Extreme-ultraviolet light generator, and method for manufacturing electronic device

Abstract

To provide an extreme-ultraviolet light generator, and a method for manufacturing an electronic device.SOLUTION: An extreme-ultraviolet light generator comprises: a chamber including a first space where a target is irradiated with a laser beam to generate extreme-ultraviolet light, and a second space in which an EUV collector mirror is arranged; a first partition wall which has a first opening through which extreme-ultraviolet light passes, and is positioned between the first space and the second space; a connection part which connects the chamber and the external device; a second partition wall which has a second opening through which extreme-ultraviolet light passes, and is positioned inside the connection part; a gas supply port which allows gas to pass through the second space; a first exhaust port opening in the first space; a second exhaust port opening in a third space which is inside the connection part and is positioned between a second partition wall and the external device; a first sensor arranged in the third space; and a processor which calculates a first flow rate of gas passing through the first opening on the basis of a measurement result by the first sensor, and adjusts a supply flow rate of gas supplied through the gas supply port.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an extreme ultraviolet light generating apparatus and a method for manufacturing an electronic device.

Background Art

[0002] In recent years, with the miniaturization of semiconductor processes, the miniaturization of transfer patterns in the photolithography of semiconductor processes has been rapidly progressing. In the next generation, microfabrication of 10 nm or less will be required. For this reason, the development of a semiconductor exposure apparatus combining an apparatus for generating extreme ultraviolet (EUV) light with a wavelength of about 13 nm and a reduction projection reflective optical system has been expected.

[0003] As an EUV light generating apparatus, the development of a LPP (Laser Produced Plasma) type apparatus using plasma generated by irradiating a target material with laser light has been progressing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] An extreme ultraviolet light generation apparatus according to one aspect of the present disclosure includes a chamber including a first space in which a target is irradiated with laser light to generate extreme ultraviolet light, and a second space in which an EUV collector mirror is disposed that reflects the extreme ultraviolet light and outputs it to an external device; a first partition wall having a first opening through which the extreme ultraviolet light passes and positioned between the first space and the second space; a connection part connecting the chamber to the external device; and a second partition wall having a second opening through which the extreme ultraviolet light passes and positioned inside the connection part. The gas supply system includes a wall, a gas supply port that passes gas to be supplied to the second space, a first exhaust port that opens into the first space, a second exhaust port that opens into a third space located inside the connection part between the second partition wall and the external device, a first sensor arranged in the third space, and a processor that calculates a first passing flow rate of the gas passing through the first opening based on the measurement result by the first sensor and adjusts the supply flow rate of the gas supplied through the gas supply port based on the first passing flow rate.

[0006] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a chamber including a first space in which a target is irradiated with laser light to generate extreme ultraviolet light, and a second space in which an EUV collector mirror is disposed that reflects the extreme ultraviolet light and outputs it to an exposure tool; a first partition having a first opening through which the extreme ultraviolet light passes and positioned between the first space and the second space; a connection part that connects the chamber and the exposure tool; a second partition having a second opening through which the extreme ultraviolet light passes and positioned inside the connection part; a gas supply port through which a gas supplied to the second space passes; and a gas supply port that opens into the first space. The method includes generating extreme ultraviolet light using an extreme ultraviolet light generating device that includes a first exhaust port, a second exhaust port that opens into a third space located inside the connecting portion between the second partition wall and the exposure device, a first sensor arranged in the third space, and a processor that calculates a first passing flow rate of gas passing through the first opening based on the measurement result by the first sensor and adjusts the supply flow rate of gas supplied through the gas supply port based on the first passing flow rate, outputting the extreme ultraviolet light to the exposure device, and exposing the extreme ultraviolet light onto a photosensitive substrate in the exposure device to manufacture an electronic device.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a first space where a target is irradiated with a laser beam to generate extreme ultraviolet light, and a second space where an EUV condenser mirror that reflects the extreme ultraviolet light and outputs it to an inspection device is disposed. A chamber including: a first partition having a first opening through which the extreme ultraviolet light passes and located between the first space and the second space; a connection portion connecting the chamber and the inspection device; a second partition having a second opening through which the extreme ultraviolet light passes and located inside the connection portion; a gas supply port for passing a gas supplied to the second space; a first exhaust port opening to the first space; a second exhaust port opening to a third space located inside the connection portion between the second partition and the inspection device; a first sensor disposed in the third space; and a processor that calculates a first flow rate of the gas passing through the first opening based on a measurement result by the first sensor and adjusts a supply flow rate of the gas supplied through the gas supply port based on the first flow rate. The method includes irradiating a mask with the extreme ultraviolet light generated by an extreme ultraviolet light generating device including the above components in an inspection device to inspect for defects in the mask, selecting a mask using the results of the inspection, and exposing and transferring a pattern formed on the selected mask onto a photosensitive substrate.

Brief Description of the Drawings

[0008] Some embodiments of the present disclosure will be described below by way of example only with reference to the accompanying drawings. [Figure 1] FIG. 1 shows the configuration of an LPP-type EUV light generation system according to a comparative example. [Figure 2] FIG. 2 shows the configuration of the EUV light generation device shown in FIG. 1. [Figure 3] FIG. 3 shows the configuration of an EUV light generation system according to a first embodiment. [Figure 4] FIG. 4 is a flowchart showing an operation of setting a supply flow rate of a gas in the first embodiment. [Figure 5] FIG. 5 shows the configuration of an EUV light generation system according to a second embodiment. [Figure 6] FIG. 6 is a flowchart showing an operation of setting a supply flow rate of a gas in the second embodiment. [Figure 7] FIG. 7 shows a data table created in a first method for calculating a second flow rate based on the absolute value of the pressure difference. [Figure 8] FIG. 8 schematically shows the configuration of an exposure apparatus connected to an EUV light generation system. [Figure 9] FIG. 9 schematically shows the configuration of an inspection apparatus connected to an EUV light generation system. Embodiment

[0009] <Content> 1. Comparative Example 1.1 Configuration 1.2 Operation 2. Problems of the Comparative Example EUV light generation system 11a that controls the supply flow rate F2 based on the exhaust flow rate E1 3.1 Configuration 3.2 Operation 3.3 Function EUV light generation system 11b that controls the supply flow rate F2 based on the pressure P2 in the third space 910 4.1 Configuration 4.2 Operation 4.3 Function 5. Others 5.1 Examples of the external device 6 5.2 Supplementary Explanation

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Also, not all of the configurations and operations described in each embodiment are essential as the configurations and operations of the present disclosure. Note that the same reference numerals are assigned to the same components, and redundant explanations are omitted.

