XPS measuring method for material interface thickness
By obtaining the target interface thickness sequence in XPS technology and setting the standard interface thickness, the problem of inaccurate interface thickness measurement caused by the too small ratio of the etching area size to the analyzed area size is solved, and higher measurement accuracy and reliability are achieved.
Patent Information
- Application Number
- CN202411831121.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-03-04
Smart Images
Figure CN119555002A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of material detection and analysis, and in particular to an XPS determination method for material interface thickness. Background Art
[0002] In the field of materials science, especially in the study of layered film materials, accurate determination of interface structure is crucial to understanding the electrical and optical properties of materials. With the development of technology, X-ray Photoelectron Spectroscopy (XPS) technology has been widely used in interface determination technology because it can provide information on the chemical state of material surfaces and interfaces. The development path of XPS technology has undergone a transformation from single surface analysis to complex interface structure analysis, and its technological progress has provided important tools and methods for the development of interface science.
[0003] At present, XPS technology has become an indispensable technical means in the field of interface determination. Through XPS, researchers can obtain information such as the elemental composition, chemical state, and electronic structure of the material surface and interface. Although XPS technology has made certain progress in interface determination, the existing technology still has shortcomings. When the ratio of the etching area size to the analysis area size is too small, it will cause serious distortion of the material layer structure data, thereby affecting the accuracy of the interface thickness measurement. Summary of the invention
[0004] The main purpose of the present invention is to propose an XPS determination method for material interface thickness, aiming to solve the technical problem in the prior art that when the ratio of the etching area size to the analysis area size is too small, the material layer structure data will be seriously distorted, thereby affecting the accuracy of the interface thickness determination.
[0005] To achieve the above object, in a first aspect, the present invention provides an XPS method for measuring the thickness of a material interface, comprising the following steps:
[0006] Obtaining a target interface thickness sequence of the sample to be tested; wherein the target interface thickness sequence includes a plurality of target interface thicknesses arranged in sequence, each of the target interface thicknesses corresponds to a preset etching area, and the signal collection areas corresponding to all the target interface thicknesses decrease in sequence;
[0007] The target interface thickness that meets the preset conditions is used as the standard interface thickness of the sample to be tested; wherein the preset conditions are that the ratio of the preset etching area to the signal collection area is greater than a first preset value, and the difference between the target interface thickness and the previous target interface thickness is not greater than a second preset value, and / or the difference between the target interface thickness and the next target interface thickness is not greater than the second preset value.
[0008] In one embodiment, the step of using the target interface thickness that meets the preset conditions as the standard interface thickness of the sample to be tested includes:
[0009] The target interface thickness that satisfies the conditions that the ratio of the preset etching area to the preset scanning area is greater than 1 and the difference between any two adjacent target interface thicknesses is no greater than 1 nm is used as the standard interface thickness of the sample to be tested.
[0010] In one embodiment, the step of using the target interface thickness that meets the preset conditions as the standard interface thickness of the sample to be tested includes:
[0011] The target interface thickness that satisfies the conditions that the ratio of the preset etching area to the preset scanning area is greater than 3 and the difference between any two adjacent target interface thicknesses is no greater than 1 nm is taken as the standard interface thickness of the sample to be tested.
[0012] In one embodiment, the step of using the target interface thickness satisfying the ratio of the preset etching area to the preset scanning area being greater than 3 and the difference between any two adjacent target interface thicknesses being no greater than 1 nm as the standard interface thickness of the sample to be tested comprises:
[0013] The target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area being greater than 6 and less than 10, and the difference between any two adjacent target interface thicknesses being less than 1 nm is taken as the standard interface thickness of the sample to be tested.
