579427 Α7579427 Α7
經濟部智慧財產局員工消費合作社印製 五、發明説明（） 發明領域： 本發明係有關於一種使用橢圓儀（Ellipsometer)系統來 獲得材料層之光學特性參數的方法。特別是有關於一種於 先獲得可靠的材料層之厚度（Thickness ; t)之使用橢圓儀系 統來獲得材料層之光學特性參數的方法。 發明背景： 在光學微影（Photolithography)的製程中，使堆疊膜 (Film stack)的反射率（Refiectivity)最小化是控制關鍵尺 寸（Critical Dimension ; CD)之均勻度（Unif〇rmity)的基 本要求，亦即反射率愈小，則堆疊膜之各不同厚度處之關 鍵尺寸的差異愈小，因而使光學微影製程的品質愈好。然 而’反射率的計算係根據堆疊膜之光學特性參數：厚度t、 光折射率（Index of Refraction ; η)和光消散係數（Extinction Coefficient ; k)而來。故光學特性參數η、k和t的準確與 否攸關著反射率的計算結果的可靠度，進而關係著光學微 影製程的設計與選擇’如發展使用新波長的光學微影製 程。 目前在工業界中，光譜满圓儀（Spectr〇sc〇pic Ellipsometer ; SE)是一種公認用來量測光學特性參數n、k 和t的工具。橢圓儀主要是利用光在入射待測物質之前後， 光之偏振型態的改變來求取材料層之光學特性參數η、k和 t。橢圓儀並不直接取得光學特性參數η、k和t，而係先根 據ί&η(ψ)?Λ = σ = Γρ/Γ3來獲得1|/和^，其中1|/為振幅參數；^ 本紙張尺度適用中國國家標準(CNS)A4規格(210x297公變) -..............^.........、耵---------^ (請光閱讀背面之注意事項再填寫本頁) 579427 A7 五、發明說明（ 為相彳立、 (請£閲讀背面之注意事項再填寫本頁) ’ rp、rs为別為P平面（光之入射平面）和S平面 (與光之入射平面垂直的平面）的複數（Complex)弗芮耳反 射係數。光譜橢圓儀量測到複數比值.rp/rs為波長的函數 (Function) 〇 睛參照第1圖，第丨圖為繪示習知之光譜橢圓儀取得 的光學特性參數n、k和t值的流程示意圖。當光譜橢圓儀 =射晶圓（步驟100)後，光譜橢圓儀取得並建立複數個量測 資料曲線（步驟110)。接著，光譜橢圓儀的計算系統收集晶 圓上之堆疊層的資料（步驟200)，然後，如步驟210所示， 輸入起始猜測值（Guess Value)，再建立與那些量測資料曲 線相對應的模擬資料曲線（步驟220)。然後，比較量測資料 曲線是否與模擬資料曲線相符合（步驟23〇)，若比較結果為 是”，則進行步驟260來建立分散模型（Dispersi〇n Model) ’以及步驟24〇來輸入所需的波長後，便可求得所 需的η、k和t(步驟27〇);若結果為“否，，，則另外設定新 的猜測值（步驟250)，建立與模擬資料曲線（步驟22〇)後， 再進行步驟230來比較量測資料曲線是否與模擬資料曲線 相符合。一直重覆（Iterate)步驟250、步驟22〇和步驟23〇 直至量測資料曲線與模擬資料曲線相符合於一定誤差之内 經濟部智慧財產局員工消費合作社印製 為止。 由於受到光源波長和其他設計上的限制，使用單一的 光譜橢圓儀系統來量測n、k和t值，只能有效地量測薄膜 之某範圍的η、k和t值，故先進的橢圓儀系統必須整合數 經濟部智慧財產局員工消費合作社印製 579427 五、發明説明（ 種不同技術，以提高薄膜之„ , 门哥联之η、k和t值之量測與計算的 精準度和範圍。例如：美國Tu 、闼 Therma-Wave公司所生產的Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the Invention () Field of the Invention: The present invention relates to a method for obtaining optical characteristics parameters of a material layer using an Ellipsometer system. In particular, there is a method for obtaining an optical property parameter of a material layer using an ellipsometry system before obtaining a reliable thickness (Thickness; t) of the material layer. Background of the Invention: In the process of photolithography, minimizing the reflectivity of the film stack is the basic requirement for controlling the uniformity of the critical dimension (CD). That is, the smaller the reflectivity, the smaller the difference in key dimensions at different thicknesses of the stacked film, so the better the quality of the optical lithography process. However, the calculation of the 'reflectivity' is based on the optical characteristic parameters of the stacked film: thickness t, optical index of refraction (η), and light dissipation coefficient (Extinction Coefficient; k). Therefore, the accuracy of the optical characteristic parameters η, k, and t is related to the reliability of the calculation result of the reflectivity, and further relates to the design and selection of the optical lithography process, such as the development of an optical lithography process using a new wavelength. At present in the industry, the Spectroscope Ellipsometer (SE) is a widely recognized tool for measuring optical characteristic parameters n, k and t. The ellipsometer mainly uses the change of the polarization mode of the light before and after it enters the substance to be measured to obtain the optical characteristic parameters η, k and t of the material layer. Ellipsometry does not directly obtain the optical characteristic parameters η, k and t, but first obtains 1 | / and ^ according to ί & η (ψ)? Λ = σ = Γρ / Γ3, where 1 | / is the amplitude parameter; ^ This paper size applies to China National Standard (CNS) A4 specification (210x297 public variable) -.............. ^ ........., 耵 ------ --- ^ (please read the precautions on the back and then fill out this page) 579427 A7 V. Description of the invention (for stand-up, (please read the precautions on the back and fill out this page) 'rp and rs are not P Complex (Complex) Frere reflection coefficient of plane (incidence plane of light) and S plane (plane perpendicular to incident plane of light). Spectral ellipsometry measures the ratio of complex numbers. Rp / rs is a function of wavelength (Function) 〇See Figure 1. Figure 丨 shows the flow chart of the optical characteristic parameters n, k, and t obtained by the conventional spectroscopic ellipsometer. When the spectroscopic ellipsometer = the wafer (step 100), the spectroscopic ellipsometer Obtain and establish a plurality of measurement data curves (step 110). Next, the calculation system of the spectroscopic ellipsometer collects data of the stacked layers on the wafer (step 200), and then, as shown in step 210 Enter the initial guess value (Guess Value), and then create the simulated data curves corresponding to those measured data curves (step 220). Then, compare whether the measured data curves match the simulated data curves (step 23). If the comparison result is "Yes", then proceed to step 260 to establish a Dispersion Model and step 24 to enter the required wavelengths, and then obtain the required η, k, and t (step 27) ; If the result is "No," then set a new guess (step 250), establish and simulate the data curve (step 22), and then proceed to step 230 to compare whether the measured data curve matches the simulated data curve .Iterate steps 250, 22, and 23 until the measurement data curve matches the simulated data curve within a certain error. It is printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. Other design limitations, using a single spectroscopic ellipsometry system to measure n, k, and t values, can only effectively measure a range of η, k, and t values of the film, so the advanced ellipse The system must be integrated by the Consumer Property Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs to print 579427. 5. Description of the invention (different technologies to improve the accuracy and scope of the measurement and calculation of η, k and t values of the film For example: produced by American Tu, 闼 Therma-Wave
Opti-Probe 系統，便替人7 , σ 了光譜橢圓儀（Spectroscopic Ellipsometer ; SE)模組、水土 … 先束剖面反射儀（Beam ProHleThe Opti-Probe system replaces the Spectroscopic Ellipsometer (SE) module, water and soil… for Beam ProHle
Reflectometry ; BPR)模会且 业 土 光束剖面橢圓儀（Beam ProfileReflectometry (BPR) Beam Profile Ellipsometer
Ellipsometer; BPE)模組笨。计丄。^ ^ 寺其中SE模組係以重氫深紫外 光（Deuterium DUV )為光源，BpR模組和βρε模組係以 雷射光（Laser)為光源。在如第！圖所示之步驟23〇中，當 前述之各模組在進行計算時，分別會賦予不同的權值。請 參照第2圖，第2圖為繪示習知之系統量測與計算n、k和 t值的流程示意圖。其中〇.55和〇·45為各模組所給予之權 值，此權值可依個別狀況而定，並非固定。最終之n、k 和t值40係由BPR模組所得之分散模型2〇和se模組所 得之分散模型10透過加權表30 ( Weighting Table )，來 建立複合的分散模型5 0後而得。 然而’請參照第3圖，第3圖為緣示使用習知之系統 Ϊ測晶圓之有機抗反射塗佈（Anti-reflecting Coating ; ARC) 層而得之n、k和t值的等高線示意圖，其中此有機抗反射 塗佈層係由Track旋轉塗佈（Spin Coating)機所完成。由第3 圖可清楚看出，晶圓的有機抗反射塗佈層上之各處的厚度 有相當的差異。其偏差（Deviation)範圍為15.97埃。若注意 其厚度等高線，並非同心圓。而此不規則的厚度等高線違 反了 Track旋轉塗佈機旋轉的同心圓行為，所以此η、k 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) ...............^.........、玎.........^ (請先閲讀背面之注意事項再填寫本頁) 579427 經濟部智慧財產局員工消費合作社印製 、發明説明（） 和t測量配方（Recipe)的正確性需進一步驗證。