EUV light generation apparatus and method for manufacturing electronic devices

Abstract

The purpose is to suppress the adhesion of debris to the focusing mirror and to prevent debris from entering external equipment. [Solution] The EUV light generation apparatus comprises a chamber that generates EUV light in a plasma generation region, a focusing mirror that reflects the EUV light toward an external device, a differential exhaust chamber provided on the optical path of the reflected EUV light, a gas supply port that supplies gas to the space between the differential exhaust chamber and the focusing mirror, a first partition wall disposed between the plasma generation region and the focusing mirror, the first partition wall having a gas inlet through which gas flows in from the focusing mirror side to the plasma generation region side and through which EUV light passes, a main gas exhaust port that exhausts the gas that has flowed in from the focusing mirror side to the plasma generation region side via the gas inlet, and a narrowing member disposed between the gas supply port and the focusing mirror that allows the EUV light reflected by the focusing mirror to pass through and narrows the gas flow from the gas supply port toward the gas inlet.

Description

Technical Field

[0001] The present disclosure relates to an EUV light generating device 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 optical lithography 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 that combines a device for generating extreme ultraviolet (EUV) light with a wavelength of about 13 nm and a reduction projection reflective optical system is expected.

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] An EUV light generation apparatus according to one aspect of the present disclosure comprises: a chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light; a focusing mirror disposed in the chamber that reflects the EUV light toward an external device; a differential exhaust chamber provided on the optical path of the EUV light reflected by the focusing mirror; a gas supply port that supplies gas to the space between the differential exhaust chamber and the focusing mirror; a first partition wall disposed between the plasma generation region and the focusing mirror, the first partition wall having a gas inlet through which the gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side and through which the EUV light toward the focusing mirror passes; a main gas exhaust port that exhausts the gas that has flowed from the focusing mirror side to the plasma generation region side via the gas inlet; and a narrowing member disposed between the gas supply port and the focusing mirror that allows the EUV light reflected by the focusing mirror to pass through and narrows the gas flow toward the gas inlet from the gas supply port.

[0006] A manufacturing method relating to one aspect of this disclosure comprises a chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light, a focusing mirror disposed within the chamber that reflects the EUV light toward an external device, a differential exhaust chamber provided on the optical path of the EUV light reflected by the focusing mirror, a gas supply port that supplies gas to the space between the differential exhaust chamber and the focusing mirror, and a first partition wall disposed between the plasma generation region and the focusing mirror, wherein the gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side, and The EUV light generation apparatus comprises a first partition wall through which EUV light from a plasma generation region toward a focusing mirror passes; a main gas exhaust port for exhausting gas that has flowed from the focusing mirror side toward the plasma generation region side via the gas inlet; and a constricting member positioned between a gas supply port and a focusing mirror, which allows the EUV light reflected by the focusing mirror to pass through and narrows the gas flow toward the gas inlet from the gas supply port toward the gas inlet. The EUV light generated by the apparatus is output to an exposure apparatus, and the EUV light is exposed onto a photosensitive substrate in the exposure apparatus in order to manufacture an electronic device.

[0007] A manufacturing method relating to one aspect of this disclosure comprises a chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light, a focusing mirror disposed within the chamber that reflects the EUV light toward an external device, a differential exhaust chamber provided on the optical path of the EUV light reflected by the focusing mirror, a gas supply port that supplies gas to the space between the differential exhaust chamber and the focusing mirror, and a first partition wall disposed between the plasma generation region and the focusing mirror, wherein the gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side and also flows from the plasma generation region. The EUV light generation apparatus comprises a first partition wall through which EUV light directed toward a light mirror passes, a main gas exhaust port for exhausting gas that has flowed from the focusing mirror side to the plasma generation region side via the gas inlet, and a narrowing member positioned between the gas supply port and the focusing mirror, which allows the EUV light reflected by the focusing mirror to pass through and narrows the gas flow from the gas supply port toward the gas inlet. The EUV light generated by the apparatus is irradiated onto a mask to inspect for defects in the mask, a mask is selected using the inspection results, and the pattern formed on the selected mask is exposed and transferred onto a photosensitive substrate. [Brief explanation of the drawing]

