Lithography Scanner System and Method for Telecentric Anomaly Calibration of Lithography Scanner System

Abstract

The present invention provides a lithography scanner system and a telecentric anomaly calibration method for a lithography scanner system. The lithography scanner system is provided with a second light source component for emitting a second emitted light between a first light source component and a variable slit component. When the second light source component emits the second emitted light and the measurement unit is irradiated by the second emitted light, the central position of the light spot formed by the second emitted light irradiating on a first measurement component is measured, so as to calculate the telecentricity of the illumination component. In this way, by introducing a second light source component for measuring telecentricity in the lithography scanner system, the interference problem caused by using the first emitted light for lithography to measure the telecentricity of the illumination component is avoided. At the same time, the measurement of telecentricity can be directly completed in the lithography scanner system, so as to improve the measurement and calibration efficiency of telecentricity.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a lithography scanner system and a method for far - center anomaly calibration of a lithography scanner system. Background Art

[0002] With the development of projection lithography technology, the performance of the projection optical system of lithography machines has been gradually improved. Currently, lithography machines have been successfully applied to the field of integrated circuit manufacturing with sub - micron and deep sub - micron resolutions. When manufacturing integrated circuit chips with a lithography machine, it is required that the projection objective lens (PO) has high resolution and good telecentric performance to achieve the preparation of high - integration - degree chips.

[0003] Currently, the telecentric performance of the entire exposure system is composed of the telecentricity of the objective lens, the telecentricity of the illumination component, and the telecentricity caused by the installation position error between the objective lens and the illumination component. The telecentricity of the illumination component is determined by the relative position relationship of each component inside the illumination component. Whether it is in the on - site integration stage of the lithography machine manufacturer, the customer - side integration stage, or the production stage, it is time - consuming and laborious to test the system telecentricity of the entire exposure system and check whether there are anomalies in the telecentricity of each module and component.

[0004] In the prior art, when performing telecentricity measurement, a test mask with a square aperture is usually used. That is, the projection objective lens projects a square light spot onto the silicon wafer surface. The ESS (sensor) on the workbench moves the workbench along the direction perpendicular to different heights in the image space at different heights in the image space to scan the edge of the square aperture, find the position of the 50% light intensity point, then calculate the center coordinate point position of the square aperture, obtain the coordinates of the chief ray of the light spot at different heights, thereby obtaining the position of the chief ray, and calculate the angle between the chief ray and the optical axis, which is the telecentricity within this field of view. However, in the current measurement method, the light source used for lithography is used for scanning projection, and the light source used for lithography usually brings large interference. At the same time, it is necessary to perform off - line measurement or calibration of telecentricity, thus causing the problem of low efficiency in telecentricity measurement and calibration. Summary of the Invention

[0005] The purpose of the present invention is to provide a lithography scanner system and a method for far - center anomaly calibration of a lithography scanner system to solve the problems of large interference and low efficiency in the far - center measurement and far - center anomaly calibration of the existing lithography scanner system and lithography scanner system.

[0006] To solve the above problems, the present invention provides a lithography scanner system, including a first light source component, an illumination component with a variable slit component, a mask, an objective lens, and a workbench arranged in sequence, wherein the first light source component emits a first emitted light for lithography;

[0007] A second light source assembly, coaxially disposed between the first light source assembly and the variable slit assembly, and configured to emit second emitted light, wherein the wavelength of the second emitted light is different from that of the first emitted light;

[0008] A first measurement assembly, located between the illumination assembly and the reticle, on the optical path of the second emitted light, and movably disposed along the optical axis of the second emitted light, for measuring the center position of the light spot formed by the second emitted light irradiating on the first measurement assembly to obtain the telecentricity of the illumination assembly.

[0009] Optionally, the second emitted light emitted by the second light source assembly is visible light.

[0010] Optionally, the illumination assembly includes a cylindrical lens, an illumination mode adjustment lens group, an optical homogenizer, and a coupling light group with a variable slit assembly arranged in sequence, wherein the second light source assembly is disposed between the first light source assembly and the illumination mode adjustment lens group.

[0011] Optionally, an optical path switching assembly is further disposed between the first light source assembly and the illumination mode adjustment lens group. The optical diffraction assembly and the second light source assembly are disposed on the optical path switching assembly, and the optical path switching assembly can selectively connect the optical diffraction assembly or the second light source assembly to the optical path.

[0012] Optionally, the optical path switching assembly has a rotation axis. A part of the optical path switching assembly around the rotation axis is provided with at least one optical diffraction assembly and a standby position for forming different far-field scenarios. The second light source assembly is disposed at the standby position; wherein, when performing photolithographic exposure, the optical path switching assembly is rotated along the rotation axis to make the optical diffraction assembly located on the optical path of the first emitted light; and when performing telecentric measurement, the first light source assembly is turned off, and the optical path switching assembly is rotated along the rotation axis to make the optical path of the second emitted light emitted by the second light source assembly coincide with the optical path of the first emitted light emitted by the first light source assembly during photolithography.

[0013] Optionally, the lithography scanner system further includes a second measurement assembly located between the second light source assembly and the variable slit assembly and close to the variable slit assembly, and the second measurement assembly is used for performing telecentric measurement of the variable slit surface in the illumination assembly.

[0014] Optionally, the first measurement assembly includes at least two measurement units, and at least two of the measurement units are arranged staggeredly in sequence.

[0015] Optionally, the measurement unit is a photoelectric sensor.

[0016] Optionally, the photoelectric sensor is a silicon photodiode.