若使用其他 只專門做厚度量測的技術來量測有機抗反射塗佈層之厚 度，會得到同心圓型式的厚度等高線圖（雖然其平均厚度 相近）。而此才符合旋轉塗佈的行為，故如第2圖所示之 將各模組賦予權值以求的分散模型的關係而得解，並不是 最佳方式，很可能會找錯n、k和t的解，而無法據以判 斷製程的效能（Performanee卜 因此，非常迫切需要發展一種使用橢圓儀系統來獲得 材料層之光學特性參數的方法。藉以有效和準確地量測和 計算出材料層之光學特性參數n、t，且縮小n、丈 的偏差值，並使厚度t的對應圖形（Mapping)具有高度的 一致性，不會因使用不同的橢圓儀量測計算技術而有所不 同。 發明目的及概述： ^鑒於上述在習知之材料層之光學特性參數η、k和t的 置測與計算之偏差過大，故無法精確地得知n、k和t值， 特別是材料層之厚度t，因而極易造成晶圓品質與製程的 誤判。 因此，本發明的主要目的為提供一種使用橢圓儀系統 來獲得材料層之光學特性參數的方法。藉以提高材料層之 光學特性參數η、k和t值的精準與精確度，並使厚度丈 的對應圖形具有高度的一致性，不會因使用不同的橢圓儀 量測計算技術而有所不同。 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐） ...............裝.........訂.........^ (請C閲讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 五、發明説明（） 上所述之目^本發明提供了—種使用橢圓儀 與特^仔材科層之複數個光學特性參數的方4，這些光 予特性參數為材料層之厚度t、 1 L 光折射率η和光消散係數 ’此方法至少包括：使用且古眉 Μ 具有厚度量測計算專長的第一 达广+ W計屢之厚度t ;將此厚度t做 為旱度已知值輸入至至少一第-撼一 弟一橢圓儀兀件；以及由此至 =-第二橢圓儀元件量測計算出材料層之光折射率η和光 消散係數k。 發明詳細說明： 本發明揭露-種使用橢圓儀系統來獲得材料層之光學 特性參數的方法。本發明係採厚度先算(Thick_㈣的 方式，來獲得材料層之厚度、光折射率n和光消散係數k。 請參照第4圖，第4圖為繪示本發明之使用橢圓儀系 統來獲得材料層之光學特性參數的方法的流程示意圖。首 先使用具有厚度量測計算專長的摘圓儀元件，來準確地 獲得材料層之厚度t(如步驟3〇〇所示”所謂具有厚度量測 計异專長的第一橢圓儀元件’係指此第一橢圓儀元件專精 於材料層之厚度的置測與計算，所得之厚度值的偏差最 小，精確度和-致性最高。通常，此等技術特性可由薇商 (Vendor)所提供的資料來獲得。例如：美國丁以⑽ △司所生產的BPR模組係以雷射光為光源，便具有厚度量 測计算的專長。因此，本發明先使用例如BPR模組來獲得 高精確和可靠度的材料層之厚度t。當然’ BpR模組並非本 本紙張尺度適财關家標準(CNS)A4規格(21〇χ297公楚) ...............^.........、町.........^ (請七閲讀背面之注意事項再填寫本頁) 579427 A7 B7 五、發明説明（） 發明之專利申請之必需，只要是具有厚 儀器均可適用於本發明。 兮我的重測 接著’例如由㈣模組量測計算出的厚度t 故可將此厚度u做厚度已知值，輸入至其他之至少一第 二橢圓儀元件（如步驟3 1 〇所-、Λ丄 外所不），再由此第二橢圓 裝 計算出材料層之光折射率η和光消散係數k(如步驟⑽所 示）。換言之，於步驟300的計算中，只採用厚度t的計算 結果，而不採用光折射率n和光消散係數k;而於步驟320 的计异中，只採用光折射率n和光消散係數k的計算姓果， 而不採用厚度t。步驟310和步驟32〇所使用之其他： 訂 元件可為任何具SE模組生產之供應商提供。如第二贿圓儀 元件有兩種以上的橢圓儀元件，則這些橢圓儀元件所得之 各組光折射率η和光消散係數让間須經適當的. 以獲得最終之η和k。 鼻 線 請參照第5圖，第5圖為緣示使用本發明之方法量測 晶圓之有機抗反射塗佈層而得之η、““值的等高線干音 圖。其中係先使用BPR模組來獲得厚度t，接著以此厚度二 為厚度已知值輸入至SE模組’再由SE模組計算出光折又射 率η和光消散係數k。由第5圖與前述之第3圖的比較可 清楚得知··使用本發明之方法所得的厚度t的偏差m胃 減少：i 15.97埃減少至7.62$，且厚度t的對應胃^ 整齊的同心圓圖形。 請參照第6圖，第6圖為繪示分別使用本發明之方法 着 謙 I I I 着 I I a I 着 着 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐） 579427 五 經濟部智慧財產局員工消費合作社印製 A7 - _B7__— —___ 、發明說明（） 與習知之方法（如第2圖所示）量測晶圓之有機抗反射塗佈 層而得之η、k和t值的結果比較表。由第6圖可知，各個 晶圓插槽中的晶圓之η和k的測量值，其標準偏差值 (Standard Deviation)大幅地減少。另一方面，請參照第7 圖’第7圖為繪示使用本發明之方法量測不同厚度之晶圓 之有機抗反射塗佈層的厚度專南線示意圖。不同厚度之晶 圓之有機抗反射塗佈層的厚度均具有相似的圖形特徵 (Signature)，如同心圓圖形。故可證明本發明之方法具有 高度的一致性。以上所述之有機抗反射塗佈層僅為舉例說 明’本發明可用來量測各種材料層，故本發明並不在此限。 綜合以上所述，本發明之優點為提供一種使用橢圓儀 系統來獲得材料層之光學特性參數的方法。本發明可以提 高材料層之光學特性參數η、k和t之量測與計算的精準與 精確度，並使厚度t的對應圖形具有高度的一致性，不會 因使用不同的橢圓儀量測計算技術而有所不同，其圖形特 徵亦不會因不同厚度而有重大差異。 如熟悉此而技術之人員所暸解的，以上所述僅為本發 明之較佳實施例而已，並非用以限定本發明之申請專利範 圍；凡其它未脫離本發明所揭示之精神下所完成之等效改 變或修飾，均應包含在下述之申請專利範圍内。 圖式簡單說明： 本發明的較佳實施例已於前述之說明文字中輔以下列 圖形做更詳細的闡述，其中： 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) ...............^.........、訂.........^ (請、先閲讀背面之注意事項再填寫本頁) 579427 五、發明説明（ 經濟部智慧財產局員工消費合作社印製 啊狀侍的 η、k和ί值的流程示意圖； 第2圖為繪示習知之系統量測與 程示意圖； n、k和t值的流 第3圖為繪示使用習知之系統量剛曰曰 塗佈層而得之n、k和t值的等高線示专圖之有機抗反射 第4圖為繪示本發明之使用橢圓 之光學特性參數的方法的流程示意g;系、·4來獲得材料層 第5圖為繪示使用本發明之方法 射塗佈層而得之n、“, t值的等高線示意；圓之有機抗反 第6圖為繪示分別使用本發明 一 在與習知之方法（如 第2圖所示）量測晶圓之有機抗反射 〜1师層而得之 k法口 t 值的結果比較表；以及 第7圖為繪示使用本發明之方法 古1測不同厚度之晶圓 之有機抗反射塗佈層的厚度等高線示意圖。 圖號對照說明： 10 SE模組所得之分散模型 BPR模組所得之分散模型 加權表 最終之η、k和t值 建立複合的分散模型 20 30 40 50 步驟100照射晶圓 ...............t.........、可.........