[0008] Some embodiments of this disclosure are described below, merely as examples, with reference to the accompanying drawings. [Figure 1] Figure 1 is a schematic diagram of an EUV light generation apparatus related to a comparative example, viewed from the horizontal direction. [Figure 2] Figure 2 is a schematic diagram of an EUV light generation apparatus related to a comparative example, viewed from the vertical direction. [Figure 3] Figure 3 is a schematic diagram showing the configuration of the chamber of an EUV light generation apparatus according to a comparative example. [Figure 4] Figure 4 is a schematic diagram showing the configuration of the EUV light generation apparatus according to the first embodiment. [Figure 5] Figure 5 is a schematic diagram showing the configuration of the chamber of the EUV light generation apparatus according to the first embodiment. [Figure 6]FIG. 6 is a diagram schematically showing the configuration of a chamber of an EUV light generating apparatus according to a first modification of the first embodiment. [Figure 7] FIG. 7 is a diagram showing a modification of a cylindrical structure. [Figure 8] FIG. 8 is a diagram schematically showing the configuration of a chamber of an EUV light generating apparatus according to a second modification of the first embodiment. [Figure 9] FIG. 9 is a diagram showing a cross section of a block along the line A-A in FIG. 8. [Figure 10] FIG. 10 is a diagram schematically showing the configuration of an EUV light generating apparatus according to the second embodiment. [Figure 11] FIG. 11 is a diagram schematically showing the configuration of an EUV light generating apparatus according to a first modification of the second embodiment. [Figure 12] FIG. 12 is a diagram schematically showing the configuration of an EUV light generating apparatus according to a second modification of the second embodiment. [Figure 13] FIG. 13 is a diagram schematically showing the configuration of an exposure apparatus. [Figure 14] FIG. 14 is a diagram schematically showing the configuration of an inspection apparatus. Embodiment

[0009] <Content> 1. Comparative Example 1.1 Configuration 1.2 Operation 1.3 Problems 2. First Embodiment 2.1 Configuration 2.2 Operation 2.3 Effects 2.4 Modifications 2.4.1 First Modification 2.4.2 Second Modification 3. Second Embodiment 3.1 Configuration 3.2 Operation 3.3 Effects 3.4 Modifications 3.4.1 First Modification 3.4.2 Second Modification 4. Method for Manufacturing an Electronic Device

[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 the embodiments are essential as the configurations and operations of the present disclosure. The same reference numerals are assigned to the same components, and redundant descriptions are omitted.

[0011] 1. Comparative Example 1.1 Configuration FIGS. 1 and 2 schematically show the configuration of an EUV light generation apparatus 2 according to a comparative example. FIG. 1 is a schematic view of the EUV light generation apparatus 2 seen from the horizontal direction. FIG. 2 is a schematic view of the EUV light generation apparatus 2 seen from the vertical direction.

[0012] The EUV light generation apparatus 2 includes a chamber 3, a target supply device 4, and a laser device 5. The chamber 3 is a hermetically sealable container. The target supply device 4 supplies a droplet-shaped target TG into the chamber 3. The target TG is liquid tin. The target supply device 4 discharges the target TG from the nozzle 4a at a constant period toward a plasma generation region AR located directly below the nozzle 4a. The diameter of the target TG is 10 μm to 30 μm.

[0013] The chamber 3 is formed with a window 31 for allowing pulsed laser light output from a laser device 5 disposed outside the chamber 3 to enter the interior. The pulsed laser light transmitted through the window 31 is irradiated onto the target TG in the plasma generation region AR. The pulsed laser light is an example of the "laser light" according to the technology of the present disclosure.

