TWI837431B

TWI837431B - Aberration measurement method, article manufacturing method and exposure device

Info

Publication number: TWI837431B
Application number: TW109137033A
Authority: TW
Inventors: 齊藤悠樹
Original assignee: 日商佳能股份有限公司
Priority date: 2019-11-08
Filing date: 2020-10-26
Publication date: 2024-04-01

Abstract

本公開關於像差測量方法、物品製造方法以及曝光裝置。像差測定方法包括：藉由在投影光學系統的光軸方向上的多個位置處測量透射配置於前述投影光學系統的物體側的物體側標記、前述投影光學系統以及配置於前述投影光學系統的像側的像側標記的光的光量，從而獲取表示前述光軸方向上的位置與前述光量的關係的光量分佈的工程；求出表示前述光量分佈中的以前述投影光學系統的焦點位置為對稱軸的非對稱性的特徵量的工程；以及根據前述特徵量來決定前述投影光學系統的像差量的工程。The present disclosure relates to an aberration measurement method, an article manufacturing method, and an exposure device. The aberration measurement method includes: obtaining a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity by measuring the light quantity transmitted through an object side mark arranged on the object side of the projection optical system, the projection optical system, and an image side mark arranged on the image side of the projection optical system at multiple positions in the optical axis direction of the projection optical system; obtaining a characteristic quantity representing the asymmetry of the light quantity distribution with the focal position of the projection optical system as the symmetry axis; and determining the aberration quantity of the projection optical system based on the characteristic quantity.

Description

Aberration measurement method, article manufacturing method, and exposure device

本發明關於像差測量方法、物品製造方法以及曝光裝置。The present invention relates to an aberration measuring method, an article manufacturing method and an exposure device.

如半導體元件、液晶顯示元件以及薄膜磁頭等那樣具有微細圖案的物品是使用光刻技術來製造的。此時，使用藉由投影光學系統將原版的圖案投影到基板而將原版的圖案轉印到基板的曝光裝置。為了以高的精度將原版的圖案轉印到基板，需要調整投影光學系統的像差。投影光學系統的像差可能因由於照射曝光光而產生的熱、大氣壓等而變動。因而，投影光學系統的像差應在曝光任務的期間等被調整。在國際公開04/059710號說明書中，記載有如下方法：利用投影光學系統將包括週期圖案的物體側標記投影到像面側標記上，一邊在投影光學系統的光軸方向的多個位置處分別對像面側標記進行掃描，一邊進行測量。但是，在國際公開04/059710號說明書所記載的方法中，需要在投影光學系統的光軸方向的多個位置處分別對像面側標記進行掃描，所以測量所需的時間長。Items with fine patterns such as semiconductor elements, liquid crystal display elements, and thin-film magnetic heads are manufactured using photolithography technology. At this time, an exposure device is used to transfer the original pattern to the substrate by projecting the original pattern onto the substrate using a projection optical system. In order to transfer the original pattern to the substrate with high precision, it is necessary to adjust the aberration of the projection optical system. The aberration of the projection optical system may change due to heat, atmospheric pressure, etc. generated by irradiation of exposure light. Therefore, the aberration of the projection optical system should be adjusted during the exposure task, etc. The specification of International Publication No. 04/059710 describes a method in which an object side mark including a periodic pattern is projected onto an image side mark using a projection optical system, and the image side mark is scanned at multiple positions in the optical axis direction of the projection optical system while being measured. However, in the method described in the specification of International Publication No. 04/059710, it is necessary to scan the image side mark at multiple positions in the optical axis direction of the projection optical system, so the measurement takes a long time.

本發明提供有利於在短時間內測量投影光學系統的像差的技術。本發明的第1方面關於一種像差測量方法，前述像差測量方法包括：藉由在投影光學系統的光軸方向上的多個位置處測量透射配置於前述投影光學系統的物體側的物體側標記、前述投影光學系統以及配置於前述投影光學系統的像側的像側標記的光的光量，從而獲取表示前述光軸方向上的位置與前述光量的關係的光量分佈的工程；求出表示前述光量分佈中的以前述投影光學系統的焦點位置為對稱軸的非對稱性的特徵量的工程；以及根據前述特徵量來決定前述投影光學系統的像差量的工程。本發明的第2方面關於一種物品製造方法，前述物品製造方法包括：測量工程，依照前述第1方面的像差測量方法而測量曝光裝置的投影光學系統的像差量；調整工程，根據在前述測量工程中測量出的像差量來調整前述投影光學系統的像差；曝光工程，在前述調整工程之後，利用前述曝光裝置對塗敷有感光材料的基板進行曝光；顯影工程，在前述曝光工程之後，使前述感光材料顯影；以及處理工程，對經由前述顯影工程的前述基板進行處理，前述物品製造方法從經由前述處理工程的前述基板得到物品。本發明的第3方面關於一種曝光裝置，前述曝光裝置具備原版載置台、投影光學系統、基板載置台、配置於前述基板載置台的受光部以及控制部，前述受光部在前述投影光學系統的光軸方向上的多個位置處測量透射配置於前述投影光學系統的物體側的物體側標記、前述投影光學系統以及配置於前述投影光學系統的像側的像側標記的光的光量，前述控制部根據來自前述受光部的輸出，求出表示前述光軸方向上的位置與前述光量的關係的光量分佈，求出表示前述光量分佈中的以前述投影光學系統的焦點位置為對稱軸的非對稱性的特徵量，根據前述特徵量來決定前述投影光學系統的像差量。The present invention provides a technique that is useful for measuring the aberration of a projection optical system in a short time. The first aspect of the present invention relates to an aberration measurement method, which includes: obtaining a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity by measuring the light quantity transmitted through an object side mark arranged on the object side of the projection optical system, the projection optical system, and an image side mark arranged on the image side of the projection optical system at multiple positions in the optical axis direction of the projection optical system; obtaining a characteristic quantity representing the asymmetry of the light quantity distribution with the focal position of the projection optical system as the symmetry axis; and determining the aberration quantity of the projection optical system based on the characteristic quantity. The second aspect of the present invention relates to a method for manufacturing an article, the method comprising: a measurement process, measuring the aberration of the projection optical system of the exposure device according to the aberration measurement method of the first aspect; an adjustment process, adjusting the aberration of the projection optical system according to the aberration measured in the measurement process; an exposure process, after the adjustment process, exposing a substrate coated with a photosensitive material using the exposure device; a development process, after the exposure process, developing the photosensitive material; and a processing process, processing the substrate after the development process, the method for manufacturing an article obtains an article from the substrate after the processing process. The third aspect of the present invention relates to an exposure device, which includes an original plate mounting table, a projection optical system, a substrate mounting table, a light receiving unit arranged on the substrate mounting table, and a control unit. The light receiving unit measures the amount of light transmitted through an object side mark arranged on the object side of the projection optical system, the projection optical system, and an image side mark arranged on the image side of the projection optical system at multiple positions in the optical axis direction of the projection optical system. The control unit obtains a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity based on the output from the light receiving unit, obtains a characteristic quantity representing the asymmetry of the light quantity distribution with the focal position of the projection optical system as the symmetry axis, and determines the aberration amount of the projection optical system based on the characteristic quantity.