^ (請f閱讀背面之注意事項再填寫本頁) 579427 A7 B7 五、發明説明（） 經濟部智慧財產局員工消費合作社印製 1 10 取得並 建 立 複 數 個 量 測 資料 曲 線 200 收 集 晶 圓 上 之 堆 疊 層的 資 料 210 輸 入 起 始 猜 測 值 220 建 立 模 擬 資 料 曲 線 230 比 較 量 測 資 料 曲 線 是否 與 模 擬 資 料 曲 線 相 符 合 240 輸 入 所 需 的 波 長 250 設 定 新 的 猜 測 值 260 建 立 分 散模 型 270 求 得 所 需 的 η 、k和t 300 使 用 具 有 厚 度 量 測 計算 專 長 的 第 一 橢 圓 儀 元 件 來 獲 得 厚 度 t 3 10 將 此 厚 度 t 做 為 厚 度已 知 值 輸 入 至 至 少 一 第 二 橢 圓 儀 元 件 320 由 此 至 少 一 第 二 橢 圓儀 元 件 量 測 計 算 出 材 料 層 之 光 折 射 率 η 和 光 消 散係 數 k 10 (請尤閲讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐)Ellipsometer; BPE) module is stupid. Counting. ^ ^ Among them, the SE module uses Deuterium DUV as the light source, and the BpR module and βρε module use laser as the light source. In Rudi! In step 23 shown in the figure, when the foregoing modules are performing calculations, different weights are assigned to them. Please refer to Fig. 2. Fig. 2 is a schematic diagram showing a conventional system for measuring and calculating n, k and t values. Among them, 0.55 and 0.45 are the weights given by each module. This weight can be determined according to individual conditions and is not fixed. The final n, k, and t values of 40 are obtained from the dispersion model 20 obtained from the BPR module and the dispersion model 10 obtained from the se module through a weighting table 30 to establish a composite dispersion model 50. However, please refer to FIG. 3, which is a schematic diagram showing the contour lines of n, k, and t values obtained by measuring the organic anti-reflecting coating (ARC) layer of the wafer using a conventional system. The organic anti-reflection coating layer is completed by a Track spin coating machine. It can be clearly seen from Fig. 3 that the thicknesses of the organic anti-reflection coating layers on the wafer are quite different. The Deviation range is 15.97 Angstroms. If you pay attention to its thickness contour, it is not a concentric circle. And this irregular thickness contour line violates the concentric circle behavior of the Track spin coater, so this η, k paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) ... ....... ^ ........., 玎 ......... ^ (Please read the notes on the back before filling out this page) 579427 Employees' Consumption of Intellectual Property Bureau, Ministry of Economic Affairs The correctness of the cooperative's printed, invention description () and t-measuring recipe (Recipe) needs further verification. If other thickness-only techniques are used to measure the thickness of the organic anti-reflection coating layer, the thickness contour map of the concentric circle pattern will be obtained (although the average thickness is similar). This is in line with the behavior of spin coating. Therefore, as shown in Figure 2, the relationship between the distributed models that assign weights to each module to solve the problem is not the best way. It is likely to find the wrong n and k. And t can not be used to judge the effectiveness of the process (Performanee, therefore, it is very urgent to develop a method using the ellipsometry system to obtain the optical characteristics of the material layer. In order to effectively and accurately measure and calculate the material layer The optical characteristic parameters n, t, and the deviation values of n and z are reduced, and the corresponding mapping (thickness) of the thickness t is highly consistent, and will not be different by using different ellipsometry measurement calculation techniques. Purpose and summary of the invention: ^ In view of the above-mentioned deviations in the measurement and calculation of the optical characteristic parameters η, k and t of the conventional material layer, the values of n, k and t cannot be accurately known, especially the