System and method for characterizing samples in a small box using XPS for multiple measurement scenarios

Abstract

A system for characterizing a film layer within a measurement box is disclosed. The system obtains a first mixture fraction corresponding to a first X-ray beam, where the mixture fraction represents the fraction of the first X-ray beam within a measurement box of a wafer sample. The measurement box represents a hole structure disposed above a substrate and has a film layer disposed within the hole structure. The system obtains a contribution value of the measurement box corresponding to the first X-ray beam, where the contribution value represents the contribution of a species signal outside the measurement box to the same species signal within the measurement box. The system uses the first X-ray beam to obtain a first measurement detection signal corresponding to a measurement of the measurement box. The system determines a measurement value of the film layer based on the first measurement detection signal, the contribution value, and the first mixture fraction.

Description

Technical Field

[0001] The present disclosure relates generally to techniques for characterizing and measuring semiconductor structures, and particularly to techniques for characterizing and measuring material layers in a cell using X-ray photoelectron spectroscopy (XPS) in the context of multiple measurements. Background Art

[0002] Integrated circuits (ICs) typically include many layers formed on a silicon substrate. As integrated circuits become smaller and the thickness of the layers comprising the integrated circuit decreases, the performance of the devices formed by these layers often depends on the thickness of a particular layer. For example, a transistor formed on a silicon substrate can have different characteristics depending on the thickness of the transistor's gate.

[0003] The layers on an IC are deposited on a substrate using deposition techniques, where patterns are etched into the layers to form various IC components. Such patterns include trenches or fillers (boxes). When trenches or boxes are coated with additional layers of material and the trenches and boxes are small, checking the appropriate layer thickness and verifying the coating material deposited within the trenches and boxes can become difficult. Therefore, it may be useful to determine the thickness of the film layer within the small box area.

[0004] The thickness of a film layer deposited on a substrate can be determined using one of several techniques. One technique is X-ray photoelectron spectroscopy (XPS). With XPS, an XPS spectrum is obtained by irradiating a substrate with an X-ray beam while measuring the kinetic energy and number of electrons escaping from the top layer of the substrate.

[0005] 1. Problem to be solved

[0006] As IC components are manufactured smaller and smaller, the X-ray beam used for the XPS method may not fit within the cell area. When an X-ray beam with a beam size larger than the cell area is used, it irradiates both the area within the cell and the area surrounding the cell, resulting in the collected XPS signal emanating from material both within and around the cell. Therefore, it is difficult to determine which portion of the XPS signal corresponds to material originating solely from within the cell. There is a need to improve the analytical accuracy of XPS methods for small cell areas. Summary of the Invention

[0007] The following summary of the disclosure is included to provide a basic understanding of some aspects and features of the disclosure. This summary is not an extensive overview of the disclosure and, as such, is not intended to specifically identify key or important elements of the disclosure or to delineate the scope of the disclosure. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description presented below.

[0008] The disclosed embodiments enable the use of XPS to characterize and measure film layers within a cell in multiple measurement scenarios. In some disclosed embodiments, XPS measurements are used to analyze specific properties of a film layer within the cell, such as the thickness or composition of the film layer, with some spillover of the XPS signal outside the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other aspects and features of the present disclosure will become apparent from the detailed description which proceeds with reference to the accompanying drawings.It should be understood that the detailed description and the accompanying drawings provide various non-limiting examples of various embodiments of the present disclosure as defined by the appended claims.

[0010] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain and illustrate the principles of the present disclosure. The drawings are intended to illustrate the main features of the exemplary embodiments in a diagrammatic manner. The drawings are not intended to depict every feature of actual embodiments or the relative sizes of the depicted elements, and are not drawn to scale.

[0011] Figure 1 is a partial cross-section of a wafer sample illustrating measurements according to some embodiments;

[0012] Figure 1A is a schematic diagram illustrating an example of determining the layer thickness of a film stack outside a cell structure;

[0013] Figure 1B is a schematic diagram illustrating an example of determining the layer thickness of a film stack inside a cell structure;

[0014] Figure 2 An example of a measuring device is shown;

[0015] Figure 3A illustrates an example of measurement of a reference wafer sample using nominal beam 1;

[0016] Figure 3B illustrates an example of measurement of a reference wafer sample using beam 2 having a larger spot diameter;

[0017] Figure 4A illustrates an example of measurement of a measurement wafer sample using a nominal beam 1;

[0018] Figure 4B illustrates an example of measurement of a measurement wafer sample using a beam 2 having a larger spot diameter;

[0019] Figure 5 illustrates an example of measurement of a measurement wafer sample using a nominal beam 1;

[0020] Figure 6 is a flow chart illustrating an example of a method;

[0021] Figure 7 is a partial cross section of an example of a wafer sample having a cassette showing two film layers;

[0022] Figure 8A An example of measurement of a reference wafer sample using X-ray scanning is shown;

[0023] Figure 8B An example of measurement of a reference wafer sample using Y line scanning is shown;

[0024] Figure 9 An example of a simulation of beam parameters of an X-ray beam is shown;

[0025] Figure 10A Figure 2 shows an example of simulated and measured mixture fractions versus the central cross section in the Y direction.

[0026] Figure 10B Figure 2 shows an example of simulated and measured mixture fractions versus the central cross section in the X direction.

[0027] Figure 10C An example illustrating mixing fraction versus beam position relative to the box center for an X-ray scan;

[0028] Figure 11A An example of measuring a wafer sample using X-ray scanning is shown;

[0029] Figure 11B FIGURE 1 illustrates an example of measurement of a wafer sample using Y-line scanning;

[0030] Figure 12 is a flow chart illustrating an example of a method;

[0031] Figure 13 is a flow chart illustrating an example of a method;

[0032] Figure 14 is a flow chart illustrating an example of a method;

[0033] Figure 15 is a flow chart illustrating an example of a method;

[0034] Figure 16 is an example of a pad positioned above a substrate;

[0035] Figure 17 is a flowchart illustrating an example of a method; and

[0036] Figure 18 is an example of a simulation of the thickness of a material. DETAILED DESCRIPTION

[0037] Embodiments of the characterization and measurement methods / systems are described with reference to the accompanying drawings. Different embodiments or combinations thereof may be used for different applications or achieve different benefits. Depending on the results sought to be achieved, the various features disclosed herein may be utilized partially or fully, individually or in combination with other features, thereby balancing advantages with requirements and constraints. Therefore, certain benefits will be emphasized with reference to various embodiments, but are not limited to the disclosed embodiments. That is, the features disclosed herein are not limited to the embodiments in which they are described, but may be "mixed and matched" with other features and incorporated into other embodiments.

[0038] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, processes, and components are not described in detail in order to avoid obscuring the present invention.

[0039] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification.The invention, however, both as to its organization and method of operation, together with objects, features and advantages thereof, may be best understood by reference to the following detailed description when read in connection with the accompanying drawings.

[0040] It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. In addition, where deemed appropriate, reference numerals may be repeated in the figures to indicate corresponding or similar elements.

[0041] Any reference in the specification to any of the systems, methods, and non-transitory computer-readable media shall apply mutatis mutandis to any other aspects of the systems, methods, and non-transitory computer-readable media. For example, any reference to a system shall apply mutatis mutandis to a method that can be performed by the system and a non-transitory computer-readable medium that can store instructions executable by the system.

[0042] Because at least one of the illustrated embodiments of the present invention can be implemented, for the most part, using electronic components and circuits known to those skilled in the art, details will not be explained to any greater extent than deemed necessary as described above in order to understand and appreciate the basic concepts of the invention and so as not to obscure or distract from the teachings of the invention.

[0043] Any numbers or values ​​shown below should be considered as non-limiting examples.

[0044] Various examples relate to film layers made of SiO2 and substrates made of Si. It should be noted that these are merely non-limiting examples of materials, and that the film layers may be made of materials other than SiO2 and / or the substrate may be made of materials other than Si. Any reference to SiO2 and Si should apply, mutatis mutandis, to any film layer material and substrate material, respectively.

[0045] Figure 1 A cross section of a portion of a semiconductor wafer sample 100 is illustrated, illustrating a characterization or measurement process, such as determining the type and / or thickness of a type of thin film layer on the sample (e.g., approximately 0 nm to 10 nm thick). A base layer 101, such as a wafer substrate, is made of silicon, and a layer of insulator 105 is formed over the base layer 101. In this example, a silicon dioxide layer is formed over the Si substrate base layer. The silicon dioxide layer 105 is patterned by etching holes in the shape of square or round boxes 110, having a slide length or diameter of 30 μm in this particular example. In actual production, many such holes would be formed in the insulating layer 105, but for the purpose of understanding the embodiments, only one such hole will be described. The hole in this example does not reach the substrate, so that a thin film of silicon dioxide 115 remains in the bottom of the hole over the base layer 101. Although in Figure 1 In this example, a silicon dioxide layer 105 is formed on a silicon substrate 101 and etched to form a box 110, but any other material (silicon nitride, other oxides or nitrides, etc.) or fabrication process (e.g., selective deposition, etc.) may be used to form the box 110. The box 110 may be rectangular, circular, trench-shaped, etc. Additionally, an intervening layer of a different material may be present between the substrate 101 and the dielectric layer 105 in which the hole is formed.

[0046] According to one embodiment, XPS is used to characterize the cassette 110, ie, to determine the presence of a film layer and the composition and thickness of the film layer within (or beneath) the cassette 110. Figure 1 As an example, in an embodiment, XPS is used to determine whether a silicon dioxide film layer remains at (or beneath) the cassette 110 and, if so, the thickness of such a film layer.

[0047] In one embodiment, X-ray irradiation Figure 1The sample shown is taken and the resulting photoelectron emission from the sample is examined (indicated by the arrows). If the X-ray beam generates a spot 120 that fits within a 30 μm box 110, the attenuation of the emission from the Si substrate 101 caused by the SiO2 layer 115 (referred to herein as the Si signal) can be used to calculate the thickness of the SiO2 layer 115. However, in this specific example, because the generated X-ray beam has a spot 120 with a diameter greater than the size of 30 μm, the XPS signal overflows outside the box 110. In this case, the attenuation of the emission from the SiO2 has a component of the signal inside the box and a component of the signal outside the box (e.g., overflow). According to one embodiment, multiple measurements are performed on a reference to the box 110 to determine the mixing fraction of the beam (the fraction of the beam inside the box). Using the mixing fraction, multiple measurements are performed on the box 110 to determine the contribution value of the species signal outside the box that contributes to the same species signal inside the box. The mixing fraction and the contribution value can then be used to calculate the thickness of the SiO2 layer 115.

