TWI768218B - Illumination uniformity compensation method and device for lithography machine, lighting system and lithography machine - Google Patents

Illumination uniformity compensation method and device for lithography machine, lighting system and lithography machine Download PDF

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TWI768218B
TWI768218B TW108123013A TW108123013A TWI768218B TW I768218 B TWI768218 B TW I768218B TW 108123013 A TW108123013 A TW 108123013A TW 108123013 A TW108123013 A TW 108123013A TW I768218 B TWI768218 B TW I768218B
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compensation
illumination
lithography machine
distribution
lighting system
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TW202001443A (en
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錢俊
湛賓洲
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大陸商上海微電子裝備（集團）股份有限公司
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70058—Mask illumination systems
    • G03F7/70091—Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/20—Exposure; Apparatus therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70058—Mask illumination systems
    • G03F7/70191—Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like

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  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
  • Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)

Abstract

本發明提供了一種光刻機照度均勻性補償方法及裝置、照明系統及光刻機，通過採集一定時間內光刻機的基準面上的照度分布數據，以在照明系統生命週期內不同時期下，將對應時期的補償區設置於曝光光路的補償面上，對入射至基準面的光強度進行補償，使照明系統在其生命週期內的照度均勻性滿足控制要求，通過增加補償位置，實現對照明系統整個生命週期內的照度均勻性進行預補償，在實現均勻補償的同時，延長均勻補償的生命週期，以降低成本、提高可靠性、降低了製造成本及技術難度，並且，由於所述補償板是通過繞中心軸旋轉以切換補償位置的，減少可動機構，優化了控制策略。The invention provides a method and device for compensating the illumination uniformity of a lithography machine, an illumination system and a lithography machine. , set the compensation area of the corresponding period on the compensation surface of the exposure light path, and compensate the light intensity incident on the reference surface, so that the illumination uniformity of the lighting system in its life cycle can meet the control requirements. The illuminance uniformity in the entire life cycle of the lighting system is pre-compensated. While achieving uniform compensation, the life cycle of uniform compensation is extended to reduce costs, improve reliability, and reduce manufacturing costs and technical difficulties. The plate is rotated around the central axis to switch the compensation position, reducing the movable mechanism and optimizing the control strategy.

Description

光刻機照度均勻性補償方法及裝置、照明系統及光刻機Illumination uniformity compensation method and device for lithography machine, lighting system and lithography machine

本發明係關於光刻領域，尤其是關於一種光刻機照度均勻性補償方法及裝置、照明系統及光刻機。 The present invention relates to the field of lithography, in particular to a method and device for compensating illumination uniformity of a lithography machine, an illumination system and a lithography machine.

投影式光刻機是一種將遮罩面圖案轉移到基板面/矽片面形成所需要的圖案，進而集成出需要的面板/集成電路(IC)的設備。投影式光刻機中的曝光系統主要承擔遮罩圖形的精確投影與曝光等任務。其中，照明系統為光刻機遮罩面提供均勻的照明光斑，是投影式光刻機的能量來源，遮罩面的光斑能量和照度均勻性是照明系統的重要指標，光斑能量的大小決定了光刻機的產率，而照度均勻性決定了投影式光刻機曝光時曝光線條方向性寬度的相對差異，間接地影響到投影式光刻機的分辨率。對於大視場的掃描光學曝光系統，其曝光視場大多為大長寬比的長方形結構，因為曝光視場尺寸的不對稱性，其照度均勻性普遍低於對稱結構的視場。 A projection lithography machine is a device that transfers the mask surface pattern to the substrate surface/silicon wafer surface to form the required pattern, and then integrates the required panel/integrated circuit (IC). The exposure system in the projection lithography machine is mainly responsible for the precise projection and exposure of the mask pattern. Among them, the lighting system provides a uniform illumination spot for the mask surface of the lithography machine, which is the energy source of the projection lithography machine. The spot energy and illumination uniformity of the mask surface are important indicators of the lighting system. The size of the spot energy determines The productivity of the lithography machine, and the uniformity of illumination determines the relative difference in the directional width of the exposure lines when the projection lithography machine is exposed, which indirectly affects the resolution of the projection lithography machine. For a scanning optical exposure system with a large field of view, the exposure field of view is mostly a rectangular structure with a large aspect ratio. Due to the asymmetry of the size of the exposure field of view, the uniformity of illumination is generally lower than that of a symmetrical structure.

投影式光刻機對於曝光視場的照度均勻性有著十分高的要求，為了實現對投影式光刻機的整個生命週期內的照度均勻性進行補償，現有的補償方法通常成本很高，且可靠性較低。 The projection lithography machine has very high requirements for the illumination uniformity of the exposure field of view. In order to compensate the illumination uniformity in the entire life cycle of the projection lithography machine, the existing compensation methods are usually expensive and reliable. low sex.

本發明的目的在於提供一種照度均勻性補償方法及裝置、照明系統及光刻機，在實現均勻補償的同時，延長均勻補償的生命週期。 The purpose of the present invention is to provide an illumination uniformity compensation method and device, an illumination system and a lithography machine, which can extend the life cycle of the uniform compensation while realizing the uniform compensation.

為了達到上述目的，本發明提供了一種照度均勻性補償方法，用於補償光刻機中照明系統的照度均勻性，以調整光刻機的基準面上的照度分布，包括：步驟1、在光刻機定期維護過程中，採集一定時間內由所述照明系統在基準面上產生的照度分布數據；步驟2、根據採集到的所述照度分布數據，獲得基準面上的照度分布隨時間的變化趨勢，建立照明系統中投影物鏡的透過率衰減模型；步驟3、根據基準面上的照度分布和所述投影物鏡的透過率衰減模型，推算在照明系統生命週期內不同時期的基準面上的照度分布；步驟4、根據推算的基準面上的照度分布和期望的基準面上的照度分布，計算出在照明系統生命週期內不同時期下的預補償透過率分布；步驟5、根據多個時期的預補償透過率分布在一補償板上製作多個補償區，所述補償板用於在照明系統生命週期內不同時期下，將對應時期的補償區設置於所述照明系統的補償面上，以對入射至基準面的光強度進行補償。 In order to achieve the above purpose, the present invention provides an illumination uniformity compensation method, which is used for compensating the illumination uniformity of the illumination system in the lithography machine to adjust the illumination distribution on the reference plane of the lithography machine, including: step 1. During the regular maintenance of the engraving machine, the illuminance distribution data generated by the lighting system on the reference plane within a certain period of time are collected; step 2, according to the collected illuminance distribution data, the change of the illuminance distribution on the reference plane with time is obtained Trend, establish the transmittance attenuation model of the projection objective lens in the lighting system; Step 3, according to the illuminance distribution on the datum plane and the transmittance attenuation model of the projection objective lens, calculate the illuminance on the datum plane at different periods in the life cycle of the lighting system distribution; step 4, calculate the pre-compensated transmittance distribution in different periods in the life cycle of the lighting system according to the estimated illuminance distribution on the reference plane and the expected illuminance distribution on the reference plane; step 5, according to the multiple periods of The pre-compensation transmittance is distributed on a compensation board to make a plurality of compensation areas, and the compensation board is used to set the compensation areas of the corresponding period on the compensation surface of the lighting system under different periods in the life cycle of the lighting system, so as to Compensates for the light intensity incident on the reference surface.