thickness of the material layer t, which can easily cause misjudgment of wafer quality and process. Therefore, the main object of the present invention is to provide a method for obtaining optical characteristics of a material layer using an ellipsometry system, thereby improving the material layer. The precision and accuracy of the optical characteristic parameters η, k, and t values, and the high consistency of the corresponding graphics of the thickness measurement, will not be different due to the use of different ellipsometry measurement calculation techniques. This paper scale applies China National Standard (CNS) A4 specification (210X297 mm) ............... install ......... order ......... ( Please read the notes on the back and fill in this page.) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (). 4 of the plurality of optical characteristic parameters, these light pre-characteristic parameters are the thickness t of the material layer, 1 L optical refractive index η, and light dissipation coefficient. This method includes at least: The thickness t of Yidaguang + W meter; this thickness t is input as a known value of the dryness to at least one first ellipse and ellipse element; and from this to the second ellipse element measurement The light refractive index η and the light dissipation coefficient k of the material layer are calculated. Detailed description of the invention: The present invention discloses a method using an ellipsometry system to Method for obtaining the optical characteristic parameters of the material layer. The present invention adopts the method of calculating thickness first (Thick_㈣) to obtain the thickness of the material layer, the light refractive index n, and the light dissipation coefficient k. Please refer to FIG. 4, which is a drawing The schematic flow chart of the method for obtaining the optical characteristic parameters of the material layer using the ellipsometry system of the present invention. Firstly, the thickness t of the material layer is accurately obtained by using a circle picker element with thickness measurement and calculation expertise (such as step 300). “The so-called first ellipsometer element with special expertise in thickness measurement” shown here means that this first ellipse element is specialized in the measurement and calculation of the thickness of the material layer. The deviation of the thickness value obtained is the smallest, and the accuracy and -Highest consistency. Usually, these technical characteristics can be obtained from the information provided by Vendor. For example, the BPR module produced by the United States Ding Yi △ Company uses laser light as the light source, and has expertise in thickness measurement and calculation. Therefore, the present invention first uses, for example, a BPR module to obtain a highly accurate and reliable material layer thickness t. Of course, 'BpR module is not a paper-size standard (CNS) A4 specification (21〇χ297 公 楚) ............... ^ ........ . 、 Machi ............ ^ (Please read the precautions on the back and fill in this page) 579427 A7 B7 V. Description of the invention () Required for the patent application of the invention, as long as it has a thick instrument于 发明。 