504565 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明（i ) 發明領域 本發明係有關一種以穿透光譜量測薄膜的光學常數及 厚度的方法，具有非破壞性量測、同時量測光學常數及薄 膜厚度、即時監控膜厚等特性。 發明背景 目前決定薄膜厚度的方法，可分爲接觸式與非接觸式 兩種，光學非接觸式量測通常使用反射光譜儀（reflectance 8口6(：1；1*〇011〇1：〇111616]：)及橢圓儀（611丨？$〇11^16〇等儀器。 反射光譜儀以光學理論配合薄膜的光學常數（optical constants)，模擬反射光譜量測結果以計算薄膜厚度。橢圓 儀則是以不同角度量測薄膜的反射光譜分佈，迴歸光學常 數及薄膜厚度。利用反射光譜量測薄膜厚度前，必須知道 薄膜的光學常數，常見的物質可以由文獻資料得到，其它 少見的物質則多半利用橢圓偏光儀迴歸。光學常數變動爲 量測誤差的最大來源，目前的光學常數文獻資料僅適用於 以特定製程方法製備的薄膜，與其它製程方法的差異性頗 大，但即使是同一種製程方法，鍍膜的物理參數也會影響 光學常數的變動。 橢圓儀可以同時迴歸光學常數與薄膜厚度，然而橢圓 偏光儀的構造複雜、精密度要求高，造成售價高昂、校正 困難等缺點，而且橢圓儀利用各種入射角度迴歸光學常數 與薄膜厚度，無法在鍍膜製程中即時監控膜厚，提供鍍膜 製程中的必要資訊。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） _«^--------tr--------- (請先閱讀背面之注音？事項再填寫本頁) 504565 Α7 ______ Β7 五、發明說明（2 ) (請先閱讀背面之注意事項再填寫本頁) 以實驗裝置與實驗方法的觀點，穿透光譜的量測遠比 反射光譜與偏光光譜簡單且精確，如果以穿透光譜取代反 射光譜或偏光光譜的量測，對於薄膜厚度量測、光學常數 量測及鍍膜即時監控等硏究有極大的助益。 發明要旨 本發明的主要目的即在提供一種非接觸式的可同時量 測薄膜光學常數及厚度的方法。 本發明的另一目的在提供一種可即時監控薄膜厚度的 方法。 爲了達成上述發明目的，依照本發明內容而完成的一 種以穿透光譜量測一透明基板上的沈積薄膜之光學常數及 厚度的方法包含申請專利範圍第1項所描述的步驟。 本發明方法的其他可能變化可參見申請專利範圍中附 屬項的描述。 發明之詳細說明 經濟部智慧財產局員工消費合作社印製 光學常數（折射率w，refractive index與消光係數灸， extinction coefHcient)分別爲複折射率（complex refractive index，m +Μ:)的實部與虛部，界面間的反射率可由Fresnel 方程式計算= Πη+Πηι 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 504565 A7 B7 五、發明說明（ 其中L爲入射光源由第η層進入第m層（第η層與第m層相臨) 時的反射係數（Fresnel reflection coefficient)，由第η層進入 第m層的穿透係數爲 2ΐΙη (2) Ιη+Πη 當入射光束通過多層的界面時，入射光束在多層界面 間因穿透（transmit)、反射（reflect)、吸收（absorb)形成了複 雜的光束群，各界面反射光束到達偵測器的相位不同，彼 此干涉產生了波動現象的光譜。薄膜上下界面間的反射光 相位差（P)爲： φ = 4md / λ (3) (請先閱讀背面之注音？事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 其中Α爲入射光源的波長，d爲薄膜厚度，Μ値爲光行程長 (optical path length)。對光譜而言，波峰在兩光束同相位時 (2m/ = U，ί爲整數）產生，反相位時（2Μ = (ί + ^μ)產生波谷， 所以薄膜厚度可以下列方程式計算： 2 (4) 其中4與毛爲光譜中兩相臨波峰與波谷的波長。此外，反 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 504565 A7 B7 五、發明說明（4 ) 射光譜亦可以下列方程式表示： (請先閱讀背面之注意事項再填寫本頁) 及=r〇1 (义)+ ^ (又>12 (又X。(乂）· c〇s〇) +，01 (；l)r12 (；L)r10 (；l)r12 (；1>10 (义)cos〇)2 —… (5) 其中及爲反射率（reflectance)，由於OS|r_(；L)| S1且 ，經過二次反射之後，反射光束強度對於總反射 光束強度沒有太大的影響。經由反射光譜的模擬可以決定 薄膜的厚度，目前市面上以反射光譜量測薄膜厚度的機 種，大都是以此種方法計算，例如Filmetrics F-20及Sentech FTP 500等。 基本上光學常數隨著波長與溫度而變動，然而溫度效 應對光學常數的影響很小，在一般的量測範圍內可以忽略 不計。若將光學常數對波長展開，爲一種分散函數 (dispersion function)，適當的分散函數可以利用於光學常數: 的迴歸計算。 經濟部智慧財產局員工消費合作社印製 常用的分散函數爲Cauchy方程式： η{λ) -αΛ-b!)ί (+c/24 +...) (6) 及Sellmeier方程式： η(Λ) = α + δ/(Λ2-c)-dA2 (7) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 504565 Α7504565 Printed by A7 B7, Consumer Cooperatives, Intellectual Property Bureau, Ministry of Economic Affairs V. Description of the Invention (i) Field of the Invention The present invention relates to a method for measuring the optical constant and thickness of a thin film by a transmission spectrum. Measure optical constants and film thickness, monitor film thickness and other characteristics in real time. BACKGROUND OF THE INVENTION Current methods for determining the thickness of a film can be divided into two types: contact and non-contact. Optical non-contact measurement usually uses a reflection spectrometer (reflectance 8 port 6 (: 1; 1 * 〇011〇1: 〇111616). :) and ellipsometer (611 丨? $ 〇11 ^ 16〇 and other instruments. The reflection spectrometer uses optical theory to match the optical constants of the film, and simulates the reflection spectrum measurement results to calculate the film thickness. The ellipsometer is different Measure the