[0048] Figure 2 An example of an X-ray system 200 for characterization or measurement processes, as used in various embodiments disclosed herein, is shown. The operations and analyses of the system described herein can be performed by one or more computers 205. In one embodiment, computer 205 can be a standalone computer located at a customer site. Computer 205 can store instructions for software on a suitable non-volatile computer-readable storage medium and can execute the instructions in hardware using one or more processors to implement the techniques described herein.

[0049] Electron gun 210 emits an electron beam, which is directed to strike anode 215, which is made of aluminum in this example. Consequently, X-rays are generated at the anode and directed toward monochromator 220. The X-rays are then diffracted at the monochromator. In this example, monochromator 220 is made of quartz crystal and is configured to focus only Al Kα X-rays onto wafer 225. A small amount of this Al Kα can also be collected at flux detector 230. The signal from flux detector 230 can be converted from X-ray counts to a flux number. The flux number can be used as a reference indicator of the X-rays striking the wafer.

[0050] The primary Al Kα X-ray beam is directed to strike the wafer 225. As the X-rays pass through the multi-layer wafer 225, electrons and secondary X-rays are emitted from each of the multi-layer wafers. The XPS energy analyzer 240 collects the emitted electrons and directs them toward the XPS detector 245. The XPS energy analyzer 240 typically separates the emitted electrons according to their energy, similar to a prism that separates white light by photon frequency. Therefore, the signal generated by the XPS detector 245 can be used to measure the number of electrons (i.e., intensity) at each specific energy. A sample graph generated by the computer 205 that plots the intensity (number of electrons) versus the binding energy is displayed on the monitor 250.

[0051] The graph illustrated in monitor 250 illustrates how materials within a sample can be identified. In this particular example, wafer 225 is made of silicon and has a first silicon dioxide layer 105 or a thin film layer of silicon monoxide 115. The various peaks in the graph can be used to identify the materials present in the sample under inspection (here, wafer 225).

[0052] According to one embodiment, the attenuation of the XPS signal from one layer is used to infer the presence of a different material layer above it. Furthermore, if the X-ray beam is contained within the box 110, the attenuation can be used to quantify the thickness of the layer above. For an X-ray beam with spillover of species signal outside the box 110, the mixing fraction f can be used to quantify the fraction of the beam inside the box (e.g., f) and the fraction of the beam outside the box (e.g., 1-f), which can be used to calculate the spillover of the species signal.

[0053] Steering Figure 1 A specific example of Figure 1B For example, in the case of a mixture fraction f = 1, for a cover layer SiO2 with a thickness of t0, the type S ( Figure 1B The signal in the middle will be attenuated as follows: Si =I Si 'e(-t0 / λSi ,SiO) , where I Si ' (sometimes referred to as reference intensity or reference electron count) is the intensity of photoelectrons from species Si before passing through the layer SiO2, and λ Si,SiO is a material parameter (effective attenuation length (EAL)) of a specific type of photoelectron from species Si that passes through the material SiO2, for example, a silicon 2p photoelectron emitted from silicon and passing through SiO2. In this disclosure, the abbreviation EAL of material A in material B may be used, but it should be understood to refer to a specific photoelectron emitted from the material. When other species are present (in addition to the SiO2 thin layer and / or in addition to the Si substrate), the intensity index (in I Si In case of Si and / or I SiOSiO in the case of Si , K SiO ,λ Si,SiO and / or λ SiO ) will change to reflect the different categories (different materials).

[0054] Based on the above equation, if Figure 1B As illustrated, for an X-ray beam with a mixing fraction less than 1, the Si species signal attenuation can be modeled as follows: Si Model =fe (-t0 / λSi’SiO) / K Si , where f is the mixture fraction, and K Si is a constant representing the effective contribution of Si to the signal intensity. Therefore, the attenuation signal of silicon passing through the SiO2 cover layer is expressed as an exponential ratio of the thickness of the cover layer to the effective attenuation length of silicon passing through SiO2, which is given by the silicon scaling factor K Si scaled by , and further scaled by the mixture fraction f.

[0055] The signal generation of the SiO2 species can be similarly modeled as follows: SiO Model =f(1-e (-t0 / λSiO) ) / K SiO , where K SiO is a constant representing the effective contribution of SiO2 to the signal intensity, λ SiO is the material parameter (effective attenuation length (EAL)) of a particular type of photoelectron from the species SiO2 passing through the material SiO2. Thus, the signal from the SiO2 capping layer is expressed as a function of the ratio of the thickness of the capping layer to the effective attenuation length of silicon passing through SiO2, given by the silicon scaling factor K. SiO scaled by , and further scaled by the mixture fraction f.

[0056] Steering Figure 1A , for a thick cover layer 105 (about 100 nm), the Si type signal attenuation can be approximately zero. That is, assuming that the cover layer 105 is thick enough so that I Si It will not be generated outside the box. The SiO2 signal can be modeled as follows: SiO Model =(lf) / K SiO Therefore, the SiO2 signal can be expressed as the SiO2 scaling factor K SiO , and further scaled by the spillover factor (1-f).

[0057] Reference again Figure 1 The wafer sample to be characterized is a substrate of material B and includes a cassette having a thickness of t formed thereon. thick(For example, Figure 1 The first layer of material A (about 100 nm) and the thickness of the inside of the box are t thin (For example, Figure 1 The remaining film layer of material A (about 2 nm in the middle). A and I B The light emission will be attenuated independently by the presence of layer A, reducing the mixed fraction representing the fraction of the X-ray beams of weights A and B directed inside the box, and the intensity is modified by the contribution of the overflow representing the X-ray beam outside the box. Subsequent figures may refer to the substrate as material B and the cover layer as material A.

[0058] In one embodiment, the raw intensity numbers are not used directly because the flux variation from measurement to measurement and also from tool to tool needs to be taken into account. Therefore, the X-ray flux numbers can be used to normalize the raw intensity. In one embodiment, the raw intensity numbers are used directly as the species signal. In one embodiment, I Si ' or 1 / K Si The value of is known and can be used as a constant to scale the species signal based on requirements or experience. For example, I Si The value of ' can be obtained by performing XPS measurements on the wafer substrate before depositing the top layer, and it can be the photoelectron intensity per a certain unit of incident X-ray flux or a certain nominal flux, etc.

[0059] In some embodiments, the measured intensity ratio (I SiO / I Si ) can be compared with the total model strength ratio (I SiO M / I Si M ) for further characterization Figure 1 For example, the residual function (or evaluation function (M)) can be determined as follows:

[0060]

[0061] in, and

[0062] Among them, M represents the evaluation function, represents the measured intensity ratio, Modeling ratio representing species intensity, I Si Indicates the measured species intensity of Si, I SiO represents the measured species intensity of SiO2, t0 represents the thickness of the SiO2 film 115 inside the box 110, K Sirepresents a constant indicating the effective contribution of Si to the intensity of the species signal, K SiO represents a constant indicating the effective contribution of SiO2 to the intensity of the species signal, and f represents the mixing fraction indicating the fraction of the incident beam inside the cell, etc.

[0063] If it is assumed that no I is generated outside the box 110 Si , then there will be no K Si Contribute and I SiO M and I Si M It can be approximated as follows:

[0064] as well as

[0065] The M function can be In this example, there are more unknowns than intensity ratios. Therefore, we need additional data points to characterize box 110.

[0066] In the following disclosure, multiple measurements (first beam and second beam) are used with a reference wafer sample to characterize Figure 1 The box 110, as shown in FIG3 to Figure 6 to solve for multiple unknowns as further described in .

[0067] Figure 3A The diagram shows a measurement using a nominal beam 1 to characterize a reference sample 300, and Figure 3B The figure shows a measurement of a reference sample 300 using a beam 2 having a larger spot diameter according to one embodiment. The reference sample 300 may represent Figure 1 The sample 100 is a sample 100 having a box 310 with a side length of 30 μm. The reference sample 300 has a Si substrate (not shown) of known material and a SiO2 capping layer 305 of known material. Here, to increase the number of data points, beam 1 and beam 2 are used to characterize the reference sample 300. Beam 1 has a spot with a diameter of 40 μm, providing a first mixture fraction f1, and beam 2 has a spot with a diameter of 50 μm, providing a second mixture fraction f2. In addition, to reduce the number of unknowns, the reference wafer has the same size of 30 μm as the known species and the same species thickness as the SiO2 film layer 315, for example, with a thickness of 2 nm.

[0068] In one embodiment, to produce a sample 300 with a known thickness, a similar box (hole structure) with a side length of 200 μm (not shown) can be used to etch the wafer sample 300 and a 40 μm beam can be used to characterize the 200 μm box to provide a known thickness. Here, it is assumed that the 200 μm box is etched by a similar process as the 30 μm box, and both the 200 μm box and the 30 μm box have the same film thickness inside these boxes. Since the 40 μm beam applied to the 200 μm box should have all kinds of signals inside the box (e.g., no overflow), the thickness can be calculated by the attenuation equation I as described above. Si =I Si 'e (-’t0 / λSi,SiO) to confirm.

[0069] With a 30 μm cell and a known film material (SiO2) and known thickness (2 nm), the merit function for characterizing sample 300 using beam 1 can be as follows:

[0070]

[0071] Where M1 represents the evaluation function of beam 1, represents the measured intensity ratio of beam 1, The modeled ratio representing the intensity of the type of beam 1, measured I Si1 represents the measured species intensity of Si using beam 1, I SiO1 represents the measured species intensity of SiO2 using beam 1, t represents the thickness of the SiO2 film 315 inside the box 310, K SiO represents a constant indicating the effective contribution of SiO 2 to the intensity of the species signal, and f1 represents a first mixture fraction.

[0072] The merit function for characterizing sample 300 using beam 2 may be as follows:

[0073]

[0074] Where M2 represents the evaluation function of beam 2, represents the measured intensity ratio of beam 2, The modeled ratio representing the intensity of the type of beam 2, measured I Si2 represents the measured species intensity of Si using beam 2, I SiO2 represents the measured species intensity of SiO2 using the light beam 2, t represents the thickness of the SiO2 film 315 inside the box 310, K SiOrepresents a constant indicating the effective contribution of SiO2 to the intensity of the species signal, and f2 represents the second mixture fraction. (Note that in the merit function, the symbols SiO1 and SiO2 represent the silicon dioxide signals obtained from beam 1 and beam 2, rather than silicon monoxide and silicon dioxide.)

