accommodates at least four collimators. Each collimator can be operatively coupled to a corresponding optical channel (e.g., an optical fiber cable). An optical signal traveling through each optical channel can be received by the collimator corresponding to the optical signal, and the optical signal received by the collimator can be parallelized by the lens of the collimator into a collimated beam including collimated optical signals. Figure 3 An example of a collimator accommodated in the sensor head 120 is described.

[0027] Subsystem 130 includes an optical detector 132 operatively coupled to switching device 134, a processing device 136 operatively coupled to components 132 and 134, and a memory device 138 operatively coupled to processing device 136. In some embodiments, optical detector 132 is a spectrometer. As further shown, lamp 133 is provided as a subcomponent of optical detector 132. Alternatively, lamp 133 can be embodied as a separate or independent component from optical detector 132. Lamp 133 can be configured to produce a strong signal with a minimum output (e.g., about 75% saturation). In some embodiments, lamp 133 includes a flash tube or a flash lamp.

[0028] In this illustrative example, the system 100 includes a single lamp 133 and a single optical detector 132. In other embodiments, the system 100 includes multiple lamps and a single spectrometer. In other embodiments, the system 100 includes a single lamp and multiple spectrometers. In other embodiments, the system 100 includes multiple lamps and multiple spectrometers such that the switching device 134 is not required.

[0029] System 100 can be used to develop and / or optimize etching recipes based on the analysis of etching process iterations. In this example, it is assumed that four samples are placed or mounted on carrier wafer 110, and sensor head 120 includes four collimators. However, such an embodiment should not be considered as limiting. It is also assumed that the iteration of the etching process has been started based on the etching recipe 139 stored in memory 138. The etching recipe 139 has etching recipe conditions (e.g., gas type, gas concentration, pressure, power, pulse, etc.), which control the etching effect on the material during the iteration of the etching process. As will be described in further detail below, the analysis of the material thickness of each material over time can be used to determine whether one or more etching parameters (e.g., etching selectivity and / or etching rate) meet the etching parameter target of the etching process.

[0030] A request to initiate an iteration of the etching process may be received by the processing device 136. The processing device 136 may cause the carrier wafer 110 to be exposed to the etchant in a manner determined based on the etching recipe 139. In order to measure one or more etching parameters during the iteration of the etching process, a data collection process may be performed using a multi-reflection measurement method. For example, the sensor head 120 may receive an input signal generated by the lamp 133 via an optical channel (e.g., a bundle of optical fiber cables). Each of the collimators of the sensor head 120 corresponds to a collection cylinder for obtaining reflectometry measurements at different locations above the carrier wafer 110 corresponding to corresponding sampling points. In this illustrative example, there are collection cylinders 122-1 to 122-3, which are aligned with corresponding positions corresponding to three of the samples disposed on the carrier wafer 110. Although not shown, a fourth collection cylinder corresponding to a fourth sample on the carrier wafer 110 is occluded by the collection cylinder 122-2. Accordingly, four collection cylinders may be implemented.

[0031] The output signal is generated based on the spectral reflection of the input signal generated by the lamp 133 from the material to which they correspond. More specifically, when the input signal is reflected away from the corresponding position of the carrier wafer 110, some of the input signal is reflected from the incident surface and some of the input signal is transmitted into the material. When these transmitted signals reach the bottom of the material, another reflection may occur. Depending on factors such as, for example, wavelength, travel distance, etc., the incident optical signal reflection and the transmitted optical signal reflection constructively and / or destructively interfere with each other, thereby generating the output signal.

[0032] The output signal is routed to the switching device 134 via the optical channel to distribute and route the output signal to the optical detector 132. In some embodiments, the switching device 134 is a multiplexer. More specifically, the switching device 134 can switch a separate optical channel (e.g., optical fiber) coupled to the lamp 133, and switch a separate optical channel coupled to the optical detector 132 for performing analysis (e.g., spectral measurement) on the serial output signal. However, in alternative embodiments, multiple optical detectors and / or lamps can be used instead of the switching device 134, so that each optical channel and / or lamp is coupled to a corresponding optical detector.