reflection spectral distribution, return optical constant, and film thickness of the film at an angle. Before measuring the film thickness using the reflection spectrum, you must know the optical constant of the film. Common materials can be obtained from literature, and other rare materials mostly use elliptical polarization. The regression of optical constants is the largest source of measurement error. The current literature of optical constants is only applicable to thin films prepared by specific process methods, which is quite different from other process methods, but even for the same process method, coatings The physical parameters will also affect the change of the optical constant. The ellipsometer can return the optical constant and the film thickness at the same time. However, the ellipsometry has a complicated structure and high precision requirements, causing shortcomings such as high price and difficult calibration. Moreover, the ellipsometer uses various incident angles to return optical constants and film thickness. It cannot monitor the film thickness in the coating process and provide coating. Necessary information in the manufacturing process. This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) _ «^ -------- tr --------- (Please read first Note on the back? Matters should be filled out on this page) 504565 Α7 ______ Β7 V. Description of the invention (2) (Please read the notes on the back before filling out this page) From the perspective of the experimental device and method, measure the distance of the transmission spectrum The specific reflection spectrum and polarized light spectrum are simple and accurate. If the reflection spectrum or polarized light spectrum measurement is replaced by the transmission spectrum, it will be of great help to the research of thin film thickness measurement, optical constant quantity measurement, and real-time monitoring of coatings. The main object of the present invention is to provide a non-contact method for simultaneously measuring the optical constant and thickness of a thin film. Another object of the present invention is to provide a film thickness that can be monitored in real time. Method. In order to achieve the above-mentioned object of the invention, a method for measuring the optical constant and thickness of a deposited film on a transparent substrate by a transmission spectrum completed in accordance with the present invention includes the steps described in item 1 of the scope of patent application. For other possible variations of the method, please refer to the description of the appended item in the scope of the patent application. Detailed description of the invention The optical constants (refractive index w, refractive index and extinction coefHcient) printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economics are complex The refractive index (m + M :) of the real part and the imaginary part, and the reflectance between the interfaces can be calculated by the Fresnel equation = Πη + Πηι This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm 504565 A7 B7 V. Description of the invention (where L is the reflection coefficient when the incident light source enters the m-th layer from the n-th layer (n-th layer is adjacent to the m-th layer), and enters the m-th layer from the n-th