[0075] Referring to the first and second evaluation functions (M1, M2), the known value is the type signal I Si1 , I SiO1 (First measurement using beam 1), category signal I Si2 , I SiO2 (Second measurement using beam 2), t and K SiO The unknown values ​​are the mixture fractions f1 and f2. Since there are two equations with two unknowns, the mixture fractions f1 and f2 can be calculated independently using the merit functions M1 and M2. In another embodiment, the mixture fractions can be calculated using the merit functions through regression techniques.

[0076] Once the mixture fraction of beam 1 and beam 2 is known, such as Figures 4A to 4B As shown in , the characterization process can then perform additional measurements on a measurement sample 400 having an unknown material and an unknown thickness using the same respective beams 1 and 2 as long as the dimensions of the box remain the same as the reference sample.

[0077] Figure 4A illustrates the measurement of a measurement sample 400 using a nominal beam 1, and Figure 4B 1 illustrates a measurement of a reference sample 400 using a beam 2 according to one embodiment. The reference sample 400 may represent Figure 1 The measurement sample 400 may be provided by the customer, wherein the box 410 has a known box size of 30 μm×30 μm, similar to Figures 3A to 3B Dimensions of the reference sample 300.

[0078] As previously described, beam 1 has a spot size of 40 μm in diameter, providing a first mixture fraction f1, and beam 2 has a spot size of 50 μm in diameter, providing a second mixture fraction f2. Furthermore, since the measurement sample 400 has the same 30 μm cell size as the reference sample 300, the mixture fractions f1 and f2 will be the same as previously described for Figures 3A to 3B Here, the measurement sample 400 has a substrate (not shown) of unknown material B and a cover layer 405 of unknown material A. Within the box 410, a film layer 415 of material A is located on the surface of the substrate of material B.

[0079] Multiple measurements can be used to characterize the measurement sample 400, such as beam 1 (40 μm spot) in measurement 1, where raw intensity data is collected and stored for measurement 1. Next, the X-ray beam can be adjusted to provide beam 2 (50 μm larger spot) to characterize the measurement sample 400 in measurement 2, and raw intensity data for measurement 2 is collected and stored.

[0080] After measurement, the merit functions characterizing beam 1 and beam 2 can be as follows:

[0081] M(I A1 ,I B1 .I A2 ,I B2 f1,f2,t,K A )=M1+M2,

[0082] as well as

[0083]

[0084] in, And among them, The modeled intensity of the type signal A representing beam 1 or beam 2, represents the modeling intensity of the type signal B of beam 1 or beam 2, M represents the evaluation function, and I A1 represents the measured species intensity of material A using beam 1, I B1 represents the measured species intensity of material B using beam 1, I A2 represents the measured species intensity of material A using beam 2, I B2 represents the measured species intensity of material B using light beam 2, f1 represents the first mixture fraction, f2 represents the second mixture fraction, t represents the thickness of the film layer 415 of material A inside the box 410, K A represents a constant indicating the effective contribution of A to the strength of the species signal, and λ 1,2 is a material parameter (effective attenuation length (EAL)) of a particular type of photoelectron from species A, B passing through material A. Note that λ can be derived based on the binding energy of the species signal by a lookup table or from the NIST database.

[0085] In this case, there are two measured signal ratios and two unknowns (t and K) in the evaluation function M. A The evaluation function M can be solved numerically to obtain the unknowns (t and K A In one embodiment, regression can be used to simultaneously find the raw spectral ratios that make the measurements (e.g., I A1 / I B1 and I A2 / IB2 ) and the modeled or estimated photoemission intensity ratio (e.g., I A1 M / I B1 M and I A2 M / I B2 M ) minimizes the evaluation function between t and K A The value of , as obtained by the above expression.

[0086] For example, you can iterate over different t and K in the expression A Value, to model the ratio intensity I A1 M / I B1 M Different values ​​are generated and then inserted into the evaluation function M1 until the value of M1 is minimized to determine t and K A At the same time, t and K can be used iteratively in the expression A , to model the intensity I A2 M and I B2 M Different values ​​are generated and then inserted into the evaluation function M2 until the values ​​of M1 and M2 are minimized to simultaneously determine t and K A Here, the signal (1-f 1,2 ) / K A The part contributes to the species signal from outside the box to inside the box.

[0087] Figure 5 The figure shows a typical optical beam 1 (40 μm spot) for a laser beam with a known cover material (K A )505 and unknown thickness (t) of known material K A The measurement of the sample 500 of the film layer 515 can represent Figures 4A to 4B In one embodiment, the sample 500 can be prepared with a box 510 having a side length of 30 μm. Figures 4A to 4B The same blanket material as in sample 400 is manufactured in a batch process. Since the mixture fraction and blanket material 505 are known from previous measurements, the thickness measurements of the film layer can be calculated.

[0088] For example, the merit function for measuring sample 500 using beam 1 may be as follows:

[0089]

[0090] Measurement ratio of type signal I A1 / I B1 It can be obtained from the XPS measurement of sample 500. A and f1 are from the previous measurements (from Figures 4A to 4B is known in the measurement of , so t can be calculated based on the evaluation function M1.

[0091] Figure 6 is a flow chart illustrating a method of characterizing cartridge 110 according to one embodiment. Process 600 may be performed by processing logic that may include software, hardware, or a combination thereof. For example, process 600 may be performed by Figure 2 Executed by computer 205.

[0092] Reference Figure 6 , at box 601, the processing logic obtains a first mixing fraction f1 corresponding to a first X-ray beam (beam 1), where the mixing fraction represents the fraction of the first X-ray beam inside a measurement box (box 510) measuring a wafer sample (sample 500), and the measurement box represents a hole structure disposed above a substrate and having a membrane layer disposed inside the hole structure.

[0093] For example, Figure 3A As described, with known thickness and known material K SiO The reference sample 300 can be used to obtain a first mixture fraction f1 corresponding to a first X-ray beam (beam 1). As previously described, the mixture fraction can be calculated using a merit function M1. The mixture fraction f1 can represent the portion of the X-ray beam inside the box where the X-ray beam is directed to the box, and the overflow (1-f1) indicates the portion of the X-ray beam outside the box.

[0094] The measuring box (box 510) can be made of Figure 5 Here, the sample 500 may be provided by a customer and is identical to the reference sample 300 in that it has at least one hole with a known size of 30 μm×30 μm, wherein the covering material A may be known and the thickness of the film layer at the bottom of the hole is unknown.

[0095] In one embodiment, obtaining a first mixture fraction f1 corresponding to a first X-ray beam (beam 1) includes: obtaining a first reference detection signal of a reference sample (a sample wafer having a reference sample 300) (an XPS signal measured using beam 1 on the reference sample 300); obtaining a first reference measurement ratio (I SiO1 / I Si1 ) (determined by finding the binding energy of SiO2 and Si and determining the XPS signal peak); and based on the first reference measurement ratio (I SiO1 / I Si1 )Determine the first mixture fraction f1.

[0096] In one embodiment, obtaining a first reference detection signal (XPS signal) includes providing a reference box 310 to be irradiated to a reference sample (reference sample 300), wherein the reference box has a film layer (SiO2) of known thickness (e.g., 2 nm) and a known contribution factor (K SiO ); generate a first X-ray beam (Beam 1) having a first condition (spot size of 40 μm in diameter); direct the first X-ray beam (Beam 1) toward a reference sample (reference sample 300); collect measurements to obtain a first reference detection signal (XPS signal). Here, the contribution factor K SiO represents the effective contribution of SiO2 electrons to the species intensity in the XPS signal.

[0097] In one embodiment, based on the first reference measurement ratio (I SiO1 / I Si1 ) determining the first mixture fraction f1 comprises: determining a first residual function (M1) having a first mixture fraction f1 corresponding to the first X-ray beam (beam 1); calculating a first reference measurement ratio (I SiO1 / I Si1 ) and the first modeling intensity ratio (I SiO1 M / I Si1 M ); and calculating a first mixture fraction f1 based on the first reference measurement ratio and the first modeled intensity ratio.

[0098] At block 603 , processing logic obtains the contribution value (1−f1) / K of the measurement box (box 510 ) corresponding to the first X-ray beam. A , the contribution value indicates that the type of signal outside the measurement box contributes to the same type of signal inside the measurement box.

[0099] For example, Figures 4A to 4B As shown, the type signal contribution value is (1-f1) / K A You can use K A As mentioned above, the measurement sample 400 can be provided by the customer to calculate K A , where sample 400 has at least one pore structure (box 410) with known dimensions of 30 μm×30 μm, identical to reference sample 300. In addition, the cover layer material 405 of sample 400 is unknown, and the membrane layer 415 inside the pore structure 410 has an unknown material with an unknown thickness.

[0100] Using beam 1 with a spot size of 40 μm, measurements can be performed to collect the measured species intensity ratios for beam 1. Using beam 2 with a spot size of 50 μm (e.g., a larger spot), measurements can be performed to collect the measured species intensity ratios for beam 2. Using the measured species ratio intensities and the calculated mixture fractions f1 and f2, the thickness t and K can be simultaneously calculated using regression A Using K A And f1 value, the species signal contribution value can be calculated as (1-f1) / K A .

[0101] In one embodiment, the processing logic further calculates the second mixture fraction f2, including: obtaining a second reference detection signal of the reference sample (XPS measurement of the reference sample 300 using beam 2); obtaining a second reference measurement ratio (I SiO2 / I Si2 ); and based on the second reference measurement ratio (I SiO2 / I Si2 ) Determine the second mixture fraction f2.

[0102] In one embodiment, obtaining the second reference detection signal (XPS signal) includes providing a reference box 310 to be irradiated to a reference sample (a reference sample having sample 300), wherein the reference box 310 has a film layer with a known thickness (2 nm) and a known contribution factor (K SIO ); generating a second X-ray beam (Beam 2) having a second condition (spot diameter = 50 μm); directing the second X-ray beam (Beam 2) toward the reference sample; and collecting measurements to obtain a second reference detection signal (XPS signal).