可選的，在步驟3中，根據基準面上的照度分布和所述投影物鏡的透過率衰減模型，利用一預補償計算模型，推算在照明系統生命週期內不同時期的基準面上的照度分布，所述預補償計算模型為：

Figure 108123013-A0305-02-0003-1
Optionally, in step 3, according to the illuminance distribution on the datum plane and the transmittance attenuation model of the projection objective lens, a pre-compensation calculation model is used to calculate the illuminance distribution on the datum plane at different periods in the life cycle of the lighting system. , the pre-compensation calculation model is:
Figure 108123013-A0305-02-0003-1

其中，T為所述補償面的透過率分布，MI為補償前補償面上的照度分布，M為補償後基準面上的照度分布，F為從補償面到基準面的能量傳遞函數；其中MI通過

Figure 108123013-A0305-02-0004-3
反卷積得到，Mo為測量得到的補償前基準面上的照度分布。 Among them, T is the transmittance distribution of the compensation surface, MI is the illumination distribution on the compensation surface before compensation, M is the illumination distribution on the reference surface after compensation, and F is the energy transfer function from the compensation surface to the reference surface; pass
Figure 108123013-A0305-02-0004-3
Obtained by deconvolution, Mo is the measured illuminance distribution on the reference plane before compensation.

可選的，通過所述預補償模型得到所述基準面上的透過率分布的步驟包括：沿光刻機的掃描方向將所述補償面離散為垂直於掃描方向的i個平行的第一環帶；沿光刻機的掃描方向將所述基準面離散為垂直於掃描方向的j個平行的第二環帶，其中i>j；沿所述補償面的中心軸開始向外依次計算出每個所述第一環帶上的透過率分布以得到所述補償面的透過率分布。 Optionally, the step of obtaining the transmittance distribution on the reference plane through the pre-compensation model includes: discretizing the compensation plane into i parallel first rings perpendicular to the scanning direction along the scanning direction of the lithography machine. belt; along the scanning direction of the lithography machine, the reference plane is discretized into j parallel second annular belts perpendicular to the scanning direction, where i>j; starting from the central axis of the compensation surface and outwards, calculate each transmittance distribution on the first annular band to obtain the transmittance distribution of the compensation surface.

可選的，所述預補償計算模型可轉換為：

Figure 108123013-A0305-02-0004-2
Optionally, the pre-compensation calculation model can be converted into:
Figure 108123013-A0305-02-0004-2

其中，M1、M2....Mj為基準面的中心軸開始向外的第一個、第二個….第j個第二環帶上的照度分布，T為補償面上的透過率分布，T1、T2....Ti為從補償面的中心軸開始向外的第一個、第二個….第i個第一環帶上的透過率分布，K11....K1j....Ki1....Kij為補償面的第1個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第1個第一環帶在基準面的第j個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第j個第二環帶上的離散係數。 Among them, M1, M2....Mj is the illuminance distribution on the first, second....jth second annular belt from the center axis of the reference plane outward, and T is the transmittance distribution on the compensation surface , T1, T2....Ti is the transmittance distribution on the first, second....i-th first annular belt from the center axis of the compensation surface outward, K11....K1j.. ..Ki1....Kij is the dispersion coefficient of the first first annulus of the compensation plane on the first second annulus of the reference plane....The first first annulus of the compensation plane on the datum plane Dispersion coefficient on the jth second annular zone....Dispersion coefficient of the i-th first annular zone of the compensation surface on the 1st second annular zone of the reference surface....The i-th first annular zone of the compensation surface The dispersion coefficient on the jth second annulus of the datum.

可選的，根據轉換後的預補償計算模型，通過以下公式得到所述補償面上i個第一環帶的透過率分布T1、T2....Ti：

Figure 108123013-A0305-02-0005-4
Optionally, according to the converted pre-compensation calculation model, the transmittance distributions T1, T2....Ti of the i first annular bands on the compensation surface are obtained by the following formula:
Figure 108123013-A0305-02-0005-4

可選的，將對應時期的補償區設置於所述照明系統的補償面上包括：在照明系統位於基準面的照明視場內，沿光刻機掃描方向的兩側位置至少分別布置一個具有相同預補償透過率分布的補償區。 Optionally, arranging the compensation area of the corresponding period on the compensation surface of the illumination system includes: in the illumination field of view of the illumination system located on the reference plane, arranging at least one location on both sides along the scanning direction of the lithography machine with the same Compensation area for pre-compensating transmittance distribution.

本發明還提供了一種實現所述的光刻機照度均勻性補償方法的照度均勻性補償裝置，所述照度均勻性補償裝置包括補償組件、驅動組件及控制組件；所述補償組件包括補償板及設置於所述補償板表面的若干組補償區，每組所述補償區中至少包括兩個補償區，且每組補償區中的所有補償區均沿周向設置並關於所述補償板的軸向對稱且具有相同的透過率分布；所述驅動組件驅動所述補償板繞補償板的中心軸旋轉，所述控制組件根據照度均勻性的控制要求控制所述驅動組件，以將所述補償板中某一組補償區切換入照明系統的照明視場內，使所述照明視場內的照度均勻性滿足控制要求。 The present invention also provides an illumination uniformity compensation device for realizing the illumination uniformity compensation method of a lithography machine. The illumination uniformity compensation device includes a compensation component, a driving component and a control component; the compensation component includes a compensation plate and a Several groups of compensation areas are arranged on the surface of the compensation plate, each group of the compensation areas includes at least two compensation areas, and all the compensation areas in each group of compensation areas are arranged in the circumferential direction and are about the axis of the compensation plate symmetrical and have the same transmittance distribution; the driving component drives the compensation plate to rotate around the central axis of the compensation plate, and the control component controls the driving component according to the control requirements of the uniformity of illumination, so as to rotate the compensation plate A certain group of compensation areas is switched into the lighting field of view of the lighting system, so that the uniformity of illumination in the lighting field of view meets the control requirements.

本發明還提供了一種照明系統，所述照明系統包括沿著光路依次設置的光源、橢球碗組件、耦合透鏡組、石英棒、可變狹縫組件、中繼鏡組及所述的照度均勻性補償裝置，所述照度均勻性補償裝置對所述照 明系統的照度均勻性進行補償，並通過切換所述補償區，使所述照明系統在生命週期內的照度均勻性滿足控制要求。 The present invention also provides an illumination system, which includes a light source, an ellipsoid bowl component, a coupling lens group, a quartz rod, a variable slit component, a relay lens group, and the uniform illumination, which are sequentially arranged along the optical path. Compensation device for illuminance uniformity, the illuminance uniformity compensation device The illuminance uniformity of the lighting system is compensated, and by switching the compensation area, the illuminance uniformity of the lighting system in the life cycle can meet the control requirements.

可選的，所述照度均勻性補償裝置位於所述中繼鏡組的像方視場空間。 Optionally, the illumination uniformity compensation device is located in the image-side field of view space of the relay lens group.

可選的，所述光源及所述耦合透鏡組的物方焦面分別位於所述橢球碗組件的兩個焦點上。 Optionally, the object-side focal planes of the light source and the coupling lens group are respectively located at two foci of the ellipsoid bowl assembly.

可選的，所述可變狹縫組件的狹縫與所述中繼鏡組的物方焦面對準，並且，所述可變狹縫組件與所述石英棒之間的距離小於一閾值。 Optionally, the slit of the variable slit assembly is aligned with the object-side focal plane of the relay lens group, and the distance between the variable slit assembly and the quartz rod is less than a threshold .

本發明還提供了一種光刻機，包括所述照明系統。 The present invention also provides a lithography machine, including the lighting system.