layer The transmission coefficient of the layer is 2ΐΙη (2) Ιη + Πη When the incident beam passes through the multilayer interface, the incident beam is between the multilayer interfaces Because transmit, reflect, and absorb form a complex beam group, the phases of the reflected beams at each interface reaching the detector are different, and the interference produces a spectrum of wave phenomena. The phase difference (P) of the reflected light between the upper and lower interfaces of the film is: φ = 4md / λ (3) (Please read the note on the back? Matters before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs where A is the incident The wavelength of the light source, d is the film thickness, and M ， is the optical path length. For the spectrum, the wave peaks are generated when the two beams are in the same phase (2m / = U, ί is an integer), and the wave troughs are generated in the opposite phase (2M = (ί + ^ μ)), so the film thickness can be calculated by the following equation: 2 ( 4) Among them, 4 and hair are the wavelengths of the two peaks and troughs in the spectrum. In addition, the paper size applies the Chinese National Standard (CNS) A4 (210 X 297 mm) 504565 A7 B7 V. Description of the invention (4) The emission spectrum can also be expressed by the following equation: (Please read the precautions on the back before filling this page) and = r〇1 (meaning) + ^ (also &12; again X. (乂) · c〇s〇) + , 01 (; l) r12 (; L) r10 (; l) r12 (; 1 > 10 (meaning) cos〇) 2 —... (5) where is the reflectance (reflectance), because OS | r _ (; L ) | S1 And, after the second reflection, the reflected beam intensity has little effect on the total reflected beam intensity. The simulation of the reflection spectrum can determine the thickness of the film. At present, most of the models that measure the thickness of the film by the reflection spectrum on the market are It is calculated in this way, such as Filmetrics F-20 and Sentech FTP 500, etc. Basically, the optical constant varies with wavelength and temperature. However, the effect of temperature on the optical constant is small and can be ignored in the general measurement range. If the optical constant is expanded to a wavelength, it is a dispersion function, and an appropriate dispersion function can be used in Optical constant: Regression calculation. The dispersion function commonly used by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economics is the Cauchy equation: η {λ) -αΛ-b!) Ί (+ c / 24 + ...) (6) and Sellmeier equation: η (Λ) = α + δ / (Λ2-c) -dA2 (7) This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 504565 Α7
五、發明說明（5 ) 若爲複雜的分散函數，可改以Kramers-Kronig關係式表示；： ds (8) 對非晶質半導體（amorphous semiconductor)，心爲： ⑽)=Σ ΑΑΕοι(Ε-Ε§ι)丄 (Ε2 -E20l)2+CfE2l (9) 對晶質半導體（crystalline semiconductor)，心爲： 从)=Σ A, Βί+(Ε-Ε0ιΥ (10) (請先閱讀背面之注音？事項再填寫本頁) 一裳-------訂--- 以上方程式所迴歸的參數爲α、6Cd、4、4、Egl 等，而 A = π2 — A:2 且 = 。 經濟部智慧財產局員工消費合作社印製 對穿透量測而言，主要的穿透率爲、μ)·〖12μ)·(23(;ι)·...， 然而由於光束在界面層內彼此干涉，造成穿透光譜亦具有 震盪的波型。爲了簡化計算上的困難度，可以下列觀點計 算穿透光譜。將厚度遠大於薄膜的基材（substrate)視爲一光 學阻尼（optical damper)，由於在光譜量測過程中入射光爲 一連續光源，“⑷通過第二界面時雖然損失了 ‘⑷义⑷的 穿透率，然而^μ)·η2μ)反射光經第一界面再反射後減弱爲 ，卻影響到下一組的穿透光，其相位差爲 。以此觀點來看，薄膜穿透率可以下列複雜方程式 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） ,/. = ,01(2)4 (乂 ).，23(义)·.