[0017] Optionally, the silicon photodiode is a double-sided silicon photodiode, and the double-sided silicon photodiode has a photosensitive surface for sensing the first emitted light.

[0018] Optionally, one of the two directions parallel to the photosensitive surface and perpendicular to each other is defined as the X direction, and the other is the Y direction. The calculation formula for the center position of the light spot is: Where,

[0019] The X position represents the coordinate of the center point of the light spot in the X direction, and the Y position represents the coordinate of the center point of the light spot in the Y direction. The L X represents the length of the effective detection area of the double-sided silicon photodiode in the X direction; the L Y represents the length of the effective detection area of the double-sided silicon photodiode in the Y direction; X1 represents the magnitude of the first photocurrent generated by the double-sided silicon photodiode in the X direction when the second emitted light irradiates the double-sided silicon photodiode; X2 represents the magnitude of the second photocurrent generated by the double-sided silicon photodiode in the X direction when the second emitted light irradiates the double-sided silicon photodiode; Y1 represents the magnitude of the first photocurrent generated by the double-sided silicon photodiode in the Y direction when the second emitted light irradiates the double-sided silicon photodiode; Y2 represents the magnitude of the second photocurrent generated by the double-sided silicon photodiode in the Y direction when the second emitted light irradiates the double-sided silicon photodiode.

[0020] To solve the above problems, the present invention also provides a method for calibrating the telecentric abnormality of a lithography machine scanning system. The lithography machine scanning system includes a first light source assembly, an illumination assembly with a variable slit assembly, a mask, an objective lens, and a workpiece table arranged in sequence. The method for calibrating the telecentric abnormality of the lithography machine scanning system is characterized in that it includes:

[0021] When the telecentric abnormality of the lithography machine scanning system is measured at the position of the workpiece table, a second light source assembly that emits the second emitted light is arranged between the first light source assembly and the variable slit assembly, and a first measurement assembly is arranged between the illumination assembly and the mask, and the first measurement assembly is located on the optical path of the second emitted light;

[0022] Move the first measurement assembly along the optical axis direction of the second emitted light, and measure the center position of the light spot formed by the second emitted light irradiating on the first measurement assembly to obtain the telecentricity of the illumination assembly.

[0023] Determine whether the telecentric value of the illumination component is within the first preset telecentric value range. If the telecentric value of the illumination component is within the first preset telecentric range, determine that the telecentric of the objective lens is abnormal, and adjust the telecentric adjustment unit in the objective lens so that the telecentric of the objective lens is within the preset telecentric range of the objective lens, and end the calibration of the telecentric of the lithography scanner system; and, if the telecentric value of the illumination component is not within the first preset telecentric range, adjust the telecentric of the illumination component until the telecentric value of the illumination component is within the first preset telecentric range, and when the telecentric of the lithography scanner system measured at the workpiece stage position is still abnormal, adjust the telecentric adjustment unit in the objective lens so that the telecentric of the objective lens is within the preset telecentric range of the objective lens, and end the calibration of the telecentric of the lithography scanner system.

[0024] Optionally, the method for adjusting the telecentric of the illumination component includes:

[0025] Set the second measurement component between the second light source component and the variable slit component, and set it close to the variable slit component;

[0026] Move the second measurement component along the optical axis direction of the second emitted light, and measure the center position of the light spot formed by the second emitted light irradiating on the second measurement component to obtain the telecentric of the variable slit surface in the illumination component;

[0027] Determine whether the telecentric value of the variable slit surface is within the second preset telecentric value range. If the telecentric value of the variable slit surface is within the second preset telecentric range, determine that the telecentric of the rear group part of the illumination component is abnormal, and adjust the lens group of the rear group part of the illumination component until the telecentric value of the illumination component is within the first preset range, and end the adjustment of the telecentric of the illumination component; if the telecentric value of the variable slit surface is not within the second preset telecentric range, determine that the telecentric of the front group part of the illumination component is abnormal, and adjust the lens group of the front group part of the illumination component until the telecentric value of the variable slit surface is within the second preset telecentric value range, and when the telecentric value of the illumination component is still not within the first preset telecentric range, adjust the lens group of the rear group part of the illumination component until the telecentric value of the illumination component is within the first preset range, and end the adjustment of the telecentric of the illumination component.

[0028] A lithography scanner system provided by the present invention sets a second light source component for emitting a second outgoing light between a first light source component and a variable slit component. When the second light source component is turned on to emit the second outgoing light and the measuring unit is irradiated by the second outgoing light, the central position of the light spot formed on the first measuring component by the second outgoing light is measured to obtain the telecentricity of the illumination component. In this way, by introducing a second light source component for measuring telecentricity in the lithography scanner system, the interference problem caused by measuring the telecentricity of the illumination component using the first outgoing light for lithography is avoided. At the same time, the telecentricity measurement can be directly completed in the lithography scanner system to improve the efficiency of telecentricity measurement. Description of the Drawings

[0029] Figure 1 is a schematic structural diagram of a lithography scanner system according to an embodiment of the present invention;

[0030] Figure 2 is another schematic structural diagram of a lithography scanner system according to an embodiment of the present invention;

[0031] Figure 3 is a schematic structural diagram of a lithography scanner system of the prior art;

[0032] Figure 4 is a schematic structural diagram of a lithography scanner system according to an embodiment of the present invention, in which the second light source component is arranged on an optical path switching component;

[0033] Figure 5 is a schematic structural diagram of a bilateral silicon photodiode in a lithography scanner system according to an embodiment of the present invention;

[0034] Figure 6 is a top view structural diagram of a bilateral silicon photodiode in a lithography scanner system according to an embodiment of the present invention;