[0014] Also, the chamber 3 is connected to a connecting pipe 32 that communicates the interior of the chamber 3 with the interior of an external device 100. The external device 100 is an exposure device 100a or an inspection device 100b.

[0015] Furthermore, a gas supply port 6a is formed in the chamber 3. A gas supply device 6 is connected to the gas supply port 6a. The gas supply device 6 includes a gas tank and supplies gas to the space between the differential exhaust chamber 80 and the concentrating mirror 10, which will be described later.

[0016] The gas supplied by the gas supply device 6 may include, for example, hydrogen gas. This gas may be hydrogen gas with a hydrogen concentration of 100%. Alternatively, this gas may be a balance gas with a hydrogen gas concentration of about 3%, in which case the balance gas may include, for example, nitrogen (N2) gas or argon (Ar) gas. The gas supply device 6 may also be equipped with a flow control valve that allows adjustment of the gas flow rate.

[0017] Furthermore, a target recovery device 41 is provided in the chamber 3 at a position opposite the target supply device 4. The target recovery device 41 is a drain tank that recovers unwanted targets TG that did not contribute to the generation of EUV light 20 in the plasma generation region AR.

[0018] Furthermore, a partition wall 33 is provided between the plasma generation region AR and the focusing mirror 10 in the chamber 3. For example, the partition wall 33 is cylindrical, extending from the inside to the outside of the chamber 3, and surrounds the plasma generation region AR. The partition wall 33 is made of stainless steel, aluminum, or the like. For example, the partition wall 33 includes a cylindrical portion with an inner diameter of 160 mm. The partition wall 33 is also called a debris shield. The partition wall 33 is an example of the "first partition wall" related to the technology of this disclosure.

[0019] Of the two opposing ends of the partition wall 33, a gas inlet 33a is formed at the end located in the internal space, and a main gas exhaust port 33b is formed at the end located in the external space. The main gas exhaust port 33b is connected to a main exhaust system 7, which includes an exhaust pump. The main exhaust system 7 exhausts the gas supplied from the gas supply device 6 into the chamber 3 and flowing into the internal space within the partition wall 33. The shape of the gas inlet 33a is elliptical or circular.

[0020] Furthermore, the partition wall 33 has a target inlet 33c and a target outlet 33d. The target inlet 33c and the target outlet 33d are positioned to face each other on the trajectory of the target TG.

[0021] Furthermore, a laser entrance port 33e is formed in the partition wall 33. The laser entrance port 33e is positioned on the optical path of the pulsed laser light that has passed through the window 31 and entered the chamber 3.

[0022] Furthermore, the partition wall 33 is provided with sensors 9a and 9b for monitoring the plasma generation region AR or its vicinity. For example, sensor 9a is a target sensor that detects at least one of the following: the presence, trajectory, position, and velocity of the target TG. For example, sensor 9b is a sensor that monitors the emission point of the EUV light 20.

[0023] Furthermore, a laser damper 9c is provided on the partition wall 33 on the side opposite the laser entrance port 33e, with reference to the plasma generation region AR. The laser damper 9c receives pulsed laser light that was not incident on the target TG after being incident on the laser entrance port 33e. The laser damper 9c converts the incident pulsed laser light into heat.

[0024] Hereinafter, the internal space of the partition wall 33 will be referred to as the first space S1, and the space outside the partition wall 33 and within the chamber 3 will be referred to as the second space S2. The plasma generation region AR is located in the first space S1. The connecting pipe 32 is in communication with the second space S2. The gas inlet 33a, target inlet 33c, target outlet 33d, and laser inlet 33e are formed between the first space S1 and the second space S2.

[0025] The focusing mirror 10 has a reflective surface 10a which is part of the ellipsoidal surface of revolution and is located in the second space S2. A multilayer reflective film is formed on the reflective surface 10a, in which molybdenum and silicon are alternately layered. The focusing mirror 10 is positioned such that the first focal point of the ellipsoidal surface of revolution is located in the plasma generation region AR and the second focal point is located in the intermediate focal point IF. The intermediate focal point IF is located inside the connecting tube 32.