[0103] In one embodiment, based on the second reference measurement ratio (I SiO2 / I Si2 ) determining the second mixture fraction f2 further comprises: determining a second residual function (M2) having the second mixture fraction f2 and corresponding to the second X-ray beam (beam 2); calculating a second reference measurement ratio (I SiO2 / I Si2 ) and the second modeling intensity ratio (I SiO2 M / I Si2 M ); and based on the second reference measurement ratio (I SiO2 / I Si2 ) and the second modeling intensity ratio (I SiO2 M / I Si2 M ) Calculate the second mixture fraction f2.

[0104] In one embodiment, obtaining the contribution value of the measurement box corresponding to the first X-ray beam includes: obtaining a second measurement detection signal (XPS signal of sample 400 using beam 1) and a third measurement detection signal (XPS signal of sample 400 using beam 2) of the measurement sample (sample 400); obtaining a first measurement ratio (I A1 / I B1 ) and the second measurement ratio (I A2 / I B2 ); and determining a contribution value (1-f1) / K based on the first measurement ratio and the second measurement ratio A .

[0105] like Figures 4A to 4B As shown, the type signal contribution value is (1-f1) / K A You can use K A and f1 value to calculate, where thickness t and K A K can be calculated by measuring the sample 400 using beam 1 and beam 2 at the same time. A .

[0106] In one embodiment, obtaining the second measurement detection signal and the third measurement detection signal includes: providing the first measurement sample ( Figures 4A to 4B The wafer sample 400) provides a measurement box 410 to be irradiated, wherein the measurement box 410 has a film layer of unknown thickness and an unknown contribution factor (K A ); generate a first X-ray beam (beam 1) having a first condition (40 μm spot); direct the first X-ray beam (beam 1) toward a measurement sample; collect measurements to obtain a second measurement detection signal (XPS signal); generate a second X-ray beam (beam 2) having a second condition (50 μm spot); direct the second X-ray beam (beam 2) toward the measurement sample; and collect measurements to obtain a third measurement detection signal (XPS signal).

[0107] In one embodiment, based on the first measurement ratio (I A1 / I B1 ) and the second measurement ratio (I A2 / I B2 ) Determining the contribution value (1-f1) / KA includes: determining a first residual function (M1) having a first mixture fraction corresponding to the first X-ray beam (Beam 1); determining a second residual function (M2) having a second mixture fraction f2 corresponding to the second dual X-ray beam (Beam 2); and performing regression to minimize the first measurement ratio (I A1 / I B1 ) and the second measurement ratio (I A2 / I B2) and the first modeling intensity ratio (I A1 M / I B1 M ) and the second modeling intensity ratio (I A2 M / I B2 M ) to simultaneously determine the contribution value (K A or (1-f1) / K A ) and the thickness of the film layer t.

[0108] At block 605 , processing logic obtains a first measurement detection signal (XPS signal) corresponding to a measurement of a measurement box (box 510 ) using a first X-ray beam (Beam 1 ).

[0109] For example, Figure 5 As described in , a customer may provide a wafer sample having a sample 500 to be measured, wherein the sample 500 has a known capping layer material A and an unknown film thickness. An XPS measurement may be performed on the sample 500 to obtain an XPS signal / original intensity (e.g., a first measurement detection signal) of the measured sample 500.

[0110] At block 607, processing logic detects a signal based on the first measurement (measured using beam 1). Figure 5 XPS signal of sample 500), contribution value (1-f1) / K A And the first mixture fraction f1 determines the measured value of the film layer.

[0111] For example, according to Figure 5 The XPS signal collected from the sample 500 is / the original intensity. Using the known cover material A, the processing logic can obtain the measured intensity ratio (e.g., I A / I B ). Using the measured intensity ratio (I A / I B ), K A and f1, the processing logic can be derived from the evaluation function M1 using the modeling intensity ratio (I AM / I BM )Calculate the thickness t value.

[0112] In one embodiment, based on the contribution value (1-f1) / K A Determining the measured value of the film layer (eg, thickness t) using the first mixture fraction f1 includes determining a third measurement ratio (I A / I B); determining a first residual function M1 having a first mixture fraction f1 corresponding to the first X-ray beam (beam 1); and minimizing a third measurement ratio (I A / I B ) and the modeling intensity ratio (I A M / I B M ) to calculate the measured value (thickness t) of the film layer.

[0113] Therefore, Figures 3 to Figure 6 An XPS characterization technique is described for characterizing the material composition and thickness of a film layer within a 30 μm cell (well). Although 40 μm and 50 μm beams are shown, the X-ray beam can be of any spot size for calculating the corresponding mixing fraction. Furthermore, the characterization technique can be extended to more than one film layer within the cell, such as Figure 7 As further described in.

[0114] Figure 7 is a partial cross-section of a portion of a wafer sample 700 illustrating two film layers (715, 735) according to one embodiment. The sample 700 may represent Figure 1 The sample 100 has a box 710 with a side length of 30 μm and two film layers in the box 710. Figure 7 As shown, a cell 710 is formed in a blanket layer 705 of material A deposited on a substrate 701 of material B. A thin film layer 725 of material C is deposited on the blanket layer 705. Within the cell 700, a film layer 715 of material A (thickness = t1) exists on a film layer 735 of material C (thickness = t2) located on a substrate 700 of material B.

[0115] To characterize the box 700, the evaluation function may be as follows:

[0116]

[0117] in,

[0118]

[0119] as well as

[0120]

[0121] Among them, M represents the evaluation function, M i represents the evaluation function of the i-th beam, represents the modeled intensity of the type signal A of the i-th light beam, represents the modeled intensity of the type signal B of the i-th light beam, represents the modeled intensity of the type signal C of the i-th beam, I Ai represents the measured species intensity of material A of the i-th beam, I Bi represents the measured intensity of material B in the i-th beam, I Ci represents the measured species intensity of material C of the i-th beam, f i represents the i-th mixing fraction, t1 represents the film thickness of material A inside the box 110, K A represents a constant indicating the effective contribution of A to the intensity of the species signal, t2 represents the film thickness of the material C inside the box 110, K C represents a constant indicating the effective contribution of C to the strength of the species signal, and λ 1,2,3,4,5 is the material parameter (effective attenuation length (EAL)) of a particular type of photoelectron from species A, B, or C traveling through material A or C. Note that can be derived from a lookup table or from the NIST database based on the binding energy of the species signal.

[0122] There are four unknown values ​​in the above evaluation function: t1, t2, K A and K C To solve the four unknowns, two beams of different sizes are used to provide four separate measurements of the ratio I B1 / I A1 , I C1 / I A1 , I B2 / I A2 and I C2 / I A2 In the case of 4 measurement ratios and 4 unknowns, a regression method can be applied to the evaluation function to solve for the unknowns.

[0123] As previously described, different beam conditions provide different mixing fractions, for example, condition 1 provides a beam with a 40 μm spot diameter, and condition 2 provides a beam with a 50 μm spot diameter, to solve the merit function. In some embodiments, different beam positions (x or y offsets) provide different mixing fractions to solve the merit function, such as Figure 8A to Figure 1 0 further described.

[0124] Figure 8A The diagram shows the measurement of the reference sample 800 using X-ray scanning, and Figure 8B FIGURE 1 illustrates measurement of a reference sample 800 using a Y line scan according to one embodiment. The reference sample 800 may represent Figures 3A to 3B The sample 300, for example, has a known film material SiO2 and an unknown film thickness of 30 μm in the box 810. Figures 8A to 8BAs shown, multiple measurements can be performed on a measurement sample 800 using a beam 1 having a spot diameter of 40 μm with x and / or y offsets. The x and y offsets refer to x- or y-direction movement of the stage containing the sample 800. For an X scan, an example would be: using the same stage settings, at time 1, a scan can be performed at (x1, y1) = (0, 0); at time 2, a scan can be performed at (x2, y2) = (10 μm, 0); at time 3, a scan can be performed at (x2, y2) = (20 μm, 0), and so on.

[0125] In one embodiment, the mixture fraction can be expressed as a Gaussian equation, since the X-ray beam directed to the wafer sample can be assumed to be Gaussian-like. The characteristics of the beam 1 are as follows: Figures 9 to 10C For example, the light beam may be represented by a center coordinate (x c ,y c ) is used to express it. (σ x ,σ y ) is a standard deviation of the Gaussian-like beam 1 in the x and y directions. Figures 10A to 10C The measured mixture fractions and modeled Gaussian-like mixture fractions for the y and x center sections are shown in graphs 1000 to 1003. The modeled mixture fractions versus beam position are shown in graph 1005, illustrating that the Gaussian equations are very suitable for modeling the mixture fractions, as described further below. Since the center of the beam may not always coincide with the center of the box (due to small displacement errors in the stage setup), the X / Y scans have slight offsets. Since these offsets are unknown, (x c ,y c ) can be used to optimize the alignment of modeled and measured data. In addition, (σ x ,σ y ) can be optimized to one standard deviation of a hypothetical Gaussian-like X-ray beam directed at the sample.

[0126] refer to Figure 8A to Figure 1 0, the mixture fraction can be obtained by using the stage position (e.g. (x i ,y i )) and the measured offset of the beam (e.g., (x c ,y c ,σ x ,σ y )) is represented by the Gaussian equation. The mixture fraction for each scan in the scan can be as follows:

[0127]

[0128] Among them, f i represents the i-th mixing fraction of the i-th beam scan, (x i ,y i) represents the x and y position of the stage relative to the center of the box 810, (x c ,y c ) is the optimized center coordinate of the beam relative to the center of the box 810, (σ x ,σ y ) is the length of one standard deviation of a Gaussian-like X-ray beam in the x and y directions.

[0129] Next, each X / Y measurement scan can be described by an evaluation function. The evaluation function for sample 800 can be as follows:

[0130]

[0131]

[0132] as well as

[0133]

[0134] Among them, M represents the evaluation function, M i represents the evaluation function of the i-th scan, f i represents the mixture fraction of the i-th scan (f i It can be expressed as the station position (x i ,y i ) and beam measurement offset (x c ,y c ,σ x ,σ y )),(x i ,y i ) represents the x and y position of the stage of the i-th scan relative to the center of the box 810, n represents the total number of scans, represents the measured intensity of species Si for the i-th scan, represents the measured intensity of the SiO2 species in the i-th scan, K SiO represents a constant indicating the effective contribution of SiO2 to the intensity of the species signal, (x c ,y c ) is the optimized center coordinate of the light beam relative to the center of the box 810, t represents the thickness of the film layer 815 of the material SiO2 inside the box 810, and (σ x ,σ y ) is a standard deviation value in the x or y direction.