[0033] The thickness of each sample on the carrier wafer 110 over time may be measured using (spectral) reflectometry based on analysis of the output signal obtained by the optical detector 132. More specifically, the thickness of each sample may be measured using any suitable model or equation to determine the material thickness based on the intensity and / or wavelength of the output signal. For example, the amount of signal may increase with increasing thickness. The emission (e.g., plasma emission) may be subtracted from each reflectometry measurement in order to measure the amount of light that is reflected off the surface and into the collection cylinder.

[0034] The processing device 136 can use the thickness of the etching process to measure one or more etching rate parameters of the corresponding material sample over time. That is, as the etching recipe is completed, one or more etching parameters that change over time can be measured. The steps of the etching recipe 139 can cause different etching rates. Based on these results, one or more etching recipe conditions in the etching recipe conditions (e.g., gas type, gas concentration, pressure, power, pulse, etc.) can be modified to achieve the desired etching parameter target. In some embodiments, the etching recipe conditions are manually modified (e.g., a process engineer can manually modify the etching recipe conditions and repeat the data collection process). In some embodiments, the etching recipe conditions are automatically modified by the processing device 136. For example, any suitable statistical method (e.g., multivariate DoE method) and / or machine learning method can be used by the processing device 136 to automatically modify the etching recipe conditions.

[0035] Figure 2 FIG. 2 is a top view of a carrier wafer device 200 according to some embodiments. As shown, the carrier wafer device 200 includes a carrier wafer 210, such as the one described above with reference to FIG. Figure 1 The carrier wafer 110 described. The carrier wafer 210 can have a wafer notch 220, and a plurality of samples 230-1 to 230-4 can be placed or mounted at the center of the carrier wafer 210. Although four samples 230-1 to 230-4 are shown in the illustrative example, any suitable number of samples can be placed on the carrier wafer 210 according to the embodiments described herein. Each of the samples 230-1 to 230-4 can have a corresponding sample 240-1 to 240-4 disposed thereon. The position of the samples 230-1 to 230-4 on the carrier wafer 210 relative to the wafer notch 220 can be used as part of the multi-reflection measurement process described herein. For example, a fixture can be used to accurately position the samples 230-1 to 230-4 relative to the wafer notch 220.

[0036] Each sample 240-1 to 240-4 may contain a different material of interest for measuring one or more etching parameters (e.g., etching rate and / or etching selectivity). A multi-reflection measurement process may be used to analyze an etching recipe corresponding to one of the samples 240-1 to 240-4, and the thickness of each of the samples 240-1 to 240-4 may be measured over time as each step of the etching recipe is performed. The process may be repeated for other etching recipes corresponding to other samples of the samples 240-1 to 240-4. Thus, a MIEP system such as Figure 1 The system 100 can be used to monitor the removal rate of each etching recipe, and the etching parameters can be determined for each etching recipe in the etching recipe. Accordingly, multiple recipe analyses can be performed to identify the best etching selectivity. For example, using multiple in-situ measurements, statistical methods (e.g., multivariate DoE) and / or machine learning can be used to automatically obtain the best etching recipe solution.

[0037] As an illustrative example, sample 240-1 may be an oxide film sample, sample 240-2 may be a photoresist film sample, sample 240-3 may be a nitride film sample, and sample 240-4 may be a polysilicon film sample. Each of the oxide film sample, the photoresist film sample, the nitride film sample, and the polysilicon film sample may have a corresponding etching recipe that may be analyzed. Further details about this example will be referred to below. Figure 5 Give a description.

[0038] Figure 33 is a schematic diagram of an example collimator assembly 300. As shown, the collimator assembly 300 includes a collimator 310 including a lens 312. An optical channel 320 (e.g., a fiber optic cable) is coupled to the collimator 310. The optical channel 320 can carry an optical signal. The lens 312 is designed to parallelize the received optical signal to produce a collimated beam. The focal length "FL" is defined as the distance between the connection of the optical fiber 320 to the collimator 310 and the lens 312. Parameters such as the size of the optical channel, the lens type, the focal length, etc. can be adjusted to achieve adequate collimation.

[0039] The collimator 310 may be housed within a sensor head, such as that described above with reference to Figure 1 The sensor head 120. More specifically, a plurality of collimators 310 may be housed within the sensor head, each having a corresponding optical channel 320 coupled thereto and associated with a collection cylinder pointed at a location of a sample disposed on a carrier wafer.