[0026] In the plasma generation region AR, a portion of the EUV light 20 emitted from the plasma generated when pulsed laser light is irradiated onto the target TG passes from the first space S1 through the gas inlet 33a and is incident on the focusing mirror 10 located in the second space S2. The focusing mirror 10 reflects the incident EUV light 20 toward an external device 100 located in a direction different from the incident direction.

[0027] The gas supply port 6a described above is in communication with the second space S2, and is positioned so that the gas flowing into the second space S2 flows onto the reflective surface 10a of the concentrating mirror 10. The gas flow rate from the gas supply port 6a into the second space S2 is preferably in the range of 20 to 60 NLM (normal liters / min).

[0028] The laser device 5 is positioned such that the output pulsed laser light is incident on the second space S2 within the chamber 3 via the window 31 and then incident on the plasma generation region AR via the laser inlet 33e.

[0029] The laser device 5 outputs pre-pulsed laser (PPL) light and main-pulsed laser (MPL) light as pulsed laser light. Specifically, the laser device 5 includes a PPL device (not shown) that outputs PPL light and an MPL device (not shown) that outputs MPL light. For example, the PPL device is an Nd:YAG laser device, and the MPL device is either an Nd:YAG laser device or a CO2 laser device. For example, the wavelengths of the PPL light and the MPL light are equal, both being 1.06 μm. The laser device 5 outputs PPL light and MPL light in this order.

[0030] A differential exhaust chamber 80 is provided in the connecting tube 32 on the optical path of the EUV light 20. The differential exhaust chamber 80 is located near the intermediate focal point IF. The differential exhaust chamber 80 is a space sandwiched between two orifice plates 81 and 82 that are arranged to partition the connecting tube 32. Orifice plates 81 and 82 each have orifices 81a and 82a formed on the optical path of the EUV light 20. For example, the shapes of the orifices 81a and 82a are circular. Orifice plate 81 corresponds to the "first orifice plate" according to the technology of this disclosure. Orifice plate 82 corresponds to the "second orifice plate" according to the technology of this disclosure. Orifice 81a corresponds to the "first orifice" according to the technology of this disclosure. Orifice 82a corresponds to the "second orifice" according to the technology of this disclosure.

[0031] Orifices 81a and 82a are positioned so that the EUV light 20 reflected by the focusing mirror 10 passes through them. Orifice 82a is positioned closer to the external device 100 than orifice 81a. Preferably, the diameter of orifice 81a is larger than the diameter of orifice 82a. The intermediate focusing point IF may also be located at orifice 82a of the orifice plate 82.

[0032] A gas exhaust port 8a is formed in the region of the connecting pipe 32 where the differential exhaust chamber 80 is located. In other words, the gas exhaust port 8a is in communication with the differential exhaust chamber 80. The gas exhaust port 8a is connected to an exhaust system 8, which includes an exhaust pump. The exhaust system 8 maintains the differential exhaust chamber 80 at a lower pressure than the chamber 3 by exhausting the differential exhaust chamber 80.

[0033] Furthermore, the external device 100 is vented by an exhaust system (not shown). For example, the pressure inside chamber 3 is several tens of Pa, while the pressure inside the external device 100 is less than a few Pa.

[0034] In Figures 1 and 2, the X direction is the direction from the plasma generation region AR towards the main exhaust device 7, the Y direction is the vertical direction, and the Z direction is perpendicular to the X and Y directions. In this comparative example, the X, Y, and Z directions are orthogonal to each other, but they do not necessarily need to be orthogonal.