以下，參照附圖，詳細地說明實施方式。此外，以下的實施方式並不限定與請求項申請專利範圍相關的發明。在實施方式中記載有多個特徵，但這多個特徵未必全部對於發明是必需的，另外，多個特徵也可以任意地組合。進而，在附圖中，對相同或者同樣的結構附加相同的參照編號，省略重複的說明。以下，說明第1實施方式。圖1示出了第1實施方式的曝光裝置EXP的結構例。曝光裝置EXP可以具有測量投影光學系統6的像差(例如，球面像差)，根據其測量的結果來調整投影光學系統6的像差的功能。曝光裝置EXP利用投影光學系統6將原版1的圖案投影到塗敷有感光材料的基板3，由此將原版1的圖案轉印到基板3(感光材料)。以下，更具體地說明曝光裝置EXP的結構例以及動作例。曝光裝置EXP可以具備：原版載置台2，支撐原版(倍縮光罩(Reticle))1；基板載置台4，支撐基板3；以及照明光學系統5，利用曝光光對由原版載置台2支撐的原版1進行照明。另外，曝光裝置EXP可以具備：投影光學系統6，將用曝光光照明的原版1的圖案投影到由基板載置台4支撐的基板3；以及控制部CNT，控制雷射干涉計10、12以及曝光裝置EXP的各構成要素。另外，曝光裝置EXP可以具備受光部14、對準檢測系統16以及焦點檢測系統15。以下，曝光裝置EXP作為一邊在掃描方向上相互同步地對原版1和基板3進行掃描，一邊將原版1的圖案轉印到基板3的掃描曝光裝置(掃描步進裝置)而構成。然而，曝光裝置EXP也可以應用於使原版1以及基板3靜止而將原版1的圖案轉印到基板3的曝光裝置(步進裝置)。在以下的說明中，將與投影光學系統6的光軸一致的方向設為Z軸方向，將與在垂直於Z軸方向的平面內對原版1和基板3進行掃描的方向平行的方向設為Y軸方向，將與Z軸方向以及Y軸方向垂直的方向(非掃描方向)設為X軸方向。另外，將繞X軸、Y軸以及Z軸的方向分別設為θX，θY以及θZ方向。由照明光學系統5用均勻的照度分佈的曝光光對原版1的照明區域進行照明。照明光學系統5可以包括用於設定照明條件的多個照明光圈(未圖示)，能夠使用任意的照明光圈。照明光學系統5例如可以包括水銀燈，KrF準分子雷射器、ArF準分子雷射器、F2雷射器或者極端紫外光(Extreme Ultra Violet：EUV光)光源等光源。原版載置台2支撐原版1。原版載置台2能夠至少在Y軸方向上驅動原版1，優選的是能夠關於6個軸而驅動原版1。原版載置台2能夠由線性馬達等驅動機構驅動。能夠對原版載置台2設置反射鏡7。在與反射鏡7對置的位置處能夠設置雷射干涉計9。原版載置台2的X軸以及Y軸方向的位置及θZ方向的旋轉角由雷射干涉計9即時地測量，測量結果能夠被供給到控制部CNT。控制部CNT根據從雷射干涉計9供給的測量結果來控制原版載置台2的位置以及旋轉角，從而控制由原版載置台2支撐的倍縮光罩1的位置以及旋轉角。投影光學系統6能夠將原版1的圖案按照預定的投影倍率(例如，1/4或者1/5)投影到基板3。投影光學系統6包括多個光學元件，該多個光學元件包括用於調整投影光學系統6的像差(例如，球面像差)的光學元件。基板載置台4支撐基板3。基板載置台4由未圖示的基板驅動機構驅動。該基板驅動機構可以包括：Z載置台機構，在Z軸方向上驅動基板載置台4；XY載置台機構，在X軸以及Y軸方向上驅動Z載置台機構；以及基座，支撐XY載置台機構。在基板載置台4上能夠設置反射鏡8。在與反射鏡8對置的位置處能夠設置多個雷射干涉計10、12(僅圖示兩個)。基板載置台4的X軸、Y軸、Z軸方向的位置以及θZ方向的旋轉角由雷射干涉計10即時地測量，測量結果能夠被供給到控制部CNT。控制部CNT根據從雷射干涉計10、12供給的測量結果來驅動基板載置台4，從而控制基板3的位置以及旋轉角。控制部CNT例如能夠由FPGA(Field Programmable Gate Array(現場可程式化邏輯閘陣列)的簡稱。)等PLD (Programmable Logic Device(可程式化邏輯裝置)的簡稱。)、或者ASIC(Application Specific Integrated Circuit(專用積體電路)的簡稱。)、或者編入有程式的通用電腦、或者它們的全部或者一部分的組合構成。如圖2所例示那樣，在基板載置台4設置有1個或者多個基板基準板11。基板基準板11的表面位於與基板3的表面大致相同的高度。在基板基準板11上，能夠配置對準檢測系統16在測量中使用的基準標記18和受光部14在測量中使用的像側標記17。基準標記18與像側標記17的相對位置是已知的。或者，基準標記18和像側標記17也可以為共同的標記。基準標記18以及像側標記17為配置於投影光學系統6的像面側(像面或者其附近)的標記。同樣地，在原版載置台2設置具有物體側標記的原版基準板13。原版基準板13的物體側標記為配置於投影光學系統6的物體側(物體面或者其附近)的標記。原版載置台2與基板載置台4的相對位置能夠藉由使用受光部14來測量原版基準板13的物體側標記與基板基準板11的像側標記17的相對位置而測量。具體而言，由照明光學系統5對原版基準板13的物體側標記進行照明。透射該物體側標記的光透射投影光學系統6，進而透射基板基準板11的像側標記17，入射到受光部14。受光部14檢測入射的光的光量(強度)。能夠一邊在X軸方向、Y軸方向、Z軸方向上分別驅動基板載置台4，一邊由受光部14測量入射到該受光部14的光的光量。然後，能夠根據由受光部14測量的光量的變化，調整原版基準板13的物體側標記和基板基準板11的像側標記17的X軸方向以及Y軸方向的位置、及Z軸方向的位置(焦點)。物體側標記也可以配置於原版1。在圖4(a)中，用實線示出了將X軸方向(或者Y軸方向)上的基板載置台4的位置取為橫軸、將在各位置處入射到受光部14的光的光量(強度)取為縱軸的光量分佈。該光量分佈能夠藉由在X軸方向(或者Y軸方向)上的多個位置處測量透射物體側標記、投影光學系統6以及像側標記17的光的光量而獲取。在圖4(a)中，光量呈現最大值的位置為物體側標記的X軸方向(或者Y軸方向)上的位置與像側標記17的X軸方向(或者Y軸方向)上的位置一致時的基板載置台4的位置。光量呈現最大值的位置例如能夠藉由針對光量分佈的函數的擬合、或者重心處理等來求出。在圖4(b)中，用實線示出了將Z軸方向上的基板載置台4的位置取為橫軸、將在各位置處入射到受光部14的光的光量(強度)取為縱軸的光量分佈。該光量分佈能夠藉由在投影光學系統6的光軸方向(Z軸方向)上的多個位置處測量透射物體側標記、投影光學系統6以及像側標記17的光的光量而獲取。在圖4(b)中，光量呈現最大值的位置為像側標記17的Z軸方向上的位置相對於物體側標記的成像位置一致的基板載置台4的Z軸方向上的位置。這樣，將在投影光學系統6的光軸方向上的光量分佈中光量呈現最大值的位置定義為焦點位置。光量呈現最大值的位置例如能夠藉由針對光量分佈的函數的擬合、或者重心處理等來求出。焦點檢測系統15包括將檢測光投射到基板3的表面的投射系統和接收來自基板3的反射光的受光系統，由焦點檢測系統15進行的焦點檢測的結果被供給到控制部CNT。控制部CNT能夠根據焦點檢測系統15的焦點檢測的結果來驅動Z載置台機構，調整基板3的Z軸方向上的位置以及傾斜角。對準檢測系統16可以包括：投射系統，將檢測光投射到基板3的對準標記19或者基板基準板11的基準標記18；以及受光系統，接收來自對準標記19或者基準標記18的反射光。由對準檢測系統16進行的檢測的結果被供給到控制部CNT。控制部CNT根據由對準檢測系統16進行的檢測的結果來控制基板載置台4的X軸方向以及Y軸方向的位置，從而控制基板3的X軸方向以及Y軸方向的位置。以下，說明測量投影光學系統6的像差的方法。此外，在此，說明作為投影光學系統6的像差而測量球面像差的方法，但該方法還能夠應用於像散的測量。已經說明的圖4(b)例示性地示出了投影光學系統6不具有球面像差的情況下的光量分佈。圖4(b)中的虛線30為計算出的焦點位置。圖4(b)的光量分佈以虛線30為對稱軸而對稱(線對稱)。在圖5中，用實線示出了投影光學系統6具有例如100mλ的球面像差的狀態下的光量分佈。光量分佈能夠藉由在投影光學系統6的光軸方向(Z軸方向)上的多個位置處測量透射物體側標記、投影光學系統6以及像側標記17的光的光量而獲取。圖5中的虛線31為根據圖5中的實線所示的光量分佈計算出的焦點位置。圖5所示的光量分佈以虛線31為對稱軸而為非對稱(也就是說，不為線對稱)。為了評價圖5所示的光量分佈(也就是說，投影光學系統6具有球面像差的情況下的光量分佈)的非對稱性，針對光量分佈而對藉由式(1)表示的高斯函數G(z)進行擬合。在此，將光軸方向上的基板載置台4的位置設為z，將光量分佈中的最大光量(強度)設為A，將平均值設為μ，將色散設為σ，將常數項設為d。另外，π為圓周率，exp為指數函數。 [式1] ･･･(1) 擬合的初始值以及擬合的範圍優選設定為使得擬合後的高斯函數的平均值μ與焦點位置相等。高斯函數為以高斯函數的平均值μ為對稱軸(原點)的對稱的偶函數，所以藉由運算進行擬合後的高斯函數與光量分佈的差值，能夠得到表示光量分佈的非對稱性的資訊。藉由在以焦點位置為中心的預定的積分區間-a至a對該差值進行積分，從而計算非對稱分量(特徵量)。因而，將測定出的光量分佈設為I(z)時的非對稱分量AS藉由式(2)來表示。此外，a能夠任意地決定。 [式2] ･･･(2) 另外，為了使測量時的光量以及受光部14的檢測靈敏度等的影響均勻化，如式(3)所示，在與求出非對稱分量時的積分區間相同的積分區間對擬合後的高斯函數進行積分，從而計算對稱分量S。 [式3] ･･･(3) 藉由用對稱分量S對非對稱分量AS進行標準化，能夠求出規範化後的非對稱分量(規範化後的特徵量)。圖3的直線32為表示投影光學系統6的球面像差量與規範化後的非對稱分量(特徵量)的關係的特性資訊。當設為根據圖5所示的光量分佈而求出的、規範化後的非對稱分量是用符號35表示的非對稱分量時，能夠根據用直線32表示的特性資訊，將與該非對稱分量對應的球面像差量決定為用符號36表示的球面像差量。在此，直線32所示的資訊可能根據測量條件不同而不同，所以最好針對每個測量條件而求出該特性資訊。搭載於曝光裝置EXP的投影光學系統6能夠在製造階段使用干涉計等測量器來測量像差，根據其結果來調整像差。但是，還存在即使在製造階段以高精度調整了投影光學系統6的像差，仍在投影光學系統6搭載於曝光裝置EXP時，像差發生變化的情況。另外，由於在曝光時產生的熱以及使用的環境(例如，氣壓)的影響，投影光學系統6的像差可能隨時間變化。例如，考慮在圖3中用符號33表示的投影光學系統6的球面像差量由於隨時間變化而變化至如用符號34所示的球面像差量。由於如以上那樣的原委，要求在曝光裝置EXP中簡易地測量投影光學系統6的像差的技術。根據上述方法，即使由於隨時間變化而產生投影光學系統6的球面像差，也能夠在短時間內測量投影光學系統6的球面像差。如前述，預先準備表示投影光學系統6的球面像差量與規範化後的非對稱分量(特徵量)的關係的特性資訊(直線32)，從而能夠根據測量出的光量分佈來求出非對稱分量，根據該資訊和該非對稱分量來求出球面像差量。特性資訊例如能夠藉由模擬得到。能夠藉由模擬來計算在球面像差量改變時物體側標記在像側標記上形成的像。因而，能夠在多個球面像差量各自中，藉由模擬來計算在投影光學系統6的光軸方向上的多個位置的各個位置處能夠由受光部14獲取的光量。這樣，能夠關於多個球面像差量的各個球面像差量，根據藉由模擬而關於多個位置得到的光量，計算表示光軸方向上的位置與和該位置對應的光量的關係的光量分佈。而且，能夠求出與多個球面像差量分別對應的多個光量分佈各自的非對稱分量。由此，能夠得到特性資訊(直線32)。作為產生多個球面像差量的方法，有調整構成投影光學系統6的多個光學元件中的至少1個光學元件的驅動量(位置)的方法。在此，知曉驅動量與球面像差量的關係是便利的，但也可以在所設定的驅動量之下實測球面像差量。關於多個驅動量的各個驅動量，求出光量分佈，根據該光量分佈來求出非對稱分量，從而能夠得到特性資訊(直線32)。在圖6中，示出了用於生成特性資訊的處理的步驟。在工程S310中，設定或者變更球面像差量。接著，在工程S320中，針對在工程S310中設定或者變更的球面像差量，獲取表示光軸方向上的位置與和該位置對應的光量的關係的光量分佈。這能夠藉由模擬來計算在投影光學系統6的光軸方向上的多個位置處分別能夠由受光部14獲取的光量而得到。接著，在工程S330中，根據在工程S320中獲取到的光量分佈來求出特徵量(非對稱分量)。接著，在工程S340中，判斷針對其它球面像差量是否執行工程S320、S330，在針對其它球面像差量而執行工程S320、S330的情況下，返回到工程S310，如果不是這樣，則進入到工程S350。在返回到工程S310的情況下，在工程S310中，對球面像差量進行變更，進入到工程S320。在工程S350中，根據藉由重複工程S310~S330而關於多個球面像差量分別得到的特徵量(非對稱分量)來生成特性資訊。在圖7中，示出了在曝光裝置EXP中實施的處理。該處理由控制部CNT控制。在工程S410中，控制部CNT判斷是否調整投影光學系統6的球面像差。在工程S410中，控制部CNT例如能夠在針對預定數量的基板或者預定數量的批次(1個批次能夠由預定數量的基板構成)的曝光結束的情況下，判斷為調整投影光學系統6的球面像差。在此，工程S420也可以與先於基板的曝光實施的焦點測量並用，在該情況下，不需要工程S410。焦點測量為用於根據投影光學系統6的像面來調整基板的拍攝區域的高度的測量，因此，實施與工程S420同樣的處理，獲取如圖4(b)所例示的光量分佈。因而，能夠使用在該焦點測量中得到的光量分佈來實施工程S430~S450。在工程S420中，控制部CNT在投影光學系統6的光軸方向上的多個位置的各個位置處使受光部14檢測光量，根據來自受光部14的輸出，獲取表示光軸方向上的位置與和該位置對應的光量的關係的光量分佈。接著，在工程S430中，控制部CNT根據在工程S420中獲取到的光量分佈來求出特徵量(非對稱分量)。在工程S440中，控制部CNT根據在圖6所示的處理中準備的特性資訊和在工程S430中求出的特徵量(非對稱分量)，決定與該特徵量對應的球面像差量。在工程S450中，控制部CNT以使在工程S440中決定的球面像差量降低或者成為零的方式調整投影光學系統6的球面像差。該調整能夠藉由驅動投影光學系統6中的至少1個光學元件而實現。工程S450也可以僅當在工程S440中決定的球面像差量超過預先設定的閾值的情況下實施。在工程S460中，控制部CNT執行將原版1的圖案轉印到基板3的曝光。在工程S470中，控制部CNT判斷是否結束工程S410~S470的處理，在不結束的情況下返回到工程S410。以下，說明第2實施方式。作為第2實施方式而未提及的事項能夠依照第1實施方式。求出特徵量(非對稱分量)的方法不限定於高斯函數的擬合。控制部CNT例如針對藉由測量而得到的光量分佈，如式(4)所示，對以焦點位置為原點的多項式函數進行擬合，從而能夠計算非對稱分量。在此，關於n次多項式N(z)，將i次項的係數設為k_i。 [式4] ･･･(4) 在該情況下，能夠將多項式函數的僅偶數次項的積分值設為對稱分量，另外將多項式函數的僅奇數次項的積分值設為非對稱分量，進行作為表示光量分佈的非對稱性的特徵量的非對稱分量的計算。以下，具體地說明第2實施方式。控制部CNT針對藉由測量得到的光量分佈而對多項式函數進行擬合，根據該多項式函數來決定像差。圖5所示的光量分佈以虛線31為對稱軸而為非對稱(也就是說，不為線對稱)。為了評價圖5所示的光量分佈(也就是說，投影光學系統6具有球面像差的情況下的光量分佈)的非對稱性，控制部CNT針對該光量分佈而對多項式函數進行擬合。進而，控制部CNT根據擬合後的多項式函數的奇數次項來求出特徵量。以下，說明其具體例。控制部CNT對擬合後的多項式函數的多個項中的偶數次數的項和奇數次數的項分別進行處理。控制部CNT如式(5)所示，在以焦點位置為中心的預定的積分區間(-a至a的區間)對偶數次數的項進行積分，將由此得到的值設為對稱分量S。 [式5] ･･･(5) 另外，控制部CNT如式(6)所示，將在以焦點位置為中心的預定的積分區間(-a至a的區間)對奇數次數的項進行積分而得到的值設為非對稱分量AS。 [式6] ･･･(6) 控制部CNT藉由用對稱分量S對非對稱分量AS進行標準化，從而作為表示光量分佈的非對稱性的特徵量而計算非對稱分量。在此，式(5)中的積分區間的寬度與式(6)中的積分區間的寬度能夠設定成相等。以下，說明第3實施方式。作為第3實施方式而未提及的事項能夠依照第1以及第2實施方式中的至少1個實施方式。求出特徵量(非對稱分量)的方法並不限定於伴隨積分的方法。控制部CNT也可以根據針對藉由測量得到的光量分佈擬合的多項式函數的特定的次數的係數，作為表示光量分佈的非對稱性的特徵量而計算非對稱分量。以下，說明第4實施方式。作為第4實施方式而未提及的事項能夠依照第1至第3實施方式中的至少1個實施方式。求出特徵量(非對稱分量)的方法不限定於伴隨針對藉由測量得到的光量分佈的函數的擬合的方法。例如，控制部CNT如式(7)所示，關於焦點位置Z0與從焦點位置Z0起向正方向預定距離的位置a之間的區間(Z0至a的區間)對藉由測量得到的光量分佈I(z)進行積分，求出積分值α。 [式7] ･･･(7) 另外，控制部CNT如式(8)所示，關於與從焦點位置Z0起向負方向預定距離的位置a之間的區間(-a至焦點位置Z0的區間)對藉由測量得到的光量分佈I(z)進行積分，求出積分值β。 [式8] ･･･(8) 然後，控制部CNT根據兩個積分值α、β，作為表示光量分佈的非對稱性的特徵量而計算非對稱分量。在此，式(7)中的積分區間的寬度與式(8)中的積分區間的寬度能夠設定成相等。以下，說明上述實施方式的變形例。作為表示光量分佈的非對稱性的特徵量即非對稱分量也可以根據藉由測量得到的光量分佈的形狀來計算。例如，取藉由測量得到的光量分佈與和預先準備的多個球面像差量分別對應的多個光量分佈的差值。然後，能夠將與差值最小的光量分佈對應的球面像差量決定為與藉由測量得到的光量分佈對應的球面像差量。投影光學系統6的球面像差的調整既可以在曝光裝置EXP的定期保養時實施，也可以在曝光裝置EXP中斷處理時實施。在測量出的投影光學系統6的球面像差超過閾值的情況下，也可以藉由用掃描型電子顯微鏡(SEM)等測量實際地對基板進行曝光並顯影的結果中的圖案偏移以及/或者形狀而對像差量進行類推的手法等，以更高精度來測量、調整投影光學系統6的像差。這是為了檢測投影光學系統的像差而利用實施方式的像差測量方法，僅在檢測到的像差超過某個閾值時，藉由精度更高的方法來測量投影光學系統的像差並進行調整的方法。以下，說明應用了上述像差測量方法的物品製造方法。物品製造方法可以包括：測量工程，依照上述像差測量方法而測量曝光裝置EXP的投影光學系統6的像差量；以及調整工程，根據在該測量工程中測量出的像差量來調整投影光學系統6的像差。