[0040] Figure 4 is a schematic diagram of an etch recipe development subsystem ("subsystem") 400. As shown, the subsystem 400 includes a lamp 410, a switching device 420 (eg, a multiplexer), an etch chamber 430, and an optical detector 440 (eg, a spectrometer).

[0041] The lamp 410 is configured to generate a lamp signal 412, which is sent to the switching device 420 via an optical channel (e.g., a fiber optic cable). Upon receiving the lamp signal, the switching device 420 can generate a plurality of input signals 422. The number of input signals 422 can be equal to the number of samples disposed on a carrier wafer (e.g., on corresponding specimens) within the etching chamber 430. In this illustrative embodiment, there are four input signals 422, and the four input signals 422 correspond to four corresponding samples disposed on the carrier wafer. The output signals 432 are generated during the etching process performed within the etching chamber 430, wherein each of the output signals 432 is received by a corresponding collection cylinder associated with the collimator and sent to the switching device 420 via a corresponding optical channel in the optical channels 425. The switching device 420 can select one of the output signals 432 at a time as the selected signal 424 to be sent to the optical detector 440 via the optical channel 435 for analysis. In an alternative embodiment, each of the output signals 432 may be sent to a respective optical detector instead of having a switching device 420. The input path and the output path may be switched in tandem.

[0042] Figure 55 is a graph 500 showing changes in thickness observed over time for an etching recipe applied to a plurality of samples according to some embodiments. More particularly, changes in thickness over time are observed for a first sample selected by a switching device (a multiplexer in this example) denoted as "Mux 1" 510-1, a second sample selected by the switching device denoted as "Mux 2" 510-2, a third sample selected by the switching device denoted as "Mux 3" 510-3, and a fourth sample selected by the switching device denoted as "Mux 4" 510-4. The x-axis of the graph 500 represents time (s), and the y-axis of the graph 500 represents thickness changes 500 in millimeters (mm).

[0043] In this illustrative embodiment, Mux 1 510-1 may be oxide, Mux 2 510-2 may be photoresist, Mux 3 510-3 may be nitride, and Mux 4 may be polysilicon, and the etch recipe may be an oxide etch recipe corresponding to the oxide. The oxide etch recipe may include multiple steps iterated a suitable number of times. For example, in this example, the first step ("2") may be carbon tetrafluoride (CF 4 )-argon (Ar) step, the second step ("4") can be CF 4 -Trifluoromethane (CHF 3 )-Ar step, and the third step ("6") can be CHF 3 -Ar steps are iterated three times (i.e., steps "8" and "14" are also CF 4 -Ar step, steps "10" and "16" are also CF 4 -CHF 3 -Ar step, and steps "12" and 18" are also CHF 3 -Ar steps). The lines on the graph 500 represent the start and end points of each step.

[0044] As shown in the graph 500, for each of the samples Mux 1 510-1 to Mux 2 510-4 using this oxide etch recipe, a thickness change from time 0 has been observed, which means that the oxide etch recipe has a poor etch selectivity. Note that for some other etch recipes, a substantial thickness change may be observed in only one of the samples Mux 1 510-1 to Mux 2 510-4, thereby indicating good etch selectivity. For example, a photoresist etch recipe may result in a substantial thickness change being observed only in Mux 2 510-2, thereby indicating good etch selectivity.

[0045] Figure 6is a flow chart of a method 600 for implementing an etch recipe development process using multi-reflection measurement according to some embodiments. The method 600 may be performed by processing logic, which may include hardware (e.g., a processing device, a circuit system, dedicated logic, programmable logic, microcode, hardware of a device, an integrated circuit, etc.), software (e.g., instructions running or executed on a processing device), or a combination thereof. In some embodiments, the method 600 is performed by Figure 1 The processing device 136 of the embodiment of the present invention is executed. Although shown in a specific order or sequence, unless otherwise specified, the order of the process can be modified. Therefore, the described embodiments should be understood as merely examples, and the described processes can be performed in a different order, and some processes can be performed in parallel. In addition, one or more processes can be omitted in various embodiments. Therefore, not all processes are required in every embodiment. Other process flows are possible.

