Dry etching process line width real-time measuring device
The gas state substances in the dry etching process are measured in real time by mass spectrometer and the line width is calculated, which solves the problem of line width measurement in the high-deep-wide ratio dry etching process, and realizes non-destructive online measurement, reducing costs and improving productivity and product yield.
Patent Information
- Application Number
- CN202380085832.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-29
- Filing Date
- 2023-11-28
- Publication Date
- 2025-07-22
AI Technical Summary
The prior art cannot accurately measure line width in dry etching process with high aspect ratio, resulting in increased productivity and cost, and the destructive analysis method cannot be applied to mass production.
The gas state substances in the dry etching process are measured in real time by mass spectrometer, and the line width is calculated digitally, including the ratio of the amount of film etching by-products, oxygen by-products and fluorine by-products to the amount of etching gas to achieve non-destructive online measurement.
Real-time measurement of line width in the reaction chamber is achieved, unnecessary subsequent processes are avoided, production costs are reduced, productivity and process quality control are improved, and product failure rate is reduced.
Smart Images
Figure CN120359600A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an apparatus for real-time measurement of line width in a dry etching process. Background Art
[0002] Semiconductor / display products undergo a manufacturing process of forming a specific structure composed of various film materials on a substrate. The lithography process, which is a combination of a deposition process, a photolithography process, and a dry etching process, is a very important core process in the manufacture of semiconductor / display products. The dry etching process determines the structure of the semiconductor / display product by etching the thin film deposited on the substrate into a specific structure using an etching gas. Due to the ultra-fine refinement of the structure of the semiconductor / display product, the quality of the result of the dry etching process mostly determines the characteristics of the product. Therefore, after the process, the etching pattern and the etching line width, which are the results of the dry etching process, of the specimen are measured for metrology and inspection.
[0003] Methods for measuring the critical dimension (CD) and etching profile reflecting the results of a dry etching process mainly use the optical critical dimension (OCD) measurement method that utilizes optics. In the case of so-called high aspect ratio dry etching where the OCD measurement method cannot be used for measurement, a focused ion beam (FIB) sample pretreatment method that processes the sample in a way that enables the analysis of the line width by destroying the sample is used. After exposing the etching profile, a transmission electron microscope (TEM) or a scanning electron microscope (SEM) analysis method is used to measure the etching line width and the etching profile. However, with the continuous miniaturization and precision of semiconductor products, when the aspect ratio of the dry etching process structure is 20 or more, in the OCD method of optical measurement, light cannot reach the lower part of the etching structure, thereby reducing the accuracy of measuring the etching structure. Moreover, the number of such processes where the lower part of the etching structure cannot be measured is still increasing. As an alternative, the method of performing TEM / SEM analysis after FIB processing for measuring the etching line width destroys the sample, making the produced products unusable. Therefore, it cannot be applied to mass-produced semiconductor / display products. It can only be intermittently measured for selectively sampled samples after dozens or hundreds of processes. The semiconductor / display products are mass-produced with most of the line widths and structures of the dry etching process not being measured. Therefore, semiconductor / display products can only be mass-produced at the risk of potential process defects. Also, the selectively sampled samples can only be discarded, and the time required for measurement, the manpower required for pretreatment and analysis operations, the cost of analysis instruments, and the cost of constructing infrastructure continue to increase, having an adverse impact on aspects such as the cost and productivity of semiconductor / display production. Summary of the Invention
[0004] Technical Problem
[0005] The object of the present invention is to provide a real-time line width measuring device for a dry etching process that can measure the line width in real time in a reaction chamber in order to overcome the limitations of the conventional OCD analysis method as a non-destructive analysis method and the FIB, SEM / TEM analysis methods as destructive analysis methods in the dry etching process.
[0006] Technical Solution
[0007] The real-time line width measurement device for the dry etching process of the present invention includes: a reaction chamber for performing the dry etching process; a mass spectrometer for measuring the gaseous substances in the reaction chamber during the dry etching process; and a calculation unit for calculating the line width (CD) based on the data measured by the mass spectrometer through the following mathematical formula.