另外，該物品製造法包括在該調整工程之後利用曝光裝置EXP對塗敷有感光材料的基板進行曝光的曝光工程、在該曝光工程之後使該感光材料顯影的顯影工程、以及對經由該顯影工程的基板進行處理的處理工程，該物品製造法從經由該處理工程的基板得到物品。發明並不限制於上述實施方式，能夠不脫離發明的精神以及範圍，而進行各種變更以及變形。因而，為了公開發明的範圍，添加請求項。Hereinafter, the embodiments are described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention related to the scope of the patent application of the claim. A plurality of features are recorded in the embodiments, but not all of these plurality of features are necessary for the invention, and a plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same reference numbers are attached to the same or identical structures, and repeated descriptions are omitted. Hereinafter, the first embodiment is described. FIG1 shows a structural example of an exposure device EXP of the first embodiment. The exposure device EXP may have a function of measuring the aberration (for example, spherical aberration) of the projection optical system 6, and adjusting the aberration of the projection optical system 6 according to the measurement result. The exposure device EXP utilizes the projection optical system 6 to project the pattern of the original plate 1 onto the substrate 3 coated with a photosensitive material, thereby transferring the pattern of the original plate 1 to the substrate 3 (photosensitive material). The following describes a more specific structure example and operation example of the exposure device EXP. The exposure device EXP may include: an original plate mounting table 2 that supports an original plate (reticle) 1; a substrate mounting table 4 that supports a substrate 3; and an illumination optical system 5 that illuminates the original plate 1 supported by the original plate mounting table 2 with exposure light. In addition, the exposure device EXP may include: a projection optical system 6 that projects a pattern of the original plate 1 illuminated by the exposure light onto the substrate 3 supported by the substrate mounting table 4; and a control unit CNT that controls the laser interferometers 10, 12 and the various components of the exposure device EXP. In addition, the exposure device EXP may include a light receiving unit 14, an alignment detection system 16, and a focus detection system 15. In the following, the exposure device EXP is configured as a scanning exposure device (scanning stepper device) that transfers the pattern of the original plate 1 to the substrate 3 while scanning the original plate 1 and the substrate 3 synchronously in the scanning direction. However, the exposure device EXP can also be applied to an exposure device (stepper device) that transfers the pattern of the original plate 1 to the substrate 3 while keeping the original plate 1 and the substrate 3 stationary. In the following description, the direction consistent with the optical axis of the projection optical system 6 is set as the Z-axis direction, the direction parallel to the direction in which the original plate 1 and the substrate 3 are scanned in a plane perpendicular to the Z-axis direction is set as the Y-axis direction, and the direction perpendicular to the Z-axis direction and the Y-axis direction (non-scanning direction) is set as the X-axis direction. In addition, the directions around the X-axis, Y-axis, and Z-axis are set as θX, θY, and θZ directions, respectively. The illumination area of the original plate 1 is illuminated by the illumination optical system 5 with exposure light having a uniform illumination distribution. The illumination optical system 5 may include a plurality of illumination apertures (not shown) for setting illumination conditions, and any illumination aperture can be used. The illumination optical system 5 may include, for example, a light source such as a mercury lamp, a KrF excimer laser, an ArF excimer laser, an F2 laser, or an extreme ultraviolet light (EUV light) light source. The original plate mounting table 2 supports the original plate 1. The original plate mounting table 2 can drive the original plate 1 at least in the Y-axis direction, and preferably can drive the original plate 1 about 6 axes. The original plate mounting table 2 can be driven by a driving mechanism such as a linear motor. A reflecting mirror 7 can be provided on the original plate mounting table 2. A laser interferometer 9 can be provided at a position opposite to the reflecting mirror 7. The position of the original plate mounting table 2 in the X-axis and Y-axis directions and the rotation angle in the θZ direction are measured in real time by the laser interferometer 9, and the measurement results can be supplied to the control unit CNT. The control unit CNT controls the position and rotation angle of the original plate mounting table 2 according to the measurement results supplied from the laser interferometer 9, thereby controlling the position and rotation angle of the reduction mask 1 supported by the original plate mounting table 2. The projection optical system 6 can project the pattern of the original plate 1 onto the substrate 3 at a predetermined projection magnification (for example, 1/4 or 1/5). The projection optical system 6 includes a plurality of optical elements, including an optical element for adjusting the aberration (for example, spherical aberration) of the projection optical system 6. The substrate mounting table 4 supports the substrate 3. The substrate stage 4 is driven by a substrate driving mechanism not shown in the figure. The substrate driving mechanism may include: a Z stage mechanism that drives the substrate stage 4 in the Z axis direction; an XY stage mechanism that drives the Z stage mechanism in the X axis and Y axis directions; and a base that supports the XY stage mechanism. A reflective mirror 8 can be provided on the substrate stage 4. A plurality of laser interferometers 10, 12 (only two are shown) can be provided at a position opposite to the reflective mirror 8. The position of the substrate stage 4 in the X axis, Y axis, and Z axis directions and the rotation angle in the θZ direction are measured in real time by the laser interferometer 10, and the measurement results can be supplied to the control unit CNT. The control unit CNT drives the substrate mounting table 4 according to the measurement results supplied from the laser interferometers 10 and 12, thereby controlling the position and rotation angle of the substrate 3. The control unit CNT can be composed of, for example, FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), or ASIC (Application Specific Integrated Circuit), or a general-purpose computer with a program, or a combination of all or part of them. As shown in Figure 2, one or more substrate base plates 11 are arranged on the substrate mounting table 4. The surface of the substrate base plate 11 is located at approximately the same height as the surface of the substrate 3. On the substrate reference plate 11, a reference mark 18 used by the alignment detection system 16 in measurement and an image side mark 17 used by the light receiving unit 14 in measurement can be configured. The relative position of the reference mark 18 and the image side mark 17 is known. Alternatively, the reference mark 18 and the image side mark 17 can also be a common mark. The reference mark 18 and the image side mark 17 are marks configured on the image plane side (image plane or its vicinity) of the projection optical system 6. Similarly, an original plate reference plate 13 having an object side mark is set on the original plate mounting table 2. The object side mark of the original plate reference plate 13 is a mark configured on the object side (object plane or its vicinity) of the projection optical system 6. The relative position of the original plate stage 2 and the substrate stage 4 can be measured by measuring the relative position of the object side mark of the original plate base plate 13 and the image side mark 17 of the substrate base plate 11 using the light receiving unit 14. Specifically, the object side mark of