[0046] At operation 610, processing logic receives a request to initiate an iteration of an etching process using an etching recipe to etch a plurality of materials located at corresponding reflectometry measurement points in a plurality of reflectometry measurement points. The plurality of materials are pre-determined as materials of interest to determine etching rates and / or etching selectivities. The plurality of materials may correspond to corresponding specimens placed on a carrier wafer. More particularly, different materials may be placed at each measurement point. Additional specimens may be added to simulate appropriate material loads (or different specimen sizes). The carrier wafer may then be placed in a housing (e.g., a front-opening wafer standard / universal cabin (FOUP)), and the carrier wafer may be loaded into an etching chamber with a robot to undergo an etching process.

[0047] At operation 620, processing logic obtains material thickness data for each of the materials produced by the iteration of the etching process. For example, after receiving the request, processing logic may cause the plurality of materials to be exposed to an etchant determined by an etching recipe. Due to the etching recipe used, the thickness of one or more materials may decrease over time.

[0048] More particularly, the processing logic may obtain material thickness data based on an analysis performed by at least one optical detector. For example, during an etching process, at least one lamp may generate light for reflection from a carrier wafer, a collecting cylinder corresponding to a plurality of collimators may collect the reflected light to generate an output signal, and the output signal may be transmitted to at least one optical detector to generate a result based on an analysis of the wavelength and / or intensity of the output signal. For example, the at least one optical detector may be a spectrometer, and the plurality of collimators may be housed in a sensor head. The processing logic may process the results generated by the at least one optical detector to obtain material thickness data. In some embodiments, the at least one optical detector is a single optical detector operatively coupled to a switching device (e.g., a multiplexer). In an alternative embodiment, the at least one optical detector includes a plurality of optical detectors, each of the plurality of optical detectors being configured to receive a corresponding one of the output signals.

[0049] At operation 630, processing logic determines one or more etching parameters based on the material thickness data. The one or more etching parameters may include at least one of an etching rate and an etching selectivity. For example, an etching rate for a given material may be calculated based on a change in thickness over time. The etching selectivity may be calculated by comparing the change in thickness over time between at least two of the materials. For example, if a given material exhibits high removal in response to an etching recipe, while other materials exhibit low removal in response to the etching recipe, then the given material has a relatively high etching selectivity.

[0050] At operation 640, processing logic determines whether one or more etching parameters meet an etching parameter target. For example, the etching parameter target may include a threshold etching selectivity and / or a threshold etching rate to be achieved. The etching parameter target may be one or more values ​​(e.g., a specific etching selectivity and / or a specific etching rate), or may be a range of values ​​(e.g., a range of etching selectivities and / or a range of etching rates).

[0051] If at operation 640, one or more etching parameters fail to meet the etching parameter target, then at operation 650, the processing logic obtains a modified etching recipe, and at operation 610, the processing logic may receive another request to start another iteration of the etching process using the modified etching recipe. In some embodiments, the modified etching recipe can be obtained by receiving a manual modification of one or more etching recipe conditions. Examples of etching recipe conditions include, but are not limited to, gas type, gas concentration, pressure, RF power, and RF pulsing. In some embodiments, obtaining a modified etching recipe includes automatically modifying the etching recipe. More particularly, one or more etching recipe conditions can be automatically modified or adjusted based on the etching parameter target. For example, according to embodiments described herein, any suitable statistical method (e.g., multivariate DoE method) and / or machine learning method can be used to perform automatic recipe modification.

[0052] If one or more etching parameters meet the etching parameter target, this means that the etching recipe conditions are satisfactory. Therefore, the etching recipe development process can be terminated at block 660.

[0053] Figure 7 is a block diagram illustrating a computer system 700 according to some embodiments. In some embodiments, the computer system 700 is included in Figure 1 within subsystem 130.

[0054] In some embodiments, the computer system 700 is connected to other computer systems (e.g., via a network, such as a local area network (LAN), an intranet, an extranet, or the Internet). In some embodiments, the computer system 700 operates as a server or client computer in a client-server environment, or operates as a peer computer in a peer-to-peer or distributed network environment. In some embodiments, the computer system 700 is provided by a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, a network device, a server, a network router, a switch or a bridge, or any device capable of executing a set of instructions (sequential or otherwise) specifying the action to be taken by the device. In addition, the term "computer" shall include any collection of computers that execute a set (or multiple sets) of instructions individually or jointly to execute any one or more methods of the methods described herein.