[0014] In one embodiment, the step of obtaining a target interface thickness sequence of the sample to be tested includes:
[0015] Determine the current signal collection area;
[0016] For each etching operation performed on the sample to be tested with a preset etching area, a plurality of high-resolution narrow-scan spectra corresponding to the etching moments are collected; wherein an interface region is formed in the sample to be tested, a target element is formed in the interface region, and the collection area of each of the high-resolution narrow-scan spectra is the signal collection area;
[0017] Obtaining a target etching depth profile of the target element according to all the high-resolution narrow scan spectra;
[0018] According to the target etching depth profile, obtaining the etching interval duration of the interface region of the sample to be tested;
[0019] Obtaining a target interface thickness of the interface region according to the etching interval time and a preset etching rate;
[0020] After determining the new current signal acquisition area, repeat the steps of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area, and obtaining the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained; wherein the new current signal acquisition area is smaller than the current signal acquisition area.
[0021] In one embodiment, after the step of obtaining the target interface thickness of the interface region according to the etching interval time and the preset etching rate, the method further includes:
[0022] Determining whether the target interface thickness is obtained for the first time;
[0023] If it is obtained for the first time, the step of determining a new current signal acquisition area is executed, and the step of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area is repeated, and the step of obtaining the target interface thickness of the interface area according to the etching interval length and the preset etching rate is repeated until a target interface thickness sequence is obtained.
[0024] In one embodiment, after the step of determining whether the target interface thickness is obtained for the first time, the method further includes:
[0025] If it is not the first time to obtain, determine whether the difference between the value of the target interface thickness and the value of the previous target interface thickness meets the preset condition;
[0026] If the preset condition is not met, the step of determining a new current signal acquisition area, and repeatedly performing the step of acquiring high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with the preset etching area, to the step of acquiring the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained;
[0027] If the preset condition is met, the current signal acquisition area and the preset scanning area corresponding to the interface thickness that meets the preset condition are used as the optimal acquisition condition.
[0028] In one embodiment, the step of obtaining the etching interval duration of the interface region of the sample to be tested according to the target etching depth profile includes:
[0029] According to the target etching depth profile, the interface region of the sample to be tested is obtained; wherein the interface region is a region where the signal intensity in the target etching depth profile is 16%-84%;
[0030] The etching interval duration corresponding to the interface region is obtained.
[0031] In one embodiment, the step of obtaining the etching interval duration corresponding to the interface region includes:
[0032] The starting time and the ending time corresponding to the preset area are screened out from the target etching depth profile diagram to obtain the etching interval duration of the interface area.
[0033] In one embodiment, the step of obtaining a target etching depth profile of the target element according to all the high-resolution narrow scan spectra includes:
[0034] Performing background subtraction operations on each of the high-resolution narrow scan spectra in turn to obtain corresponding signal intensities;
[0035] The target etching depth profile of the corresponding target element is established according to the signal intensity and the corresponding etching time.
[0036] The technical solution of the present invention obtains a target interface thickness sequence of the sample to be tested, and uses the target interface thickness that meets the preset conditions as the standard interface thickness of the sample to be tested. When in use, the target etching thickness corresponding to the multiple standard interface thicknesses that simultaneously satisfies the ratio of the preset etching area to the preset scanning area is greater than the first preset value and the difference between any two adjacent target interface thicknesses is not greater than the second preset value is used as the standard interface thickness. The present invention can form two evaluation conditions in the dimension that the ratio of the preset etching area to the signal acquisition area is greater than the first preset value, and the difference between the target interface thickness and the previous target interface thickness and / or the next target interface thickness is not greater than the second preset value, and use these two evaluation conditions to simultaneously determine the interface thickness, thereby avoiding the situation where the ratio of the etching area size to the analysis area size is too small, causing serious distortion of the material layer structure data and affecting the accuracy of the interface thickness measurement, thereby ensuring the accuracy of the interface thickness test results. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0038] Figure 1 A flow chart of the XPS determination method of material interface thickness provided by the present invention;
[0039] Figure 2 for Figure 1 Flow chart of step S100 in the example;
[0040] Figure 3 for Figure 2 Flow chart of step S150 in the example;
[0041] FIG4( a ) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 3 according to an example of the present invention;
[0042] FIG4( b ) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 4 according to an example of the present invention;
[0043] FIG4( c ) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 5 according to an example of the present invention;
[0044] FIG4(d) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 6 according to an example of the present invention;
[0045] FIG4( e ) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 8 according to an example of the present invention;
[0046] FIG4( f ) is an etching depth profile diagram when the ratio of the preset etching area to the preset collection area is 10 according to an example of the present invention.