In the present invention. Then my retesting is followed by, for example, the thickness t calculated by the ㈣ module measurement, so this thickness u can be used as a known thickness and input to at least one other second ellipsometry element (as in step 3 1 〇 所- , Λ 丄 other than), and then calculate the light refractive index η and light dissipation coefficient k of the material layer from the second ellipse device (as shown in step）). In other words, in the calculation of step 300, only the calculation result of the thickness t is used instead of the light refractive index n and the light dissipation coefficient k; and in the calculation of the difference in step 320, only the calculation of the light refractive index n and the light dissipation coefficient k is used. Surname fruit, without using thickness t. Others used in step 310 and step 32: The order component can be provided by any supplier with SE module production. If there are more than two types of ellipsometry elements in the second circle instrument, the light refractive index η and light dissipation coefficient of each set of these ellipsometry elements must be appropriately passed to obtain the final η and k. Nose line Please refer to FIG. 5, which is a dry contour chart of η and “” values obtained by measuring the organic anti-reflection coating layer of the wafer using the method of the present invention. Among them, the BPR module is used to obtain the thickness t, and then the thickness 2 is used as the thickness known value to be input to the SE module ', and then the refractive index η and the light dissipation coefficient k are calculated by the SE module. It can be clearly seen from the comparison between FIG. 5 and the aforementioned FIG. 3 that the deviation t of the thickness t obtained using the method of the present invention is reduced in stomach: i 15.97 angstroms are reduced to 7.62 $, and the thickness of the corresponding stomach t Concentric circles graphics. Please refer to Figure 6. Figure 6 shows the method of using the present invention respectively. Zhu Qian III Zhu II a I Zhu Yuan This paper is in accordance with China National Standard (CNS) A4 (210X297 mm) 579427 Five Intellectual Property of the Ministry of Economic Affairs Bureau's Consumer Cooperative printed A7-_B7__ — — ___, invention description () and the conventional method (as shown in Figure 2) to measure the η, k and t values of the organic anti-reflection coating on the wafer Results comparison table. It can be seen from FIG. 6 that the standard deviation values of the measured values of η and k of the wafers in each wafer slot are greatly reduced. On the other hand, please refer to FIG. 7 and FIG. 7 is a schematic diagram showing the thickness of the organic anti-reflective coating layer of wafers with different thicknesses measured by the method of the present invention. The thickness of the organic anti-reflection coatings of crystals with different thicknesses all have similar signature features, like heart-shaped patterns. Therefore, it can be proved that the method of the present invention has high consistency. The organic anti-reflection coating layer described above is merely an example. The invention can be used to measure various material layers, so the invention is not limited thereto. To sum up, the advantage of the present invention is to provide a method for obtaining optical characteristic parameters of a material layer using an ellipsometry system. The invention can improve the accuracy and precision of the measurement and calculation of the optical characteristic parameters η, k, and t of the material layer, and make the corresponding graph of