[0035] Figure 7 is an equivalent circuit schematic diagram of a bilateral silicon photodiode in a lithography scanner system according to an embodiment of the present invention;

[0036] Figure 8 is a schematic structural diagram of a first measuring component in a lithography scanner system according to an embodiment of the present invention;

[0037] Figure 9 is another schematic structural diagram of a first measuring component in a lithography scanner system according to an embodiment of the present invention;

[0038] Figure 10 is a schematic flow diagram of a method for calibrating telecentricity abnormality of a lithography scanner system according to an embodiment of the present invention;

[0039] Reference Signs

[0040] 1 - First light source assembly; 2 - Cylindrical mirror;

[0041] 3 - Zoom lens group; 4 - Beam rotation mirror group;

[0042] 5 - Optical homogenizer; 6 - Coupling optical group;

[0043] 60 - Condensing lens; 61 - Focal plane of the condensing lens;

[0044] 62 - Variable slit assembly; 63 - Illumination unit;

[0045] 7 - Mask; 8 - Objective lens;

[0046] 9 - Workpiece stage; 10 - Illumination assembly;

[0047] 20 - Illumination mode adjustment lens group;

[0048] 100 - Optical path switching assembly; 101 - Rotation axis;

[0049] 102 - Optical diffraction assembly; 103 - Spare gear;

[0050] 200 - Second light source assembly;

[0051] 310 - First measurement assembly; 320 - First measurement assembly;

[0052] 301 - Measurement unit. Detailed implementation manners

[0053] The following further describes in detail the lithography scanner system and the far - center anomaly calibration method of the lithography scanner system proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non - precise scales, only for conveniently and clearly assisting in explaining the purpose of the embodiments of the present invention. In addition, the structures shown in the accompanying drawings are often part of the actual structures. In particular, the emphasis that each accompanying drawing needs to show is different, and sometimes different scales are used.

[0054] Figure 1 It is a schematic structural diagram of a lithography scanner system according to an embodiment of the present invention. As Figure 1 shown, this embodiment discloses a lithography scanner system, which includes a first light source assembly 1, an illumination assembly 10 having a variable slit assembly 62, a mask 7, an objective lens 8, and a workpiece stage 9 arranged in sequence, wherein the first light source assembly 1 emits a first emitted light.

[0055] A second light source assembly 200, which is coaxially arranged between the first light source assembly 100 and the variable slit assembly 62, and is used to emit second emitted light, where the wavelength of the second emitted light is different from the wavelength of the first emitted light.

[0056] A first measurement assembly 310, the first measurement assembly 310 includes at least one measurement unit 301, the first measurement assembly 310 is located on the optical path of the second emitted light, and is movably arranged along the optical axis of the second emitted light, and is used to measure the center position of the light spot formed by the second emitted light irradiating on the measurement assembly 300 when the first light source assembly 1 is turned off and the second light source assembly 200 is turned on and the first measurement assembly 310 is irradiated by the second emitted light, so as to obtain the telecentricity of the illumination assembly. Wherein, the distance and relative position relationship between the first measurement assembly 310 and the illumination assembly 10 are determined according to the actual situation and are not specifically limited herein. And, when measuring the telecentricity of the illumination assembly, the mask 7 is removed.

[0057] The lithography scanner system of this embodiment, by arranging a second light source assembly 200 for emitting second emitted light between the first light source assembly 1 and the variable slit assembly 62, and when the first light source assembly 1 is turned off, the second light source assembly 200 is turned on to emit the second emitted light, and the measurement unit 301 is irradiated by the second emitted light, measure the center position of the light spot formed by the second emitted light irradiating on the first measurement assembly 310, so as to obtain the telecentricity of the illumination assembly. In this way, by introducing a second light source assembly 200 for measuring telecentricity into the lithography scanner system, the interference problem caused by using the first emitted light for lithography to measure the telecentricity of the illumination assembly is avoided. At the same time, the telecentricity measurement can be directly completed in the lithography scanner system to improve the efficiency of telecentricity measurement.

[0058] Figure 2 It is another structural schematic diagram of the lithography scanner system of an embodiment of the present invention. Figure 3 It is a structural schematic diagram of a lithography scanner system in the prior art. Specifically, in combination with Figures 2 to 3 As shown, the lithography scanner system in this embodiment includes an illumination assembly 10, and the illumination assembly 10 has a variable slit assembly 62. And, the lithography scanner system further includes a second measurement assembly 320 located between the second light source assembly 200 and the variable slit assembly 62 and close to the variable slit assembly 62, and the second measurement assembly 320 is used to perform telecentricity measurement of the variable slit surface in the illumination assembly 10. Wherein, the distance and relative position relationship between the second measurement assembly 320 and the slit assembly 62 are determined according to the actual situation and are not specifically limited herein.

[0059] More specifically, continue to refer to Figures 1 to 3 As shown, the lithography scanner system includes: a first light source assembly 1, an illumination assembly 10 with a variable slit assembly 62, a reticle 7, an objective lens 8, and a workpiece stage 9 arranged in sequence; the second light source assembly 200 is arranged between the first light source assembly 1 and the variable slit assembly 62, and the second measurement assembly 320 is arranged between the variable slit assembly 62 and the second light source assembly 200 and is close to the variable slit assembly 62 to perform telecentric measurement of the variable slit surface in the illumination assembly 10.