[0011] 1. Comparative Example 1.1 Configuration FIG. 1 shows the configuration of an LPP-type EUV light generation system 11 according to a comparative example, and FIG. 2 shows the configuration of the EUV light generation apparatus 1 shown in FIG. 1. In FIGS. 1 and 2, an X direction, a Y direction, and a Z direction perpendicular to each other are shown. FIG. 1 is a view of the EUV light generation system 11 seen in the Y direction, and FIG. 2 is a view of the EUV light generation apparatus 1 seen in the Z direction. The Y direction is the output direction of the target 27, and the Z direction is the output direction of the EUV light.

[0012] The EUV light generation apparatus 1 is used together with a laser apparatus 3. In the present disclosure, a system including the EUV light generation apparatus 1 and the laser apparatus 3 is referred to as an EUV light generation system 11. The EUV light generation apparatus 1 includes a chamber 2, an inner wall 37, and a first partition wall 38.

[0013] The chamber 2 is a sealable container and has a substantially cylindrical shape. The central axis of the cylinder is parallel to the Y direction, and a target supply unit 26 and a target recovery unit 28 are arranged at the position of the central axis. A plasma generation region 25 is located between the target supply unit 26 and the target recovery unit 28. The internal space of the chamber 2 includes a first space 20a, a second space 20b, and a peripheral space 20c. The inner wall 37 and the first partition wall 38 are located between the first space 20a and the second space 20b.

[0014] The inner wall 37 has a cylindrical shape and penetrates the side surface of the chamber 2. The central axis of the cylinder is parallel to the X direction. A part of the inner wall 37 is located inside the chamber 2 and is arranged to cover the plasma generation region 25. Another part of the inner wall 37 is located outside the chamber 2 and is connected to an exhaust device 30. The space inside the inner wall 37 and inside the chamber 2 is the first space 20a. The first space 20a has a first exhaust port 36 between the space inside the inner wall 37 and outside the chamber 2. An exhaust valve 39 with an adjustable opening degree is arranged between the first exhaust port 36 and the exhaust device 30.

[0015] The first partition wall 38 divides the space inside the chamber 2 and outside the inner wall 37 into a second space 20b and a peripheral space 20c surrounding the inner wall 37. The first partition wall 38 has a first opening 371.

[0016] Inside the chamber 2, the inner wall 37 has a first opening 371, a laser passage opening 372, and target passage openings 373 and 374. The first opening 371 of the inner wall 37 is common with the first opening 371 of the first partition wall 38 and is configured to communicate the second space 20b with the first space 20a. The laser passage opening 372 and the target passage openings 373 and 374 are configured to communicate the peripheral space 20c with the first space 20a.

[0017] The target supply unit 26 supplies a target 27 containing a target substance into the chamber 2. The material of the target substance may include tin, terbium, gadolinium, lithium, xenon, or any combination of two or more of them.

[0018] A window 21 is disposed on the wall of the chamber 2. Pulsed laser light 33 output from the laser device 3 passes through this window 21. A first gas supply device 41 that supplies a gas with a flow rate F1 to the peripheral space 20c is connected to the chamber 2. The gas to be supplied is, for example, hydrogen gas.

[0019] An EUV condenser mirror 23 having a reflecting surface in the shape of a rotating ellipsoid is disposed in the second space 20b. A multilayer reflection film in which molybdenum and silicon are alternately laminated is formed on the reflecting surface. The EUV condenser mirror 23 has first and second foci. The EUV condenser mirror 23 is disposed such that its first focus is located in the plasma generation region 25 and its second focus is located in the intermediate focus point 292. The pressure P1 in the second space 20b is measured by a pressure sensor 71 disposed in the chamber 2. The pressure sensor 71 corresponds to the second sensor in the present disclosure. The exhaust device 30 is controlled such that the pressure P1 in the second space 20b is within the target range. In the present disclosure, the target range of the pressure P_{1} may be referred to as the first target range.

[0020] The first aperture 371 is located in the optical path of the radiant light 251 including EUV light generated in the plasma generation region 25 and traveling toward the EUV condenser mirror 23. The EUV passage port 50 is located in the optical path of the reflected light 252 traveling from the EUV condenser mirror 23 toward the intermediate focus point 292. The EUV condenser mirror 23 is arranged such that the central axis of the optical path of the reflected light 252 is inclined with respect to the central axis of the optical path of the radiant light 251, and is configured to output the reflected light 252 to the external device 6 through the optical path outside the first aperture 371. The optical path outside the first aperture 371 means an optical path that does not pass through the first aperture 371.

[0021] The EUV light generation apparatus 1 includes a connection pipe 29 that connects the chamber 2 and the chamber of the external device 6. The external device 6 is a device that functions using EUV light, and may be the exposure apparatus 6a shown in FIG. 8 or the inspection apparatus 6b shown in FIG. 9. Inside the connection pipe 29, a wall (not shown) having an aperture formed at the position of the intermediate focus point 292 may be provided. A gas supply pipe 54 is connected to the connection pipe 29, and a second gas supply device 42 that supplies gas at a supply flow rate F2 is connected to the gas supply pipe 54 through a gas supply port 52. The gas to be supplied is, for example, hydrogen gas. The gas supplied from the second gas supply device 42 into the connection pipe 29 flows into the second space 20b through the EUV passage port 50.

[0022] The gas supply pipe 54 is not limited to being connected to the connection pipe 29, and may be connected to the chamber 2 to supply gas to the second space 20b.

[0023] The EUV light generation apparatus 1 includes a target sensor (not shown) and a laser light transmission device. The target sensor detects at least one of the presence, trajectory, position, and speed of the target 27. The target sensor may have an imaging function. The laser light transmission device is disposed between the laser device 3 and the chamber 2, and includes an optical element for defining the transmission state of the laser light 33 and an actuator for adjusting the position, posture, etc. of this optical element.