the original plate base plate 13 is illuminated by the illumination optical system 5. The light that passes through the object side mark passes through the projection optical system 6, and then passes through the image side mark 17 of the substrate base plate 11, and is incident on the light receiving unit 14. The light receiving unit 14 detects the light amount (intensity) of the incident light. The light receiving unit 14 can measure the light amount of the light incident on the light receiving unit 14 while driving the substrate stage 4 in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. Then, the position of the object side mark of the original plate 13 and the image side mark 17 of the substrate base plate 11 in the X-axis direction and the Y-axis direction, and the position (focus) in the Z-axis direction can be adjusted according to the change in the light amount measured by the light receiving unit 14. The object side mark can also be arranged on the original plate 1. In Figure 4 (a), the solid line shows the light amount distribution with the position of the substrate mounting table 4 in the X-axis direction (or Y-axis direction) as the horizontal axis and the light amount (intensity) of the light incident on the light receiving unit 14 at each position as the vertical axis. The light amount distribution can be obtained by measuring the light amount of light transmitted through the object side mark, the projection optical system 6 and the image side mark 17 at multiple positions in the X-axis direction (or Y-axis direction). In FIG. 4(a), the position where the light quantity presents the maximum value is the position of the substrate stage 4 when the position of the object side mark in the X-axis direction (or the Y-axis direction) coincides with the position of the image side mark 17 in the X-axis direction (or the Y-axis direction). The position where the light quantity presents the maximum value can be obtained by, for example, fitting a function for the light quantity distribution or performing a gravity center process. In FIG. 4(b), a solid line shows the light quantity distribution with the position of the substrate stage 4 in the Z-axis direction as the horizontal axis and the light quantity (intensity) of the light incident on the light receiving unit 14 at each position as the vertical axis. The light quantity distribution can be obtained by measuring the light quantity transmitted through the object side mark, the projection optical system 6, and the image side mark 17 at multiple positions in the optical axis direction (Z axis direction) of the projection optical system 6. In FIG. 4(b), the position where the light quantity presents the maximum value is the position in the Z axis direction of the image side mark 17 relative to the imaging position of the object side mark on the substrate mounting table 4. In this way, the position where the light quantity presents the maximum value in the light quantity distribution in the optical axis direction of the projection optical system 6 is defined as the focal position. The position where the light quantity presents the maximum value can be obtained, for example, by fitting a function for the light quantity distribution or by centroid processing. The focus detection system 15 includes a projection system that projects detection light onto the surface of the substrate 3 and a light receiving system that receives reflected light from the substrate 3. The result of focus detection performed by the focus detection system 15 is supplied to the control unit CNT. The control unit CNT can drive the Z stage mechanism according to the result of focus detection by the focus detection system 15 to adjust the position and tilt angle of the substrate 3 in the Z-axis direction. The alignment detection system 16 may include: a projection system that projects detection light onto the alignment mark 19 of the substrate 3 or the reference mark 18 of the substrate reference plate 11; and a light receiving system that receives reflected light from the alignment mark 19 or the reference mark 18. The result of detection performed by the alignment detection system 16 is supplied to the control unit CNT. The control unit CNT controls the position of the substrate mounting table 4 in the X-axis direction and the Y-axis direction based on the detection result performed by the alignment detection system 16, thereby controlling the position of the substrate 3 in the X-axis direction and the Y-axis direction. The following describes a method for measuring the aberration of the projection optical system 6. In addition, here, a method for measuring spherical aberration as the aberration of the projection optical system 6 is described, but this method can also be applied to the measurement of astigmatism. The already described FIG4(b) exemplarily shows the light distribution when the projection optical system 6 does not have spherical aberration. The dotted line 30 in FIG4(b) is the calculated focal position. The light distribution of FIG4(b) is symmetrical (line symmetrical) with the dotted line 30 as the symmetry axis. In FIG5 , the solid line shows the light distribution in a state where the projection optical system 6 has a spherical aberration of, for example, 100 mλ. The light distribution can be obtained by measuring the light amount of light transmitted through the object side mark, the projection optical system 6, and the image side mark 17 at multiple positions in the optical axis direction (Z-axis direction) of the projection optical system 6. The dotted line 31 in FIG5 is the focal point position calculated based on the light distribution shown by the solid line in FIG5 . The light distribution shown in FIG5 is asymmetric (that is, not line symmetric) with the dotted line 31 as the symmetry axis. In order to evaluate the asymmetry of the light distribution shown in FIG5 (that is, the light distribution when the projection optical system 6 has spherical aberration), the Gaussian function G(z) represented by equation (1) is fitted to the light distribution. Here, the position of the substrate mounting table 4 in the optical axis direction is set to z, the maximum light amount (intensity) in the light distribution is set to A, the average value is set to μ, the dispersion is set to σ, and the constant term is set to d. In addition, π is pi, and exp is an exponential function. [Equation 1] ･･･(1) The initial value of the fitting and the fitting range are preferably set so that the average value μ of the Gaussian function after fitting is equal to the focal position. The Gaussian function is an even function symmetrical with the average value μ of the Gaussian function as the symmetry axis (origin), so by calculating the difference between the Gaussian function after fitting and the light distribution, information representing the asymmetry of the light distribution can be obtained. The asymmetric component (characteristic quantity) is calculated by integrating the difference in a predetermined integration interval -a to a centered at the focal position. Therefore, the asymmetric component AS when the measured light distribution is set to I(z) is expressed by formula (2). In addition, a can be determined arbitrarily. [Formula 2] ･･･(2) In order to make the influence of the light quantity during measurement and the detection sensitivity of the light receiving unit 14 uniform, as shown in formula (3), the fitted Gaussian function is integrated in the same integration interval as the integration interval when the asymmetric component is obtained, thereby calculating the symmetric component S. [Formula 3] ･･･(3) By normalizing the asymmetric component AS with the symmetric component S, the normalized asymmetric component (normalized characteristic quantity) can be obtained. The straight line 32 in FIG. 3 is characteristic information indicating the relationship between the spherical aberration amount of the projection optical system 6 