[0047] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0049] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0050] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0051] The invention provides an XPS determination method for material interface thickness.
[0052] See also Figure 1 to Figure 4(f) For ease of understanding, the XPS determination method of the material interface thickness includes the following steps:
[0053] S100, obtaining a target interface thickness sequence of a sample to be tested.
[0054] Among them, the target interface thickness sequence includes multiple target interface thicknesses arranged in sequence, each of the target interface thicknesses corresponds to a preset etching area, and the signal collection areas corresponding to all the target interface thicknesses decrease in sequence; the target interface thickness sequence of the sample to be tested is obtained.
[0055] In this embodiment, the sample to be tested is a hybrid structure formed by disposing a silicon dioxide layer on one surface of a silicon substrate, and the region corresponding to the interface thickness is a transition region between the silicon dioxide layer and the silicon substrate.
[0056] For ease of understanding, when performing an etching operation, first an etching area is determined on the surface of the silicon dioxide layer, and laser etching is performed on the etching area using a laser. During the laser etching operation, data is collected at each etching moment to obtain a high-resolution narrow-scan spectrum corresponding to each etching moment, and a background subtraction operation is performed on the high-resolution narrow-scan spectrum to obtain the ratio relationship between the corresponding etching moment and the signal intensity of the oxygen element, and the corresponding interface area is obtained, and the corresponding interface thickness is determined based on the corresponding interface area.
[0057] The area corresponding to the etching area is taken as the preset etching area, and the preset etching area is the scanning area of the laser spot when the laser etching operation is performed on the surface of the silicon dioxide layer each time. The example signal scanning area is the scanning area corresponding to the scanning when the acquisition device performs signal acquisition in the etching area.
[0058] The target interface thickness sequence illustrated in this embodiment includes multiple target interface thicknesses, and the process of obtaining each target interface thickness is as follows:
[0059] First, during the etching process, the high-resolution narrow scan spectra corresponding to each etching moment are obtained in turn, and then the background subtraction operation is performed on the high-resolution narrow scan spectra to obtain the corresponding signal intensity of the target element. After all signal intensities are obtained, an etching depth profile is established based on the relationship between the signal intensity and the corresponding etching moment. After the corresponding etching depth profile is obtained, the etching interval duration corresponding to the signal intensity in the interface region is used as the etching interval duration of the interface region in the etching depth profile. After the obtained etching interval duration is obtained, the obtained etching interval duration and the preset etching speed are used to solve the target interface thickness. According to the etching sequence of the etching operation on the sample to be tested, the obtained multiple target interface thicknesses are sorted to form a target interface thickness sequence.
[0060] The interface region is the region where the signal intensity of oxygen element in the etching depth analysis diagram is located between 16% and 84%.
[0061] In one embodiment, step S100 includes:
[0062] S110: Determine the current signal collection area.
[0063] In this embodiment, the high-resolution narrow-scan spectrum is a spectrum of oxygen in the silicon dioxide layer. "High resolution" means that it has a high resolution and can clearly distinguish signals with very close physical quantities such as frequency (corresponding to chemical shift in magnetic resonance spectrum, etc.), energy (energy range in infrared spectrum, ultraviolet-visible spectrum, etc.). "Narrow scan" means that the oxygen in the sample to be tested is scanned and data is collected in a relatively narrow frequency or energy range.
[0064] S120. For each etching operation performed on the sample to be tested with a preset etching area, collect high-resolution narrow-scan spectra corresponding to multiple etching moments; wherein an interface region is formed in the sample to be tested, and a target element is formed in the interface region, and the collection area of each high-resolution narrow-scan spectra is the signal collection area.
[0065] In this embodiment, the target element is oxygen.
[0066] S130, obtaining a target etching depth profile of the target element according to all the high-resolution narrow scan spectra.