[0135] Multiple X / Y scans are performed to provide x i 、y i 、 values, where the i-th is the corresponding scan. K SiOThe value of is known because the sample 800 has a known SiO2 layer 805 and a SiO2 film inside the box 810. The unknown variable in this case is: x c 、y c , t, σ x , σ y Therefore, 5 measurement scans can provide 5 species intensity ratios to solve for the five unknown variables x c 、y c , t, σ x , σ y , and the unknowns can be solved by applying regression techniques to the merit function M. The offset of the characterized beam, such as the determined (x c ,y c ,σ x ,σ y ), a new measurement sample 1100 of unknown film thickness of unknown material A can be characterized, such as Figures 11A to 11B As shown in .

[0136] Figure 11A The diagram shows the measurement of the measurement sample 1100 using X-ray scanning, and Figure 11B FIGURE 1 illustrates measurement of a sample 1100 using Y line scanning according to one embodiment. The sample 1100 may represent Figures 8A to 8B The reference sample 800 has a box 1110 with a side length of 30 μm and a cover layer 1105 of material A. The measurement scan can be described by an evaluation function. The evaluation function can be as follows:

[0137]

[0138] Among them, M represents the evaluation function, M i represents the evaluation function of the i-th scan, represents the intensity ratio of the measured species for the i-th scan, represents the modeled species intensity ratio of the i-th scan, (x i ,y i ) represents the x and y positions of the stage of the i-th scan relative to the center of the box 1110, I Ai represents the measured intensity of species A in the i-th scan, I Bi represents the measured intensity of type B in the i-th scan, (σ x ,σ y ) is the standard deviation in the x or y direction, (x c ,y c ) is the optimized center coordinate of the light beam relative to the center of the box 1110, t represents the thickness of the film layer 1115 of material A inside the box 1110, K A,B represents a constant indicating the effective contribution of A and B to the strength of the species signal.

[0139] The unknown variable in this case is: x c 、y c ,t,K A,B Therefore, the four measurement scans can provide four species intensity ratios to solve for the four unknown variables x using regression techniques. c 、y c ,t,K A,B Although only one film layer of an unknown material with an unknown thickness is characterized in FIG11 , the X / Y line scan characterization technique can be applied to a sample of a cartridge having more than one film layer with one or more unknown materials, where additional scans can be provided to characterize any additional unknown parameters. Alternatively, other parameters, such as K, can be characterized by providing additional measurement data from additional measurement scans. B .

[0140] Figure 12 is a flow chart illustrating a method according to one embodiment. Process 1200 may be performed by processing logic that may include software, hardware, or a combination thereof. For example, process 1200 may be performed by Figure 2 Executed by computer 205.

[0141] Reference Figure 12 At block 1201, the processing logic obtains the beam Gaussian parameters (x c ,y c ,σ x ,σ y ), wherein the beam Gaussian parameters include at least the offset coordinate (x ) of the X-ray beam to the center of the box (eg, box 1110) of the sample (eg, sample 1100) c ,y c ), wherein the measuring box (e.g., box 1110) represents a pore structure, wherein the membrane layer 1115 is disposed inside the pore structure, and the pore structure is formed on a layer 1105 above a substrate fabricated inside the pore structure.

[0142] For example, Figures 8A to 8B As shown in FIG, a wafer sample 800 is provided for characterization using X / Y line scanning to obtain the beam Gaussian parameters (x c ,y c ,σ x ,σ y The evaluation function for sample 800 is used to solve for unknowns using the species intensity ratios obtained from the X / Y line scan, e.g. (x c ,y c ,σ x ,σ y ) beam Gaussian parameters. In one embodiment, the beam Gaussian parameters include the offset coordinates (x c ,yc ).

[0143] In one embodiment, the beam Gaussian parameters include an optimized standard deviation value (σ x ,σ y ).

[0144] In one embodiment, the unknowns include the measured thickness t of film layer 815. In this case, additional X / Y line scans can be performed to obtain additional measured intensity ratios, so that the number of known measured intensity ratios is equal to or greater than the unknown variable to be solved. Thereafter, regression can be used to simultaneously determine the measured thickness t and the beam Gaussian parameters.

[0145] At block 1203 , processing logic obtains a measurement detection signal (XPS signal) corresponding to a measurement of the measurement box (box 1110 ) using a first X-ray beam (beam 1 ).

[0146] At block 1205, processing logic generates a signal based on the measured detection signal (XPS signal) and the scan parameters (XPS signal). c ,y c ) Determine the measured value (thickness) of the film layer.

[0147] In one embodiment, the processing logic obtains additional scanning parameters for stage adjustment for adjusting the stage coordinates of the measurement box; obtains additional measurement detection signals corresponding to the measurement at each stage adjustment; and obtains additional measurement values ​​(K) of the measurement box based on the measured additional detection signals, the contribution values, and the scanning parameters. B ).

[0148] In one embodiment, the processing logic performs stage adjustment in the X or Y direction; and performs a measurement scan after the stage adjustment to obtain additional measurement detection signals.

[0149] Therefore, a method for characterizing a film layer within a measurement box using electron energy spectroscopy is provided, comprising: obtaining a first mixing fraction corresponding to a first X-ray beam, wherein the mixing fraction represents the fraction of the first X-ray beam inside a measurement box for measuring a wafer sample, wherein the measurement box represents a hole structure disposed above a substrate and having a film layer disposed inside the hole structure; obtaining a contribution value of the measurement box corresponding to the first X-ray beam, the contribution value representing that a type signal outside the measurement box contributes to a same type signal inside the measurement box; obtaining a first measurement detection signal corresponding to a measurement of the measurement box using the first X-ray beam; and determining a measurement value of the film layer based on the first measurement detection signal, the contribution value, and the first mixing fraction.

[0150] Obtaining a first mixture fraction corresponding to the first X-ray beam includes: obtaining a first reference detection signal of a reference wafer sample; obtaining a first reference measurement ratio from a species signal of the first reference detection signal; and determining the first mixture fraction based on the first reference measurement ratio.

[0151] Obtaining a first reference detection signal includes: providing a reference box to be irradiated to a reference wafer sample, wherein the reference box has a film layer with a known thickness and a known contribution factor; generating a first X-ray beam having a first condition; directing the first X-ray beam toward the reference wafer sample; and collecting measurements to obtain the first reference detection signal.

[0152] Determining a first mixture fraction based on a first reference measurement ratio includes: determining a first residual function having a first mixture fraction corresponding to a first X-ray beam; calculating the first reference measurement ratio and a first modeled intensity ratio; and calculating the first mixture fraction based on the first reference measurement ratio and the first modeled intensity ratio.

[0153] A second mixture fraction is also calculated, including: obtaining a second reference detection signal of the reference sample; obtaining a second reference measurement ratio from the species signal of the second reference detection signal; and determining a second mixture fraction based on the second reference measurement ratio.

[0154] Obtaining a second reference detection signal includes: providing a reference box to be irradiated to a reference wafer sample, wherein the reference box has a film layer with a known thickness and a known contribution factor; generating a second X-ray beam having a second condition; directing the second X-ray beam toward the reference wafer sample; and collecting measurements to obtain the second reference detection signal.

[0155] Determining the second mixture fraction based on the second reference measurement ratio further includes: determining a second residual function having a second mixture fraction corresponding to the second X-ray beam; calculating the second reference measurement ratio and the second modeled intensity ratio; and calculating the second mixture fraction based on the second reference measurement ratio and the second modeled intensity ratio.

[0156] Obtaining a contribution value of the measurement box corresponding to the first X-ray beam includes: obtaining a second measurement detection signal and a third measurement detection signal of the measurement sample; obtaining a first measurement ratio and a second measurement ratio from type signals of the second measurement detection signal and the third measurement detection signal; and determining the contribution value based on the first measurement ratio and the second measurement ratio.

[0157] Obtaining the second measurement detection signal and the third measurement detection signal includes: providing a measurement box to be irradiated to a measurement sample, wherein the measurement box has a film layer of unknown thickness and an unknown contribution factor inside; generating a first X-ray beam with a first condition; directing the first X-ray beam toward the measurement sample; collecting measurements to obtain the second measurement detection signal; generating a second X-ray beam with a second condition; directing the second X-ray beam toward the measurement sample; and collecting measurements to obtain the third measurement detection signal.

[0158] Determining the contribution value based on the first measurement ratio and the second measurement ratio includes: determining a first residual function having a first mixing fraction corresponding to the first X-ray beam; determining a second residual function having a second mixing fraction corresponding to the second dual X-ray beam; and performing regression to minimize the difference between the first measurement ratio and the second measurement ratio and the modeled intensity ratio for the first residual function and the second residual function to simultaneously determine the contribution value and the thickness value of the film layer.

[0159] Determining a measurement value of the film layer based on the contribution value and the first mixture fraction includes: determining a third measurement ratio based on a species signal of the first measurement detection signal; determining a first residual function having a first mixture fraction corresponding to the first X-ray beam; and calculating the measurement value of the film layer by minimizing the difference between the third measurement ratio and the modeled intensity ratio used for the first residual function.

[0160] According to various aspects, a system for characterizing a film layer within a measurement box is provided, comprising: a stage supporting a measurement wafer sample; an X-ray source generating a first X-ray beam to irradiate the measurement wafer sample located above at least one region of the measurement wafer sample having the measurement box, wherein the measurement wafer sample comprises a first layer of a first material disposed above a substrate made of a substrate material, the first layer having a hole structure formed therein to form a wall of the measurement box, and a first film layer of the first material disposed within the hole structure; an electron analyzer dividing electrons emitted from the measurement wafer sample according to different electron energies; an electron detector detecting the electrons after passing through the electron analyzer and outputting a detection signal; and and a processor that receives a detection signal and determines, based on the detection signal, species signals in energy bands corresponding to electrons emitted from the first material and the substrate material, wherein the processor further performs the following operations: obtaining a first mixing fraction corresponding to the first X-ray beam, wherein the mixing fraction represents the fraction of the first X-ray beam inside a measurement box for measuring a wafer sample; obtaining a contribution value of the measurement box corresponding to the first X-ray beam, the contribution value representing the contribution of the species signal outside the measurement box to the same species signal inside the measurement box; obtaining a first measurement detection signal corresponding to the measurement of the measurement box using the first X-ray beam; and determining a measurement value of the film layer based on the first measurement detection signal, the contribution value, and the first mixing fraction.