and the normalized asymmetric component (characteristic quantity). When it is assumed that the normalized asymmetric component obtained based on the light quantity distribution shown in FIG. 5 is the asymmetric component represented by symbol 35, the spherical aberration amount corresponding to the asymmetric component can be determined as the spherical aberration amount represented by symbol 36 based on the characteristic information represented by the straight line 32. Here, the information shown by the straight line 32 may differ depending on the measurement conditions, so it is best to obtain the characteristic information for each measurement condition. The projection optical system 6 mounted on the exposure device EXP can measure the aberration using a measuring instrument such as an interferometer during the manufacturing stage, and adjust the aberration based on the result. However, even if the aberration of the projection optical system 6 is adjusted with high precision during the manufacturing stage, there is a situation where the aberration changes when the projection optical system 6 is mounted on the exposure device EXP. In addition, due to the influence of the heat generated during exposure and the environment in which it is used (for example, air pressure), the aberration of the projection optical system 6 may change over time. For example, consider that the spherical aberration amount of the projection optical system 6 represented by the symbol 33 in Figure 3 changes to the spherical aberration amount as shown by the symbol 34 due to changes over time. Due to the above reasons, a technology for easily measuring the aberration of the projection optical system 6 in the exposure device EXP is required. According to the above method, even if the spherical aberration of the projection optical system 6 is generated due to time-varying changes, the spherical aberration of the projection optical system 6 can be measured in a short time. As mentioned above, characteristic information (straight line 32) indicating the relationship between the spherical aberration amount of the projection optical system 6 and the normalized asymmetric component (characteristic amount) is prepared in advance, so that the asymmetric component can be obtained based on the measured light quantity distribution, and the spherical aberration amount can be obtained based on the information and the asymmetric component. The characteristic information can be obtained, for example, by simulation. The image formed by the object side mark on the image side mark when the spherical aberration amount changes can be calculated by simulation. Therefore, it is possible to calculate the amount of light that can be obtained by the light receiving unit 14 at each of the multiple positions in the optical axis direction of the projection optical system 6 by simulation for each of the multiple spherical aberration amounts. In this way, it is possible to calculate, for each of the multiple spherical aberration amounts, a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity corresponding to the position based on the light quantity obtained for the multiple positions by simulation. Moreover, it is possible to find the asymmetric components of each of the multiple light quantity distributions corresponding to the multiple spherical aberration amounts. Thus, characteristic information (straight line 32) can be obtained. As a method for generating multiple spherical aberration amounts, there is a method of adjusting the drive amount (position) of at least one of the multiple optical elements constituting the projection optical system 6. Here, it is convenient to know the relationship between the drive amount and the spherical aberration amount, but the spherical aberration amount can also be measured under the set drive amount. For each drive amount of multiple drive amounts, the light amount distribution is calculated, and the asymmetric component is calculated based on the light amount distribution, so that the characteristic information (straight line 32) can be obtained. In Figure 6, the steps of the processing for generating characteristic information are shown. In process S310, the spherical aberration amount is set or changed. Then, in process S320, for the spherical aberration amount set or changed in process S310, the light amount distribution representing the relationship between the position in the optical axis direction and the light amount corresponding to the position is obtained. This can be obtained by calculating the amount of light that can be received by the light receiving unit 14 at multiple positions in the optical axis direction of the projection optical system 6 through simulation. Then, in process S330, the characteristic amount (asymmetric component) is obtained based on the light amount distribution obtained in process S320. Then, in process S340, it is determined whether processes S320 and S330 are performed for other spherical aberration amounts. If processes S320 and S330 are performed for other spherical aberration amounts, the process returns to process S310. If not, the process proceeds to process S350. If the process returns to process S310, the spherical aberration amount is changed in process S310, and the process proceeds to process S320. In process S350, characteristic information is generated based on characteristic quantities (asymmetric components) respectively obtained about a plurality of spherical aberration quantities by repeating processes S310 to S330. FIG. 7 shows the processing performed in the exposure device EXP. The processing is controlled by the control unit CNT. In process S410, the control unit CNT determines whether to adjust the spherical aberration of the projection optical system 6. In process S410, the control unit CNT can, for example, determine that the spherical aberration of the projection optical system 6 is adjusted when exposure of a predetermined number of substrates or a predetermined number of batches (one batch can be composed of a predetermined number of substrates) is completed. Here, process S420 can also be used in conjunction with focus measurement performed prior to exposure of the substrate. In this case, process S410 is not required. The focus measurement is a measurement for adjusting the height of the photographing area of the substrate according to the image plane of the projection optical system 6. Therefore, the same processing as that of step S420 is performed to obtain the light quantity distribution as shown in FIG. 4( b). Therefore, steps S430 to S450 can be performed using the light quantity distribution obtained in the focus measurement. In step S420, the control unit CNT causes the light receiving unit 14 to detect the light quantity at each of a plurality of positions in the optical axis direction of the projection optical system 6, and obtains the light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity corresponding to the position based on the output from the light receiving unit 14. Next, in step S430, the control unit CNT obtains the characteristic quantity (asymmetric component) based on the light quantity distribution obtained in step S420. In process S440, the control unit CNT determines the spherical aberration amount corresponding to the characteristic amount based on the characteristic information prepared in the process shown in Figure 6 and the characteristic amount (asymmetric component) calculated in process S430. In process S450, the control unit CNT adjusts the spherical aberration of the projection optical system 6 in such a way that the spherical aberration amount determined in process S440 is reduced or becomes zero. The adjustment can be achieved by driving at least one optical element in the projection optical system 6. Process S450 can also be implemented only when the spherical aberration amount determined in process S440 exceeds a preset threshold value. In process S460, the control unit CNT