[0067] The etching interval duration illustrated in this embodiment is the interval etching duration corresponding to the region with a signal intensity of 16%-84% in the etching depth profile.
[0068] S140, obtaining the etching interval duration of the interface region of the sample to be tested according to the target etching depth profile.
[0069] In this embodiment, when obtaining the etching interval duration of the interface area of the sample to be tested according to the target etching depth analysis diagram, the time between the etching moment corresponding to the signal intensity of 16% in the target etching depth analysis diagram and the etching moment corresponding to the signal intensity of 84% in the target etching depth analysis diagram is taken as the etching interval duration.
[0070] S150, obtaining a target interface thickness of the interface region according to the etching interval time and a preset etching rate.
[0071] In this embodiment, according to the etching interval time and the preset etching rate, the process of obtaining the target interface thickness of the interface region is: multiplying the etching interval time by the preset etching rate to obtain the target interface thickness.
[0072] S160. After determining the new current signal acquisition area, repeat the step of acquiring high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area, and the step of acquiring the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained; wherein the new current signal acquisition area is smaller than the current signal acquisition area.
[0073] In this embodiment, by reducing the current signal collection area, the area corresponding to the signal collection area is made closer to the central area of the laser spot, and by reducing the current signal collection area, the accuracy of obtaining a high-resolution narrow-scan spectrum is improved.
[0074] It should be further clarified and explained that, in this embodiment, when laser etching is performed using a laser, an arc-shaped pit structure is formed in the silicon dioxide layer or silicon substrate area. When collecting signals, the signal intensity of the oxygen element corresponding to the area closer to the pit bottom structure is more accurate. Therefore, when collecting high-resolution narrow-scan spectra, the smaller the collection area, the more accurate the corresponding signal intensity.
[0075] In one embodiment, step S150 includes:
[0076] S151, determining whether the target interface thickness is obtained for the first time.
[0077] In this embodiment, when determining whether the target interface thickness is obtained for the first time, it is mainly determined whether the laser etching operation is the first etching.
[0078] S152. If it is the first time to obtain, execute the step of determining a new current signal acquisition area, repeat the step of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area, and then obtain the target interface thickness of the interface area according to the etching interval and the preset etching rate, until the target interface thickness sequence is obtained.
[0079] In this embodiment, by judging whether the target interface thickness is obtained for the first time, and if it is obtained for the first time, determining a new current signal acquisition area, repeating the steps of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area, and obtaining the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained, so that the present invention can more accurately obtain the target interface thickness when used, and can ensure the accuracy of the obtained target interface thickness.
[0080] In one embodiment, after step S151, the method further includes:
[0081] S153, if it is not the first time to obtain, determine whether the difference between the value of the target interface thickness and the value of the previous target interface thickness meets a preset condition;
[0082] S154. If the preset condition is not met, the step of determining a new current signal acquisition area, repeating the step of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with the preset etching area, and obtaining the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained.
[0083] S155. If the preset condition is met, the current signal acquisition area and the preset scanning area corresponding to the interface thickness that meets the preset condition are used as the optimal acquisition condition.
[0084] In this embodiment, the preset condition is that the difference between the value of the target interface thickness and the value of the previous target interface thickness is no greater than 1 nm.
[0085] In this embodiment, by taking the current signal collection area and the preset scanning area that meet the preset conditions as the optimal conditions, the present invention can ensure the acquisition accuracy of the interface thickness when performing signal collection.
[0086] In one embodiment, step S140 includes:
[0087] S141, acquiring the interface region of the sample to be tested according to the target etching depth profile; wherein the interface region is a region in which the signal intensity in the target etching depth profile is 16%-84%;
[0088] S142, obtaining the etching interval duration corresponding to the interface region.
[0089] In this embodiment, the accuracy of the interface region can be ensured by taking the region in the target etching depth profile where the signal intensity is 16%-84% as the interface region.