[0035] 1.2 Operation The operation of the EUV light generation apparatus 2 in the comparative example will now be explained. First, the target supply device 4 ejects the target TG from the nozzle 4a at a constant period. The ejected target TG passes through the target inlet 33c and heads towards the plasma generation region AR. The laser device 5 generates EUV light 20 by irradiating the target TG supplied to the plasma generation region AR at a constant period with pulsed laser light at a constant period. The timing of the output of pulsed laser light from the laser device 5 is determined based on the target TG passage timing signal from the sensor 9a.

[0036] EUV light 20 generated in the plasma generation region AR and directed toward the focusing mirror 10 passes through the gas inlet 33a and is reflected by the focusing mirror 10 toward the external device 100. The EUV light 20 reflected by the focusing mirror 10 passes through the orifices 81a and 82a in the connecting tube 32 and is incident on the external device 100. In the external device 100, predetermined processing is performed using the EUV light 20.

[0037] The gas supplied from the gas supply port 6a to the second space S2 within the chamber 3 mainly flows toward the focusing mirror 10, and then flows into the first space S1 through the gas inlet 33a, target inlet 33c, target outlet 33d, and laser inlet 33e. The gas that flows into the first space S1 is exhausted by the main exhaust system 7 through the main gas exhaust port 33b. This flow of gas from the second space S2 to the first space S1 suppresses the diffusion of debris generated in the plasma generation region AR toward the second space S2 where the focusing mirror 10 is located. The debris is residual mist remaining after a portion of the target TG has not been plasma-generated by pulsed laser irradiation. For example, the residual mist consists of fine particles of liquid tin.

[0038] Furthermore, some of the debris may adhere to the reflective surface 10a of the focusing mirror 10. The deposits on the reflective surface 10a react with radicals generated when the gas in the second space S2 is excited by the EUV light 20, becoming volatile substances. These radicals are, for example, hydrogen radicals. In this way, the reflective surface 10a is cleaned by the volatilization of the deposits.

[0039] 1.3 Challenges Figure 3 schematically shows the configuration of the chamber 3 of the EUV light generator 2 according to the comparative example. In Figure 3, the partition wall 33 is schematically shown as a flat plate.

[0040] As shown in Figure 3, the gas supplied from the gas supply port 6a to the second space S2 branches and flows not only toward the first space S1 but also toward the connecting pipe 32. A portion of the gas flows into the connecting pipe 32 toward the external device 100 and enters the differential exhaust chamber 80 through the orifice 81a. The differential exhaust chamber 80 is provided to reduce the inflow of gas into the external device 100, so most of the gas that enters the differential exhaust chamber 80 is exhausted from the gas exhaust port 8a. A portion of the gas that enters the differential exhaust chamber 80 enters the external device 100 through the orifice 82a.

[0041] Most of the debris generated in the plasma generation region AR is exhausted by the main exhaust system 7 along with the gas flowing from the second space S2 into the first space S1 via the gas inlet 33a. However, a small amount of debris may enter the second space S2 via the gas inlet 33a. As described above, the gas supplied to the second space S2 from the gas supply port 6a is exhausted in multiple directions, so the debris that enters the second space S2 may diffuse and enter the external device 100 through the orifices 81a and 82a along with some of the gas. If debris containing tin or the like enters the external device 100, the elements constituting the internal EUV optical system will be contaminated, and the optical performance will deteriorate. Deterioration of optical performance may necessitate maintenance.

[0042] This disclosure aims to suppress the adhesion of debris to the focusing mirror 10 and to suppress the intrusion of debris into the external device 100.

[0043] 2. First Embodiment 2.1 Configuration The EUV light generation apparatus 2 according to the first embodiment of this disclosure has the same configuration as the EUV light generation apparatus 2 according to the comparative example, except that the configuration of the chamber 3 is different.