在本發明提供的光刻機照度均勻性補償方法中，通過採集一定時間內光刻機的基準面上的照度分布數據，建立投影物鏡的透過率衰減模型，以推算在照明系統生命週期內不同時期的基準面上的照度分布，根據推算的基準面上的照度分布和期望的基準面上的照度分布，計算出照明系統生命週期內不同時期下的預補償透過率分布，然後根據多個時期的預補償透過率分布在補償板上製作補償區，以在照明系統生命週期內不同時期下，將對應時期的補償區設置於照明系統的補償面上，對入射至基準面的光強度進行補償，使照明系統在其生命週期內的照度均勻性滿足控制要求，通過增加補償位置，實現對照明系統整個生命週期內的照度均勻性進行預補償，在實現均勻補償的同時，延長均勻補償的生命週期，以降低成本、提高可靠性、降低了製造成本及技術難度，並且，由於所述補償板是通過繞中心軸旋轉以切換補償位置的，減少可動機構，優化了控制策略。 In the method for compensating the illumination uniformity of the lithography machine provided by the present invention, the transmittance attenuation model of the projection objective lens is established by collecting the illuminance distribution data on the reference plane of the lithography machine within a certain period of time, so as to calculate the difference in the illumination system life cycle. The illuminance distribution on the datum plane of the period, according to the estimated illuminance distribution on the datum plane and the expected illuminance distribution on the datum plane, calculate the pre-compensation transmittance distribution in different periods in the life cycle of the lighting system, and then according to multiple periods The pre-compensated transmittance of the luminaire is distributed on the compensation plate to make a compensation area, so that the compensation area of the corresponding period is set on the compensation surface of the lighting system under different periods of the life cycle of the lighting system to compensate the light intensity incident on the reference surface. , so that the illumination uniformity of the lighting system in its life cycle meets the control requirements, and by adding compensation positions, pre-compensation for the illumination uniformity in the entire life cycle of the lighting system is realized, and the life of uniform compensation is extended while achieving uniform compensation. cycle to reduce cost, improve reliability, reduce manufacturing cost and technical difficulty, and because the compensation plate is rotated around the central axis to switch the compensation position, the movable mechanism is reduced, and the control strategy is optimized.

1:補償板 1: Compensation board

11:補償區 11: Compensation area

201:光源 201: Light Source

202:橢球碗組件 202: Ellipsoid Bowl Assembly

203:耦合透鏡組 203: Coupling lens group

204:石英棒 204: Quartz Rod

205:可變狹縫組件 205: Variable slit assembly

206:中繼鏡組 206: Relay lens group

207:照度均勻性補償裝置 207: Illumination uniformity compensation device

S1~S5:步驟 S1~S5: Steps

圖1a-圖1c為本發明實施例提供的三種補償板的示意圖；圖2為本發明實施例提供的照度均勻性補償裝置的形成方法的一流程圖；圖3為本發明實施例提供的照度均勻性補償裝置的形成方法的又一流程圖；圖4為本發明實施例提供的當前基板上的照度分布的一示意圖；圖5為本發明實施例提供的當前基板上的照度分布的又一示意圖；圖6為本發明實施例提供的當前補償面上的透過率分布的示意圖；圖7為本發明實施例提供的預期透過率分布的示意圖；圖8為本發明實施例提供的設計補償板的補償區的示意圖；圖9為本發明實施例提供的補償後基板上的照度分布的示意圖；圖10為本發明實施例提供的預補償計算模型的示意圖；圖11為本發明實施例提供的補償板環帶劃分的示意圖；圖12為本發明實施例提供的補償板透過率分布的計算原理的示意圖；圖13為本實施例提供的照明系統的示意圖。 1a-1c are schematic diagrams of three compensation plates provided by an embodiment of the present invention; FIG. 2 is a flowchart of a method for forming an illumination uniformity compensation device provided by an embodiment of the present invention; FIG. 3 is an illumination intensity provided by an embodiment of the present invention. Another flowchart of a method for forming a uniformity compensation device; FIG. 4 is a schematic diagram of the illuminance distribution on the current substrate provided by an embodiment of the present invention; FIG. 5 is another example of the illuminance distribution on the current substrate provided by the present invention. Schematic diagram; FIG. 6 is a schematic diagram of transmittance distribution on the current compensation surface provided by an embodiment of the present invention; FIG. 7 is a schematic diagram of an expected transmittance distribution provided by an embodiment of the present invention; FIG. 8 is a design compensation plate provided by an embodiment of the present invention. Figure 9 is a schematic diagram of the illuminance distribution on the substrate after compensation provided by an embodiment of the present invention; Figure 10 is a schematic diagram of a pre-compensation calculation model provided by an embodiment of the present invention; Figure 11 is provided by an embodiment of the present invention. Figure 12 is a schematic diagram of the calculation principle of the transmittance distribution of the compensation plate provided by the embodiment of the present invention; Figure 13 is a schematic diagram of the lighting system provided by the present embodiment.

下面將結合示意圖對本發明的具體實施方式進行更詳細的描述。根據下列描述和申請專利範圍，本發明的優點和特徵將更清楚。需說明的是，附圖均採用非常簡化的形式且均使用非精準的比例，僅用以方便、明晰地輔助說明本發明實施例的目的。 The specific embodiments of the present invention will be described in more detail below with reference to the schematic diagrams. The advantages and features of the present invention will become more apparent from the following description and the scope of the claims. It should be noted that, the accompanying drawings are all in a very simplified form and in inaccurate scales, and are only used to facilitate and clearly assist the purpose of explaining the embodiments of the present invention.

為了提高光刻機的照度均勻性，可以採用以下三種方法進行照度均勻性補償：第一種照度均勻性補償方案為採用在補償板上鍍鉻，對基準面的能量分布進行調整，但考慮到光刻機的照明系統中的光學鏡片在 長期的使用過程中存在持續不斷的透過率衰減，此種補償方案的生命週期相對於照明系統的整體生命週期過短，需要不斷更換補償板，製造成本較高；第二種照度均勻性補償方案為採用擋片伸縮，得到不同的光路去除量，以實現照度均勻性補償，但對於每個擋片均需設計可動機構，且可動機構的運動範圍和控制精度直接決定均勻性補償的範圍和補償的精度，這極大地增加了成本、設計難度和可靠性風險，第三種照度均勻性補償方案為通過至少兩塊透過率分布為高階次曲線的補償板，相互疊加使用，但這種方案與第二種方案一樣，均需要設計可動機構，存在諸多設計和應用成本的缺點。 In order to improve the illumination uniformity of the lithography machine, the following three methods can be used to compensate the illumination uniformity: the first illumination uniformity compensation scheme is to use chrome plating on the compensation plate to adjust the energy distribution of the reference surface, but considering the light The optical lens in the illumination system of the engraving machine is in There is continuous transmittance attenuation in the long-term use process. The life cycle of this compensation scheme is too short compared to the overall life cycle of the lighting system. The compensation board needs to be replaced continuously, and the manufacturing cost is high; the second compensation scheme for illuminance uniformity In order to use the expansion and contraction of the baffle to obtain different light path removal amounts to achieve illumination uniformity compensation, but for each baffle, a movable mechanism needs to be designed, and the movement range and control accuracy of the movable mechanism directly determine the range and compensation of uniformity compensation. This greatly increases the cost, design difficulty and reliability risks. The third illumination uniformity compensation scheme is to use at least two compensation plates with transmittance distribution as a high-order curve, which are superimposed on each other, but this scheme is different from Like the second solution, a movable mechanism needs to be designed, and there are many disadvantages of design and application cost.

發明人發現，投影式光刻機的照明視場通常為大長寬比的矩形，且照度均勻性劣化趨勢通常為U字形，所以照度均勻性補償裝置的透過率分布可以設計為與之相反的倒U字形分布。這樣，照度均勻性補償裝置的中心區域的補償量非常小，在一定的範圍內，可以近似認為不需要補償，那麼，所述照度均勻性補償裝置的中心區域無需鍍鉻，可以在所述照度均勻性補償裝置中設計多組補償區。發明人進一步發現，為了設計所述照度均勻性補償裝置的多組補償區，需要長期持續採集所述光刻機的基準面上的照度分布數據，並由長期得到的照度分布數據歸納出投影物鏡透過率衰減趨勢，所述投影物鏡透過率衰減趨勢為隨著時間的推移衰減越大，從所述衰減趨勢可以推算出所述投影物鏡未來可能衰減的趨勢，從而進行預補償，進一步，由於在計算照度均勻性補償裝置的補償板的透過率分布時，會涉及大量的反卷積運算，十分的費時和費力，發明人發現還可以通過合理的近似計算以提高計算效率。 The inventor found that the illumination field of view of the projection lithography machine is usually a rectangle with a large aspect ratio, and the deterioration trend of the illumination uniformity is usually U-shaped, so the transmittance distribution of the illumination uniformity compensation device can be designed to be opposite to it. Inverted U-shaped distribution. In this way, the compensation amount in the central area of the illuminance uniformity compensation device is very small. Within a certain range, it can be approximated that no compensation is required. Then, the central area of the illuminance uniformity compensation device does not need to be chrome-plated, and the illuminance uniformity compensation device can be Multiple sets of compensation zones are designed in the sexual compensation device. The inventor further found that, in order to design multiple sets of compensation areas of the illumination uniformity compensation device, it is necessary to continuously collect the illumination distribution data on the reference plane of the lithography machine for a long time, and summarize the projection objective lens from the illumination distribution data obtained for a long time. The transmittance attenuation trend, the attenuation trend of the transmittance of the projection objective lens is that the attenuation increases with time. From the attenuation trend, the possible attenuation trend of the projection objective lens in the future can be calculated, so as to perform pre-compensation. When calculating the transmittance distribution of the compensation plate of the illuminance uniformity compensation device, a large number of deconvolution operations are involved, which is very time-consuming and labor-intensive.