[0060] Among them, the illumination assembly 10 includes a cylindrical lens 2, a zoom lens group 3, an illumination mode adjustment lens group 20, and a coupling light group 6 with a variable slit assembly arranged in sequence. Among them, the illumination mode adjustment lens group 20 includes a beam rotation lens group 4 and an optical homogenizer 5. The coupling light group 6 includes a condenser lens 60, a condenser lens focal plane 61, a variable slit 62, and an illumination unit 63 arranged in sequence on the measurement optical path. Among them, the second light source assembly 200 is arranged between the first light source assembly 1 and the zoom lens group 3.

[0061] Figure 4 It is a schematic structural diagram of the second light source assembly in the lithography scanner system of an embodiment of the present invention being arranged on the optical path switching assembly. Combining Figures 1 to 4 As shown, in this embodiment, an optical path switching assembly 100 is further arranged between the first light source assembly 1 and the zoom lens group 3. The second light source assembly 200 and the optical diffraction assembly 102 are arranged on the optical path switching assembly 100, and the optical path switching assembly 100 can selectively connect the optical diffraction assembly 102 or the second light source assembly 200 to the optical path.

[0062] Focus on referring to Figure 4 As shown, in this embodiment, the optical path switching assembly 100 has a rotation axis 101. At least one optical diffraction assembly 102 for forming different far-field scenarios and a spare gear 103 are arranged on the part of the optical path switching assembly 100 surrounding the rotation axis 101. The second light source assembly 200 is arranged on the spare gear 103. Since the optical path switching assembly 100 is an inherent device of the lithography scanner system, setting the second light source assembly 200 on the spare gear 103 of the optical path switching assembly 100 can improve space utilization.

[0063] Further, when performing photolithographic exposure, rotate the optical path switching component 100 along the rotation axis 101 so that the optical diffraction component 102 is located on the optical path of the first emitted light emitted by the first light source component 1. At this time, after the second emitted light is diffracted by the optical diffraction component 102 and passes through the above-mentioned various optical elements, it is irradiated onto the workpiece stage to perform photolithography on the workpiece to be photolithographed.

[0064] In addition, when performing telecentric measurement, turn off the first light source component 1, turn on the second light source component 200 and rotate the rotation axis 101 to rotate the optical path switching component 100 so that the optical path of the second emitted light emitted by the second light source component 200 coincides with the optical path of the first emitted light emitted by the first light source component 1 during photolithography. In this embodiment, preferably, the shape of the optical path switching component 100 is circular, and the shape of the optical path switching component 100 can also be square, oval, etc. The shape of the optical path switching component 100 is not specifically limited herein and shall be subject to the actual situation. In an alternative embodiment, the optical path switching component 100 can also be provided with a hollow, so that the weight of the optical path switching component 100 can be reduced. In addition, in this embodiment, the rotation axis 101 is a cylinder, and the method of rotating the rotation axis 101 can be manual rotation or driving the rotation axis to rotate by using a motor. Specifically, it is not specifically limited herein and shall be subject to the actual situation.

[0065] Further, in this embodiment, the emitted light emitted by the second light source component 200 is visible light. When the light emitted by the second light source component 200 is visible light, the light source energy of the visible light is stable, and the problem of measurement interference caused by light in other bands can be avoided. In addition, the light emitted by the first light source component 1 is laser light, for example, it can be DUV light (ultraviolet enhanced xenon lamp light).

[0066] Further, in this embodiment, the measurement unit 301 is a photoelectric sensor. In this embodiment, the photoelectric sensor is a silicon photodiode. More specifically, the photoelectric sensor is a silicon photodiode. Among them, the silicon photodiode has a photosensitive surface, and the silicon photodiode separates two resistance layers by a p-n junction, and the middle layer is a low-doped n-type silicon substrate; the photosensitive surface is formed by ion-implanting a p-type resistance layer, and there is a first contact at each end thereof. The other surface opposite to the photosensitive surface is formed by ion-implanting an n-type resistance layer, and there is a second contact at each end thereof. Preferably, the connection line of the two first contacts and the connection line of the two second contacts are perpendicular to each other. When the first emitted light irradiates the photosensitive surface, photocurrents I1 and I2 will be generated between the incident point and the contact electrode. Among them, the magnitudes of the photocurrents I1 and I2 are inversely proportional to the distance between the incident point and the contact electrode. Therefore, by calculating the distribution of the photocurrents I1 and I2, the center position of the light spot irradiated on the photosensitive surface can be accurately calculated. However, the silicon photodiode in the existing design can only measure the position in one direction parallel to the photosensitive surface.

[0067] Figure 5 is a schematic structural diagram of a double-sided silicon photodiode in a lithography scanner system according to an embodiment of the present invention; Figure 6 is a schematic top view structural diagram of a double-sided silicon photodiode in a lithography scanner system according to an embodiment of the present invention; Figure 7 is a schematic equivalent circuit diagram of a double-sided silicon photodiode in a lithography scanner system according to an embodiment of the present invention. In this embodiment, the silicon photodiode is a double-sided silicon photodiode, and the double-sided silicon photodiode has a photosensitive surface for sensing the second emitted light.