[0008] CD = {a1 × Σ[amount of film etching by-products]} × {a2 × Σ[amount of oxygen by-products]} × {a3 × Σ[amount of fluorine by-products]} / {a4 × Σ[amount of etching gas]}
[0009] Wherein, a1, a2, a3 and a4 are predefined proportional constants.
[0010] Moreover, the film etching by-products may include one or more of SiF, SiF2, SiF3, SiF4, SiCl, SiCl2, SiCl3, SiCl4, SiH, SiH2, SiH3, SiH4, CF, CF2, CF3, CF4, NF, NF2, NF3, OF, OF2, GeF, GeF2, GeF3, GeF4, BF, BF2, BF3, PF, PF2, PF3, WF, WF2, WF3, WF4, WF5, WF6, WCl, WCl2, WCl3, WCl4, WCl5, WCl6, AlCl, AlCl2, AlCl3, HfF, HfF2, HfF3, HfF4, HfF5, HfF6, CoF, CoF2, CoF3 and CoF4.
[0011] Moreover, the oxygen by-products may include one or more of O2, O, CO, CO2, NO, NO2, SO, SO2 and H2O.
[0012] Moreover, the fluorine by-products may include one or more of F, F2 and HF.
[0013] Moreover, the etching gas residues may include one or more of CF4, CHF3, CH2F2, CH3F, C2F2, C2F4, C2F6, C3F4, C3F6, C3F8, C4F6, C4F8, C4F 10 , HF, F2, HCl, Cl2, CCl4, HBr, Br2, HI and I2.
[0014] Moreover, in the above formula, "Σ[amount of film etching by-products]" can be the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" can be the sum of the amounts of all oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" can be the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" can be the sum of the amounts of all etching gases measured by the mass spectrometer.
[0015] Moreover, in the above formula, "Σ[amount of film etching by-products]" can be the sum of the amounts of some substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" can be the sum of the amounts of some substances in the oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" can be the sum of the amounts of some substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" can be the sum of the amounts of some substances in the etching gas measured by the mass spectrometer.
[0016] Moreover, the above-mentioned some substances may include the top n substances with a high degree of relevance found through experiments, and n can be a preset natural number.
[0017] Moreover, the above-mentioned some substances can be determined through deep learning or machine learning analysis.
[0018] Moreover, a1, a2, a3, and a4 can be the same.
[0019] Moreover, at least some of a1, a2, a3, and a4 can be different from each other.
[0020] Moreover, a1, a2, a3, and a4 can be determined through deep learning or machine learning analysis.
[0021] Moreover, the calculation unit can calculate the upper-end line width, the middle-line width, and the lower-end line width respectively by calculating the line width according to different times of performing the dry etching process.
[0022] Furthermore, the present invention can provide a method for real-time measurement of the line width in a dry etching process.
[0023] In this case, the method for real-time measurement of the line width in the dry etching process of the present invention includes: a step of measuring the gaseous state substances in the reaction chamber during the dry etching process by using a mass spectrometer; and a step of calculating the line width (CD) through the following formula based on the data measured by the mass spectrometer.
[0024] CD = {a1 × Σ[amount of film etching by-products]} × {a2 × Σ[amount of oxygen by-products]} × {a3 × Σ[amount of fluorine by-products]} / {a4 × Σ[amount of etching gas]}
[0025] Wherein, a1, a2, a3 and a4 are predetermined proportional constants.
[0026] And, the film etching by-products may include one or more of SiF, SiF2, SiF3, SiF4, SiCl, SiCl2, SiCl3, SiCl4, SiH, SiH2, SiH3, SiH4, CF, CF2, CF3, CF4, NF, NF2, NF3, OF, OF2, GeF, GeF2, GeF3, GeF4, BF, BF2, BF3, PF, PF2, PF3, WF, WF2, WF3, WF4, WF5, WF6, WCl, WCl2, WCl3, WCl4, WCl5, WCl6, AlCl, AlCl2, AlCl3, HfF, HfF2, HfF3, HfF4, HfF5, HfF6, CoF, CoF2, CoF3 and CoF4.