圖2和圖3為本實施例提供的光刻機照度均勻性補償方法，包括： S1：在光刻機定期維護過程中，採集一定時間內由照明系統在基準面(在本申請實施例中，可以為遮罩面或基板面)上產生的照度分布數據；S2：根據採集到的所述照度分布數據，獲得基準面上的照度分布隨時間的變化趨勢，建立照明系統中投影物鏡的透過率衰減模型；S3：根據基準面上的照度分布和投影物鏡的透過率衰減模型，推算在照明系統生命週期內不同時期的基準面上的照度分布；S4：根據推算的基準面上的照度分布和期望的基準面上的照度分布，計算出在照明系統生命週期內不同時期下的預補償透過率分布；S5：根據多個時期的預補償透過率分布在一補償板上製作多個補償區，所述補償板用於在照明系統生命週期內不同時期下，將對應時期的補償區設置於所述照明系統的補償面(在本申請實施例中，所述補償面位於所述投影物鏡和所述基準面之間)上，以對入射至基準面的光強度進行補償。 FIG. 2 and FIG. 3 provide a method for compensating the illumination uniformity of a lithography machine in this embodiment, including: S1: During the regular maintenance of the lithography machine, collect the illuminance distribution data generated by the lighting system on the reference plane (in the embodiment of the present application, it may be the mask plane or the substrate plane) within a certain period of time; S2: According to the collected The described illuminance distribution data, obtain the variation trend of the illuminance distribution on the reference plane with time, and establish the transmittance attenuation model of the projection objective lens in the lighting system; S3: According to the illuminance distribution on the datum plane and the transmittance attenuation model of the projection objective lens, Calculate the illuminance distribution on the reference plane at different periods in the life cycle of the lighting system; S4: According to the estimated illuminance distribution on the reference plane and the expected illuminance distribution on the reference plane, calculate the illuminance distribution at different periods in the life cycle of the lighting system. Pre-compensation transmittance distribution; S5: Make a plurality of compensation areas on a compensation plate according to the pre-compensation transmittance distribution of multiple periods, and the compensation plate is used for different periods in the life cycle of the lighting system. The area is arranged on the compensation surface of the illumination system (in the embodiment of the present application, the compensation surface is located between the projection objective lens and the reference surface), so as to compensate the light intensity incident on the reference surface.

具體的，請參閱圖3，首先，利用光刻機會定期維護這一情況，持續不斷的採集所述光刻機基準面的照度分布數據，以得到一定時間內光刻機的基準面上的照度分布數據。如圖4所示，圖4中的橫坐標與縱坐標均為位置，可以看出，基準面的中心區域的照度較其邊緣區域照度較高、並且更均勻，通過計算得出，圖中的光刻機的照度均勻性為1.54%。再通過當前基準面上的照度分布結合期望的基準面上的照度分布(照度均勻性指標)，可以推算出所述光刻機在補償後的目標照度分布，如圖5所示。根據所述基準面上當前的照度分布、基準面上期望的照度分布，利用預補償計算模型計算出所述補償板的當前透過率分布，如圖6所示，此時，可以通過 所述補償板的當前透過率分布設計出一組補償區，該組補償區的透過率分布為當前透過率分布。 Specifically, please refer to FIG. 3. First, use the lithography machine to regularly maintain this situation, and continuously collect the illumination distribution data of the reference surface of the lithography machine to obtain the illuminance of the reference surface of the lithography machine within a certain period of time. distribution data. As shown in Figure 4, the abscissa and ordinate in Figure 4 are both positions. It can be seen that the illuminance of the central area of the datum plane is higher and more uniform than that of the edge area. The illumination uniformity of the lithography machine is 1.54%. Then, by combining the illuminance distribution on the current reference plane with the illuminance distribution on the desired reference plane (illuminance uniformity index), the compensated target illuminance distribution of the lithography machine can be calculated, as shown in FIG. 5 . According to the current illuminance distribution on the reference surface and the expected illuminance distribution on the reference surface, the current transmittance distribution of the compensation plate is calculated by using the pre-compensation calculation model, as shown in FIG. A group of compensation areas are designed for the current transmittance distribution of the compensation plate, and the transmittance distribution of the group of compensation areas is the current transmittance distribution.

接下來，根據採集到的基準面上的照度分布隨時間的變化趨勢，建立如圖1所示的投影物鏡的透過率衰減模型，本實施例中，所述一定時間可以為一個月或者一年，不限於此。然後根據當前基準面上的照度分布及所述投影物鏡的衰減模型可以推算出在所述光刻機的生命週期內，不同時期的基準面上的照度分布，然後根據推算的基準面上的照度分布和期望的基準面上的照度分布，利用預補償計算模型，計算出光刻機生命週期內不同時期下的預補償透過率分布，然後將多個時期的預補償透過率分布在補償板上製作補償區，圖7為其中一個補償區的預補償透過率分布圖。 Next, the transmittance attenuation model of the projection objective lens as shown in FIG. 1 is established according to the variation trend of the illuminance distribution on the collected reference surface with time. In this embodiment, the certain period of time may be one month or one year. , not limited to this. Then, according to the illuminance distribution on the current datum plane and the attenuation model of the projection objective lens, the illuminance distribution on the datum plane in different periods in the life cycle of the lithography machine can be calculated, and then according to the calculated illuminance on the datum plane Distribution and the expected illuminance distribution on the reference plane, use the pre-compensation calculation model to calculate the pre-compensation transmittance distribution in different periods in the life cycle of the lithography machine, and then distribute the pre-compensation transmittance of multiple periods on the compensation plate A compensation area is made, and FIG. 7 is a pre-compensated transmittance distribution diagram of one of the compensation areas.

可選的，在照射至基準面的照明視場內，沿光刻機掃描方向的兩側至少分別布置一個具有相同預補償透過率分布的補償區，以對照明視場的照度均勻性進行補償，當然，也可以布置多個補償區，實現不同的補償效果。 Optionally, in the illumination field of view irradiated to the reference plane, at least one compensation area with the same pre-compensated transmittance distribution is arranged on both sides along the scanning direction of the lithography machine to compensate the illumination uniformity of the illumination field of view. , of course, multiple compensation areas can also be arranged to achieve different compensation effects.

接著，請參閱圖8，結合如圖6所示的所述補償板的當前透過率分布及如圖7所示的所述補償板的預補償透過率分布，在補償板上製作補償區，並在光刻機生命週期內不同時期下，將對應時期的補償區設置於曝光光路的補償面上，對入射至基準面的光強度進行補償。此時，根據圖9所示，對所述光刻機的照度均勻性進行補償後，所述光刻機的照度均勻性為0.89%，較補償前的1.54%提高了0.65%。 Next, referring to FIG. 8 , in combination with the current transmittance distribution of the compensation plate as shown in FIG. 6 and the pre-compensated transmittance distribution of the compensation plate as shown in FIG. 7 , a compensation area is fabricated on the compensation plate, and In different periods in the life cycle of the lithography machine, the compensation area of the corresponding period is set on the compensation surface of the exposure optical path to compensate the light intensity incident on the reference surface. At this time, as shown in FIG. 9 , after compensating the illuminance uniformity of the lithography machine, the illuminance uniformity of the lithography machine is 0.89%, which is 0.65% higher than the 1.54% before compensation.