[0068] Specifically, as Figures 5 to 7 shown, one of the two directions parallel to the photosensitive surface and perpendicular to each other is defined as the X direction, and the other is the Y direction. The photosensitive surface of the double-sided silicon photodiode in this embodiment has 4 third contacts; the other surface opposite to the photosensitive surface also has 4 fourth contacts. Focus on Figure 7As shown in the figure, in the equivalent circuit of the bilateral silicon photodiode of this embodiment, a capacitor, a shunt resistor, and a PN junction diode are connected in parallel and then connected in series with two position resistors. Among them, the position resistors are equivalently formed by the ion-implanted p-type resistor layer and the ion-implanted n-type resistor layer. When the second emitted light irradiates the photosensitive surface, the incident light generates a photocurrent Ip. The photocurrent Ip is shunted in the X direction to generate a first photocurrent X1 and a second photocurrent X2, and is shunted in the Y direction to generate a first photocurrent Y1 and a second photocurrent Y2. Then, by calculating the distributions of the photocurrents X1, X2, Y1, and Y2, the center position of the light spot irradiated on the photosensitive surface can be accurately calculated. In addition, the bilateral silicon photodetector also has four pins. Two of the four pins are located on the photosensitive surface to lead out the first photocurrent X1 and the second photocurrent X2 in the X direction, and the other two of the four pins are used to lead out the first photocurrent Y1 and the second photocurrent Y2 in the Y direction. Preferably, the connection line between the two pins for leading out the first photocurrent X1 and the second photocurrent X2 in the X direction and the connection line between the two pins for leading out the first photocurrent Y1 and the second photocurrent Y2 in the Y direction are perpendicular to each other.

[0069] In this embodiment, the calculation formula for using the bilateral silicon photodiode to calculate the center position of the light spot is:

[0070] Among them, the X position represents: the coordinate of the center point of the light spot in the X direction, and the Y position represents: the coordinate of the center point of the light spot in the Y direction, and the L X represents: the length of the effective detection area of the bilateral silicon photodiode in the X direction; the L Y represents: the length of the effective detection area of the bilateral silicon photodiode in the Y direction; X1 represents: the magnitude of the first photocurrent generated by the bilateral silicon photodiode in the X direction when the second emitted light irradiates the bilateral silicon photodiode; X2 represents: the magnitude of the second photocurrent generated by the bilateral silicon photodiode in the X direction when the first emitted light irradiates the bilateral silicon photodiode; Y1 represents: the magnitude of the first photocurrent generated by the bilateral silicon photodiode in the Y direction when the second emitted light irradiates the bilateral silicon photodiode: Y2 represents: the magnitude of the second photocurrent generated by the bilateral silicon photodiode in the Y direction when the second emitted light irradiates the bilateral silicon photodiode.

[0071] Figure 8 is a schematic structural diagram of the first measurement component in the lithography machine scanning system according to an embodiment of the present invention. As Figure 8As shown, in this embodiment, the first measurement component 310 includes at least two measurement units 301, and at least two of the measurement units 301 are arranged staggeredly in sequence. Specifically, in this embodiment, at least two of the measurement units 301 are arranged in a checkerboard pattern. Among them, the measurement unit 301 can be disposed on the substrate of the first measurement component 310 or embedded in the substrate of the first measurement component 310, and no specific limitation is made here. The number, size, and arrangement of the measurement units 301 in the first measurement component 310 are not specifically limited herein and can be set according to the actual needs of the telecentric test.

[0072] In this embodiment, continue to refer Figure 8 As shown, taking the KrF 0.85NA exposure system as an example, when the magnification of the illumination unit 63 is 1:3.5, the field of view size of the illumination field on the variable slit surface is 29.7mm * 9.1mm, then 5 double-sided silicon photodiodes with a size of 5mm * 3mm arranged in a checkerboard pattern can be used for telecentric testing.

[0073] Figure 9 is another structural schematic diagram of the first measurement component in the lithography scanner system of an embodiment of the present invention. As Figure 9 shown, in this embodiment, the first measurement component 310 includes at least two measurement units 301, and a plurality of the measurement units 301 are arranged in a straight line. As Figure 9 shown, in this embodiment, taking the immersion 1.35NA exposure system as an example, when the magnification of the illumination component 63 is 1:1, the field of view size of the illumination field on the variable slit surface is 16204mm * 22mm, then 5 double-sided silicon photodiodes with a size of 10mm * 10mm or 20mm * 20mm arranged in a straight line can be used for telecentric testing. In addition, the above two exposure systems and the sizes, quantities, and arrangement manners of the corresponding double-sided silicon diodes are only examples. In practice, they can be set according to specific requirements, subject to actual needs.

[0074] In addition, in this embodiment, the structure of the second measurement component 320 is the same as that of the first measurement component 310, that is, the second measurement component 320 includes at least two measurement units 301, and at least two of the measurement units 301 are arranged staggeredly in sequence. Among them, the arrangement manner and structure of the measurement units 301 on the second measurement component 320 are the same as those of the measurement units 301 on the first measurement component 310, so no further description is given here.

[0075] Next, refer Figure 9Describe the telecentric measurement process of the lighting component in this embodiment. In this embodiment, first, move the first measurement component 310 for the first time along the optical path direction of the second emitted light. Assume that the first measurement unit 301 from left to right on the first measurement component 310 is irradiated by the second emitted light. At this time, the first measurement component 310 has a first position Z1 along the direction of the second emitted light path, and calculate according to the above formula to obtain the central position coordinates X position 1 and Y position 1 of the first light spot A1 formed on the first measurement component 310. According to the first position Z1 and the central position coordinates X position 1 and Y position 1 of the first light spot A1 in the direction perpendicular to the optical path of the second emitted light to obtain the position of the first light spot A1. Then repeat the above process to obtain the position of the third light spot A3, the position of the fourth light spot A4, and the position of the fifth coordinate A5. In this way, the included angle between the connection line of the first light spot A1 to the fifth light spot A5 and the optical path of the second emitted light is the telecentricity of the lighting component measured by the first measurement component 310.