[0044] Figure 4 schematically shows the configuration of the EUV light generator 2 according to the first embodiment. Figure 5 schematically shows the configuration of the chamber 3 of the EUV light generator 2 according to the first embodiment. In this embodiment, a flat partition wall 34 is provided between the gas supply port 6a and the focusing mirror 10 in the second space S2. The partition wall 34 is positioned to intersect with the optical path of the EUV light 20 reflected by the focusing mirror 10, dividing the second space S2 into a region on the focusing mirror 10 side and a region on the external device 100 side. The partition wall 34 is an example of a "second partition wall" according to the technology of this disclosure.

[0045] The partition wall 34 has an opening 34a, and is positioned so that the EUV light 20 reflected by the focusing mirror 10 passes through the opening 34a. Preferably, the shape of the opening 34a is similar to the cross-sectional shape of the EUV light 20 at the location of the partition wall 34. For example, the shape of the opening 34a is elliptical or circular.

[0046] The size of the opening 34a is preferably larger than the size of the cross-section of the EUV light 20 at the position of the partition wall 34. If the diameter of the gas inlet 33a is D1, the diameter of the opening 34a is D2, the diameter of the orifice 81a is D3, and the diameter of the orifice 82a is D4, then it is preferable that the relationship shown in equation (1) or equation (2) below is satisfied. Here, diameter refers to the diameter of a circle or the major axis of an ellipse. D2≧D1>D3>D4 ···(1) D1≧D2>D3>D4 ···(2)

[0047] The gas flowing into the chamber 3 from the gas supply port 6a flows mainly through the opening 34a of the partition wall 34 towards the gas inlet 33a. Therefore, the gas flow from the gas supply port 6a towards the gas inlet 33a is constricted by the opening 34a. Here, constriction refers to partially narrowing the gas flow path or partially suppressing the diffusion of gas. The partition wall 34 is an example of a "constricting member that narrows the gas flow" according to the technology of this disclosure.

[0048] It is preferable that the partition wall 34 is positioned between the gas supply port 6a and the concentrating mirror 10, on the side closer to the gas supply port 6a than to the concentrating mirror 10. Alternatively, the partition wall 34 may be positioned between the differential exhaust chamber 80 and the concentrating mirror 10, on the side closer to the differential exhaust chamber 80 than to the concentrating mirror 10. For this to work, the gas supply port 6a must be positioned closer to the differential exhaust chamber 80 than to the concentrating mirror 10. The gas supply port 6a may be located in the connecting pipe 32.

[0049] 2.2 Operation The operation of the EUV light generator 2 according to this embodiment is the same as in the comparative example, except for the gas flow in the chamber 3. In this embodiment, the gas supplied from the gas supply port 6a to the second space S2 in the chamber 3 flows mainly toward the gas inlet 33a, but this gas flow is rectified by being narrowed at the opening 34a of the partition wall 34 and flows toward the focusing mirror 10. That is, the gas flowing through the opening 34a flows toward the focusing mirror 10 at many positions along the cross-section of the opening 34a. As a result, the gas flow velocity is improved compared to the case where the partition wall 34 does not exist, as in the comparative example.

[0050] 2.3 Effects In this embodiment as well, some of the debris generated in the plasma generation region AR may enter the second space S2 through the gas inlet 33a. However, in this embodiment, the gas passing through the opening 34a of the partition wall 34 is rectified and its flow velocity is improved, so the entry and diffusion of debris from the opening 34a to the external device 100 side is suppressed. As a result, the intrusion of debris into the external device 100 is suppressed. Therefore, according to this embodiment, the partition wall 33 as a debris shield can suppress the adhesion of debris to the focusing mirror 10, and the partition wall 34 as a constricting member can suppress the intrusion of debris into the external device 100.

[0051] This suppresses the degradation of the optical performance of the external device 100 due to debris, and reduces the frequency of maintenance.

[0052] 2.4 Variations Next, various modifications of the first embodiment will be described. The following first and second modifications differ from the first embodiment only in the configuration of the constricting member and the arrangement of the gas supply port 6a.