[0027] And, the oxygen by-products may include one or more of O2, O, CO, CO2, NO, NO2, SO, SO2 and H2O.
[0028] And, the fluorine by-products may include one or more of F, F2 and HF.
[0029] And, the etching gas residues may include one or more of CF4, CHF3, CH2F2, CH3F, C2F2, C2F4, C2F6, C3F4, C3F6, C3F8, C4F6, C4F8, C4F 10 , HF, F2, HCl, Cl2, CCl4, HBr, Br2, HI and I2.
[0030] And, in the formula, "Σ[amount of film etching by-products]" may be the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" may be the sum of the amounts of all oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" may be the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" may be the sum of the amounts of all etching gases measured by the mass spectrometer.
[0031] Moreover, in the above formula, "Σ[amount of film etching by-products]" can be the sum of the amounts of some substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" can be the sum of the amounts of some substances in the oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" can be the sum of the amounts of some substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" can be the sum of the amounts of some substances in the etching gas measured by the mass spectrometer.
[0032] Moreover, the above-mentioned some substances may include the top n substances found to have a high degree of relevance through experiments, and n may be a predetermined natural number.
[0033] Moreover, the above-mentioned some substances can be determined through deep learning or machine learning analysis.
[0034] Moreover, a1, a2, a3, and a4 can be the same.
[0035] Moreover, at least some of a1, a2, a3, and a4 can be different from each other.
[0036] Moreover, a1, a2, a3, and a4 can be determined through deep learning or machine learning analysis.
[0037] On the other hand, the present invention can provide a method that applies the above-mentioned real-time line width measurement method for dry etching process at different times during the dry etching process to calculate the upper-end line width, middle-section line width, and lower-end line width respectively.
[0038] Effects of the Invention
[0039] The real-time line width measurement device for dry etching process of the present invention measures the gaseous substances in the reaction chamber during the dry etching process by using a mass spectrometer, and calculates the line width based on the data measured by the mass spectrometer, so that the line width can be measured in real time in the reaction chamber.
[0040] By using a wafer that has not formed the desired line width in the initial treatment during the process to avoid unnecessary subsequent processes, production costs can be reduced and economic efficiency can be improved. Also, the function of automatic process control for continuously maintaining process quality can be achieved through the automatic control of the process time or etching conditions during the real-time etching process. Additionally, a line width measurement method that measures and calculates during the process without an additional etching line width measurement step can monitor the etching line width of the entire wafer or sample without additional reduction in productivity, thereby blocking the occurrence of potential quality risks caused by the limitations of the conventional line width measurement method that measures by intermittent sampling among all mass-produced samples. As a result, it can be flexibly applied in the monitoring of etching defects and yield improvement of all mass-produced samples. Moreover, by early detecting abnormalities in the etching environment such as the reaction chamber in real time to diagnose the state of semiconductor manufacturing equipment, the product rejection rate can be reduced and the productivity of good products can be increased. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Figure 1 The following is a schematic diagram of a real-time line width measurement device for a dry etching process according to an embodiment of the present invention.
[0042] Figure 2 The following is a graph showing a proportional relationship between the line width and the amount of SiF4, which is an example of a film etching by-product. The horizontal axis represents the line width (nm), and the vertical axis represents the amount of SiF4 (a.u.).
[0043] Figure 3 The following is a graph showing a proportional relationship between the line width and the amount of NO, which is an example of a film etching by-product. The horizontal axis represents the line width (nm), and the vertical axis represents the amount of NO (a.u.).
[0044] Figure 4 The following is a graph showing an inverse proportional relationship between the line width and the amount of C4F6, which is an example of a film etching by-product. The horizontal axis represents the line width (nm), and the vertical axis represents the amount of C4F6 (a.u.).