··· / 1 504565 A7 __ B7 五、發明說明（6 ) 表示：5. Description of the invention (5) If it is a complex dispersion function, it can be expressed by the Kramers-Kronig relationship; ds (8) For amorphous semiconductors, the heart is: ⑽) = Σ ΑΑΕοι (Ε- Ε§ι) 丄 (Ε2 -E20l) 2 + CfE2l (9) For crystalline semiconductors, the heart is: from) = Σ A, Βί + (Ε-Ε0ιΥ (10) (Please read the note on the back first ? Please fill in this page again.) Yichang ------- Order --- The parameters returned by the above equation are α, 6Cd, 4, 4, Egl, etc., and A = π2 — A: 2 and =. Economy Printed by the Ministry of Intellectual Property Bureau's Consumer Cooperative for the penetration measurement, the main penetration rate is μ) · 〖12μ) · (23 (; ι) · ..., but because the beams are in the interface layer with each other The interference results in the transmission spectrum also having an oscillating wave form. In order to simplify the computational difficulty, the transmission spectrum can be calculated from the following viewpoints. The substrate with a thickness much larger than the film is regarded as an optical damper. Since the incident light is a continuous light source during the spectral measurement process, "⑷ ' Transmittance, however, ^ μ) · η2μ) reflected light is weakened by re-reflection through the first interface, but it affects the next group of transmitted light with a phase difference of. From this point of view, the film transmittance can be as follows Complex equations The paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm), /. =, 01 (2) 4 (乂)., 23 (meaning) ···· / 1 504565 A7 __ B7 V. Description of Invention (6) means:
Tf = ^01 W ·tn(Λ) ·/23μ)«... + ^01 W ·tn(Λ) ·t23(λ) ·...r10(A) ·rn(λ) ·cos(^,) +/01 (a) ·，12 ⑷·，23 μ) · ...λ2。(/i). d (/i). cosh )2 + … +/01 μ) · /12 μ) ·，23 μ) · .·，21 W.厂23 μ). c〇s(>2) +(乂 H2 (义)·，23 (仆(义)·心乂) · c〇s(% )2 + … + /01 ⑷· L ⑷· /23 (义)....r10 (A) · r12 (斗厂21 ⑷· r23 (仆^ + Ll (2) 乂2 (乂）·广23 (2) · *·’1〇 (乂）· r23 (A) · Gl (乂）· ,21 (乂）· C0S(Pl ) · C0S(炉2 ) + … (11) 其中7}代表薄膜穿透率，而。經過整理，式（11) 可簡化爲： _1 G (乂) · ’12 (A) ·尸23 (乂）·厂1。(乂）· COS(Pl ) · COS(% ) l-r21(A)-r23(^)*cos(^2) 1 - b W · η〇 (乂). cos(奶）· cos〇2) (12) .·裝--------訂---------^9. (請先閱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 基材對於元件總穿透的影響爲光學阻尼效應，元件系統等 於是空氣-薄膜-空氣-基材系統，對於單層薄膜而言，元件 的總穿透率可表示爲： T = Tsub(A)^0](A)-tnW· l-^loW-^W-COS^) (13) -9 - 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 504565 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明說明（7 ) 其中U爲基材的穿透光譜，單層薄膜（複折射率Π+Α)前後 對稱，空氣的折射率爲1，而消光係數爲0，式（13)可改寫 爲： —j- (H) ^ *|c〇s(^)| n+\ 首先忽略消光係數的影響（Μ直假設爲〇)，以數値方法 配合式（14)模擬穿透光譜，可先初步決定π(Α)與d値，將求 得與d値代回式（14)可計算軾1)値，經反複計算可以得 到收斂結果。 以上述方法可同時量測薄膜的光學常數及薄膜厚度， 對於薄膜厚度量測、光學常數量測及鍍膜即時監控等硏究 有極大的助益，其具體步驟配合圖1所示的流程圖說明如 下： 1) 以至少包括多波長光源模組（multi - wavelength light module)、入射光源強度偵測器（incident light intensity detector)及數位類比訊號轉換器（digital -analog signal converter)等裝置量測尙未進行沈積之 透明基板對一入射光束的穿透光譜； 2) 設定沈積條件； 3) 進行薄膜沈積； 4) 於薄膜沈積之同時測量該透明基板及薄膜的穿透光 -10 - T = TmM) 2n n-\-\ ：-------«^--------tr--------- (請先閱讀背面之注咅？事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 504565 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明（8 ) 譜； 5) 觀察波峰及波谷的數目是否大於1? 6) 若否，則增加沈積時間並重覆步驟3)至5)直到波峰 及波谷的數目大於1 ; 7) 決定分散函數η(λ)及假設該薄膜的消光係數爲零； 8) 尋找薄膜的折射率及厚度的數値分析可能收斂範 圍； 9) 使用數値分析方法以式（14)計算出該薄膜的折射率 及厚度； 10) 使用該薄膜的折射率及厚度的數値分析結果計 算出該薄膜的理論消光係數； 11) 重覆步驟9)至10)，使用該理論消光係數以數値 分析方法計算出該薄膜的折射率及厚度的更新値， 直至薄膜的折射率及厚度的數値分析値收斂； 12) 檢查光譜模擬的差異是否落於一預設範圍內？