[0090] In one embodiment, step S130 includes:
[0091] S131. According to the preset area, the start time and the end time corresponding to the preset area are screened out from the target etching depth profile diagram to obtain the etching interval duration of the interface area of the sample to be tested.
[0092] In this embodiment, the preset area exemplified is an interface area.
[0093] In one embodiment, step S120 includes:
[0094] S121, performing background subtraction operations on each of the high-resolution narrow scan spectra in turn to obtain corresponding signal strengths;
[0095] S122: Establish the target etching depth profile of the corresponding target element according to the signal strength and the corresponding etching time.
[0096] It should be particularly and clearly stated that the sample to be tested in the example includes a silicon plate and a silicon dioxide layer formed on the silicon plate, and the interface region is formed between the silicon plate and the silicon dioxide layer.
[0097] S200: taking the target interface thickness that meets preset conditions as the standard interface thickness of the sample to be tested.
[0098] Among them, the preset condition is that the ratio of the preset etching area to the signal collection area is greater than a first preset value, and the difference between the target interface thickness and the previous target interface thickness is not greater than a second preset value, and / or the difference between the target interface thickness and the next target interface thickness is not greater than the second preset value.
[0099] It should be particularly and clearly stated that the first preset value of the example is 1. The second preset value of the example is 1 nm.
[0100] In this embodiment, the ratio of the preset etching area to the signal collection area is greater than the first preset value and the difference between the target interface thickness and the previous target interface thickness is not greater than the second preset value or the difference between the target interface thickness and the next target interface thickness is not greater than the second preset value, so that the present invention can ensure the acquisition accuracy of the standard interface thickness.
[0101] In some exemplary embodiments, the target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area is greater than 1 and the difference between any two adjacent target interface thicknesses is no greater than 1 nm is used as the standard interface thickness of the sample to be tested.
[0102] In other exemplary embodiments, the target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area being greater than 3 and the difference between any two adjacent target interface thicknesses being no greater than 1 nm is used as the standard interface thickness of the sample to be tested.
[0103] In this embodiment, by obtaining a target interface thickness sequence of the sample to be tested, the target interface thickness that meets the preset conditions is used as the standard interface thickness of the sample to be tested. When in use, the target etching thickness corresponding to the multiple standard interface thicknesses that simultaneously satisfies the ratio of the preset etching area to the preset scanning area is greater than the first preset value and the difference between any two adjacent target interface thicknesses is not greater than the second preset value is used as the standard interface thickness. This allows the present invention to form two evaluation conditions in the dimension that the ratio of the preset etching area to the signal acquisition area is greater than the first preset value, and the difference between the target interface thickness and the previous target interface thickness and / or the next target interface thickness is not greater than the second preset value, and use these two evaluation conditions to simultaneously determine the interface thickness, thereby avoiding the situation where the ratio of the etching area size to the analysis area size is too small, causing serious distortion of the material layer structure data and affecting the accuracy of the interface thickness measurement, thereby ensuring the accuracy of the interface thickness test results.
[0104] In some further exemplary embodiments, the target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area being greater than 6 and not greater than 10, and the difference between any two adjacent target interface thicknesses being not greater than 1 nm is taken as the standard interface thickness of the sample to be tested.
[0105] It should be particularly and clearly stated that the target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area being greater than 6 and not greater than 10, and the difference between any two adjacent target interface thicknesses being not greater than 1 nm, is taken as the standard interface thickness of the sample to be tested.