[0161] Obtaining a first mixture fraction corresponding to the first X-ray beam includes: obtaining a first reference detection signal of a reference wafer sample; obtaining a first reference measurement ratio from a species signal of the first reference detection signal; and determining the first mixture fraction based on the first reference measurement ratio.

[0162] Obtaining a first reference detection signal includes: providing a reference box to be irradiated to a reference wafer sample, wherein the reference box has a film layer with a known thickness and a known contribution factor; generating a first X-ray beam having a first condition; directing the first X-ray beam toward the reference wafer sample; and collecting measurements to obtain the first reference detection signal.

[0163] Determining a first mixture fraction based on a first reference measurement ratio includes: determining a first residual function having a first mixture fraction corresponding to a first X-ray beam; calculating the first reference measurement ratio and a first modeled intensity ratio; and calculating the first mixture fraction based on the first reference measurement ratio and the first modeled intensity ratio.

[0164] The operations also include calculating a second mixture fraction, including obtaining a second reference detection signal of the reference sample; obtaining a second reference measurement ratio from a species signal of the second reference detection signal; and determining a second mixture fraction based on the second reference measurement ratio.

[0165] Obtaining a second reference detection signal includes: providing a reference box to be irradiated to a reference wafer sample, wherein the reference box has a film layer with a known thickness and a known contribution factor; generating a second X-ray beam having a second condition; directing the second X-ray beam toward the reference wafer sample; and collecting measurements to obtain the second reference detection signal.

[0166] In addition, a method for characterizing a film layer within a measurement box using electron energy spectra is provided, comprising: obtaining beam Gaussian parameters corresponding to an X-ray beam, wherein the beam Gaussian parameters include at least offset coordinates from the X-ray beam to the center of a measurement box for measuring a wafer sample, wherein the measurement box represents a hole structure disposed above a substrate and has a film layer disposed inside the hole structure; obtaining a measurement detection signal corresponding to measurement of the measurement box using an X-ray beam; and determining a measurement value of the film layer based on the measurement detection signal and the beam Gaussian parameters.

[0167] In addition, additional scanning parameters of the stage adjustment for adjusting the stage coordinates of the measurement box are obtained; additional measurement detection signals corresponding to the measurements are obtained at each stage adjustment; and additional measurement values ​​of the measurement box are determined based on the measured additional detection signals, the contribution values ​​and the scanning parameters.

[0168] and performing stage adjustment in the X or Y direction; and performing a measurement scan after the stage adjustment to obtain an additional measurement detection signal.

[0169] Aspects of the present disclosure include a method for characterizing a film layer within a measurement box (small box) using electron spectroscopy, comprising: obtaining a first mixing fraction corresponding to a first X-ray beam, wherein the mixing fraction represents the fraction of the first X-ray beam inside a measurement box of a sample, wherein the measurement box represents a pore structure and a film layer that can be disposed above a substrate; obtaining a contribution value of the measurement box corresponding to the first X-ray beam, the contribution value representing the contribution of a species signal outside the measurement box to the same species signal inside the measurement box; obtaining a first measurement detection signal corresponding to a measurement of the measurement box using the first X-ray beam; and determining a measurement value of the film layer based on the first measurement detection signal, the contribution value, and the first mixing fraction. The film layer can be located between the pore structure and the pore structure or can be disposed inside the pore structure. Any reference to a film layer within the pore structure should be applied to a film layer located below the pore structure with appropriate modifications as appropriate.

[0170] In a further aspect, a system for characterizing a film layer within a measurement box using electron energy spectroscopy is provided. The system includes: a stage for supporting a wafer sample; an X-ray source for generating an X-ray beam to irradiate the wafer sample located above at least one region of the wafer sample having the measurement box, wherein the measurement wafer sample includes a first layer of a first material disposed on a substrate made of a substrate material, the first layer having a hole formed therein to form a wall of the measurement box, and a first film layer of the first material disposed inside the hole; an electron analyzer for dividing electrons emitted from the wafer sample according to different electron energies; an electron detector for detecting electrons after passing through the electron analyzer and outputting a detection signal; and a processor for receiving the detection signal and generating an X-ray beam based on the detection signal. The processor further performs the following operations: obtaining a first mixing fraction corresponding to the first X-ray beam, wherein the mixing fraction represents the fraction of the first X-ray beam inside the measurement box of the wafer sample; obtaining a contribution value of the measurement box corresponding to the first X-ray beam, the contribution value representing that the species signal outside the measurement box contributes to the same species signal inside the measurement box; obtaining a first measurement detection signal corresponding to the measurement of the measurement box using the first X-ray beam; and determining a measurement value of the film layer based on the first measurement detection signal, the contribution value and the first mixing fraction.

[0171] In a further aspect, a method for characterizing a film layer within a measurement box using electron energy spectroscopy is provided, comprising: obtaining beam Gaussian parameters corresponding to an X-ray beam, wherein the beam Gaussian parameters include at least offset coordinates of a center of a measurement box from the X-ray beam to a sample, wherein the measurement box represents a pore structure having a film layer disposed therein; obtaining a measurement detection signal corresponding to a measurement of the measurement box using the X-ray beam; and determining a measurement value of the film layer based on the measurement detection signal and the beam Gaussian parameters.

[0172] A system for characterizing a first film layer of a sample can be provided and can include electron optics and a processor. Figure 2 A non-limiting example of the system is illustrated in FIG. 2 - the processor may be a computer 205 or may be included in a computer 205, and the electron optics may include, for example, at least some of an electron gun 210, an anode 215, a monochromator 220, a flux detector 230, an XPS energy analyzer 240, and an XPS detector 245.

[0173] The electron optics are configured to irradiate the first film layer (eg, Figure 1 The first film layer is made of a first film layer material and is located above a substrate made of a substrate material.

[0174] The electron optics are further configured to detect electrons emitted from the first sample region to provide a detection signal.

[0175] The processor can be configured to determine a species signal based on the detection signal, and the species signal can include (i) a first film layer material species signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material species signal in an energy band corresponding to electrons emitted from the substrate material.

[0176] The processor may also be configured to determine a measurement value of the first film layer based on: (i) the species signal, (ii) mixing information (e.g., f) indicating a fraction of the X-ray spots that impinge on the first film layer, and (iii) a material contribution value of the first film layer (e.g., K SiO ), which represents the effective contribution of the first film layer material to at least one of the species signals.

[0177] The detection signal may be an X-ray photoelectron spectroscopy (XPS) detection signal.

[0178] The measured value can be the thickness of the film layer. The material of the film layer can be determined based on the frequency band of the species signal.

[0179] The processor is configured to determine the thickness of the membrane layer based on a value of an evaluation function (eg, M), the value of the evaluation function being determined based on a difference between the actual attenuation of the membrane layer and the modeled attenuation of the membrane layer. The actual attenuation of the membrane layer may be determined by The modeling attenuation of the membrane layer can be expressed as Various examples of evaluation functions are provided above.

[0180] The processor may be configured to determine the thickness of the film layer based on a value of an evaluation function, wherein the value of the evaluation function is determined based on: (i) a first film layer material type signal (e.g., I SiO, (ii) substrate material type signal (e.g. -I Si ), (iii) the modeled first film material type signal (e.g., I SiO M ) and (iv) modeled substrate material type signals (e.g. Si M ).

[0181] The attenuation parameter of the first film layer (e.g., λ) related to the photoelectrons generated in the first film layer can be used based on the mixing information. SiO ), the thickness of the first film layer and the material contribution value of the first film layer are used to calculate the modeled first film layer material type signal.

[0182] Based on the mixing information, the thickness of the film layer, the attenuation parameter of the first film layer related to the photoelectrons generated in the substrate (e.g., λ Si,SiO ) and a substrate material contribution value (e.g., K Si ) to calculate the substrate material type signal.

[0183] The mixing information may indicate the intensity distribution of the beam relative to the one or more film layers. Thus, the mixing information may indicate the intensity distribution of the beam over the one or more film layers - for example, the percentage of radiation that impinges on the measurement box relative to the total radiation.

[0184] The mixing information may include one or more beam Gaussian parameters. Examples of beam Gaussian parameters are shown above.

[0185] The membrane layer may be positioned over the upper surface of an additional sample sub-region - see, e.g. Figure 16 16. A pad of interest 1610 is positioned above a substrate 1620. The X-ray spot 1620 illuminates the pad of interest 1610 and a first sample sub-region, also referred to as an irrelevant region or contamination region, that contributes a spillover signal to the signal sensed by the detector.

[0186] The membrane layer may be located below the upper surface of the additional sample sub-region. For example, see Figure 1 and Figure 7 .

[0187] The sample area may include a second membrane layer made of a second membrane layer material and located outside the first sample sub-area. Figure 7 , which illustrates two film layers 715 and 735 , we will assume that the second film layer is denoted as 715 .

[0188] In this case, the processor is further configured to determine, based on the detection signal, a species signal of the second film layer material in an energy band corresponding to electrons emitted from the second film layer material. The processor is further configured to determine a measurement value of the second film layer based on (i) the species signal, (ii) the mixing information, and (ii) a second film layer material contribution value representing an effective contribution of the second film layer material to at least one of the species signals.

[0189] When there are two film layers, more information may need to be collected because there are more unknown variables associated with the two film layers. This may require performing one or more additional measurements, which may involve causing electron optics to illuminate a second sample area that may include the second film layer and the second sample sub-area with an X-ray spot; and detecting electrons emitted from the second sample area to provide a detection signal. Examples of additional measurements are shown in FIG. Figure 8A and Figure 8B Middle picture.

[0190] Figure 13 is a flow chart illustrating a method according to one embodiment. The method 1300 may be performed by processing logic that may include software, hardware, or a combination thereof. For example, the method 1300 may be performed by Figure 2 Executed by computer 205.

[0191] Method 1300 may begin with step 1310 of irradiating a first sample region including a first membrane layer and a first sample subregion with an X-ray spot through electron optics. The first membrane layer is made of a first membrane layer material and is located above a substrate made of a substrate material.

[0192] Step 1310 may be followed by step 1320 of detecting electrons emitted from the first sample region by electron optics to provide a detection signal.