若 是，輸出光學常數及薄膜厚度的數値分析結果並結 束；若否， 13) 檢查是否有其它的的分散函數？若否則結束， 若是， 14) 選用該分散函數回到步驟8)。 實施例 爲驗證本發明方法，首先以真空鍍膜技術，在1 mm玻 璃基材上製備氧化鎢薄膜，鎢鈀材由美國Pure Tech公司製 -1 1 - 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） _·«t--------tr--------- (請先閱讀背面之注咅？事項再填寫本頁) 川4565 經濟部智慧財產局員工消費合作社印製 A7 B7 1、發明說明（9 ) 造，純度99.95 %。薄膜製備方法爲射頻濺鍍（RF power* sputtering)，功率設定爲200瓦，操作過程中氬氣流量10 seem，氧氣流量5 seem，系統壓力爲10 mTorr。 製備完成的元件送至德國，以Sentech SE500(橢圓偏光 法）量測該薄膜的5個位置的特性，測試報告顯示此氧化鎢 薄膜的折射率於490 nm波長時介於2.04至2.15之間，消光係 數則趨近於零。位於中點的薄膜折射率爲2.108，及薄膜厚 度爲257.7 nm。配合此光學參數的量測結果，改以Sentech FTP500(反射光譜法，波長量測範圍490 nm至910 nm)量測 薄膜厚度，測試報告顯示中央位置的薄膜厚度爲249 nm。 其次，以Hitactn U-4001光譜分析儀（波長量測範圍450 nm至2500 nm)量測此元件中點位置的穿透光譜，並以本發 明方法迴歸光學常數與薄膜厚度，結果顯示薄膜厚度爲 248.92 nm，折射率則符合Cauchy方程式之描述，於490 nm 波長時折射率爲2.08，與Sentech SE500/FTP500量測結果一 致。以本發明方法模擬的穿透光譜（虛線）與Hitachi U-4001 量測的穿透光譜（實線）同時顯示於圖2。另外，折射率迴歸 結果顯示於圖3。 此外，以不同製程參數（包括固定、旋轉、位置不同） 製備的氧化鎢薄膜，其折射率迴歸結果顯示於圖4，與文獻 結果（Rottkay etal.，1997)近似。由圖4可以了解不同製程參 數所製備的薄膜其光學常數也不盡相同，傳統反射光譜儀 (如Filmetrics F-20)僅內建有限的光學常數資料庫，無法區 分薄膜材質的差異，因次計算的誤差將無法避免。以本發 -12 - 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） *t--------tr--------- (請先閱讀背面之注意事項再填寫本頁) 504565 A7 __B7 五、發明說明（10 ) 明方法配合穿透光譜的量測，不僅可計算薄膜厚度，也可 同時迴歸薄膜的光學常數，對於薄厚量測、光學常數量測 及鍍膜即時監控等硏究需求有極大的貢獻。 圖示說明 圖1爲本發明方法的一流程方塊圖。 圖2顯示本發明方法模擬的薄膜中間位置的穿透光譜 (虛線）與Hitachi U-4001光譜分析儀量測的穿透光譜（實 線）。 圖3顯示本發明方法量測的薄膜中間位置的折射率。 圖4顯示以不同製程參數（包括固定、旋轉、位置不同） 製備的氧化鎢薄膜，以本發明方法量測的折射率與文獻結 果（Rottkay et al·，1997)。 (請先閱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 -13- 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）Tf = ^ 01 W · tn (Λ) · / 23μ) «... + ^ 01 W · tn (Λ) · t23 (λ) · ... r10 (A) · rn (λ) · cos (^, ) + / 01 (a) ·, 12 ⑷ ·, 23 μ) · ... λ2. (/ i). d (/ i). cosh) 2 +… + / 01 μ) · / 12 μ) ·, 23 μ) · ··, 21 W. Factory 23 μ). c〇s (> 2 ) + (乂 H2 (义) ·, 23 (仆 (义) · 心 乂) · c〇s (%) 2 +… + / 01 L · L ⑷ · / 23 (义) ...... r10 (A ) R12 (Dougong 21 ⑷ r23 (仆 ^ + Ll (2) 乂 2 (乂) · Guang 23 (2) 21 (乂) · C0S (Pl) · C0S (furnace 2) +… (11) where 7} represents the film transmittance, and after finishing, formula (11) can be simplified to: _1 G (乂) · '12 (A) · Corpse 23 (乂) · Plant 1. (乂) · COS (Pl) · COS (%) l-r21 (A) -r23 (^) * cos (^ 2) 1-b W · η〇 (乂). Cos (milk) · cos〇2) (12). · Install -------- order --------- ^ 9. (Please read the precautions on the back before filling (This page) The impact of printed substrates from the Intellectual Property Bureau of the Ministry of Economic Affairs and the Consumer Cooperative on the total penetration of components is an optical damping effect. The component system is equal to an air-film-air-substrate system. For a single-layer film, the component The total transmittance can be expressed as: T = Tsub (A) ^ 0] (A) -tnW · l- ^ loW- ^ W-COS ^) (13) -9-This paper size applies to Chinese national standards CNS) A4 specification (210 X 297 mm) 504565 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (7) where U is the transmission spectrum of the substrate, and the single-layer film (complex refractive index Π + Α) Back and forth symmetry, the refractive index of air is 1, and the extinction coefficient is 0. Equation (13) can be rewritten as: —j- (H) ^ * | c〇s (^) | n + \ First ignore the effect of extinction coefficient (M is assumed to be 0). Using the numerical method and equation (14) to simulate the transmission spectrum, we can first determine π (Α) and d 値. We can calculate 轼 by substituting d 値 into equation (14). 