[0024] The EUV light generation device 1 further includes a processor 5. The processor 5 is a processing device including a memory 501 storing a control program and a CPU (central processing unit) 502 that executes the control program. The processor 5 is specially configured or programmed to execute various processes included in the present disclosure. The processor 5 controls the entire EUV light generation system 11. The processor 5 processes the detection results of the target sensor and controls, based on the detection results of the target sensor, the timing at which the target 27 is output, the output direction of the target 27, etc. Further, the processor 5 controls the oscillation timing of the laser device 3, the traveling direction of the laser beam 33, the condensing position of the laser beam 33, etc.

[0025] 1.2 Operations The laser beam 33 output from the laser device 3 passes through the window 21 and enters the chamber 2. The laser beam 33 is guided to the plasma generation region 25 through the laser passage port 372.

[0026] The target 27 output from the target supply unit 26 reaches the plasma generation region 25 through the target passage port 373. The target 27 is irradiated with the laser beam 33. Among the plurality of targets 27, the targets 27 that are not plasmaized without being irradiated with the laser beam 33 pass through the plasma generation region 25, further pass through the target passage port 374, and reach the target recovery unit 28.

[0027] The target 27 irradiated with the laser beam 33 is plasmaized, and emission light 251 is emitted from the plasma. The emission light 251 passes through the first aperture 371 and enters the EUV condenser mirror 23. The EUV light included in the emission light 251 is reflected by the EUV condenser mirror 23 with a higher reflectivity than light in other wavelength ranges. The reflected light 252 including the EUV light reflected by the EUV condenser mirror 23 is condensed at the intermediate condensing point 292 and output to the external device 6. Note that a plurality of pulses included in the laser beam 33 may be irradiated to one target 27. The plurality of pulses include, for example, a prepulse and a main pulse.

[0028] The exhaust device 30 exhausts the gas in the first space 20a to the outside of the inner wall 37 and outside the chamber 2 via the exhaust valve 39. As a result, the pressure in the first space 20a is maintained lower than both the pressure in the peripheral space 20c and the pressure P1 in the second space 20b. Consequently, gas flows from the second space 20b toward the first space 20a at the first opening 371, and gas flows from the peripheral space 20c toward the first space 20a at the laser passage port 372 and the target passage ports 373 and 374. Therefore, the debris of the target material generated near the plasma generation region 25 is suppressed from moving from the first space 20a to the peripheral space 20c and the second space 20b. Also, the deposition of the debris of the target material on optical components such as the EUV condenser mirror 23 and the window 21 is suppressed.

[0029] 2. Problems of the Comparative Example The pressure P1 in the second space 20b of the chamber 2 is around 100 Pa, for example, and the pressure inside the chamber of the external device 6 is 10 Pa or less, around 1 Pa, for example. Therefore, in the comparative example, a part of the gas inside the chamber 2 may flow into the chamber of the external device 6. As an improvement measure for the comparative example, in order to reduce the inflow of gas into the chamber of the external device 6, it is conceivable to arrange a differential exhaust device including a second exhaust port 61 described later in the connecting pipe 29. In this improvement measure, a part of the gas inside the chamber 2 is exhausted from the second exhaust port 61.

[0030] Thus, the gas supplied from the second gas supply device 42 not only flows out through the first opening 371, but also flows out to the external device 6 in the comparative example and flows out from the second exhaust port 61 in the improvement measure. Therefore, even if the supply flow rate F2 of the gas supplied from the second gas supply device 42 is known, it is difficult to know the first passage flow rate M1 of the gas passing through the first opening 371.

[0031] Although it is possible to know the first passing flow rate M1 by measuring the flow rate of the first exhaust port 36, since the gas passing through the first exhaust port 36 contains a large amount of debris of the target substance, the accuracy of the flow sensor is likely to decrease, and accurate measurement is difficult.

[0032] Since the debris of the target substance is suppressed from moving from the first space 20a to the second space 20b by the gas flowing from the second space 20b to the first space 20a through the first opening 371, it is not preferable that the first passing flow rate M1 is too small. On the other hand, if the first passing flow rate M1 is too large, the flow rate of the gas in the plasma generation region 25 and its surroundings increases, so the trajectory of the target 27 becomes unstable, and thus the generation of EUV light may become unstable.

[0033] The embodiment described below relates to controlling the supply flow rate F2 of the gas supplied from the second gas supply device 42 so that the first passing flow rate M1 of the gas from the second space 20b to the first space 20a falls within an appropriate range.

[0034] 3. EUV Light Generation System 11a That Controls Supply Flow Rate F2 Based on Exhaust Flow Rate E1 3.1 Configuration FIG. 3 shows the configuration of the EUV light generation system 11a according to the first embodiment. In the first embodiment, a differential exhaust device is arranged at a position between the intermediate focus point 292 of the connection pipe 29 and the portion connected to the gas supply pipe 54. The differential exhaust device includes a part of the connection pipe 29, second and third partition walls 92 and 93 located inside the connection pipe 29, and an exhaust pipe 64 branched from the connection pipe 29 between the second and third partition walls 92 and 93. The combination of the connection pipe 29 and the exhaust pipe 64 corresponds to the connection part in the present disclosure.

[0035] The second partition wall 92 includes a second opening 921 through which the reflected light 252 passes and a partition plate 922 that surrounds the second opening 921. The third partition wall 93 includes a third opening 931 that is smaller than the second opening 921 and a partition plate 932 that surrounds the third opening 931, and is arranged so that the reflected light 252 that passes through the second opening 921 passes through the third opening 931 and is output to the external device 6. The exhaust pipe 64 is connected to the exhaust device 31 via a second exhaust port 61. A flow rate sensor 62 and a valve 63 are arranged in the exhaust pipe 64 between the second exhaust port 61 and a portion connected to the connecting pipe 29. The flow rate sensor 62 is an example of a first sensor in the present disclosure, and is configured to measure the exhaust flow rate E1 of the gas passing through the second exhaust port 61.