executes exposure to transfer the pattern of the original plate 1 to the substrate 3. In process S470, the control unit CNT determines whether to end the processing of processes S410~S470, and returns to process S410 if it is not ended. The second embodiment is described below. Matters not mentioned as the second embodiment can be in accordance with the first embodiment. The method for obtaining the characteristic quantity (asymmetric component) is not limited to the fitting of the Gaussian function. For example, the control unit CNT fits a polynomial function with the focal position as the origin for the light distribution obtained by measurement, as shown in formula (4), thereby being able to calculate the asymmetric component. Here, for the nth-order polynomial N(z), the coefficient of the i-th order term is set to k_i. [Formula 4] ･･･(4) In this case, the integral value of only the even-order terms of the polynomial function can be set as the symmetric component, and the integral value of only the odd-order terms of the polynomial function can be set as the asymmetric component, and the asymmetric component can be calculated as a characteristic quantity representing the asymmetry of the light distribution. The second embodiment is described in detail below. The control unit CNT fits the polynomial function to the light distribution obtained by measurement, and determines the aberration based on the polynomial function. The light distribution shown in Figure 5 is asymmetric with the dotted line 31 as the symmetry axis (that is, it is not line symmetric). In order to evaluate the asymmetry of the light distribution shown in FIG5 (that is, the light distribution when the projection optical system 6 has spherical aberration), the control unit CNT fits the polynomial function for the light distribution. Furthermore, the control unit CNT obtains the characteristic quantity based on the odd-order terms of the fitted polynomial function. The following is a specific example. The control unit CNT processes the even-order terms and the odd-order terms of the multiple terms of the fitted polynomial function separately. As shown in formula (5), the control unit CNT integrates the even-order terms in a predetermined integration interval (the interval from -a to a) centered on the focal position, and sets the resulting value as the symmetric component S. [Formula 5] ･･･(5) In addition, the control unit CNT sets the value obtained by integrating the odd-numbered terms in a predetermined integration interval (interval from -a to a) centered on the focal point position as the asymmetric component AS as shown in formula (6). [Formula 6] ･･･(6) The control unit CNT calculates the asymmetric component as a characteristic quantity representing the asymmetry of the light quantity distribution by normalizing the asymmetric component AS with the symmetric component S. Here, the width of the integration interval in equation (5) and the width of the integration interval in equation (6) can be set to be equal. The third embodiment is described below. Matters not mentioned as the third embodiment can be in accordance with at least one of the first and second embodiments. The method for obtaining the characteristic quantity (asymmetric component) is not limited to the method of adjoint integration. The control unit CNT can also calculate the asymmetric component as a characteristic quantity representing the asymmetry of the light quantity distribution based on a coefficient of a specific degree of a polynomial function fitted to the light quantity distribution obtained by measurement. The fourth embodiment is described below. Matters not mentioned as the fourth embodiment can be implemented in accordance with at least one of the first to third embodiments. The method of obtaining the characteristic quantity (asymmetric component) is not limited to the method of fitting a function with respect to the light quantity distribution obtained by measurement. For example, the control unit CNT integrates the light quantity distribution I(z) obtained by measurement with respect to the interval between the focal position Z0 and the position a at a predetermined distance in the positive direction from the focal position Z0 (interval from Z0 to a), as shown in formula (7), and obtains the integral value α. [Formula 7] ･･･(7) In addition, the control unit CNT integrates the light intensity distribution I(z) obtained by measurement with respect to the interval between the position a at a predetermined distance in the negative direction from the focal position Z0 (the interval from -a to the focal position Z0), and obtains the integral value β. [Equation 8] ･･･(8) Then, the control unit CNT calculates the asymmetric component as a characteristic quantity representing the asymmetry of the light distribution based on the two integral values α and β. Here, the width of the integral interval in equation (7) and the width of the integral interval in equation (8) can be set to be equal. A modified example of the above-mentioned embodiment is described below. The asymmetric component, which is a characteristic quantity representing the asymmetry of the light distribution, can also be calculated based on the shape of the light distribution obtained by measurement. For example, the difference between the light distribution obtained by measurement and multiple light distributions corresponding to multiple spherical aberration quantities prepared in advance is taken. Then, the spherical aberration quantity corresponding to the light distribution with the smallest difference can be determined as the spherical aberration quantity corresponding to the light distribution obtained by measurement. The adjustment of the spherical aberration of the projection optical system 6 can be performed during the regular maintenance of the exposure device EXP or during the interruption of the exposure device EXP. When the measured spherical aberration of the projection optical system 6 exceeds the threshold value, the aberration of the projection optical system 6 can be measured and adjusted with higher accuracy by using a scanning electron microscope (SEM) or the like to measure the pattern shift and/or shape in the result of actually exposing and developing the substrate and inferring the aberration amount. This is a method of measuring the aberration of the projection optical system by using an aberration measurement method of the implementation method in order to detect the aberration of the projection optical system. Only when the detected aberration exceeds a certain threshold value, the aberration of the projection optical system is measured and adjusted by a method with higher accuracy. The following is an explanation of a method for manufacturing an article to which the above-mentioned aberration measurement method is applied. The article manufacturing method may include: a measurement process, measuring the aberration amount of the projection optical system 6 of the exposure device EXP according to the above-mentioned aberration measurement method; and an adjustment process, adjusting the aberration of the projection optical system 6 according to the aberration amount measured in the measurement process. In addition, the article manufacturing method includes an exposure process of exposing a substrate coated with a photosensitive material using the exposure device EXP after the adjustment process, a development process of developing the photosensitive material after the exposure process, and a processing process of processing the substrate after the development process, and the article manufacturing method obtains an article from the substrate after the processing process. The invention is not limited to the above-mentioned embodiments, and various changes and deformations can be made without departing from the spirit and scope of the invention. Therefore, in order to disclose the scope of the invention, the claim items are added.