[0076] In addition, in this embodiment, the photosensitive surface of the bilateral silicon photodiode is a single continuous surface, so there are no gaps and dead zones. Therefore, the silicon photodiode in this embodiment can be applied to large-range position detection. However, the bilateral silicon photodiode has no definite mechanical center. Therefore, when using the bilateral silicon photodiode in this embodiment for measurement, it is necessary to determine the center of the silicon photodiode.

[0077] Among them, the method for determining the center of the silicon photodiode in this embodiment includes the following steps.

[0078] First, take the current position as 0°, and record the positions dx1 and dy2 of the bilateral silicon photodiode in the X direction and the Y direction at this time.

[0079] Then, rotate the bilateral silicon photodiode by 180°, and record the positions dx2 and dy2 of the bilateral silicon photodiode in the X direction and the Y direction at this time.

[0080] Finally, calculate through the formulas dx = (dx1 + dx2) / 2 and dy = (dx2 + dy2) / 2 to obtain the center dx and dy of the bilateral silicon photodiode.

[0081] Figure 10 is the telecentric anomaly calibration method of the lithography machine scanning system according to an embodiment of the present invention. Combine Figure 10 、 Figures 1 to 3As shown, this embodiment discloses a method for calibrating the telecentric abnormality of a lithography scanner system. The lithography scanner system includes a first light source assembly 1, an illumination assembly 10 with a variable slit assembly 62, a mask 7, an objective lens 8, and a workpiece table 9 arranged in sequence. Among them, the method for calibrating the telecentric abnormality of the lithography scanner system includes:

[0082] In step S10: When the telecentric abnormality of the lithography scanner system is measured at the position of the workpiece table 9, a second light source assembly 200 that emits a second emitted light is arranged between the first light source assembly 1 and the variable slit assembly 62, and a first measurement assembly 310 is arranged between the illumination assembly 10 and the mask 7, and the first measurement assembly 310 is located on the optical path of the second emitted light. In addition, in this embodiment, the mask 7 is usually removed, the first light source assembly 1 is turned off, and the second light source assembly 200 is turned on. And,

[0083] In this embodiment, the second light source assembly 200 can be directly arranged on the optical path switching assembly 100. Preferably, the second light source assembly 200 can be directly arranged on the standby gear 103 of the optical path switching assembly 100. Since the optical path switching assembly 100 is an inherent device of the lithography scanner system, arranging the second light source assembly 200 on the standby gear 103 of the optical path switching assembly 100 can improve the space utilization rate.

[0084] And, in this embodiment, the emitted light emitted by the second light source assembly 200 is visible light. When the light emitted by the second light source assembly 200 is visible light, the light source energy of the visible light is stable, which can avoid the problem of measurement interference caused by light in other bands. And, the light emitted by the first light source assembly 1 is laser light, for example, it can be DUV light (ultraviolet-enhanced xenon lamp light).

[0085] In step S20: Move the first measurement assembly 310 along the optical axis direction of the second emitted light, and measure the center position of the light spot formed by the second emitted light irradiating on the first measurement assembly 310 to obtain the telecentricity of the illumination assembly 10. Among them, the method for calculating the telecentricity value of the illumination assembly 10 is as described above, and will not be elaborated here.

[0086] In step S30: Determine whether the telecentric value of the illumination component 10 is within the first preset telecentric value range. If the telecentric value of the illumination component 10 is within the first preset telecentric range, then determine that the telecentric of the objective lens 8 is abnormal, and adjust the telecentric adjustment unit within the objective lens 8 so that the telecentric of the objective lens is within the preset telecentric range of the objective lens, and end the calibration of the telecentric of the lithography scanner system; and if the telecentric value of the illumination component 10 is not within the first preset telecentric range, then adjust the telecentric of the illumination component 10 until the telecentric value of the illumination component 10 is within the first preset telecentric range, and when the telecentric of the lithography scanner system measured at the position of the worktable 9 is still abnormal, adjust the telecentric adjustment unit within the objective lens 8 so that the telecentric of the objective lens 8 is within the preset telecentric range of the objective lens, and end the calibration of the telecentric of the lithography scanner system.

[0087] In this embodiment, since the telecentric of the lithography scanner system measured at the position of the worktable 9 is related to the illumination component 10 and the objective lens 8. When the telecentric of the lithography scanner system measured at the position of the worktable 9 is abnormal, if the telecentric of the illumination component 10 is within the first preset telecentric value range, it means that the telecentric of the objective lens 8 is abnormal. After adjusting the telecentric of the objective lens 8 to within the preset telecentric range of the objective lens, the telecentric of the lithography scanner system measured at the position of the worktable 9 will be adjusted to be normal, and at this time, the calibration of the telecentric of the lithography scanner system is ended.

[0088] When the telecentric value of the illumination component 10 is not within the first preset telecentric range, after adjusting the telecentric value of the illumination component 10 to the first preset range, it is necessary to further determine whether the telecentric of the lithography scanner system measured at the position of the worktable 9 is normal. If the telecentric of the lithography scanner system measured at the position of the worktable 9 is normal, then end the calibration of the telecentric of the lithography scanner system. If the telecentric of the lithography scanner system measured at the position of the worktable 9 is still abnormal, at this time, it is determined that the telecentric of the objective lens 8 is still abnormal, that is, it is necessary to adjust the telecentric adjustment unit within the objective lens 8 so that the telecentric of the objective lens 8 is within the preset telecentric range of the objective lens. At this time, the telecentrics of both the illumination component 10 and the objective lens 8 are normal, and then the calibration of the telecentric of the lithography scanner system can be ended.

[0089] Further, in this embodiment, the method of adjusting the telecentric adjustment unit within the objective lens may be to adjust the position, angle, etc. of the telecentric adjustment unit within the objective lens relative to the objective lens. And, in this embodiment, the first preset telecentric range and the telecentric range of the preset objective lens are not specifically defined herein and shall be subject to the actual situation.