[0036] The space between the second partition 92 and the third partition 93 is referred to as a third space 910, and the space between the EUV passage port 50 and the second partition 92 is referred to as a fourth space 900. The third space 910 includes not only the inside of the connecting pipe 29 but also the inside of the exhaust pipe 64 to which the second exhaust port 61 opens. By exhausting the gas inside the third space 910 through the second exhaust port 61, the gas inside the chamber 2 is prevented from flowing into the chamber of the external device 6. Although the third partition 93 is not an essential component in the present disclosure, the presence of the third partition 93 further prevents the gas inside the chamber 2 from flowing into the chamber of the external device 6. The fourth space 900 includes not only the inside of the connecting pipe 29 but also the inside of the gas supply pipe 54 to which the gas supply port 52 opens.

[0037] 3.2 Operation 4 is a flowchart showing the operation of setting the gas supply flow rate F2 in the first embodiment. The operation shown in FIG. 4 is performed in a preparation stage for starting the generation of EUV light in the EUV light generation apparatus 1.

[0038] In S1, the processor 5 fully opens the exhaust valve 39 and operates the following exhaust devices at maximum power. External device 6: Exhaust device (not shown) Exhaust device 30 of chamber 2 Differential pumping device 31

[0039] Regarding the exhaust device of the external device 6, instead of being controlled by the processor 5, it may be controlled by a processor (not shown) of the external device 6.

[0040] In S2, the processor 5 controls the first gas supply device 41 so that the first gas supply device 41 starts supplying gas at a flow rate F1.

[0041] In S3, the processor 5 calculates an initial set value of the gas supply flow rate F2 by the second gas supply device 42 according to the following formula. F2 = M1t + M2p

[0042] M1t is the target value of the first passing flow rate M1 of the gas at the first opening 371, and is set to a value that can suppress the movement of debris of the target substance from the first space 20a to the second space 20b or the instability of the trajectory of the target 27. M2p is the assumed value of the second passing flow rate M2 of the gas at the second opening 921, and is calculated from the assumed value of the pressure difference between the second space 20b and the third space 910 and the size of the second opening 921.

[0043] In S4, the processor 5 controls the second gas supply device 42 so that the second gas supply device 42 starts supplying gas at a supply flow rate F2.

[0044] In S5, the processor 5 adjusts the opening degree of the exhaust valve 39 and the power of the exhaust device 30 so that the pressure P1 measured by the pressure sensor 71 is within the target range. Alternatively, only one of the exhaust valve 39 and the exhaust device 30 may be adjusted. In the present disclosure, the process of S5 is sometimes referred to as the first process.

[0045] In S6, the processor 5 calculates the second passing flow rate M2 at the second opening 921 based on the measurement result of the flow rate sensor 62. For example, assuming that the outflow of gas from the third space 910 to the external device 6 is negligibly small, the exhaust flow rate E1 measured by the flow rate sensor 62 can be directly used as the second passing flow rate M2. Alternatively, the outflow rate of gas from the third space 910 to the external device 6 can be calculated from the assumed value of the pressure difference between the third space 910 and the external device 6 and the size of the third opening 931, and the second passing flow rate M2 can be calculated by adding this outflow rate and the exhaust flow rate E1.

[0046] In S7, the processor 5 determines whether the value obtained by subtracting the second passing flow rate M2 from the supply flow rate F2, that is, the first passing flow rate M1, is within the target range. The upper limit of the target range of the first passing flow rate M1 is, for example, a value obtained by adding a positive number ΔM to the target value M1t, and the lower limit of the target range of the first passing flow rate M1 is, for example, a value obtained by subtracting a positive number ΔM from the target value M1t. In the present disclosure, the target range of the first passing flow rate M1 may be referred to as the second target range. If the first passing flow rate M1 is not within the target range (S7: NO), the processor 5 proceeds to S8. If the first passing flow rate M1 is within the target range (S7: YES), the processor 5 proceeds to S9.

[0047] In S8, when the first passing flow rate M1 is smaller than the lower limit of the target range, the processor 5 increases the supply flow rate F2, and when the first passing flow rate M1 is larger than the upper limit of the target range, the processor 5 decreases the supply flow rate F2. In the present disclosure, the processes of S6 to S8 may be referred to as the second process.

[0048] After S8, the processor 5 returns the process to S4 and continues the adjustment until the first passing flow rate M1 is within the target range using the new value of the supply flow rate F2.

[0049] In S9, the processor 5 ends the processing of this flowchart assuming that the setting of the supply flow rate F2 is completed. Thereafter, the output of the target 27 and the output of the laser beam 33 are started, and the output of EUV light is started.

[0050] 3.3 Function (1) According to the first embodiment, the EUV light generation device 1 includes a chamber 2, a first partition wall 38, a connection portion including a connection pipe 29, a second partition wall 92, a gas supply port 52, a first exhaust port 36, a second exhaust port 61, a first sensor, and a processor 5. The chamber 2 includes a first space 20a where EUV light is generated by irradiating a target 27 with laser light 33, and a second space 20b where an EUV condenser mirror 23 that reflects EUV light and outputs it to an external device 6 is disposed. The first partition wall 38 has a first opening 371 through which EUV light passes and is located between the first space 20a and the second space 20b. The connection portion connects the chamber 2 and the external device 6. The second partition wall 92 has a second opening 921 through which EUV light passes and is located inside the connection portion. The gas supply port 52 allows the gas supplied to the second space 20b to pass through. The first exhaust port 36 opens into the first space 20a. The second exhaust port 61 opens into a third space 910 that is inside the connection portion and located between the second partition wall 92 and the external device 6. The first sensor is disposed in the third space 910. The processor 5 calculates a first passing flow rate M1 of the gas passing through the first opening 371 based on the measurement result by the first sensor, and adjusts a supply flow rate F2 of the gas supplied through the gas supply port 52 based on the first passing flow rate M1.

[0051] According to this, based on the measurement result by the first sensor disposed in the third space 910, the first passing flow rate M1 of the gas passing through the first opening 371 can be calculated, so that the supply flow rate F2 can be adjusted so that the first passing flow rate M1 falls within an appropriate range. Therefore, it is possible to suppress the debris of the target substance from moving to the second space 20b through the first opening 371 or the trajectory of the target 27 from becoming unstable.