[0045] Figure 5 The following is a graph showing a proportional relationship between the line width and {Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]}. The horizontal axis represents the line width (nm), and the vertical axis represents {Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]} (a.u.). DETAILED DESCRIPTION OF THE EMBODIMENTS
[0046] A real-time line width measurement device for a dry etching process according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0047] Figure 1This is a schematic diagram of the real-time line width measurement device 10 for the dry etching process according to an embodiment of the present invention.
[0048] Referring to Figure 1 , the real-time line width measurement device 10 for the dry etching process includes a reaction chamber 11, a mass spectrometer 12, and a calculation unit 13.
[0049] The dry etching process is carried out in the reaction chamber 11. In this way, when etching gas is injected into the reaction chamber 11 and plasma is generated, the etching gas produces volatile reaction by-products due to the chemical reaction on the wafer surface, and the by-products can fall off from the wafer surface to perform the dry etching process in a way of removing the film. Such a dry etching process and the structure of the reaction chamber itself are substantially the same as the known structures, or those skilled in the art to which the present invention pertains can easily derive similar structures therefrom, so the detailed description thereof is omitted here.
[0050] The mass spectrometer 12 functions to measure the gas state substances in the reaction chamber 11 in real time during the dry etching process. The mass spectrometer 12 can be directly connected through the interior of the reaction chamber 11, or can be connected to the exhaust line (fore-line, exhaust line) of the reaction chamber 11. The structure of such a mass spectrometer itself is substantially the same as the known structures, or those skilled in the art to which the present invention pertains can easily derive it, so the detailed description thereof is omitted here.
[0051] The calculation unit 13 functions to calculate the line width based on the data measured by the mass spectrometer 12.
[0052] More specifically, the calculation unit 13 can utilize the situation where the line width is proportional to the amount of film etching by-products, the amount of oxygen by-products, and the amount of fluorine by-products in the reaction chamber 11 during the dry etching process, and inversely proportional to the amount of etching gas (refer to Figures 2 - 4 ), and calculate the line width (CD) through the following formula 1.
[0053] Formula 1: CD = a × Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]
[0054] Where a is a proportionality constant.
[0055] The value of a can be determined through experiments. For example, during the dry etching process for the test, the gas state substances in the reaction chamber 11 are measured using the mass spectrometer 12, and then the actual line width is measured. The data measured by the mass spectrometer 12 are respectively substituted into Formula 1 so that the result has the same value as the actual line width, thereby the proportionality constant can be obtained. Furthermore, such experiments can be repeated multiple times, for example, to obtain the optimal proportionality constant in the way of obtaining the average value.
[0056] Furthermore, the value of a can be determined by deep learning or machine learning analysis. Therefore, the accuracy can be further improved as the dry etching process proceeds.
[0057] For example, the film etching by-products may include one or more of SiF, SiF2, SiF3, SiF4, SiCl, SiCl2, SiCl3, SiCl4, SiH, SiH2, SiH3, SiH4, CF, CF2, CF3, CF4, NF, NF2, NF3, OF, OF2, GeF, GeF2, GeF3, GeF4, BF, BF2, BF3, PF, PF2, PF3, WF, WF2, WF3, WF4, WF5, WF6, WCl, WCl2, WCl3, WCl4, WCl5, WCl6, AlCl, AlCl2, AlCl3, HfF, HfF2, HfF3, HfF4, HfF5, HfF6, CoF, CoF2, CoF3 and CoF4.
[0058] Also, for example, the oxygen by-product may include one or more of O2, O, CO, CO2, NO, NO2, SO, SO2, and H2O.
[0059] Furthermore, for example, the fluorine by-product may include one or more of F, F2 and HF.
[0060] Also, for example, the etching gas may include CF4, CHF3, CH2F2, CH3F, C2F2, C2F4, C2F6, C3F4, C3F6, C3F8, C4F6, C4F8, C4F 10 , HF, F2, HCl, Cl2, CCl4, HBr, Br2, HI and I2.