[0055] In another aspect, the computer system 700 includes a processing device 702, a volatile memory 704 (e.g., a random access memory (RAM)), a non-volatile memory 706 (e.g., a read-only memory (ROM) or an electrically-erasable programmable ROM (EEPROM)), and a data storage device 716, which communicate with each other via a bus 708.

[0056] In some embodiments, the processing device 702 is provided by one or more processors, such as a general-purpose processor (e.g., a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a microprocessor that implements other types of instruction sets, or a microprocessor that implements a combination of multiple instruction sets) or a special-purpose processor (e.g., an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), or a network processor).

[0057] In some embodiments, the computer system 700 further includes a network interface device 722 (e.g., coupled to the network 774). In some embodiments, the computer system 700 also includes a video display unit 710 (e.g., LCD), an alphanumeric input device 712 (e.g., keyboard), a cursor control device 714 (e.g., mouse), and a signal generating device 720.

[0058] In some embodiments, the data storage device 716 includes a non-transitory computer-readable storage medium 724 having stored thereon instructions 726 encoding any one or more of the methods or functions described herein. For example, the instructions 726 may include Figure 1 The etch recipe component 139, when executed, can implement a method for etch recipe development, such as Figure 6 Method 600.

[0059] In some embodiments, the instructions 726 also reside, in whole or in part, within the volatile memory 704 and / or within the processing device 702 during execution by the computer system 700, and thus, in some embodiments, the volatile memory 704 and the processing device 702 also constitute machine-readable storage media.

[0060] Although the computer-readable storage medium 724 is shown as a single medium in the illustrative example, the term "computer-readable storage medium" shall include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of executable instructions. The term "computer-readable storage medium" shall also include any tangible medium that can store or encode a set of instructions for execution by a computer, the instructions causing the computer to perform any one or more of the methods described herein. The term "computer-readable storage medium" shall include, but is not limited to, solid-state memories, optical media, and magnetic media.

[0061] In some embodiments, the methods, components, and features described herein are implemented by discrete hardware components, or integrated into the functionality of other hardware components (such as ASICs, FPGAs, DSPs, or similar devices). In some embodiments, the methods, components, and features are implemented by firmware modules or functional circuitry within a hardware device. In some embodiments, the methods, components, and features are implemented in any combination of hardware devices and computer program components, or in a computer program.

[0062] Unless otherwise specifically stated, terms such as "training", "identifying", "further training", "retraining", "causing", "receiving", "providing", "obtaining", "optimizing", "determining", "updating", "initializing", "generating", "adding" or similar terms refer to actions and processes performed or implemented by a computer system that manipulate and transform data represented as physical (electronic) quantities within computer system registers and memories into other data similarly represented as physical quantities within computer system memories or registers or other such information storage, transmission or display devices. In some embodiments, the terms "first", "second", "third", "fourth", etc., as used herein, are meant as labels to distinguish different elements and do not have an ordinal meaning based on their numerical names.

[0063] The examples described herein also relate to a device for performing the methods described herein. In some embodiments, the device is specially constructed to perform the methods described herein, or includes a general-purpose computer system selectively programmed by a computer program stored in the computer system. Such a computer program is stored in a computer-readable tangible storage medium.

[0064] The methods and illustrative examples described herein are not inherently related to any particular computer or other device. In some embodiments, various general purpose systems are used according to the teachings described herein. In some embodiments, more specialized devices are constructed to perform the methods described herein and / or each of their individual functions, routines, subroutines, or operations. Examples of the structures of various these systems are set forth in the above description.

[0065] The above description is intended to be illustrative, not limiting. Although the present disclosure has been described with reference to specific illustrative examples and embodiments, it will be appreciated that the present disclosure is not limited to the described examples and embodiments. The scope of the present disclosure should be determined with reference to the appended claims together with the full scope of equivalents to which the claims are entitled.

Claims

1. A system for measuring etching parameters, comprising: a memory storing instructions to facilitate an etch recipe development process; and at least one processing device operatively coupled to the memory, wherein the instructions, upon execution by the at least one processing device, cause the at least one processing device to facilitate the etch recipe development process by performing operations comprising: obtaining, from an optical detector, first material thickness data for a first material and second material thickness data for a second material resulting from an iteration of an etching process using an etching recipe, wherein the first material is located at a first reflectometry measurement point and the second material is located at a second reflectometry measurement point that is different from the first reflectometry measurement point; and One or more etching parameters are determined based on at least the first material thickness data and the second material thickness data.