[0052] (2) According to the first embodiment, the first sensor is a flow rate sensor 62 that measures an exhaust flow rate E1 of the gas passing through the second exhaust port 61, and the processor 5 calculates the first passing flow rate M1 based on the exhaust flow rate E1.

[0053] According to this, by using the exhaust flow rate E1 of the gas passing through the second exhaust port 61, the first passing flow rate M1 can be accurately calculated, and the supply flow rate F2 can be accurately adjusted.

[0054] (3) According to the first embodiment, the processor 5 calculates the second passing flow rate M2 of the gas passing through the second opening 921 based on the exhaust flow rate E1, and calculates the difference between the supply flow rate F2 and the second passing flow rate M2 as the first passing flow rate M1.

[0055] According to this, since the second passing flow rate M2 of the gas passing through the second opening 921 is calculated, the first passing flow rate M1 can be calculated more accurately. [[ID=IM11]]

[0056] (4) According to the first embodiment, the processor 5 calculates the difference between the supply flow rate F2 and the exhaust flow rate E1 as the first passing flow rate M1.

[0057] According to this, on the assumption that the amount of gas flowing from the third space 910 to the external device 6 is sufficiently small, the first passing flow rate M1 can be simply calculated assuming that the exhaust flow rate E1 and the second passing flow rate M2 are equal.

[0058] (5) According to the first embodiment, the EUV light generating device 1 includes a third partition wall 93 disposed between the third space 910 and the external device 6, and the third partition wall 93 has a third opening 931 through which EUV light passes and which is smaller than the second opening 921.

[0059] [[ID=IM24]] According to this, by configuring a differential exhaust device including the third partition wall 93, the amount of gas flowing from the third space 910 to the external device 6 can be limited, and the first passing flow rate M1 can be accurately calculated. Further, since the gas pressure in the third space 910 can be kept low, the loss due to the absorption of EUV light in the third space 910 can be suppressed.

[0060] (6) According to the first embodiment, the connection portion includes a connection pipe 29 through which EUV light passes, and an exhaust pipe 64 that branches from the connection pipe 29 and is connected to the second exhaust port 61 and includes a flow rate sensor 62.

[0061] According to this, the exhaust flow rate E1 is measured in the exhaust pipe 64 branching off from the connecting pipe 29, so that the exhaust flow rate E1 can be measured accurately.

[0062] (7) According to the first embodiment, the EUV collector mirror 23 outputs the EUV light to the external device 6 via an optical path outside the first opening 371.

[0063] This separates the first space 20a in which debris of the target material is generated from the second, third, and fourth spaces 20b, 910, and 900 which include the optical path of the EUV light from the EUV collector mirror 23 to the external device 6, thereby making it possible to prevent debris of the target material from entering the second, third, and fourth spaces 20b, 910, and 900.

[0064] (8) According to the first embodiment, the processor 5 decreases the supply flow rate F2 when the first through flow rate M1 is greater than the upper limit M1t+ΔM of the target range, and increases the supply flow rate F2 when the first through flow rate M1 is less than the lower limit M1t-ΔM of the target range.

[0065] This allows the supply flow rate F2 to be adjusted so that the first through flow rate M1 falls within the target range.

[0066] (9) According to the first embodiment, the EUV light generation system 1 includes an exhaust device 30 connected to the first exhaust port 36 and a pressure sensor 71 that measures the pressure P1 in the second space 20b. The processor 5 controls the exhaust device 30 so that the pressure P1 in the second space 20b falls within a target range, and then calculates a first through flow rate M1 based on the measurement result from the flow rate sensor 62, and adjusts the supply flow rate F2 based on the first through flow rate M1.

[0067] When the pressure P1 in the second space 20b changes, the first gas flow rate M1 passing through the first opening 371 may change. By adjusting the supply flow rate F2 based on the first gas flow rate M1 calculated after the pressure P1 in the second space 20b is within the target range, both the pressure P1 in the second space 20b and the first gas flow rate M1 can be controlled within their respective target ranges.

[0068] (10) According to the first embodiment, the EUV light generation device 1 includes an exhaust device 30 connected to the first exhaust port 36 and a pressure sensor 71 that measures the pressure P1 in the second space 20b. The processor 5 controls the exhaust device 30 so that the pressure P1 in the second space 20b is within the first target range, calculates the first gas flow rate M1 based on the measurement result by the flow rate sensor 62, and reduces the supply flow rate F2 when the first gas flow rate M1 is greater than the upper limit M1t + ΔM of the second target range, and increases the supply flow rate F2 when the first gas flow rate M1 is less than the lower limit M1t - ΔM of the second target range. The processes S6 to S8 are alternately performed until the first gas flow rate M1 is within the second target range.

[0069] When the supply flow rate F2 changes, the pressure P1 in the second space 20b may change. By alternately performing the process of S5 and the processes of S6 to S8, both the pressure P1 in the second space 20b and the first gas flow rate M1 can be controlled within their respective target ranges.

[0070] (11) According to the first embodiment, the EUV light generation device 1 includes an exhaust device 30 connected to the first exhaust port 36, an exhaust valve 39 disposed between the first exhaust port 36 and the exhaust device 30, and a pressure sensor 71 that measures the pressure P1 in the second space 20b. The processor 5 controls the opening degree of the exhaust valve 39 so that the pressure P1 in the second space 20b is within the target range, then calculates the first gas flow rate M1 based on the measurement result by the flow rate sensor 62, and adjusts the supply flow rate F2 based on the first gas flow rate M1.

[0071] According to this, the flow rate of the exhaust gas is adjusted by adjusting the opening degree of the exhaust valve 39, so that the pressure P1 in the second space 20b can be accurately controlled.

[0072] (12) According to the first embodiment, the EUV light generation system 1 includes an exhaust device 30 connected to a first exhaust port 36, an exhaust valve 39 disposed between the first exhaust port 36 and the exhaust device 30, and a pressure sensor 71 that measures a pressure P1 in the second space 20b. The processor 5 alternately performs the following processes until the first through flow rate M1 falls within the second target range: a process S5 in which the exhaust valve 39 is controlled to open so that the pressure P1 in the second space 20b falls within a first target range; and processes S6 to S8 in which the processor 5 calculates a first through flow rate M1 based on the measurement result of the flow sensor 62, and decreases the supply flow rate F2 when the first through flow rate M1 is greater than an upper limit M1t+ΔM of the second target range, and increases the supply flow rate F2 when the first through flow rate M1 is less than a lower limit M1t-ΔM of the second target range.