轼 1 ) 値, the convergence result can be obtained after repeated calculations. The above method can simultaneously measure the optical constant and film thickness of the film, which is of great help to the research of film thickness measurement, optical constant quantity measurement, and real-time monitoring of coatings. The specific steps are described in conjunction with the flowchart shown in Figure 1. As follows: 1) Measure with devices including at least a multi-wavelength light module, incident light intensity detector, and digital-analog signal converter. Transmission spectrum of a transparent substrate without deposition to an incident beam; 2) Set deposition conditions; 3) Perform thin film deposition; 4) Measure the transmitted light of the transparent substrate and the thin film at the same time as the film deposition -10-T = TmM ) 2n n-\-\: ------- «^ -------- tr --------- (Please read the note on the back? Matters before filling out this page) This paper scale applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 504565 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of invention (8) Spectrum; 5) Observe whether the number of peaks and troughs Greater than 1? 6) if not, increase deposition Repeat steps 3) to 5) until the number of peaks and troughs is greater than 1; 7) Determine the dispersion function η (λ) and assume that the extinction coefficient of the film is zero; 8) Numerical analysis to find the refractive index and thickness of the film Possible convergence range; 9) Calculate the refractive index and thickness of the film using formula (14) using numerical analysis; 10) Calculate the theoretical extinction coefficient of the film using numerical analysis of the refractive index and thickness of the film; 11) Repeat steps 9) to 10), and use the theoretical extinction coefficient to calculate the update of the refractive index and thickness of the thin film by mathematical analysis method, until the numerical analysis of the refractive index and thickness of the thin film converges; 12) Check whether the differences in the spectrum simulation fall within a preset range? If yes, output the numerical analysis results of optical constants and film thickness and end; if not, 13) Check if there are other dispersion functions? If it is not finished, if yes, 14) select the scatter function and return to step 8). Example In order to verify the method of the present invention, a tungsten film was first prepared on a 1 mm glass substrate by vacuum coating technology. The tungsten and palladium material was manufactured by American Pure Tech Company. 1 1-This paper applies Chinese National Standard (CNS) A4 Specifications (210 X 297 mm) _ · «t -------- tr --------- (Please read the note on the back? Matters before filling out this page) Chuan 4565 Ministry of Economic Affairs Wisdom A7 B7 printed by the Consumer Cooperative of the Property Bureau 1. Description of invention (9), purity 99.95%. The thin film preparation method is RF power * sputtering, with a power setting of 200 watts, an argon flow rate of 10 seem, an oxygen flow rate of 5 seem, and a system pressure of 10 mTorr during operation. The prepared components were sent to Germany, and the characteristics of the five positions