EXP:曝光裝置 1:原版 3:基板 6:投影光學系統 14:受光部EXP: Exposure device 1: Original plate 3: Substrate 6: Projection optical system 14: Light receiving unit

[圖1]是示出第1實施方式的曝光裝置的結構例的圖。 [圖2]是示出基板載置台的結構例的圖。 [圖3]是例示球面像差與非對稱分量(特徵量)的關係的圖。 [圖4]是例示光量分佈的圖。 [圖5]是例示投影光學系統具有球面像差的情況下的光量分佈的圖。 [圖6]是示出用於生成特性資訊的處理的步驟的圖。 [圖7]是示出在曝光裝置中實施的處理的圖。[FIG. 1] is a diagram showing a structural example of an exposure device according to the first embodiment. [FIG. 2] is a diagram showing a structural example of a substrate stage. [FIG. 3] is a diagram illustrating the relationship between spherical aberration and an asymmetric component (characteristic amount). [FIG. 4] is a diagram illustrating light quantity distribution. [FIG. 5] is a diagram illustrating light quantity distribution when a projection optical system has spherical aberration. [FIG. 6] is a diagram showing the steps of processing for generating characteristic information. [FIG. 7] is a diagram showing processing performed in an exposure device.

32:表示投影光學系統的球面像差量與規範化後的非對稱分量(特徵量)的關係的特性資訊 32: Characteristic information showing the relationship between the spherical aberration amount of the projection optical system and the normalized asymmetric component (characteristic amount)