進一步，如圖10所示，所述預補償計算模型為：

Figure 108123013-A0305-02-0010-5
Further, as shown in Figure 10, the pre-compensation calculation model is:
Figure 108123013-A0305-02-0010-5

Figure 108123013-A0305-02-0010-6
Figure 108123013-A0305-02-0010-6

其中，F為從補償面到基準面的能量傳遞函數，通過仿真得到；Mo為測量得到基準面在補償前的照度分布，MI為所述補償面在補償前的照度分布，通過公式2反卷積(deconvolution)求出；M為基準面在補償後的照度分布，由照度均勻性指標推算出，通常可以作為公式1的輸入矩陣，T為所述補償板的透過率分布，通過公式1反卷積求出，通常可以作為公式1的輸出矩陣。採用直接反卷積求出補償板的透過率分布T為一個連續的函數圖形，需要通過多次反卷積計算，計算效率較低。 Among them, F is the energy transfer function from the compensation surface to the reference surface, obtained by simulation; Mo is the illuminance distribution of the reference surface before compensation obtained by measurement, MI is the illuminance distribution of the compensation surface before compensation, which is reversed by formula 2 The product (deconvolution) is obtained; M is the illuminance distribution of the reference plane after compensation, which is calculated from the illuminance uniformity index, which can usually be used as the input matrix of formula 1, and T is the transmittance distribution of the compensation plate, which is reversed by formula 1. The convolution is obtained, which can usually be used as the output matrix of Equation 1. The transmittance distribution T of the compensation plate is obtained by direct deconvolution as a continuous function graph, which requires multiple deconvolution calculations, and the calculation efficiency is low.

發明人發現，由於所述投影式光刻機的照明系統的照度均勻性，對於靜態均勻性要求較低，其照明視場均為大長寬比的矩形視場，其照度分布存在中間低，四周高的一般性規律，根據預補償計算模型的計算原理，本實施例採用另一種環帶補償法進行補償面上透過率分布的計算。首先沿光刻機的掃描方向對所述補償面及基準面劃分垂直於掃描方向的平行的環帶，所述補償面上具有i個第一環帶，所述基準面上具有j個第二環帶，所述i>j，所述補償面的第一環帶內部做勻化處理，所述第一環帶之間進行離散補償，如圖11所示，只要所述第一環帶及所述第二環帶劃分足夠密集，就可以保證補償精度，同時提高計算效率。圖11為所述補償板的環帶計算原理的示意圖，採用如圖11所示的高效率的近似計算方法，可以簡化反卷積運算，該方法通過由內向外，迭代求解的方式，獲得離散的透過率分布。 The inventor found that due to the uniformity of illumination of the illumination system of the projection lithography machine, the requirement for static uniformity is low, the illumination field of view is a rectangular field of view with a large aspect ratio, and the illumination distribution is low in the middle. According to the general law of the surrounding height, according to the calculation principle of the pre-compensation calculation model, this embodiment adopts another annular compensation method to calculate the transmittance distribution on the compensation surface. First, along the scanning direction of the lithography machine, the compensation surface and the reference surface are divided into parallel annular bands perpendicular to the scanning direction, the compensation surface has i first annular bands, and the reference surface has j second annular bands For the endless belt, i>j, the first endless belt of the compensation surface is homogenized inside, and discrete compensation is performed between the first endless belts, as shown in Figure 11, as long as the first endless belt and If the second annular zone is sufficiently densely divided, the compensation accuracy can be ensured, and the calculation efficiency can be improved at the same time. Fig. 11 is a schematic diagram of the calculation principle of the annular band of the compensation plate. The deconvolution operation can be simplified by using the high-efficiency approximate calculation method as shown in Fig. 11. This method obtains discrete transmittance distribution.

具體的，請繼續參閱圖12，通過離散和仿真，將所述預補償計算模型簡化為一般運算：

Figure 108123013-A0305-02-0011-7
Specifically, please continue to refer to Fig. 12. Through discretization and simulation, the pre-compensation calculation model is simplified to general operations:
Figure 108123013-A0305-02-0011-7

其中，矩陣[M]中的M1、M2....Mj為基準面的中心軸開始向外的第一個、第二個….第j個第二環帶上的照度分布，T為補償面上的透過率分布，矩陣[T]中的T1、T2....Ti為從補償面的中心軸開始向外的第一個、第二個….第i個第一環帶上的透過率分布，[K]中的K11....K1j....Ki1....Kij為補償面的第1個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第1個第一環帶在基準面的第j個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第j個第二環帶上的離散係數；其中，矩陣[M]可以通過測量得到，矩陣[K]可以通過仿真得到。 Among them, M1, M2....Mj in the matrix [M] is the illuminance distribution on the first, second....jth second ring belt from the central axis of the reference plane outward, and T is the compensation The transmittance distribution on the surface, T1, T2....Ti in the matrix [T] are the first, second....i-th first ring belt from the center axis of the compensation surface outwards Transmission distribution, K11....K1j....Ki1....Kij in [K] is the dispersion of the first first annular zone of the compensation surface on the first second annular zone of the reference surface Coefficient....Dispersion coefficient of the 1st first ring zone of the compensation surface on the jth second ring zone of the reference surface....The i-th first ring zone of the compensation surface is on the 1st second ring of the reference surface Discrete coefficient on the belt....Discrete coefficient of the i-th first annular belt of the compensation surface on the j-th second annular belt of the reference plane; wherein, the matrix [M] can be obtained by measurement, and the matrix [K] can be obtained by Simulation is obtained.

公式(3)可聯立成以下方程組：

Figure 108123013-A0305-02-0012-8
Formula (3) can be combined into the following equations:
Figure 108123013-A0305-02-0012-8

又因為i>j，[K]矩陣有秩，可以通過循環迭代法或最小二乘法求解方程組(4)的最小殘差解T1、T2....Ti，最終獲得所述補償面上的透過率分布[Ti]。這種計算所述補償板透過率分布的方法效率極高，並且，只要環帶劃分足夠密集，就可以保證補償精度。 And because i>j, the [K] matrix has rank, the minimum residual solutions T1, T2....Ti of the equation system (4) can be solved by the loop iteration method or the least square method, and finally the compensation surface can be obtained. Transmission distribution [Ti]. This method of calculating the transmittance distribution of the compensation plate is extremely efficient, and as long as the annulus is divided sufficiently densely, the compensation accuracy can be guaranteed.

有鑑於此，本實施例提供了一種實現光刻機照度均勻性補償方法的照度均勻性補償裝置，請參閱圖1a-圖1c，所述照度均勻性補償裝置包括補償組件、驅動組件及控制組件；所述補償組件包括補償板1及設置於所述補償板表面的若干組補償區，每組所述補償區11中至少有兩個補償區 11，且每組補償區11中的所有補償區11均沿周向設置並關於所述補償板的軸向對稱且具有相同的透過率分布；所述驅動組件驅動所述補償板繞補償板的中心軸旋轉，所述控制組件根據照度均勻性的控制要求控制所述驅動組件，以將所述補償板中某一組補償區11切換入照明視場內，使所述照明視場內的照度均勻性滿足控制要求。 In view of this, the present embodiment provides an illumination uniformity compensation device for realizing a method for compensating the illumination uniformity of a lithography machine. Please refer to FIGS. 1a-1c. The illumination uniformity compensation device includes a compensation component, a driving component and a control component ; The compensation assembly includes a compensation plate 1 and several groups of compensation areas arranged on the surface of the compensation plate, and each group of the compensation areas 11 has at least two compensation areas 11, and all the compensation regions 11 in each group of compensation regions 11 are arranged in the circumferential direction and are symmetrical about the axial direction of the compensation plate and have the same transmittance distribution; the driving component drives the compensation plate around the compensation plate. The central axis rotates, and the control assembly controls the drive assembly according to the control requirements of the uniformity of illuminance, so as to switch a certain group of compensation areas 11 in the compensation plate into the illumination field of view, so that the illuminance in the illumination field of view is The uniformity meets the control requirements.