[0053] 2.4.1 First Variation Figure 6 schematically shows the configuration of the chamber 3 of the EUV light generator 2 according to the first modification of the first embodiment. In this modification, a cylindrical structure 35 is provided instead of the partition wall 34. Also in this modification, the gas supply port 6a is located in the connecting pipe 32.

[0054] The cylindrical structure 35 is positioned between the gas supply port 6a and the concentrating mirror 10 so that the EUV light 20 reflected by the concentrating mirror 10 passes through its interior. Specifically, the cylindrical structure 35 is connected to the end of the connecting pipe 32. The cylindrical structure 35 may be integrally molded with the connecting pipe 32.

[0055] The shape of the opening 35a located at the end of the cylindrical structure 35 on the side of the focusing mirror 10 is preferably similar to the cross-sectional shape of the EUV light 20 at the location of the opening 35a. For example, the shape of the opening 35a is elliptical or circular. That is, the cylindrical structure 35 is elliptical or cylindrical. In this modified example, the cross-sectional area of ​​the internal space of the cylindrical structure 35 is constant along the optical path of the EUV light 20. Here, the cross-sectional area refers to the area of ​​the surface obtained by cutting the internal space in a direction perpendicular to the optical path of the EUV light 20.

[0056] The size of the opening 35a is preferably larger than the size of the cross-section of the EUV light 20 at the position of the opening 35a. If the diameter of the gas inlet 33a is D1, the diameter of the opening 35a is D2, the diameter of the orifice 81a is D3, and the diameter of the orifice 82a is D4, then it is preferable that the relationship of equation (1) or equation (2) above is satisfied.

[0057] The gas supply port 6a is positioned to supply gas to the internal space of the cylindrical structure 35. The gas supplied from the gas supply port 6a to the internal space of the cylindrical structure 35 flows mainly from the opening 35a toward the gas inlet 33a. Therefore, the gas flow from the gas supply port 6a toward the main gas exhaust port 33b is constricted by the cylindrical structure 35. The cylindrical structure 35 is an example of a "constricting member that narrows the gas flow" according to the technology of this disclosure.

[0058] In this modified example, as in the above embodiment, the gas passing through the cylindrical structure 35 is rectified and its flow velocity is improved, so the entry and diffusion of debris from the opening 35a to the external device 100 side is suppressed. As a result, the intrusion of debris into the external device 100 is suppressed. Therefore, according to this modified example, the partition wall 33 acting as a debris shield can suppress the adhesion of debris to the concentrating mirror 10, and the cylindrical structure 35 acting as a constricting member can suppress the intrusion of debris into the external device 100.

[0059] In this modified example, the cross-sectional area of ​​the cylindrical structure 35 is kept constant, but as shown in Figure 7, the cylindrical structure 35 may be configured such that the cross-sectional area of ​​the internal space decreases along the direction of propagation of the EUV light 20.

[0060] 2.4.2 Second Variation Figure 8 schematically shows the configuration of the chamber 3 of the EUV light generator 2 according to a second modification of the first embodiment. In this modification, a block 36 is provided instead of the partition wall 34. Also in this modification, the gas supply port 6a is located in the connecting pipe 32.

[0061] Block 36 has an aperture 36a through which the EUV light 20 reflected by the focusing mirror 10 passes, and surrounds the optical path of the EUV light 20. Specifically, block 36 has a tapered inclined surface toward the differential exhaust chamber 80, and the cross-sectional area of ​​the space enclosed by this surface decreases as it approaches the differential exhaust chamber 80. Block 36 may be made of sheet metal, or it may be manufactured by machining or casting. Block 36 may also be integrally molded with the chamber 3.

[0062] In this modified example, block 36 is composed of multiple members. Specifically, block 36 is composed of a first member 36b and a second member 36c. The first member 36b is fixed to the partition wall 33. The second member 36c is fixed to the chamber 3.