of the film were measured with Sentech SE500 (ellipsoidal polarization method). The test report showed that the refractive index of the tungsten oxide film was between 2.04 and 2.15 at a wavelength of 490 nm. The extinction coefficient approaches zero. The midpoint of the film has a refractive index of 2.108 and a film thickness of 257.7 nm. In accordance with the measurement results of this optical parameter, the thickness of the film was measured with Sentech FTP500 (reflection spectroscopy, wavelength measurement range 490 nm to 910 nm). The test report showed that the film thickness at the center was 249 nm. Secondly, a Hitactn U-4001 spectrum analyzer (wavelength measurement range 450 nm to 2500 nm) was used to measure the transmission spectrum of the midpoint of this element, and the optical constant and film thickness were returned by the method of the present invention. The results show that the film thickness is 248.92 nm, the refractive index conforms to the description of the Cauchy equation. At 490 nm, the refractive index is 2.08, which is consistent with the Sentech SE500 / FTP500 measurement results. The transmission spectrum (dotted line) simulated by the method of the present invention and the transmission spectrum (solid line) measured by Hitachi U-4001 are shown in Figure 2 at the same time. The refractive index regression results are shown in FIG. 3. In addition, the refractive index regression results of tungsten oxide films prepared with different process parameters (including fixed, rotating, and different positions) are shown in Figure 4, which is similar to the results in the literature (Rottkay etal., 1997). It can be understood from Figure 4 that the optical constants of films prepared with different process parameters are not the same. Traditional reflection spectrometers (such as Filmetrics F-20) have only a built-in optical constant database, which cannot distinguish the differences in film material. The error will be unavoidable. With this issue -12-This paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) * t -------- tr --------- (Please read the back first Please pay attention to this page, please fill in this page) 504565 A7 __B7 V. Description of the invention (10) The method described in conjunction with the measurement of transmission spectrum can not only calculate the film thickness, but also return the optical constant of the film. For thin measurement, optical constant Research requirements such as measurement and real-time coating monitoring have greatly contributed. Figure 1 is a flow block diagram of the method of the present invention. Figure 2 shows the transmission spectrum (dashed line) in the middle of the film simulated by the method of the present invention and the transmission spectrum (solid line) measured by a Hitachi U-4001 spectrum analyzer. FIG. 3 shows the refractive index at the middle position of the film measured by the method of the present invention. Figure 4 shows the refractive index and literature results of tungsten oxide films prepared with different process parameters (including fixed, rotating, and different positions) measured by the method of the present invention (Rottkay et al., 1997). (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs -13- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)