具體的，如圖1a所示，所述補償板1呈方形，在所述補償板1的上表面設置有兩組補償區11，每組所述補償區11中的兩個補償區11沿著周向對稱設置，並且具有相同的透過率分布。進一步，兩組所述補償區11中的4個補償區11分別位於所述補償板1的四邊上，圖1a中示意性的展示出了所述照度均勻性補償裝置的一個補償位置，該補償板1的補償位置以90度角設置，當所述補償板1繞其中心軸旋轉90度後為所述補償板1的另一補償位置，當所述兩組補償區11的透過率分布不同時，所述補償板1的兩個補償位置具有不同的透過率分布。請參閱圖1b，與圖1a不同的是，圖1b中的補償板1呈矩形，所述補償區11相鄰設置，該補償板1的補償位置不以90度設置，當所述補償板1旋轉設定好的角度時，所述補償板1從圖1b中的一個補償位置切換至下一個補償位置，相較於圖1a中的補償板1，圖1b中的補償板1結構更緊湊。請參閱圖1c，所述補償板1還可以設置4組補償區11，其具有4個補償位置，所述4個補償位置不再以90度角設置，而是以45度角設置，所述4組補償區11均周向對稱設置，所述補償板1每旋轉45度時，實現補償位置的切換。當然，所述補償板1不限於圖1a-1c中的三種情況，所述補償板1上的補償區11還可有更多的設置方式，以形成更多的補償位置，實現對照明系統的未來可能衰減的趨勢進行預補償，以延長所述照度均勻性補償裝置的生命週期，此處不再一一舉例。 Specifically, as shown in FIG. 1a, the compensation plate 1 is square, and two sets of compensation areas 11 are provided on the upper surface of the compensation plate 1. The two compensation areas 11 in each group of the compensation areas 11 are along the Circumferentially symmetrically arranged and have the same transmittance distribution. Further, the four compensation regions 11 in the two groups of the compensation regions 11 are respectively located on the four sides of the compensation plate 1 . FIG. 1a schematically shows a compensation position of the illumination uniformity compensation device. The compensation position of the plate 1 is set at an angle of 90 degrees. When the compensation plate 1 is rotated 90 degrees around its central axis, it is another compensation position of the compensation plate 1. When the transmittance distributions of the two groups of compensation areas 11 are different , the two compensation positions of the compensation plate 1 have different transmittance distributions. Please refer to FIG. 1b. The difference from FIG. 1a is that the compensation plate 1 in FIG. 1b is rectangular, the compensation areas 11 are arranged adjacent to each other, and the compensation position of the compensation plate 1 is not set at 90 degrees. When the set angle is rotated, the compensation plate 1 switches from one compensation position in FIG. 1 b to the next compensation position. Compared with the compensation plate 1 in FIG. 1 a , the compensation plate 1 in FIG. 1 b has a more compact structure. Please refer to FIG. 1c, the compensation plate 1 can also be provided with 4 groups of compensation areas 11, which have 4 compensation positions, and the 4 compensation positions are no longer set at an angle of 90 degrees, but are set at an angle of 45 degrees. The four sets of compensation areas 11 are all arranged symmetrically in the circumferential direction, and the compensation position is switched every time the compensation plate 1 rotates by 45 degrees. Of course, the compensation plate 1 is not limited to the three situations shown in Figs. 1a-1c, and the compensation area 11 on the compensation plate 1 can also be set in more ways to form more compensation positions and realize the improvement of the lighting system. In the future, pre-compensation is performed to prolong the life cycle of the illumination uniformity compensation device, which will not be exemplified here.

進一步，為了實現所述補償板1的轉動，所述照度均勻性補償裝置還包括驅動組件及控制組件，所述驅動組件用於驅動所述補償板繞其中心軸旋轉，所述控制組件用於根據所述照度均勻性的控制要求控制所述驅動組件，例如，當所述補償位置為45度角布置時，所述控制組件控制所述驅動組件每次旋轉45度，以切換所述補償位置。 Further, in order to realize the rotation of the compensation plate 1, the illumination uniformity compensation device further includes a driving component and a control component, the driving component is used for driving the compensation plate to rotate around its central axis, and the control component is used for The driving assembly is controlled according to the control requirement of the uniformity of the illuminance. For example, when the compensation position is arranged at an angle of 45 degrees, the control assembly controls the driving assembly to rotate 45 degrees each time to switch the compensation position .

請參閱圖13，本實施例還提供了一種照明系統，所述照明系統包括沿著光路依次排列的光源201、橢球碗組件202、耦合透鏡組203、石英棒204、可變狹縫組件205(Varieble Slit，VS組件)、中繼鏡組206、所述照度均勻性補償裝置207及遮罩面，所述照度均勻性補償裝置207對所述照明系統的照度均勻性進行補償，並通過將所述補償板中某一組補償區切換入照明視場內，使所述照明系統在其生命週期內的照度均勻性滿足控制要求。 Referring to FIG. 13 , this embodiment also provides an illumination system, which includes a light source 201 , an ellipsoid bowl assembly 202 , a coupling lens group 203 , a quartz rod 204 , and a variable slit assembly 205 arranged in sequence along the optical path. (Varieble Slit, VS component), the relay lens group 206, the illuminance uniformity compensation device 207 and the mask surface, the illuminance uniformity compensation device 207 compensates the illuminance uniformity of the lighting system, and by applying A certain group of compensation areas in the compensation board is switched into the illumination field of view, so that the illumination uniformity of the illumination system in its life cycle can meet the control requirements.

具體的，所述光源201可以為一汞燈，所述光源201發出的光線由所述橢球碗組件202收集彙聚到焦面位置，所述耦合透鏡組203具有多0個光學鏡片，所述光源201處於所述橢球碗組件202的第一焦點，所述耦合透鏡組203的物方焦面處於所述橢球碗組件202的第二焦點，所述耦合透鏡組203的像方焦面與所述石英棒204的前端面對齊，以將所述橢球碗組件202彙聚的光線按照一定的NA耦合進入所述石英棒204，光線在所述石英棒204中多次反射，在所述石英棒204的後端面輸出均勻光斑，所述均勻光斑的尺寸等於勻光石英棒的後端面尺寸，所述石英棒204的後端面與所述可變狹縫組件205之間的距離小於一閾值，即在安全範圍內，所述石英棒204的後端面盡可能靠近所述可變狹縫組件205的可動刀口平面，所述可動刀口平面與所述中繼鏡組206的物方焦面對齊，所述可變狹縫組件205負責掃描視場的截取和掃描功能，將所述可變狹縫組件205的視場窗口投影放大到所 述中繼鏡組206的像方焦面，形成滿足需求的照明視場，供後續光學系統使用。所述照度均勻性補償裝置207位於所述中繼鏡組206的像方光路空間，遮罩面之前，處於合適的離焦位置。所述照度均勻性補償裝置207可以具有多個補償位置(多組補償區)，根據所述照度均勻性的控制要求旋轉所述補償板，以將合適的某組補償區切換入所述照明視場，使所述照明系統在其生命週期內的照度均勻性滿足控制要求。 Specifically, the light source 201 can be a mercury lamp, and the light emitted by the light source 201 is collected and concentrated by the ellipsoid bowl assembly 202 to the focal plane position, the coupling lens group 203 has more than 0 optical lenses, the The light source 201 is at the first focal point of the ellipsoid bowl assembly 202 , the object-side focal plane of the coupling lens group 203 is at the second focal point of the ellipsoid bowl assembly 202 , and the image-side focal plane of the coupling lens group 203 Align with the front face of the quartz rod 204 to couple the light gathered by the ellipsoid bowl assembly 202 into the quartz rod 204 according to a certain NA. The rear face of the quartz rod 204 outputs a uniform light spot, the size of the uniform light spot is equal to the size of the rear face of the even light quartz rod, and the distance between the rear face of the quartz rod 204 and the variable slit assembly 205 is less than one The threshold value, that is, within a safe range, the rear end surface of the quartz rod 204 is as close as possible to the movable knife edge plane of the variable slit assembly 205 , and the movable knife edge plane and the object focal plane of the relay lens group 206 Alignment, the variable slit assembly 205 is responsible for the interception and scanning functions of the scanning field of view, and the field of view window of the variable slit assembly 205 is projected and enlarged to all The image-side focal plane of the relay lens group 206 is used to form an illumination field of view that meets the requirements and is used by the subsequent optical system. The illuminance uniformity compensating device 207 is located in the image-side optical path space of the relay lens group 206, before the mask surface, at a suitable defocus position. The illumination uniformity compensation device 207 may have multiple compensation positions (multiple sets of compensation areas), and the compensation plate is rotated according to the control requirements of the illumination uniformity, so as to switch an appropriate group of compensation areas into the illumination view. field, so that the illumination uniformity of the lighting system in its life cycle can meet the control requirements.