[0193] Step 1320 may be followed by step 1330 in which the processor determines a type signal based on the detection signal, and the type signal may include (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material.

[0194] Step 1330 may be followed by step 1340 where the processor determines a measurement value for the first film layer based on: (i) the species signal, (ii) mixing information (e.g., f) indicating the fraction of the x-ray spot that impinges on the first film layer, and (iii) the material contribution value of the first film layer (e.g., K SiO ), which represents the effective contribution of the first film layer material to at least one of the species signals.

[0195] The detection signal may be an X-ray photoelectron spectroscopy (XPS) detection signal.

[0196] The measured value can be the thickness of the film layer. The material of the film layer can be determined based on the frequency band of the species signal.

[0197] Step 1340 may include at least one of the following:

[0198] a. Determine the thickness of the film layer based on the value of an evaluation function (e.g., M), which is determined based on the difference between the actual attenuation of the film layer and the modeled attenuation of the film layer. The actual attenuation of the film layer can be determined by The modeling attenuation of the membrane layer can be expressed as Various examples of evaluation functions are provided above.

[0199] b. Determine the thickness of the film layer based on the value of the evaluation function, the value of the evaluation function is determined based on the following: (i) the first film material type signal (eg - I SiO , (ii) substrate material type signal (e.g. -I Si ), (iii) the modeled first film material type signal (e.g., I SiO M ) and (iv) modeled substrate material type signals (e.g. Si M ).

[0200] c. Based on the mixed information, the attenuation parameter of the first film layer related to the photoelectrons generated in the first film layer (e.g., λ SiO ), the thickness of the first film layer and the material contribution value of the first film layer are used to calculate the modeled first film layer material type signal.

[0201] d. Based on the mixing information, the thickness of the film layer, and the attenuation parameter of the first film layer related to the photoelectrons generated in the substrate (e.g., λ Si,SiO ) and a substrate material contribution value (e.g., K Si ) to calculate the substrate material type signal.

[0202] The sample area may include a second membrane layer made of a second membrane layer material and located outside the first sample sub-area. Figure 7 , which illustrates two film layers 715 and 735 , we will assume that the second film layer is denoted as 715 .

[0203] In this case, step 1340 may include determining a second film layer material species signal in an energy band corresponding to electrons emitted from the second film layer material based on the detection signal. The processor is further configured to determine a measurement value of the second film layer based on (i) the species signal, (ii) the mixing information, and (ii) a second film layer material contribution value representing an effective contribution of the second film layer material to at least one of the species signals.

[0204] When two film layers are present, more information may need to be collected because there are more unknown variables associated with the two film layers. This may require performing one or more additional measurements. Step 1310 may be repeated and include irradiating a second sample region, which may include a second film layer and a second sample subregion, with an X-ray spot through electron optics. Step 1320 may be repeated and may include detecting electrons emitted from the second sample region to provide a detection signal.

[0205] Figure 14 is a flow chart illustrating a method 1400 according to one embodiment. The method 1400 may be performed by processing logic that may include software, hardware, or a combination thereof. For example, the method 1400 may be performed by Figure 2 Executed by computer 205.

[0206] Method 1300 may begin with step 1410 of obtaining a detection signal indicative of electrons emitted from a first sample region as a result of irradiating the first sample region with an X-ray spot, wherein the first sample region includes a first membrane layer and a first sample sub-region, the first membrane layer being made of a first membrane layer material and positioned above a substrate made of a substrate material.

[0207] Step 1410 may be followed by step 1320 of detecting electrons emitted from the first sample region by electron optics to provide a detection signal.

[0208] Step 1320 may be followed by step 1330 in which the processor determines a type signal based on the detection signal, and the type signal may include (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material.

[0209] Step 1330 may be followed by step 1340 where the processor determines a measurement value for the first film layer based on: (i) the species signal, (ii) mixing information (e.g., f) indicating the fraction of the x-ray spot that impinges on the first film layer, and (iii) the material contribution value of the first film layer (e.g., K SiO ), which represents the effective contribution of the first film layer material to at least one of the species signals.

[0210] The detection signal may be an X-ray photoelectron spectroscopy (XPS) detection signal.

[0211] The measured value can be the thickness of the film layer. The material of the film layer can be determined based on the frequency band of the species signal.

[0212] The sample area may include a second membrane layer made of a second membrane layer material and located outside the first sample sub-area. Figure 7 , which illustrates two film layers 715 and 735 , we will assume that the second film layer is denoted as 715 .

[0213] In this case, step 1340 may include determining a second film layer material species signal in an energy band corresponding to electrons emitted from the second film layer material based on the detection signal. The processor is further configured to determine a measurement value of the second film layer based on (i) the species signal, (ii) the mixing information, and (ii) a second film layer material contribution value representing an effective contribution of the second film layer material to at least one of the species signals.

[0214] When two membrane layers are present, more information may need to be collected - because there are more unknown variables associated with the two membrane layers.

[0215] Step 1410 can be repeated and includes obtaining a detection signal indicative of electrons emitted from a second sample region as a result of irradiating the first sample region with the X-ray spot, wherein the second sample region includes a second membrane layer and a second sample sub-region, the second membrane layer being made of a second membrane layer material and positioned over a substrate made of a substrate material.

[0216] Step 1320 may be repeated and may include detecting electrons emitted from the second sample region to provide a detection signal.

[0217] The detection signal can be considered as a weighted sum of the signal of interest (S) from the film layer or layers of interest and the signal (C) from the overflow region (the region irradiated by the X-ray beam but outside the film layer or layers) (also called the overflow signal). The weight assigned to the signal S is f, and the weight assigned to C is 1-f.

[0218] The values ​​of f and C—or f and S—need to be determined.

[0219] The overflow signal can be determined from knowledge of the semiconductor process provided by the manufacturer or by measuring an area larger than the XPS spot size that may be located on an unpatterned portion of the die. Another way to determine the overflow signal is to scan the measurement area in a systematic manner that allows the known amount of overflow to vary in the measurement data. For example, see Figure 8A and Figure 8BAs the spot covers more of the contamination area, the overflow signal will increase, while the signal of interest will decrease. By taking several points at different offsets from the center of the measurement pad, one can use this information to determine the contamination signal. An additional method to determine the overflow signal is to extrapolate the scan data to determine the signal at zero overflow.

[0220] There are several ways to determine the coefficients mentioned above. One can float the coefficients in the regression routine. Another approach is to fully characterize the power density on the XPS spot, but this may not be stable over time.

[0221] Another approach is to determine the amount of overfill using a well-characterized reference wafer sample - see e.g. Figure 5 .

[0222] Yet another way to determine the weights can involve feedforward, where the structural element is measured before and after the film layer is formed, and the detection signal after formation is compared to the detection signal after formation - to provide an indication of the effect of the film layer on the detection signal - which in turn can provide an indication of the measured value of the film layer. Assuming that C remains the same before and after formation - it can be determined and removed from the detection signal.

[0223] The detection signal before formation can be used to normalize the detection signal after formation - because the detection signal before formation provides information about the layers below the membrane layer.

[0224] Performing measurements before and after formation can provide a highly accurate evaluation of the measured values ​​and can overcome inaccuracies in the formation of the structural element, differences from one evaluation system to another, and even deviations over measurement time.

[0225] Figure 15 An example of a method 1500 of characterizing a first film layer of a sample is shown.

[0226] Method 1500 may begin with step 1510 of irradiating a preliminary first sample region with an X-ray spot. The preliminary first sample region is a first sample region before forming a first film layer within the first sample region. The preliminary first sample region may include a substrate and additional structural elements. The substrate is made of a substrate material.

[0227] Step 1510 may be followed by step 1520 of detecting electrons emitted from the preliminary first sample region to provide a preliminary detection signal.

[0228] Step 1520 may be followed by step 1530 of determining, by the processor, a preliminary species signal based on the detection signal. The preliminary species signal may include a preliminary substrate material species signal in an energy band corresponding to electrons emitted from the substrate material.

[0229] The method may continue after the first sample region including the membrane layer is formed (at step 1540 ).

[0230] Step 1540 may include irradiating the first sample region (which now includes the first membrane layer and the first sample sub-region) with an X-ray spot. The first membrane layer is made of a first membrane layer material and is located above the substrate.

[0231] Step 1540 may be followed by step 1550 of detecting electrons emitted from the first sample region to provide a detection signal.

[0232] Step 1550 may be followed by step 1560 in which the processor determines a type signal based on the detection signal, the type signal including (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material.

[0233] A measurement value for the first film layer is determined by the processor based on the preliminary species signal of step 1530 and the species signal of step 1560. This determination may include determining the contribution of the film layer based on a difference between the preliminary species signal and the species signal, and determining the measurement value based on the difference. This may include, for example, using variables such as the material contribution of the first film layer and / or using any of the models mentioned above. For example, the thickness may be determined using the following equation: Where K is the standard k-factor for generating a given species of photoelectron from a particular material, t is the thickness of the layer, and σ is the effective decay length of the material. It is assumed that k and σ are known.

[0234] According to another embodiment, an effective material model can be used to determine the measured value of the film layer, wherein the overflow signal is modeled as an effective substrate material. This effective substrate material is used as a variable in a modeling intensity equation - and the method includes solving the modeling intensity equation. An example of a modeling intensity equation is provided below.

[0235] In standard XPS film analysis, the thickness of the sample can be calculated by the following equation Determine where K is the standard k-factor for producing a given species of photoelectron from a particular material, t is the thickness of the layer, and σ is the effective decay length of the material.

[0236] The modeling strength equation can be The k′ factor for each species of interest is assumed to be derived from the bulk substrate and to float during the regression.

[0237] The value of K' can be determined by irradiating the structural element of interest with X-ray spots of different radii that should cover the entire film layer but with different regions of the overflow zone. Figure 4Aand Figure 4B Two X-ray spots of different radii are shown - but in determining k' it may be beneficial for each of the first and second X-ray spots to cover the entire film layer.

[0238] Figure 17 An example of a method 1700 of characterizing a first film layer of a sample is shown.

[0239] Method 1700 may begin with step 1710 of irradiating a first sample region including a first membrane layer and a first sample subregion with a first X-ray spot of a first radius through electron optics. The first membrane layer is made of a first membrane layer material and is positioned over a substrate made of a substrate material.

[0240] Step 1710 may be followed by step 1720 of detecting electrons emitted from the first sample region by electron optics to provide a first detection signal.