[0073] According to this, by alternately performing the process of S5 and the processes of S6 to S8, it is possible to control both the pressure P1 in the second space 20b and the first through flow rate M1 within their respective target ranges.

[0074] (13) According to the first embodiment, the gas supply port 52 opens into the fourth space 900 located inside the connection portion and between the second partition wall 92 and the chamber 2 .

[0075] This allows a gas flow from the fourth space 900 to the second space 20b, so that even if debris of the target material gets mixed into the second space 20b, it can be prevented from reaching the fourth space 900.

[0076] In other respects, the first embodiment is similar to the comparative example.

[0077] 4. EUV light generation system 11b that controls the supply flow rate F2 based on the pressure P2 in the third space 910 4.1 Configuration FIG. 5 shows the configuration of the EUV light generation system 11b according to the second embodiment. In the second embodiment, a pressure sensor 72 is connected to the connection pipe 29. The pressure sensor 72 is an example of the first sensor in the present disclosure and is configured to measure the pressure P2 in the third space 910. The flow rate sensor 62 provided in the exhaust pipe 64 in the first embodiment may be omitted in the second embodiment.

[0078] 4.2 Operation FIG. 6 is a flowchart showing the operation of setting the supply flow rate F2 of the gas in the second embodiment. The processes of S1 to S5 and S7 to S9 are the same as those in the first embodiment.

[0079] In S6, the processor 5 calculates the second passing flow rate M2 at the second opening 921 based on the absolute value ΔP of the pressure difference between the pressure P1 in the second space 20b measured by the pressure sensor 71 and the pressure P2 in the third space 910 measured by the pressure sensor 72. As methods for calculating the second passing flow rate M2 based on the absolute value ΔP of the pressure difference, there are a first method using the previously measured results and a second method performing theoretical calculations.

[0080] FIG. 7 shows a data table created in the first method for calculating the second passing flow rate M2 based on the absolute value ΔP of the pressure difference. The data table is stored in a storage medium such as the memory 501 and shows the relationship between the absolute value ΔP and the second passing flow rate M2. Theoretically, since the second passing flow rate M2 is proportional to the positive square root of the absolute value ΔP, the absolute value ΔP and the second passing flow rate M2 have a one-to-one correspondence relationship.

[0081] The second through flow rate M2 is measured as follows. In the EUV light generation system 11b, the exhaust valve 39 is closed, the supply of gas by the first gas supply device 41 is stopped, the exhaust device (not shown) of the external device 6 is stopped, and the gas supply flow rate F2 by the second gas supply device 42 is changed while the exhaust device 31 is operating. The second through flow rate M2 at this time is equal to the supply flow rate F2, so the second through flow rate M2 can be determined by knowing the supply flow rate F2. Alternatively, since the second through flow rate M2 is equal to the exhaust flow rate E1 described in the first embodiment, the measurement value of the flow rate sensor 62 described in the first embodiment may be used as the second through flow rate M2.

[0082] In this way, by measuring the second through flow rate M2 while changing the supply flow rate F2 and measuring the absolute value ΔP, it is possible to create a data table such as that shown in Fig. 7. In S6 of Fig. 6, the value of the second through flow rate M2 corresponding to the calculated absolute value ΔP is read from the data table, and interpolation is performed as necessary to calculate the second through flow rate M2.

[0083] In a second method for calculating the second passing flow rate M2 based on the absolute value ΔP of the pressure difference, a value proportional to the positive square root of the absolute value ΔP is calculated. Specifically, using the absolute value ΔP, the flow coefficient C, the cross-sectional area A of the second opening 921, and the fluid density ρ of the gas passing through the second opening 921, C×A×(2×ΔP / ρ) 1 / 2 The second passing flow rate M2 is calculated by the following equation.

[0084] In the second method, the C×A part of the above equation may be calculated using the measurement results described with reference to Fig. 7. In this case, specific values for the flow coefficient C and the cross-sectional area A are not required.

[0085] 4.3 Effect (14) According to the second embodiment, the EUV light generating apparatus 1 includes a pressure sensor 71 that measures the pressure P1 in the second space 20b and a pressure sensor 72 that measures the pressure P2 in the third space 910. The processor 5 calculates the first flow rate M1 based on the measurement results by the pressure sensors 71 and 72.

[0086] According to this, by using the measurement results by the pressure sensors 71 and 72, the first flow rate M1 can be accurately calculated. Also, since the flow rate sensor 62 may not be provided in the exhaust pipe 64, a decrease in exhaust capacity can be suppressed.

[0087] (15) According to the second embodiment, the processor 5 calculates the second flow rate M2 of the gas passing through the second opening 921 based on the measurement results by the pressure sensors 71 and 72, and calculates the difference between the supply flow rate F2 and the second flow rate M2 as the first flow rate M1.

[0088] According to this, since the second flow rate M2 of the gas passing through the second opening 921 is calculated, the first flow rate M1 can be calculated more accurately.

[0089] (16) According to the second embodiment, the EUV light generating apparatus 1 includes a storage medium that stores a data table showing the relationship between the absolute value ΔP of the pressure difference between the second and third spaces 20b and 910 and the second flow rate M2. The processor 5 calculates the absolute value ΔP based on the measurement results by the pressure sensors 71 and 72, and calculates the second flow rate M2 based on the absolute value ΔP and the data table.

[0090] According to this, by using the data table, the second flow rate M2 can be easily calculated.

[0091] (17) According to the second embodiment, the processor 5 calculates the absolute value ΔP of the pressure difference between the second and third spaces 20b and 910 based on the measurement results by the pressure sensors 71 and 72, and calculates a value proportional to the positive square root of the absolute value ΔP as the second flow rate M2.

[0092] According to this, by setting the value proportional to the positive square root of the absolute value ΔP of the pressure difference as the second flow rate M2, the theoretically accurate second flow rate M2 can be calculated.