2. The system of claim 1, wherein the first material and the second material are each disposed on a respective coupon on a carrier wafer.

3. The system of claim 1 , wherein the first reflectometry measurement point corresponds to a first collecting cylinder associated with a first collimator located above the first reflectometry measurement point, and wherein the second reflectometry measurement point corresponds to a second collecting cylinder associated with a second collimator located above the second reflectometry measurement point.

4. The system of claim 1, wherein the operations further include enabling the optical detector to selectively measure the first material thickness data and the second material thickness data.

5. The system of claim 1, wherein the one or more etching parameters include at least one of: etch selectivity or etch rate.

6. The system of claim 1, wherein the operations further comprise: determining whether the one or more etch parameters fail to meet an etch parameter target; In response to determining that the one or more etching parameters fail to meet the etching parameter target, obtaining a modified etching recipe; and A second iteration of the etching process is initiated using the modified etching recipe.

7. The system of claim 6, wherein obtaining the modified etch recipe further comprises automatically modifying one or more etch recipe conditions of the etch recipe.

8. The system of claim 7, wherein the one or more etching recipe conditions include at least one of: gas type, gas concentration, pressure, RF power, or RF pulse.

9. The system of claim 1, wherein the operations further comprise: determining whether the one or more etch parameters meet an etch parameter target; and In response to determining that the one or more etch parameters satisfy the etch parameter target, the etch recipe development process is terminated.

10. A method for measuring etching parameters, comprising the steps of: obtaining, by at least one processing device, from an optical detector, first material thickness data for a first material and second material thickness data for a second material resulting from an iteration of an etching process using an etching recipe, wherein the first material is located at a first reflectometry measurement point and the second material is located at a second reflectometry measurement point, the second reflectometry measurement point being different from the first reflectometry measurement point; and One or more etching parameters are determined by the at least one processing device based on at least the first material thickness data and the second material thickness data.

11. The method of claim 10, wherein the first material and the second material are each disposed on a respective coupon on a carrier wafer.

12. The method of claim 10, wherein the first reflectometry measurement point corresponds to a first collecting cylinder associated with a first collimator located above the first reflectometry measurement point, and wherein the second reflectometry measurement point corresponds to a second collecting cylinder associated with a second collimator located above the second reflectometry measurement point.

13. The method of claim 10, wherein the one or more etching parameters include at least one of: etch selectivity or etch rate.

14. The method of claim 10, further comprising the steps of: determining, by the at least one processing device, whether the one or more etch parameters fail to meet an etch parameter target; obtaining, by the at least one processing device, a modified etch recipe in response to determining that the one or more etch parameters fail to meet the etch parameter target; and A second iteration of the etching process is initiated by the at least one processing device using the modified etching recipe.

15. The method of claim 14, wherein obtaining the modified etch recipe further comprises automatically modifying one or more etch recipe conditions of the etch recipe.

16. The method of claim 10, further comprising the steps of: determining, by the at least one processing device, whether the one or more etch parameters meet an etch parameter target; and In response to determining that the one or more etch parameters satisfy the etch parameter target, terminating the etch recipe development process by the at least one processing device.

17. A system for measuring etching parameters, comprising: an optical detector operatively coupled to the switching device to selectively measure material thickness data generated by iterations of the etching process; a memory storing instructions to facilitate an etch recipe development process; and at least one processing device operatively coupled to the memory, the optical detector, and the switching device, wherein the instructions, once executed by the at least one processing device, cause the at least one processing device to facilitate the etch recipe development process by determining one or more etch parameters based on at least first material thickness data of a first material and second material thickness data of a second material, wherein the first material is located at a first reflectometry measurement point and the second material is located at a second reflectometry measurement point, the second reflectometry measurement point being different from the first reflectometry measurement point.

18. The system of claim 17, wherein the first material and the second material are each disposed on a respective coupon on a carrier wafer.

19. The system of claim 17, wherein the first reflectometry measurement point corresponds to a first collecting cylinder associated with a first collimator located above the first reflectometry measurement point, and wherein the second reflectometry measurement point corresponds to a second collecting cylinder associated with a second collimator located above the second reflectometry measurement point.

20. The system of claim 17, wherein the one or more etching parameters include at least one of: etch selectivity or etch rate.

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