[0106] In order to better understand the present invention, in this embodiment, a sample to be tested is described in detail with a silicon dioxide layer formed on a silicon substrate:
[0107] Instrument status confirmation: perform spectrometer ion beam alignment and inspection according to GB / T 34326 and the operating instructions provided by the instrument manufacturer to ensure that the spectrometer etching function is normal;
[0108] Sample injection and etching test: The test needs to meet the etching and data acquisition parameters required in Table 1, and then etch according to the sample thickness;
[0109] Table 1: XPS etching and data acquisition parameters;
[0110]
[0111] Please continue reading Figure 4(a) to Figure 4(f) , obtain test data with a ratio of etching area size to analysis area size of 3 (i.e., etching area size of 0.6 mm), and perform data analysis: subtract the background to determine the element spectrum peak area (i.e., signal intensity), obtain the element signal intensity and the corresponding etching interval length, and then obtain the etching depth profile of the signal relative intensity versus etching time;
[0112] The etching time interval corresponding to the interface region is obtained by linearly calculating the data points in the 16% to 84% range in the etching depth profile diagram;
[0113] Combined with the etching rate, the interface thickness information can be obtained;
[0114] Obtaining the interface thickness value when the ratio of the etching area size to the analysis area size is 3;
[0115] The etching depth profiles with the ratios of the etching area size to the analysis area size being 4, 5, 6, 8, and 10 respectively (ie, the etching area sizes are 0.8 mm, 1 mm, 1.2 mm, 1.6 mm, and 2 mm respectively) were obtained in sequence.
[0116] The corresponding etching rate and interface thickness parameters are shown in Table 2. From the observation data, we can see that:
[0117] The etching rate is inversely proportional to the etching area; the interface thickness does not change significantly at a ratio of 5 to 10 times; for thin film samples with relatively thin thickness, the etching rate can be reduced by increasing the scanning area.
[0118] Table 2: Interface thickness data of silicon dioxide standard material (GBW13971 52.61nm) on silicon wafer;
[0119]
[0120] From the data in Table 2, it can be seen that when the ratio is ≥ 6, the target interface thickness of the sample under test varies little, and the influence of the interface mixing effect can be basically ignored. For silicon dioxide film samples with a thickness of about 50nm, this parameter can be used to obtain the interface and its target interface thickness.
[0121] In this embodiment, by obtaining a target interface thickness sequence of the sample to be tested, the target interface thickness that meets the preset conditions is used as the standard interface thickness of the sample to be tested. When in use, the target etching thickness corresponding to the multiple standard interface thicknesses that simultaneously satisfies the ratio of the preset etching area to the preset scanning area is greater than 1 and the difference between any two adjacent target interface thicknesses is not greater than 1nm is used as the standard interface thickness, so that the present invention can improve the test accuracy of the interface thickness when in use.
[0122] In this embodiment, according to Table 2, Figure 4(a) to Figure 4(f) It can be seen that when the ratio of the preset etching area to the preset scanning area is 6, the values of the thickness of the two adjacent target interfaces are within 1 nm and tend to be unchanged. Therefore, the target interface thickness corresponding to the ratio of 6 is taken as the standard interface thickness.
[0123] Figure 4(a) to Figure 4(f) The normalized intensity of the example is the signal intensity, and the sputtering time of the example is the etching time.
[0124] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A method for measuring the thickness of a material interface by XPS, characterized in that: The steps include: Obtaining a target interface thickness sequence of the sample to be tested; wherein the target interface thickness sequence includes a plurality of target interface thicknesses arranged in sequence, each of the target interface thicknesses corresponds to a preset etching area, and the signal collection areas corresponding to all the target interface thicknesses decrease in sequence; The target interface thickness that meets the preset conditions is used as the standard interface thickness of the sample to be tested; wherein the preset conditions are that the ratio of the preset etching area to the signal collection area is greater than a first preset value, and the difference between the target interface thickness and the previous target interface thickness is not greater than a second preset value, and / or the difference between the target interface thickness and the next target interface thickness is not greater than the second preset value.
2. The XPS method for measuring material interface thickness according to claim 1, characterized in that: The step of using the target interface thickness that meets the preset conditions as the standard interface thickness of the sample to be tested includes: The target interface thickness that satisfies the conditions that the ratio of the preset etching area to the preset scanning area is greater than 1 and the difference between any two adjacent target interface thicknesses is no greater than 1 nm is used as the standard interface thickness of the sample to be tested.
3. The XPS determination method of material interface thickness according to claim 2, characterized in that: The step of using the target interface thickness that meets the preset conditions as the standard interface thickness of the sample to be tested includes: The target interface thickness that satisfies the conditions that the ratio of the preset etching area to the preset scanning area is greater than 3 and the difference between any two adjacent target interface thicknesses is no greater than 1 nm is taken as the standard interface thickness of the sample to be tested.