[0090] Further, in this embodiment, the method for adjusting the telecentricity of the illumination assembly includes the following steps 1 to 3.

[0091] In step 1, the second measurement assembly 320 is disposed between the variable slit assembly 62 and the second light source assembly 200, and is disposed close to the variable slit assembly 200.

[0092] In step 2, the second measurement assembly 320 is moved along the optical axis direction of the second outgoing light, and the central position of the light spot formed by the second outgoing light irradiating on the second measurement assembly 320 is measured to obtain the telecentricity of the variable slit surface in the illumination assembly.

[0093] In step 3, it is judged whether the telecentricity value of the variable slit surface is within the second preset telecentricity range. If the telecentricity value of the variable slit surface is within the second preset telecentricity range, it is judged that the telecentricity of the rear group part of the illumination assembly 10 is abnormal, and the lens group of the rear group part of the illumination assembly 10 is adjusted until the telecentricity value of the illumination assembly 10 is within the first preset range, and the adjustment of the telecentricity of the illumination assembly 10 is ended; and if the telecentricity value of the variable slit surface is not within the second preset telecentricity range, it is judged that the telecentricity of the front group part of the illumination assembly 10 is abnormal, and the lens group of the front group part of the illumination assembly 10 is adjusted until the telecentricity value of the slit assembly surface is within the second preset telecentricity range, and when the telecentricity value of the illumination assembly 10 is still not within the first preset telecentricity range, the lens group of the rear group part of the illumination assembly 10 is adjusted until the telecentricity value of the illumination assembly 10 is within the first preset telecentricity range. And the adjustment of the telecentricity of the illumination assembly is ended. In this embodiment, the second preset telecentricity range is determined according to the actual situation and is not specifically limited herein.

[0094] In this embodiment, the lens group of the front group part of the illumination assembly 10 refers to the lens group in front of the variable slit assembly 62 in the illumination assembly 10, and the lens group of the rear group part of the illumination assembly 10 refers to the lens group behind the variable slit assembly 62 in the illumination assembly 10.

[0095] The telecentricity of the illumination assembly 10 is related to the front group part and the rear group part in the illumination assembly 10. In this embodiment, the telecentricity value of the variable slit surface is the telecentricity of the front group part of the illumination assembly 10. When the telecentricity of the illumination assembly 10 is not within the first preset telecentricity range and the telecentricity value of the variable slit surface is within the second preset telecentricity range, it indicates that the telecentricity of the rear group part of the illumination assembly 10 is abnormal. At this time, the lens group of the rear group part of the illumination assembly 10 is adjusted until the telecentricity value of the illumination assembly 10 is within the first preset range, and then the adjustment of the telecentricity of the illumination assembly 10 can be ended.

[0096] When the telecentricity of the illumination component 10 is not within the first preset telecentricity range and the telecentricity value of the variable slit surface is not within the second preset telecentricity value range, it is determined that the front group part telecentricity of the illumination component 10 is abnormal. Then, the lens group of the front group part of the illumination component 10 is adjusted to make the telecentricity value of the variable slit surface within the second preset telecentricity value range. After that, it is also necessary to determine whether the telecentricity of the illumination component 10 is within the first preset telecentricity range at this time. If the telecentricity of the illumination component 10 is within the first preset telecentricity range at this time, the calibration of the telecentricity of the illumination component 10 is completed. If the telecentricity of the illumination component 10 is not within the first preset telecentricity range, it indicates that the telecentricity of the lens group of the rear group part of the illumination component 10 is abnormal. In this way, the lens group of the rear group part of the illumination component 10 needs to be adjusted until the telecentricity of the illumination component 10 is within the first preset telecentricity range, and then the adjustment of the telecentricity of the illumination component 10 is ended.

[0097] It should be noted that the various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. In addition, the different parts among the embodiments can also be combined and used, and the present invention does not limit this.

[0098] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure are within the protection scope of the claims.

Claims

1. A lithography scanner system, characterized in that, It includes a first light source component, an illumination component with a variable slit component, a mask, an objective lens, and a workpiece stage arranged in sequence. Among them, the first light source component emits a first outgoing light for lithography. A second light source component, which is coaxially arranged between the first light source component and the variable slit component and is used to emit a second outgoing light. The wavelength of the second outgoing light is different from that of the first outgoing light. A first measurement component, which is located between the illumination component and the mask, on the optical path of the second outgoing light, and is movably arranged along the optical axis of the second outgoing light. It is used to measure the center position of the light spot formed by the second outgoing light irradiating on the first measurement component to obtain the telecentricity of the illumination component.

2. The lithography scanner system according to claim 1, characterized in that, The second outgoing light emitted by the second light source component is visible light.

3. The lithography scanner system according to claim 1, characterized in that, The illumination component includes a cylindrical lens, an illumination mode adjustment lens group, an optical homogenizer, and a coupling light group with a variable slit component arranged in sequence. Among them, the second light source component is arranged between the first light source component and the illumination mode adjustment lens group.

4. The lithography scanner system according to claim 3, characterized in that, An optical path switching component is also arranged between the first light source component and the illumination mode adjustment lens group. An optical diffraction component and the second light source component are arranged on the optical path switching component, and the optical path switching component can selectively connect the optical diffraction component or the second light source component to the optical path.