[0061] However, the above substances are examples considering the film quality, etching gas, etc. used in the ordinary semiconductor / display wafer dry etching process. The technical concept of the present invention is not limited to this and may vary depending on the film quality, etching gas, etc. used in individual dry etching processes.
[0062] In one embodiment, the calculation unit 13 may calculate the line width using all the data measured by the mass spectrometer 12. That is, the equation 1 may be specifically expressed as the following equation 2.
[0063] Formula 2: CD = a × Σ [amount of all film-quality etching byproducts] × Σ [amount of all oxygen byproducts] × Σ [amount of all fluorine byproducts] / Σ [amount of all etching gases]
[0064] For example, when SiF, SiF2, SiF3, and SiF4 are detected as film etching by-products by the mass spectrometer 12, "Σ[amount of all film etching by-products]" in Equation 2 represents the sum of their amounts (i.e., the sum of the amounts of SiF, SiF2, SiF3, and SiF4). The same applies to the remaining oxygen by-products, fluorine by-products, and etching gases. That is, in Equation 2, "Σ[amount of all oxygen by-products]" represents the sum of the amounts of all oxygen by-products measured by the mass spectrometer 12, "Σ[amount of all fluorine by-products]" represents the sum of the amounts of all fluorine by-products measured by the mass spectrometer 12, and "Σ[amount of all etching gases]" represents the sum of the amounts of all etching gases measured by the mass spectrometer 12.
[0065] In yet another embodiment, the calculation unit 13 may calculate the line width using a part of the data measured by the mass spectrometer 12. That is, Equation 1 may be embodied as the following Equation 3.
[0066] Equation 3: CD = a × Σ[amount of a part of film etching by-products] × Σ[amount of a part of oxygen by-products] × Σ[amount of a part of fluorine by-products] / Σ[amount of a part of etching gases]
[0067] For example, when SiF, SiF2, SiF3, and SiF4 are detected as film etching by-products by the mass spectrometer 12, "Σ[amount of a part of film etching by-products]" in Equation 3 represents the sum of the amounts of some of them (for example, only the sum of the amounts of SiF2, SiF3, and SiF4 excluding SiF). The same applies to the remaining oxygen by-products, fluorine by-products, and etching gases. That is, in Equation 3, "Σ[amount of a part of oxygen by-products]" represents the sum of the amounts of some of the oxygen by-products measured by the mass spectrometer 12, "Σ[amount of a part of fluorine by-products]" represents the sum of the amounts of some of the fluorine by-products measured by the mass spectrometer 12, and "Σ[amount of a part of etching gases]" represents the sum of the amounts of some of the etching gases measured by the mass spectrometer 12.
[0068] It is possible to determine through experiments which substance's data among the data measured by the mass spectrometer 12 should be used.
[0069] For ease of understanding, for example, as described above, the film etching by-products may include one or more of SiF, SiF2, SiF3, SiF4, SiCl, SiCl2, SiCl3, SiCl4, SiH, SiH2, SiH3, SiH4, CF, CF2, CF3, CF4, NF, NF2, NF3, OF, OF2, GeF, GeF2, GeF3, GeF4, BF, BF2, BF3, PF, PF2, PF3, WF, WF2, WF3, WF4, WF5, WF6, WCl, WCl2, WCl3, WCl4, WCl5, WCl6, AlCl, AlCl2, AlCl3, HfF, HfF2, HfF3, HfF4, HfF5, HfF6, CoF, CoF2, CoF3, and CoF4. The line width can be calculated using them respectively according to the film quality, etching gas, etc. used in the relevant dry etching process, and then compared with the actual line width. In this way, they are respectively recorded in Equation 1. As "[Σ (amount of film etching by-products)]", ① the result of calculating the line width by substituting only the amount of SiF, ② the result of calculating the line width by substituting only the amount of SiF2, ③ the result of calculating the line width by substituting only the amount of SiF3, ④ the result of calculating the line width by substituting only the amount of SiF4, etc. are compared with the actual line width and arranged in the order of the size of the difference. The smaller the difference, the higher the relevance of the substance. Therefore, in the data measured by the mass spectrometer 12, only the first n substances with high ascertained relevance can be used to calculate the line width. Here, n is a natural number, and how many substances to use can be determined as needed. The same applies to the residual oxygen by-products, fluorine by-products, and etching gases.