綜上，在本發明實施例提供的光刻機照度均勻性補償方法中，通過採集一定時間內光刻機的基準面上的照度分布數據，建立投影物鏡的透過率衰減模型，以推算在照明系統生命週期內不同時期的基準面上的照度分布，根據推算的基準面上的照度分布和期望的基準面上的照度分布，計算出照明系統生命週期內不同時期下的預補償透過率分布，然後根據多個時期的預補償透過率分布在補償板上製作補償區，以在照明系統生命週期內不同時期下，將對應時期的補償區設置於曝光光路的補償面上，對入射至基準面的光強度進行補償，使照明系統在其生命週期內的照度均勻性滿足控制要求，通過增加補償位置，實現對照明系統整個生命週期內的照度均勻性進行預補償，在實現均勻補償的同時，延長均勻補償的生命週期，以降低成本、提高可靠性、降低了製造成本及技術難度，並且，由於所述補償板是通過繞中心軸旋轉以切換補償位置的，減少可動機構，優化了控制策略。 To sum up, in the illumination uniformity compensation method of the lithography machine provided by the embodiment of the present invention, the transmittance attenuation model of the projection objective lens is established by collecting the illumination distribution data on the reference plane of the lithography machine for a certain period of time, so as to estimate the illumination intensity of the lithography machine. The illuminance distribution on the datum plane at different periods in the system life cycle, according to the calculated illuminance distribution on the datum plane and the expected illuminance distribution on the datum plane, calculate the pre-compensation transmittance distribution in different periods in the life cycle of the lighting system, Then, according to the pre-compensated transmittance distribution of multiple periods, a compensation area is made on the compensation plate, so that the compensation area of the corresponding period is set on the compensation surface of the exposure optical path under different periods in the life cycle of the lighting system, and the incident light to the reference plane is not affected. The illuminance uniformity of the lighting system in its life cycle can meet the control requirements. By increasing the compensation position, the pre-compensation of the illuminance uniformity in the entire life cycle of the lighting system can be realized. While achieving uniform compensation, Extend the life cycle of uniform compensation to reduce cost, improve reliability, reduce manufacturing cost and technical difficulty, and because the compensation plate is rotated around the central axis to switch the compensation position, the movable mechanism is reduced, and the control strategy is optimized .

上述僅為本發明的優選實施例而已，並不對本發明起到任何限制作用。任何所屬技術領域的技術人員，在不脫離本發明的技術方案的範圍內，對本發明揭露的技術方案和技術內容做任何形式的等同替換或修改等變動，均屬未脫離本發明的技術方案的內容，仍屬於本發明的保護範圍之內。 The above are only preferred embodiments of the present invention, and do not have any limiting effect on the present invention. Any person skilled in the art, within the scope of not departing from the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, and does not depart from the technical solution of the present invention. content still falls within the protection scope of the present invention.

S1~S5‧‧‧步驟 Steps S1~S5‧‧‧

Claims (12)