5. The lithography scanner system according to claim 4, characterized in that, The optical path switching component has a rotation axis. On the part of the optical path switching component surrounding the rotation axis, there are at least one optical diffraction component and a standby gear for forming different far-field scenarios. The second light source component is arranged on the standby gear. When performing lithography exposure, the optical path switching component is rotated along the rotation axis so that the optical diffraction component is on the optical path of the first outgoing light. And when performing telecentric measurement, the first light source component is turned off, and the optical path switching component is rotated along the rotation axis so that the optical path of the second outgoing light emitted by the second light source component coincides with the optical path of the first outgoing light emitted by the first light source component during lithography.

6. The lithography scanner system according to claim 1, characterized in that, The lithography scanner system further includes a second measurement component located between the second light source component and the variable slit component and close to the variable slit component. The second measurement component is used to perform telecentric measurement on the variable slit surface in the illumination component.

7. The lithography scanner system according to claim 1, characterized in that, The first measurement component includes at least two measurement units, and at least two of the measurement units are arranged staggeredly in sequence.

8. The lithography scanner system according to claim 7, characterized in that, The measurement unit is a photoelectric sensor.

9. The lithography scanner system according to claim 8, characterized in that, The photoelectric sensor is a silicon photodiode.

10. The lithography scanner system according to claim 9, characterized in that, The silicon photodiode is a double-sided silicon photodiode, and the double-sided silicon photodiode has a photosensitive surface for sensing the first outgoing light.

11. The lithography scanner system according to claim 10, characterized in that, Define one of the two directions parallel to the photosensitive surface and perpendicular to each other as the X direction, and the other as the Y direction. The calculation formula for the center position of the light spot is: Among them, the X position represents the coordinate of the center point of the light spot in the X direction, and the Y position represents the coordinate of the center point of the light spot in the Y direction. The L X represents the length of the effective detection region of the double-sided silicon photodiode in the X direction; the L Y represents the length of the effective detection region of the double-sided silicon photodiode in the Y direction; X1 represents the magnitude of the first photocurrent generated by the double-sided silicon photodiode in the X direction when the second emitted light irradiates the double-sided silicon photodiode; X2 represents the magnitude of the second photocurrent generated by the double-sided silicon photodiode in the X direction when the second emitted light irradiates the double-sided silicon photodiode; Y1 represents the magnitude of the first photocurrent generated by the double-sided silicon photodiode in the Y direction when the second emitted light irradiates the double-sided silicon photodiode; Y2 represents the magnitude of the second photocurrent generated by the double-sided silicon photodiode in the Y direction when the second emitted light irradiates the double-sided silicon photodiode.

12. A method for calibrating the telecentric anomaly of a lithography scanner system, the lithography scanner system comprising a first light source assembly, an illumination assembly with a variable slit assembly, a mask, an objective lens, and a workpiece stage arranged in sequence, characterized in that, The method for calibrating the telecentricity anomaly of the lithography scanner system includes: When the telecentricity of the lithography scanner system measured at the workpiece stage position is abnormal, the second light source assembly that emits the second emitted light is arranged between the first light source assembly and the variable slit assembly, and the first measurement assembly is arranged between the illumination assembly and the reticle, and the first measurement assembly is located on the optical path of the second emitted light; Move the first measurement assembly along the optical axis direction of the second emitted light, and measure the central position of the light spot formed by the second emitted light irradiating on the first measurement assembly to obtain the telecentricity of the illumination assembly; Judge whether the telecentricity value of the illumination assembly is within the first preset telecentricity range. If the telecentricity value of the illumination assembly is within the first preset telecentricity range, then judge that the telecentricity of the objective lens is abnormal, and adjust the telecentricity adjustment unit in the objective lens so that the telecentricity of the objective lens is within the preset telecentricity range of the objective lens, and end the calibration of the telecentricity of the lithography scanner system; and, if the telecentricity value of the illumination assembly is not within the first preset telecentricity range, then adjust the telecentricity of the illumination assembly until the telecentricity value of the illumination assembly is within the first preset telecentricity range, and when the telecentricity of the lithography scanner system measured at the workpiece stage position is still abnormal, adjust the telecentricity adjustment unit in the objective lens so that the telecentricity of the objective lens is within the preset telecentricity range of the objective lens, and end the calibration of the telecentricity of the lithography scanner system.

13. The method for calibrating the telecentric anomaly of a lithography scanner system according to claim 12, characterized in that, The method for adjusting the telecentricity of the illumination assembly includes: Arrange the second measurement assembly between the second light source assembly and the variable slit assembly, and arrange it close to the variable slit assembly; Move the second measurement assembly along the optical axis direction of the second emitted light, and measure the central position of the light spot formed by the second emitted light irradiating on the second measurement assembly to obtain the telecentricity of the variable slit surface in the illumination assembly; Judge whether the telecentricity value of the variable slit surface is within the second preset telecentricity range. If the telecentricity value of the variable slit surface is within the second preset telecentricity range, then judge that the telecentricity of the rear group part of the illumination assembly is abnormal, and adjust the lens group of the rear group part of the illumination assembly until the telecentricity value of the illumination assembly is within the first preset telecentricity range, and end the adjustment of the telecentricity of the illumination assembly; if the telecentricity value of the variable slit surface is not within the second preset telecentricity range, then judge that the telecentricity of the front group part of the illumination assembly is abnormal, and adjust the lens group of the front group part of the illumination assembly until the telecentricity value of the variable slit surface is within the second preset telecentricity range, and when the telecentricity value of the illumination assembly is not within the first preset telecentricity range, then adjust the lens group of the rear group part of the illumination assembly until the telecentricity value of the illumination assembly is within the first preset telecentricity range, and end the adjustment of the telecentricity of the illumination assembly.

Images