[0093] (18) According to the second embodiment, the processor 5 calculates the absolute value ΔP of the pressure difference between the second and third spaces 20b and 910 based on the measurement results by the pressure sensors 71 and 72, and uses the absolute value ΔP, the flow coefficient C, the cross-sectional area A of the second opening 921, and the fluid density ρ of the gas passing through the second opening 921 to calculate C×A×(2×ΔP / ρ) 1 / 2 and calculates the obtained value as the second flow rate M2.

[0094] According to this, the second flow rate M2 can be calculated by theoretical calculation using the pressure difference.

[0095] In other respects, the second embodiment is the same as the first embodiment.

[0096] 5. Others 5.1 Example of the external device 6 FIG. 8 schematically shows the configuration of an exposure apparatus 6a connected to the EUV light generation system 11a. In FIG. 8, the exposure apparatus 6a as the external device 6 (see FIG. 1) includes a mask irradiation unit 608 and a workpiece irradiation unit 609. The mask irradiation unit 608 illuminates the mask pattern on the mask table MT through a reflection optical system with EUV light incident from the EUV light generation system 11a. The workpiece irradiation unit 609 forms an image of the EUV light reflected by the mask table MT on a workpiece (not shown) disposed on the workpiece table WT through a reflection optical system. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 6a exposes the workpiece to the EUV light reflecting the mask pattern by synchronously translating the mask table MT and the workpiece table WT. An electronic device can be manufactured by transferring a device pattern onto a semiconductor wafer through the above exposure process.

[0097] FIG. 9 schematically shows the configuration of the inspection apparatus 6b connected to the EUV light generation system 11a. In FIG. 9, the inspection apparatus 6b as an external apparatus 6 (see FIG. 1) includes an illumination optical system 603 and a detection optical system 606. The illumination optical system 603 reflects the EUV light incident from the EUV light generation system 11a and irradiates the mask 605 disposed on the mask stage 604. The mask 605 referred to here includes a mask blank before a pattern is formed. The detection optical system 606 reflects the EUV light from the illuminated mask 605 and forms an image on the light receiving surface of the detector 607. The detector 607 that has received the EUV light acquires an image of the mask 605. The detector 607 is, for example, a TDI (time delay integration) camera. Based on the image of the mask 605 obtained through the above process, defects of the mask 605 are inspected, and using the inspection results, a mask suitable for manufacturing an electronic device is selected. Then, an electronic device can be manufactured by exposing and transferring the pattern formed on the selected mask onto a photosensitive substrate using the exposure apparatus 6a.

[0098] Although the EUV light generation system 11a according to the first embodiment is shown in FIGS. 8 and 9, the EUV light generation system 11b according to the second embodiment may be used.

[0099] 5.2 Supplementary The above description is intended to be illustrative rather than restrictive. Thus, it is apparent to those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. It is also apparent to those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0100] The terms used throughout this specification and the claims should be construed as "non-limiting" terms unless otherwise specified. For example, terms such as "comprising," "having," "including," and "containing" should be construed to mean "not excluding the presence of elements other than those described." Also, the modifier "one" should be construed to mean "at least one" or "one or more." Further, the term "at least one of A, B, and C" should be construed to mean "A," "B," "C," "A + B," "A + C," "B + C," or "A + B + C," and should further be construed to include combinations with things other than "A," "B," and "C."

Claims

1. A chamber including a first space where a target is irradiated with a laser beam to generate extreme ultraviolet light, and a second space where an EUV condenser mirror for reflecting the extreme ultraviolet light and outputting it to an external device is disposed; A first partition wall having a first opening through which the extreme ultraviolet light passes and located between the first space and the second space; A connection part connecting the chamber and the external device; A second partition wall having a second opening through which the extreme ultraviolet light passes and located inside the connection part; A gas supply port for passing gas supplied to the second space; A first exhaust port opening to the first space; A second exhaust port opening to a third space located inside the connection part between the second partition wall and the external device; A first sensor disposed in the third space; A processor that calculates a first passing flow rate of gas passing through the first opening based on a measurement result by the first sensor, and adjusts a supply flow rate of gas supplied through the gas supply port based on the first passing flow rate; An extreme ultraviolet light generating device comprising the above.

2. The extreme ultraviolet light generating device according to Claim 1, wherein the first sensor is a flow rate sensor that measures an exhaust flow rate of gas passing through the second exhaust port, and the processor calculates the first passing flow rate based on the exhaust flow rate. An extreme ultraviolet light generating device.

3. The extreme ultraviolet light generating device according to Claim 2, wherein the processor calculates a second passing flow rate of gas passing through the second opening based on the exhaust flow rate, and calculates a difference between the supply flow rate and the second passing flow rate as the first passing flow rate. An extreme ultraviolet light generating device.

4. The extreme ultraviolet light generating device according to Claim 2, wherein the processor calculates a difference between the supply flow rate and the exhaust flow rate as the first passing flow rate. An extreme ultraviolet light generating device.

5. The extreme ultraviolet light generating device according to Claim 4, further comprising a third partition wall having a third opening through which the extreme ultraviolet light passes and which is smaller than the second opening, and disposed between the third space and the external device. An extreme ultraviolet light generating device.

6. The extreme ultraviolet light generating device according to Claim 2, wherein the connection part includes a connection pipe through which the extreme ultraviolet light passes, and an exhaust pipe branched from the connection pipe and connected to the second exhaust port and including the flow rate sensor. An extreme ultraviolet light generating device.

7. An extreme ultraviolet light generation device according to claim 1, wherein the EUV condenser mirror outputs the extreme ultraviolet light to the external device through an optical path outside the first opening; extreme ultraviolet light generation device.

8. An extreme ultraviolet light generation device according to claim 1, wherein the processor decreases the supply flow rate when the first passing flow rate is greater than the upper limit of the target range, and increases the supply flow rate when the first passing flow rate is less than the lower limit of the target range; extreme ultraviolet light generation device.

9. An extreme ultraviolet light generation device according to claim 1, further comprising an exhaust device connected to the first exhaust port, and a second sensor which is a pressure sensor for measuring the pressure in the second space; wherein the processor controls the exhaust device so that the pressure in the second space is within a target range, then calculates the first passing flow rate based on the measurement result by the first sensor, and adjusts the supply flow rate based on the first passing flow rate; extreme ultraviolet light generation device.