[0070] Moreover, in the data measured by the mass spectrometer 12, which substances' data to use can be determined through deep learning or machine learning analysis.
[0071] In yet another embodiment, a part of the film etching by-products, oxygen by-products, fluorine by-products, and etching gases can use all the data measured by the mass spectrometer 12, and a part can use a part of the data measured by the mass spectrometer 12. In this case, there can be 16 combinations. For ease of understanding, for example, Equation 1 can be concretized into the following Equation 4.
[0072] Equation 4: CD = a × Σ[amount of all film etching by-products] × Σ[amount of a part of oxygen by-products] × Σ[amount of all fluorine by-products] / Σ[amount of a part of etching gases]
[0073] Furthermore, different proportionality constants can be adopted for the amount of film etching by-products, the amount of oxygen by-products, the amount of fluorine by-products, and / or the amount of etching gases. That is, the line width can be calculated by the following Equation 5.
[0074] Equation 5: CD = {a1 × Σ[amount of film etching by-products]} × {a2 × Σ[amount of oxygen by-products]} × {a3 × Σ[amount of fluorine by-products]} / {a4 × Σ[amount of etching gas]}
[0075] Among them, at least some of a1, a2, a3, and a4 can be the same or different from each other. Such proportional constants can be determined through experiments or through deep learning or machine learning analysis.
[0076] Moreover, in Equation 5, all the data measured by the mass spectrometer 12 can be used as in Equation 2, or a part of the data measured by the mass spectrometer 12 can be used as in Equation 3. The former case is shown in Equation 6 below, and the latter case is shown in Equation 7 below.
[0077] Equation 6: CD = {a1 × Σ[amount of all film etching by-products]} × {a2 × Σ[amount of all oxygen by-products]} × {a3 × Σ[amount of all fluorine by-products]} / {a4 × Σ[amount of all etching gas]}
[0078] Equation 7: CD = {a1 × Σ[amount of a part of film etching by-products]} × {a2 × Σ[amount of a part of oxygen by-products]} × {a3 × Σ[amount of a part of fluorine by-products]} / {a4 × Σ[amount of a part of etching gas]}
[0079] Regarding Equation 7, it can be determined through experiments which substance-related data among the data measured by the mass spectrometer 12 should be used, or it can be determined through deep learning or machine learning.
[0080] Of course. As shown in Equation 4, for a part of the film etching by-products, oxygen by-products, fluorine by-products, and etching gas, all the data measured by the mass spectrometer 12 can be used, and for a part, a part of the data measured by the mass spectrometer 12 can be used.
[0081] By using such a real-time measurement method for the line width of dry etching process at different times during the dry etching process, the top line width (Top CD), middle line width (Middle CD), and bottom line width (Bottom CD) can be calculated respectively. For example, when the real-time measurement method for the line width of the dry etching process of the embodiment of the present invention is adopted at the initial stage of the process, the top line width can be calculated; when this method is adopted in the middle stage of the process, the middle line width can be calculated; and when this method is adopted in the later stage of the process, the bottom line width can be calculated.
[0082] When calculating the upper end line width, the middle part line width, and the lower end line width, different proportionality constants can be used. As shown in Formula 3, Formula 4, and Formula 7, when using a part of the data measured by the mass spectrometer 12, the relevant data of different substances can also be used.
[0083] Figure 5 To show a chart where the line width is directly proportional to {Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]}, the horizontal axis represents the line width (nm), and the vertical axis represents {Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]} (a.u.).
[0084] Refer to Figure 5 , when showing the correlation between the actual line width and {Σ[amount of film etching by-products] × Σ[amount of oxygen by-products] × Σ[amount of fluorine by-products] / Σ[amount of etching gas]} used in the real-time measurement method of the dry etching process line width of the embodiment of the present invention, the determination coefficient (R 2 ) is about 0.95, and the correlation is at a very high level. Therefore, it can be confirmed that the real-time measurement method of the dry etching process line width of the embodiment of the present invention can be used to calculate the line width with high accuracy.