4. The XPS determination method of material interface thickness according to claim 3, characterized in that: The step of using the target interface thickness satisfying that the ratio of the preset etching area to the preset scanning area is greater than 3 and the difference between any two adjacent target interface thicknesses is not greater than 1 nm as the standard interface thickness of the sample to be tested comprises: The target interface thickness that satisfies the ratio of the preset etching area to the preset scanning area being greater than 6 and less than 10, and the difference between any two adjacent target interface thicknesses being less than 1 nm is taken as the standard interface thickness of the sample to be tested.
5. The XPS method for measuring the material interface thickness according to any one of claims 1 to 4, characterized in that: The step of obtaining a target interface thickness sequence of the sample to be tested comprises: Determine the current signal collection area; For each etching operation performed on the sample to be tested with a preset etching area, a plurality of high-resolution narrow-scan spectra corresponding to the etching moments are collected; wherein an interface region is formed in the sample to be tested, a target element is formed in the interface region, and the collection area of each of the high-resolution narrow-scan spectra is the signal collection area; Obtaining a target etching depth profile of the target element according to all the high-resolution narrow scan spectra; According to the target etching depth profile, obtaining the etching interval duration of the interface region of the sample to be tested; Obtaining a target interface thickness of the interface region according to the etching interval time and a preset etching rate; Determine a new current signal acquisition area, repeat the step of acquiring high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area, and the step of acquiring the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained; wherein the new current signal acquisition area is smaller than the current signal acquisition area.
6. The XPS method for measuring material interface thickness according to claim 5, characterized in that: After the step of obtaining the target interface thickness of the interface region according to the etching interval time and the preset etching rate, the method further includes: Determining whether the target interface thickness is obtained for the first time; If it is obtained for the first time, the step of determining a new current signal acquisition area is executed, and the step of collecting high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with a preset etching area is repeated, and the step of obtaining the target interface thickness of the interface area according to the etching interval length and the preset etching rate is repeated until a target interface thickness sequence is obtained.
7. The XPS method for measuring material interface thickness according to claim 6, characterized in that: After the step of determining whether the target interface thickness is obtained for the first time, the method further includes: If it is not the first time to obtain, determine whether the difference between the value of the target interface thickness and the value of the previous target interface thickness meets the preset condition; If the preset condition is not met, the step of determining a new current signal acquisition area, and repeatedly performing the step of acquiring high-resolution narrow scan spectra corresponding to multiple etching moments for each etching operation performed on the sample to be tested with the preset etching area, to the step of acquiring the target interface thickness of the interface area according to the etching interval and the preset etching rate, until a target interface thickness sequence is obtained; If the preset condition is met, the current signal acquisition area and the preset scanning area corresponding to the interface thickness that meets the preset condition are used as the optimal acquisition condition.
8. The XPS method for measuring material interface thickness according to claim 5, characterized in that: The step of obtaining the etching interval duration of the interface region of the sample to be tested according to the target etching depth profile diagram comprises: According to the target etching depth profile, the interface region of the sample to be tested is obtained; wherein the interface region is a region where the signal intensity in the target etching depth profile is 16%-84%; The etching interval duration corresponding to the interface region is obtained.
9. The XPS method for measuring material interface thickness according to claim 8, characterized in that: The step of obtaining the etching interval duration corresponding to the interface region includes: The starting time and the ending time corresponding to the preset area are screened out from the target etching depth profile diagram to obtain the etching interval duration of the interface area.
10. The XPS method for measuring material interface thickness according to claim 5, characterized in that: The step of obtaining a target etching depth profile of the target element according to all the high-resolution narrow scan spectra comprises: Performing background subtraction on each of the high-resolution narrow scan spectra in turn to obtain corresponding signal intensities; The target etching depth profile of the corresponding target element is established according to the signal intensity and the corresponding etching time.