一種光刻機照度均勻性補償方法，其為用於補償光刻機中照明系統的照度均勻性，以調整光刻機的基準面上的照度分布，所述光刻機照度均勻性補償方法的特徵在於包括：步驟1、在光刻機定期維護過程中，採集一定時間內由所述照明系統在基準面上產生的照度分布數據；步驟2、根據採集到的所述照度分布數據，獲得基準面上的照度分布隨時間的變化趨勢，建立照明系統中投影物鏡的透過率衰減模型；步驟3、根據基準面上的照度分布和所述投影物鏡的透過率衰減模型，推算在照明系統生命週期內不同時期的基準面上的照度分布；步驟4、根據推算的基準面上的照度分布和期望的基準面上的照度分布，計算出在照明系統生命週期內不同時期下的預補償透過率分布；步驟5、根據多個時期的預補償透過率分布在一補償板上製作若干組補償區，所述補償板用於在照明系統生命週期內不同時期下，將對應時期的補償區設置於所述照明系統的補償面上，以對入射至基準面的光強度進行補償；其中，補償組件包括所述補償板及設置於所述補償板表面的所述若干組補償區，每組所述補償區中至少有兩個補償區，且每組補償區中的所有補償區均沿周向設置並關於所述補償板的軸向對稱且具有相同的透過率分布。 A method for compensating illuminance uniformity of a lithography machine, which is used to compensate the illuminance uniformity of an illumination system in a lithography machine to adjust the illuminance distribution on a reference plane of the lithography machine. It is characterized by comprising: step 1, in the regular maintenance process of the lithography machine, collect the illuminance distribution data generated by the lighting system on the reference plane within a certain period of time; step 2, obtain the reference according to the collected illuminance distribution data The change trend of the illuminance distribution on the surface with time is used to establish the transmittance attenuation model of the projection objective lens in the lighting system; step 3, according to the illuminance distribution on the reference surface and the transmittance attenuation model of the projection objective lens, calculate the life cycle of the lighting system Calculate the illuminance distribution on the datum surface in different periods in the past; Step 4, according to the calculated illuminance distribution on the datum surface and the expected illuminance distribution on the datum surface, calculate the pre-compensation transmittance distribution in different periods in the life cycle of the lighting system ; Step 5, according to the pre-compensation transmittance distribution of multiple periods, make several groups of compensation areas on a compensation plate, and the compensation plate is used to set the compensation areas of the corresponding period in all the different periods in the life cycle of the lighting system. The compensation surface of the illumination system is used to compensate the light intensity incident on the reference surface; wherein, the compensation component includes the compensation plate and the several groups of compensation areas arranged on the surface of the compensation plate, and each group of the compensation There are at least two compensation regions in the region, and all compensation regions in each group of compensation regions are arranged in the circumferential direction and symmetrical with respect to the axial direction of the compensation plate and have the same transmittance distribution. 如請求項1所述的光刻機照度均勻性補償方法，其中在步驟3中，根據基準面上的照度分布和所述投影物鏡的透過率衰減模型，利用一預補償計算模型，推算在照明系統生命週期內不同時期的基準面上的照度分布，所述預補償計算模型為：
Figure 108123013-A0305-02-0018-9
 其中，T為所述補償面的透過率分布，MI為補償前補償面上的照度分布，M為補償後基準面上的照度分布，F為從補償面到基準面的能量傳遞函數；其中MI通過
Figure 108123013-A0305-02-0018-11
反卷積得到，Mo為測量得到的補償前基準面上的照度分布。 The illumination uniformity compensation method for a lithography machine according to claim 1, wherein in step 3, according to the illumination distribution on the reference plane and the transmittance attenuation model of the projection objective, a pre-compensation calculation model is used to calculate the illumination The illuminance distribution on the reference plane at different periods in the system life cycle, the pre-compensation calculation model is:
Figure 108123013-A0305-02-0018-9
 Among them, T is the transmittance distribution of the compensation surface, MI is the illumination distribution on the compensation surface before compensation, M is the illumination distribution on the reference surface after compensation, and F is the energy transfer function from the compensation surface to the reference surface; pass
Figure 108123013-A0305-02-0018-11
Obtained by deconvolution, Mo is the measured illuminance distribution on the reference plane before compensation. 如請求項2所述的光刻機照度均勻性補償方法，其中通過所述預補償模型得到所述基準面上的透過率分布的步驟包括：沿光刻機的掃描方向將所述補償面離散為垂直於掃描方向的i個平行的第一環帶；沿光刻機的掃描方向將所述基準面離散為垂直於掃描方向的j個平行的第二環帶，其中i>j；沿所述補償面的中心軸開始向外依次計算出每個所述第一環帶上的透過率分布以得到所述補償面的透過率分布。 The method for compensating illumination uniformity of a lithography machine according to claim 2, wherein the step of obtaining the transmittance distribution on the reference plane by using the pre-compensation model comprises: discretizing the compensation surface along the scanning direction of the lithography machine are i parallel first annular zones perpendicular to the scanning direction; the reference plane is discretized into j parallel second annular zones perpendicular to the scanning direction along the scanning direction of the lithography machine, where i>j; From the center axis of the compensation surface outwards, the transmittance distribution on each of the first annular zones is sequentially calculated to obtain the transmittance distribution of the compensation surface. 如請求項3所述的光刻機照度均勻性補償方法，其中所述預補償計算模型可轉換為：
Figure 108123013-A0305-02-0018-10
 其中，M1、M2....Mj為基準面的中心軸開始向外的第一個、第二個….第j個第二環帶上的照度分布，T為補償面上的透過率分布，T1、T2....Ti為從補償面的中心軸開始向外的第一個、第二個….第i個第一環帶上的透過率分布，K11....K1j....Ki1....Kij為補償面的第1個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第1個第一環帶在基準面 的第j個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第1個第二環帶上的離散係數….補償面的第i個第一環帶在基準面的第j個第二環帶上的離散係數。 The illumination uniformity compensation method for a lithography machine according to claim 3, wherein the pre-compensation calculation model can be converted into:
Figure 108123013-A0305-02-0018-10
 Among them, M1, M2....Mj is the illuminance distribution on the first, second....jth second annular belt from the center axis of the reference plane outward, and T is the transmittance distribution on the compensation surface , T1, T2....Ti are the transmittance distributions on the first, second....i-th first annular belt from the center axis of the compensation surface outward, K11....K1j.. ..Ki1....Kij is the dispersion coefficient of the first first annulus of the compensation surface on the first second annulus of the reference surface....The first first annulus of the compensation surface on the reference surface Dispersion coefficient on the j-th second annular zone....Dispersion coefficient of the i-th first annular zone of the compensation surface on the 1-th second annular zone of the reference surface....The i-th first annular zone of the compensation surface Dispersion coefficient on the jth second annulus of the datum. 如請求項4所述的光刻機照度均勻性補償方法，其係根據轉換後的預補償計算模型，通過以下公式得到所述補償面上i個第一環帶的透過率分布T1、T2....Ti：
Figure 108123013-A0305-02-0019-12
 As claimed in claim 4, the illumination uniformity compensation method of the lithography machine is based on the converted pre-compensation calculation model, and the transmittance distributions T1 and T2 of the i first annular belts on the compensation surface are obtained by the following formula. ...Ti:
Figure 108123013-A0305-02-0019-12
 如請求項1所述的光刻機照度均勻性補償方法，其係將對應時期的補償區設置於所述照明系統的補償面上，包括：在照明系統位於基準面的照明視場內，沿光刻機掃描方向的兩側位置至少分別布置一個具有相同預補償透過率分布的補償區。 The method for compensating the illumination uniformity of a lithography machine according to claim 1, wherein the compensation area of the corresponding period is set on the compensation surface of the illumination system, including: in the illumination field of view where the illumination system is located on the reference surface, along the At least one compensation area with the same pre-compensated transmittance distribution is arranged on both sides of the scanning direction of the lithography machine. 一種實現請求項1至6中任一項所述的光刻機照度均勻性補償方法的照度均勻性補償裝置，其中所述照度均勻性補償裝置包括補償組件、驅動組件及控制組件；所述補償組件包括補償板及設置於所述補償板表面的若干組補償區，每組所述補償區中至少包括兩個補償區，且每組補償區中的所有補償區均沿周向設置並關於所述補償板的軸向對稱且具有相同的透過率分布；所述驅動組件驅動所述補償板繞補償板的中心軸旋轉，所述控制組件根據照度均勻性的控制要求控制所述驅動組件，以將所述補償板中某一組 補償區切換入照明系統的照明視場內，使所述照明視場內的照度均勻性滿足控制要求。 An illumination uniformity compensation device for realizing the illumination uniformity compensation method for a lithography machine according to any one of claims 1 to 6, wherein the illumination uniformity compensation device comprises a compensation component, a driving component and a control component; the compensation The assembly includes a compensation plate and several groups of compensation areas arranged on the surface of the compensation plate, each group of the compensation areas includes at least two compensation areas, and all the compensation areas in each group of compensation areas are arranged in the circumferential direction and are related to all the compensation areas. The axis of the compensation plate is symmetrical and has the same transmittance distribution; the driving component drives the compensation plate to rotate around the central axis of the compensation plate, and the control component controls the driving component according to the control requirements of the uniformity of illumination to Place a certain group of the compensation plates The compensation area is switched into the lighting field of view of the lighting system, so that the uniformity of the illuminance in the lighting field of view meets the control requirements. 一種照明系統，其特徵在於所述照明系統包括：沿著光路依次設置的光源、橢球碗組件、耦合透鏡組、石英棒、可變狹縫組件、中繼鏡組、及如請求項7所述的照度均勻性補償裝置，所述照度均勻性補償裝置對所述照明系統的照度均勻性進行補償，並通過切換所述補償區，使所述照明系統在生命週期內的照度均勻性滿足控制要求。 A lighting system, characterized in that the lighting system comprises: a light source, an ellipsoid bowl component, a coupling lens group, a quartz rod, a variable slit component, a relay lens group, and a light source arranged in sequence along the optical path, and as claimed in claim 7 The illumination uniformity compensation device, the illumination uniformity compensation device compensates the illumination uniformity of the lighting system, and by switching the compensation area, the illumination uniformity of the lighting system in the life cycle can meet the control Require. 如請求項8所述的照明系統，其中所述照度均勻性補償裝置位於所述中繼鏡組的像方視場空間。 The lighting system according to claim 8, wherein the illumination uniformity compensation device is located in the image-side field of view space of the relay lens group. 如請求項8所述的照明系統，其中所述光源及所述耦合透鏡組的物方焦面分別位於所述橢球碗組件的兩個焦點上。 The lighting system according to claim 8, wherein the object-side focal planes of the light source and the coupling lens group are respectively located at two focal points of the ellipsoid bowl assembly. 如請求項10所述的照明系統，其中所述可變狹縫組件的狹縫與所述中繼鏡組的物方焦面對準，並且，所述可變狹縫組件與所述石英棒之間的距離小於一閾值。 The lighting system of claim 10, wherein the slit of the variable slit assembly is aligned with the object-side focal plane of the relay lens group, and the variable slit assembly is aligned with the quartz rod The distance between them is less than a threshold. 一種光刻機，其特徵在於包括：如請求項8至11中任一項所述的照明系統。A lithography machine is characterized by comprising: the lighting system according to any one of claims 8 to 11.
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