10. An extreme ultraviolet light generation device according to claim 1, further comprising an exhaust device connected to the first exhaust port, and a second sensor which is a pressure sensor for measuring the pressure in the second space; wherein the processor performs a first process of controlling the exhaust device so that the pressure in the second space is within a first target range, and a second process of calculating the first passing flow rate based on the measurement result by the first sensor, decreasing the supply flow rate when the first passing flow rate is greater than the upper limit of the second target range, and increasing the supply flow rate when the first passing flow rate is less than the lower limit of the second target range, alternately until the first passing flow rate is within the second target range; extreme ultraviolet light generation device.

11. An extreme ultraviolet light generation device according to claim 1, further comprising an exhaust device connected to the first exhaust port, an exhaust valve disposed between the first exhaust port and the exhaust device, and a second sensor which is a pressure sensor for measuring the pressure in the second space; wherein the processor controls the opening degree of the exhaust valve so that the pressure in the second space is within a target range, then calculates the first passing flow rate based on the measurement result by the first sensor, and adjusts the supply flow rate based on the first passing flow rate; extreme ultraviolet light generation device.

12. An extreme ultraviolet light generation device according to claim 1, further comprising an exhaust device connected to the first exhaust port, wherein the exhaust device is connected to the first exhaust port, and the exhaust device is connected to the first exhaust port, and the exhaust device is connected to the first exhaust port, An exhaust valve disposed between the first exhaust port and the exhaust device; A second sensor which is a pressure sensor for measuring the pressure in the second space; further comprising; The processor; A first process of controlling the opening degree of the exhaust valve so that the pressure in the second space falls within a first target range; A second process of calculating the first flow rate through based on the measurement result by the first sensor, reducing the supply flow rate when the first flow rate through is greater than the upper limit of the second target range, and increasing the supply flow rate when the first flow rate through is less than the lower limit of the second target range; alternately performing until the first flow rate through falls within the second target range; An extreme ultraviolet light generating device.

13. The extreme ultraviolet light generating device according to claim 1, wherein the gas supply port opens into a fourth space which is inside the connection part and located between the second partition wall and the chamber; An extreme ultraviolet light generating device.

14. The extreme ultraviolet light generating device according to claim 1, wherein it further comprises a second sensor which is a pressure sensor for measuring the pressure in the second space; the first sensor is a pressure sensor for measuring the pressure in the third space; the processor calculates the first flow rate through based on the measurement results by the first and second sensors; An extreme ultraviolet light generating device.

15. The extreme ultraviolet light generating device according to claim 14, wherein the processor calculates a second flow rate through of the gas passing through the second opening based on the measurement results by the first and second sensors, and calculates the difference between the supply flow rate and the second flow rate through as the first flow rate through; An extreme ultraviolet light generating device.

16. The extreme ultraviolet light generating device according to claim 15, wherein it further comprises a storage medium storing a data table showing the relationship between the absolute value of the pressure difference between the second and third spaces and the second flow rate through; the processor calculates the absolute value based on the measurement results by the first and second sensors, and calculates the second flow rate through based on the absolute value and the data table; An extreme ultraviolet light generating device.

17. The extreme ultraviolet light generating device according to claim 15, wherein the processor calculates the absolute value of the pressure difference between the second and third spaces based on the measurement results by the first and second sensors, and calculates a value proportional to the positive square root of the absolute value as the second flow rate through; An extreme ultraviolet light generating device.

18. An extreme ultraviolet light generation device according to claim 15, comprising: The processor calculates the absolute value ΔP of the pressure difference between the second and third spaces based on the measurement results of the first and second sensors, and uses the absolute value ΔP, the flow coefficient C, the cross-sectional area A of the second opening, and the fluid density ρ of the gas passing through the second opening to calculate C×A×(2×ΔP / ρ). １／２ The value obtained by the above is calculated as the flow rate through the second opening. Extreme ultraviolet light generation device.

19. A method for manufacturing an electronic device, comprising: A chamber including a first space where a target is irradiated with a laser beam to generate extreme ultraviolet light, and a second space where an EUV condenser mirror for reflecting the extreme ultraviolet light and outputting it to an exposure apparatus is disposed; A first partition wall having a first opening through which the extreme ultraviolet light passes and located between the first space and the second space; A connection part connecting the chamber and the exposure apparatus; A second partition wall having a second opening through which the extreme ultraviolet light passes and located inside the connection part; A gas supply port for passing a gas supplied to the second space; A first exhaust port opening to the first space; A second exhaust port opening to a third space located inside the connection part between the second partition wall and the exposure apparatus; A sensor disposed in the third space; A processor that calculates a first passing flow rate of a gas passing through the first opening based on a measurement result by the sensor and adjusts a supply flow rate of the gas supplied through the gas supply port based on the first passing flow rate; Generating the extreme ultraviolet light by an extreme ultraviolet light generation device comprising the same; Outputting the extreme ultraviolet light to the exposure apparatus; Exposing the extreme ultraviolet light onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device A method for manufacturing an electronic device, including the above steps.

20. A method for manufacturing an electronic device, comprising: A chamber including a first space where a target is irradiated with a laser beam to generate extreme ultraviolet light, and a second space where an EUV condenser mirror for reflecting the extreme ultraviolet light and outputting it to an inspection apparatus is disposed; A first partition wall having a first opening through which the extreme ultraviolet light passes and located between the first space and the second space; A connection part connecting the chamber and the inspection apparatus; A second partition wall having a second opening through which the extreme ultraviolet light passes and located inside the connection part; A gas supply port for passing a gas supplied to the second space; A first exhaust port opening to the first space; A second exhaust port opening to a third space located inside the connection part between the second partition wall and the inspection apparatus; A sensor disposed in the third space; A processor that calculates a first flow rate of gas passing through the first opening based on the measurement result by the sensor, and adjusts a supply flow rate of gas supplied through the gas supply port based on the first flow rate; The extreme ultraviolet light generated by an extreme ultraviolet light generating apparatus including the same is irradiated onto a mask in the inspection apparatus to inspect for defects in the mask, A mask is selected using the result of the inspection, A pattern formed on the selected mask is exposed and transferred onto a photosensitive substrate A method for manufacturing an electronic device, including this.

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