the thickness t highly consistent, and will not be calculated by using different ellipsometry. The technology is different, and its graphic characteristics will not be significantly different due to different thicknesses. As will be understood by those skilled in the art, the above descriptions are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all others that are completed without departing from the spirit disclosed by the present invention Equivalent changes or modifications should be included in the scope of patent application described below. Brief description of the drawings: The preferred embodiment of the present invention has been described in more detail in the preceding explanatory text with the following figures, where: This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) .. ............. ^ ........., order ......... ^ (Please read the notes on the back before filling out this page) 579427 V. Description of the invention (Schematic flow chart of the values of η, k, and 啊 printed by the employee cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs; Figure 2 is a schematic diagram showing the measurement and process of a conventional system; n, k, and t values Figure 3 is a diagram showing the contours of n, k and t values obtained by applying a conventional system coating layer. The organic anti-reflection chart is shown in Figure 4. Figure 4 is an elliptical optics according to the present invention. The flow chart of the method of the characteristic parameter is shown in Figure 4; Figure 4 is used to obtain the material layer. Figure 5 shows the contours of the n, ", and t values obtained by spraying the coating layer using the method of the present invention; FIG. 6 is a diagram showing the k-thickness t obtained by measuring the organic anti-reflection of the wafer with a conventional method (as shown in FIG. 2) of the present invention (as shown in FIG. 2). The result comparison table of the values; and FIG. 7 is a schematic diagram showing the thickness contours of the organic anti-reflection coating layers of wafers of different thicknesses measured by the method of the present invention. The final η, k, and t values of the dispersion model weighting table obtained from the model BPR module establish a composite dispersion model 20 30 40 50 Step 100 Irradiate the wafer ......... t .. ....... 、 Can ......... ^ (Please read the notes on the back and fill in this page) 579427 A7 B7 V. Description of Invention () Printed by the Consumers ’Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs System 1 10 Obtain and establish a plurality of measurement data curves 200 Collect the data of the stacked layers on the wafer 210 Enter the initial guess value 220 Create an analog data curve 230 Compare whether the measurement data curve matches the analog data curve 240 Input required Wavelength 250 Set a new guess 260 Establish a dispersion model 270 Find the required η, k, and t 300 Use the first ellipsometry element with thickness measurement calculation expertise to obtain the thickness t 3 10 Enter this thickness t as a known thickness to at least one second ellipsometry element 320 From this at least one second ellipsometry element quantity Measure and calculate the refractive index η and light dissipation coefficient k 10 of the material layer (please read the notes on the back and fill in this page) This paper size is applicable to China National Standard (CNS) A4 (210X297 mm)