[0241] Step 1720 may be followed by step 1730 in which the processor determines a first type signal based on the first detection signal, and the first type signal may include (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material.

[0242] Step 1730 is followed by step 1740 of irradiating the first sample region including the first film layer and the first sample sub-region with a second X-ray spot having a second radius different from the first radius via electron optics.

[0243] Step 1740 may be followed by step 1750 of detecting electrons emitted from the first sample region by electron optics to provide a second detection signal.

[0244] Step 1750 may be followed by step 1760 in which the processor determines a second type signal based on the second detection signal, and the second type signal may include (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material.

[0245] Step 1760 is followed by step 1770 where the processor determines a measurement of the first film layer based on the first species signal and the second species signal.

[0246] Figure 18 Shown are simulations of the thickness of the material (of a thin film) as a function of the k' factor for various beam and pad sizes.Simulations of three XPS-measured SiO film thicknesses as a function of 1 / k' are provided.

[0247] For standard film analysis, 1 / k' is known to be ~0.7 and is used as input to determine the SiO film thickness. If k is allowed to vary, the solution will be undefined.

[0248] The VFIV, f = 0.57 (line 1801) and VFIIII, f = 7.05 (line 1802) curves show the effect of using 50um and 40um spots on a 30um measurement pad, respectively, where f is the fraction of the beam in the measurement pad. In the effective material model, we use two beam sizes with different amounts of contamination to uniquely define the solution. The intersection of these curves provides a unique solution for k and, therefore, a unique solution for thickness. The VFIII, f = 0.97 (line 1803) curve shows the relationship between k and thickness for a 50um beam on a 50um measurement pad, where smaller spillover results in a lower sensitivity to k'. These curves are used only as a descriptive tool, as the algorithm will use a regression method to determine the value of k for each species of interest.

[0249] A non-transitory computer readable medium storing instructions that, upon execution by a computerized system, cause the computerized system to perform the steps of method 1700 may be provided to characterize a first film layer of a sample.

[0250] A non-transitory computer-readable medium storing instructions that, upon execution by a computerized system, cause the computerized system to perform the steps of method 1500 may be provided to characterize a first film layer of a sample.

[0251] A non-transitory computer readable medium storing instructions that, upon execution by a computerized system, cause the computerized system to perform the steps of method 1400 may be provided to characterize a first film layer of a sample.

[0252] A non-transitory computer readable medium storing instructions that, upon execution by a computerized system, cause the computerized system to perform the steps of method 1300 may be provided to characterize a first film layer of a sample.

[0253] A system for characterizing a first film layer of a sample can be configured to perform method 1300 .

[0254] A system for characterizing a first film layer of a sample can be configured to perform method 1400 .

[0255] A system for characterizing a first film layer of a sample can be configured to perform method 1500 .

[0256] A system for characterizing a first film layer of a sample can be configured to perform method 1700 .

[0257] Any arrangement of components that achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components herein combined to achieve a particular functionality may be considered to be "associated" with each other such that the desired functionality is achieved, regardless of architecture or intermediary components. Likewise, any two components so associated may also be considered to be "operably connected" or "operably coupled" to each other such that the desired functionality is achieved.

[0258] Furthermore, those skilled in the art will recognize that the boundaries between the above-described operations are illustrative only. Multiple operations may be combined into a single operation; a single operation may be distributed among additional operations, and operations may be performed with at least partial overlap in time. Furthermore, alternative embodiments may include multiple instances of an operation, and the order of the operations may be altered in various other embodiments.

[0259] For another example, in one embodiment, the illustrated examples may be implemented as circuits located on a single integrated circuit or within the same device. Alternatively, the examples may be implemented as any number of separate integrated circuits or separate devices interconnected with each other in an appropriate manner.

[0260] As another example, the examples or portions thereof may be implemented as soft or code representations of physical circuitry or software or code representations convertible into logical representations of physical circuitry, such as in any suitable type of hardware description language.

[0261] However, other modifications, changes, and substitutions are possible. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

[0262] In the claims, any reference signs placed between parentheses should not be construed as limiting the claim. The word "comprising" does not exclude the presence of other elements or steps than those listed in the claim. In addition, the terms "a" or "an" as used herein are defined as one or more than one. In addition, the use of introductory phrases such as "at least one" and "one or more" in the claims should not be interpreted as implying that any specific claim containing such introduced claim elements by the indefinite article "a" or "an" is limited to an invention containing only one such element, even if the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an". The same applies to the use of definite articles. Unless otherwise specified, terms such as "first" and "second" are used to arbitrarily distinguish between the elements described by such terms. Therefore, these terms are not necessarily intended to indicate a temporal or other priority of such elements. The fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

[0263] While certain features of the present invention have been illustrated and described herein, those skilled in the art will now recognize many modifications, substitutions, changes, and equivalents. It should therefore be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention.

[0264] Any reference to any of the terms "comprising," "including," "having," may be applied mutatis mutandis to the terms "consisting of" and / or "consisting essentially of," as the case may be.

[0265] It should be understood that the processes and techniques described herein are not inherently related to any specific equipment and can be implemented by any suitable combination of components. In addition, various types of general-purpose devices can be used according to the teachings described herein. The present disclosure has been described with respect to specific examples, which are intended to be illustrative and not restrictive in all respects. It will be understood by those skilled in the art that many different combinations will be suitable for practicing the present disclosure.

[0266] In addition, by considering the specification and the practice of the disclosure disclosed herein, other implementations of the present disclosure will be apparent to those skilled in the art. It is worth noting that the expressions disclosed herein are provided as examples of specific geometric shapes of the patterned layers shown in the disclosed examples. The various aspects and / or components of the described embodiments may be used alone or in any combination. The description and embodiments are intended to be considered as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A system for characterizing a first film layer of a sample, the system comprising: An electronic optics device configured to: irradiating a first sample region including the first membrane layer and a first sample sub-region with an X-ray spot; wherein the first membrane layer is made of a first membrane layer material and is positioned above a substrate made of a substrate material; and detecting electrons emitted from the first sample region to provide a detection signal, wherein the detection signal is an X-ray photoelectron spectroscopy (XPS) detection signal; and The processor is configured to: determining a material type signal based on the detection signal, the material type signal comprising: (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material; and A measurement value of the first film layer is determined based on: (i) the material type signal, (ii) mixing information indicating a fraction of the X-ray spots that impinge on the first film layer, and (iii) a first film layer material contribution value representing an effective contribution of the first film layer material to at least one of the material type signals.

2. The system according to claim 1, wherein: The measured value is the thickness of the film layer.

3. The system according to claim 2, wherein: The processor is configured to determine the thickness of the membrane layer based on a value of a merit function, the value of the merit function being determined based on a difference between an actual attenuation of the membrane layer and a modeled attenuation of the membrane layer.

4. The system according to claim 2, wherein: The processor is configured to determine the thickness of the film layer based on a value of an evaluation function, wherein the value of the evaluation function is determined based on: (i) the first film layer material type signal, (ii) the substrate material type signal, (iii) the modeled first film layer material type signal, and (iv) the modeled substrate material type signal.

5. The system according to claim 4, wherein: The modeled first film layer material type signal is calculated based on the mixing information, a first film layer attenuation parameter associated with photoelectrons generated in the first film layer, the thickness of the film layer, and the first film layer material contribution value.

6. The system according to claim 5, wherein: The substrate material type signal is calculated based on the mixing information, the thickness of the film layer, a first film layer attenuation parameter related to the photoelectrons generated in the substrate, and a substrate material contribution value representing the effective contribution of the substrate material to at least one of the material type signals.

7. The system according to claim 1, wherein: The mixing information indicates a light beam intensity distribution associated with one or more of the film layers.

8. The system according to claim 1, wherein: The mixing information includes one or more beam Gaussian parameters.

9. The system according to claim 1, wherein: The membrane layer is positioned over the upper surface of the additional sample sub-region.

10. The system according to claim 1, wherein: The membrane layer is positioned below the upper surface of the additional sample sub-region.

11. The system according to claim 1, wherein: The sample area includes a second film layer made of a second film layer material and located outside the first sample sub-area; The processor is further configured to: determining a second film layer material type signal in an energy band corresponding to electrons emitted from the second film layer material based on the detection signal; A measurement value of the second film layer is determined based on: (i) the material type signal, (ii) the mixing information, and (iii) a second film layer material contribution value representing an effective contribution of the second film layer material to at least one of the material type signals.

12. The system according to claim 11, wherein The electron-optical device is further configured to: irradiating a second sample region including the second film layer and the second sample sub-region with the X-ray spot; and Electrons emitted from the second sample region are detected to provide a detection signal.

13. A method for characterizing a first film layer of a sample, the method comprising: irradiating a first sample region including the first membrane layer and a first sample sub-region with an X-ray spot; wherein the first membrane layer is made of a first membrane layer material and is positioned above a substrate made of a substrate material; detecting electrons emitted from the first sample region to provide a detection signal, wherein the detection signal is an X-ray photoelectron spectroscopy (XPS) detection signal; and determining, by a processor, a material type signal based on the detection signal, the material type signal comprising: (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material; and A measurement value of the first film layer is determined by the processor based on: (i) the material type signal, (ii) mixing information indicating a fraction of the X-ray spots that impinge on the first film layer, and (iii) a first film layer material contribution value representing an effective contribution of the first film layer material to at least one of the material type signals.

14. A non-transitory computer readable medium for characterizing a first film layer of a sample, the non-transitory computer readable medium storing instructions that, when executed by a computerized system, cause the computerized system to perform the following steps: Irradiating a first sample region including the first film layer and the first sample sub-region with an X-ray spot; wherein, The first membrane layer is made of a first membrane layer material and is positioned over a substrate made of a substrate material; detecting electrons emitted from the first sample region to provide a detection signal, wherein the detection signal is an X-ray photoelectron spectroscopy (XPS) detection signal; and determining, by a processor, a material type signal based on the detection signal, the material type signal comprising: (i) a first film layer material type signal in an energy band corresponding to electrons emitted from the first film layer material, and (ii) a substrate material type signal in an energy band corresponding to electrons emitted from the substrate material; and A measurement value of the first film layer is determined by the processor based on: (i) the material type signal, (ii) mixing information indicating a fraction of the X-ray spots that impinge on the first film layer, and (iii) a first film layer material contribution value representing an effective contribution of the first film layer material to at least one of the material type signals.

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