33:表示投影光學系統的球面像差量由於隨時間變化而變化至如符號34所示的球面像差量 33: Indicates that the spherical aberration of the projection optical system changes with time to the spherical aberration as shown by symbol 34

34:球面像差量 34: Spherical aberration

35:非對稱分量 35: Asymmetric component

36:球面像差量 36: Spherical aberration

Claims

A method for measuring aberrations, characterized in that it includes: a process of obtaining a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity by measuring the light quantity transmitted through an object side mark arranged on the object side of the projection optical system, the projection optical system, and an image side mark arranged on the image side of the projection optical system at each of a plurality of positions that are the same in a direction perpendicular to the optical axis direction of the projection optical system but different from each other in the optical axis direction; a process of obtaining a characteristic quantity representing the asymmetry of the light quantity distribution with the focal position of the projection optical system as the symmetry axis; and a process of determining the aberration quantity of the projection optical system based on the characteristic quantity.

According to the aberration measurement method described in claim 1, in the process of obtaining the aforementioned characteristic quantity, the aforementioned characteristic quantity is obtained based on the odd-order terms of the polynomial function fitted to the aforementioned light quantity distribution.

According to the aberration measurement method described in claim 2, in the process of obtaining the characteristic quantity, the odd-order terms are integrated in a predetermined integration interval centered on the focal position to obtain an integrated value, and the integrated value obtained is standardized using the value obtained by integrating the even-order terms of the polynomial function in the integration interval to obtain a standardized value, and the standardized value is used as the characteristic quantity to obtain.

According to the aberration measurement method described in claim 1, in the process of obtaining the aforementioned characteristic quantity, the aforementioned characteristic quantity is obtained based on the coefficient of a specific degree of the polynomial function fitted to the aforementioned light intensity distribution.

According to the aberration measurement method described in claim 1, in the process of determining the aberration amount, the aberration amount of the projection optical system is determined based on information representing the relationship between the aberration amount of the projection optical system and the characteristic amount.

According to the aberration measurement method described in claim 1, the aberration amount includes the spherical aberration amount.

A method for manufacturing an article, characterized in that it includes: a measurement process, measuring the aberration amount of the projection optical system of the exposure device according to the aberration measurement method described in any one of claims 1 to 6; an adjustment process, adjusting the aberration of the projection optical system according to the aberration amount measured in the aforementioned measurement process; an exposure process, after the aforementioned adjustment process, exposing a substrate coated with a photosensitive material using the aforementioned exposure device; a development process, after the aforementioned exposure process, developing the aforementioned photosensitive material; and a processing process, processing the aforementioned substrate after the aforementioned development process, wherein the aforementioned article manufacturing method obtains an article from the aforementioned substrate after the aforementioned processing process.

An exposure device includes an original plate stage, a projection optical system, a substrate stage, a light receiving unit arranged on the substrate stage, and a control unit. The exposure device is characterized in that the light receiving unit measures the light quantity transmitted through an object side mark arranged on the object side of the projection optical system, the projection optical system, and an image side mark arranged on the image side of the projection optical system at each of a plurality of positions which are the same in a direction perpendicular to the optical axis direction of the projection optical system but different in the optical axis direction. The control unit obtains a light quantity distribution representing the relationship between the position in the optical axis direction and the light quantity based on the output from the light receiving unit, obtains a characteristic quantity representing the asymmetry of the light quantity distribution with the focal position of the projection optical system as the symmetry axis, and determines the aberration quantity of the projection optical system based on the characteristic quantity.

According to the aberration measurement method described in claim 1, the position where the light intensity presents the maximum value in the aforementioned light intensity distribution is the aforementioned focal point position.

The exposure device according to claim 8, wherein the position where the light intensity in the light intensity distribution reaches the maximum value is the focus position.