[0085] The above-described real-time measurement device 10 for the dry etching process line width is only one of the real-time measurement devices for the dry etching process line width in various embodiments of the present invention. The technical idea of the present invention is not limited to the above embodiments, and also includes the scope that can be easily changed by those of ordinary skill in the technical field to which the present invention belongs according to the content recorded in the claimed scope of the invention.
Claims
1. A real-time measurement device for the line width of a dry etching process, characterized in that: It includes: A reaction chamber for performing a dry etching process; A mass spectrometer for measuring gaseous substances in the reaction chamber during the dry etching process; and A calculation unit that calculates the line width CD through the following formula based on the data measured by the mass spectrometer, CD = {a1 × Σ[amount of film etching by-products]} × {a2 × Σ[amount of oxygen by-products]} × {a3 × Σ[amount of fluorine by-products]} / {a4 × Σ[amount of etching gas]} where a1, a2, a3, and a4 are predetermined proportional constants.
2. The real-time line width measurement device for a dry etching process according to claim 1, wherein The film etching by-products include one or more of SiF, SiF2, SiF3, SiF4, SiCl, SiCl2, SiCl3, SiCl4, SiH, SiH2, SiH3, SiH4, CF, CF2, CF3, CF4, NF, NF2, NF3, OF, OF2, GeF, GeF2, GeF3, GeF4, BF, BF2, BF3, PF, PF2, PF3, WF, WF2, WF3, WF4, WF5, WF6, WCl, WCl2, WCl3, WCl4, WCl5, WCl6, AlCl, AlCl2, AlCl3, HfF, HfF2, HfF3, HfF4, HfF5, HfF6, CoF, CoF2, CoF3, and CoF4.
3. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that, The oxygen by-products include one or more of O2, O, CO, CO2, NO, NO2, SO, SO2, and H2O.
4. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that, The fluorine by-products include one or more of F, F2, and HF.
5. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that The etch gas residue contains one or more of CF4, CHF3, CH2F2, CH3F, C2F2, C2F4, C2F6, C3F4, C3F6, C3F8, C4F6, C4F8, C4F 10 , HF, F2, HCl, Cl2, CCl4, HBr, Br2, HI, and I2.
6. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that In the above formula, "Σ[amount of film etching by-products]" is the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" is the sum of the amounts of all oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" is the sum of the amounts of all film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" is the sum of the amounts of all etching gases measured by the mass spectrometer.
7. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that, In the above formula, "Σ[amount of film etching by-products]" is the sum of the amounts of a part of the substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of oxygen by-products]" is the sum of the amounts of a part of the substances in the oxygen etching by-products measured by the mass spectrometer, or "Σ[amount of fluorine by-products]" is the sum of the amounts of a part of the substances in the film etching by-products measured by the mass spectrometer, or "Σ[amount of etching gas]" is the sum of the amounts of a part of the substances in the etching gases measured by the mass spectrometer.
8. The real-time line width measuring device for dry etching process according to claim 7, characterized in that The part of the substances includes the first n substances with high relevance found through experiments, and n is a predetermined natural number.
9. The real-time line width measuring device for the dry etching process according to claim 7, characterized in that, The part of the substances is determined through deep learning or machine learning analysis.
10. The real-time line width measuring device for the dry etching process according to claim 1, wherein a1, a2, a3, and a4 are the same.
11. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that, At least a part of a1, a2, a3, and a4 are different from each other.
12. The real-time line width measuring device for the dry etching process according to claim 1, characterized in that, a1, a2, a3, and a4 are determined through deep learning or machine learning analysis.
13. The real-time line width measuring device for dry etching process according to claim 1, characterized in that, The calculation unit can calculate the upper end line width, the middle part line width, and the lower end line width respectively by calculating the line width at different times of performing the dry etching process.