[0063] Figure 9 shows a cross-section of block 36 along line AA in Figure 8. The first member 36b and the second member 36c may be connected, but a gap may exist between the first member 36b and the second member 36c. In the example shown in Figure 9, the opening 36a is circular, but the opening 36a may also be elliptical.

[0064] The size of the opening 36a is preferably larger than the size of the cross-section of the EUV light 20 at the position of the opening 36a. If the diameter of the gas inlet 33a is D1, the diameter of the opening 36a is D2, the diameter of the orifice 81a is D3, and the diameter of the orifice 82a is D4, then it is preferable that the relationship of equation (1) or equation (2) above is satisfied.

[0065] The gas flowing into the chamber 3 from the gas supply port 6a mainly flows through the opening 36a of block 36 towards the gas inlet 33a. Therefore, the gas flow from the gas supply port 6a toward the main gas exhaust port 33b is narrowed by the opening 36a of block 36. Block 36 is an example of a "narrowing member that narrows the gas flow" according to the technology of this disclosure.

[0066] In this modified example, as in the above embodiment, the gas passing through the opening 36a of block 36 is rectified and its flow velocity is improved, thereby suppressing the entry and diffusion of debris from the opening 36a to the external device 100. This suppresses the intrusion of debris into the external device 100. Therefore, according to this modified example, the partition wall 33 acting as a debris shield can suppress the adhesion of debris to the concentrating mirror 10, and the block 36 acting as a constricting member can suppress the intrusion of debris into the external device 100.

[0067] 3. Second Embodiment Next, a second embodiment of the present disclosure will be described. The EUV light generator 2 according to the second embodiment has the same configuration as the EUV light generator 2 according to the first embodiment, except that the configuration of the chamber 3 is different.

[0068] 3.1 Configuration Figure 10 schematically shows the configuration of the EUV light generation apparatus 2 according to the second embodiment. In this embodiment, two gas supply ports 6a and 6b are formed in the chamber 3. The gas supply devices 6 described above are connected to the gas supply ports 6a and 6b, respectively, and supply gas to the second space S2 in the chamber 3. Note that the gas supply devices 6 are not shown in Figure 10. The gas supply ports 6a and 6b are formed at symmetrical positions with respect to a plane P that contains the optical axis of the pulsed laser light output from the laser device 5. In this embodiment, the optical axis of the pulsed laser light is parallel to the Z direction, and plane P is a plane parallel to the ZY plane.

[0069] In this embodiment, the partition wall 33 surrounding the plasma generation region AR is cylindrical in shape and extends in the Y direction. In this embodiment, a main gas exhaust port 33b is formed at the end of the partition wall 33 in the extension direction, and a main exhaust device 7 is connected to the main gas exhaust port 33b. In Figure 10, the main gas exhaust port 33b and the main exhaust device 7 are not shown. The shape of the partition wall 33 is symmetrical with respect to the plane P.

[0070] In this embodiment, two gas inlets 33a and 33f are formed in the partition wall 33. The gas inlets 33a and 33f are formed in symmetrical positions with respect to the plane P. A portion of the gas supplied to the second space S2 from the gas supply ports 6a and 6b flows into the first space S1 from the gas inlets 33a and 33f.

[0071] Furthermore, the partition wall 33 is provided with a laser output port 33g in addition to the laser input port 33e on the optical axis of the pulsed laser beam. Pulsed laser beam that enters from the laser input port 33e but does not irradiate the target TG passes through the laser output port 33g. The laser damper 9c is positioned where the pulsed laser beam that has passed through the laser output port 33g enters.

[0072] In this embodiment, an auxiliary plate 90 is provided in the second space S2 in addition to the focusing mirror 10. The auxiliary plate 90 has the same shape as the focusing mirror 10 and is positioned symmetrically to the focusing mirror 10 with respect to the plane P. Sensors 9a and 9b are attached to the auxiliary plate 90. Sensors 9a and 9b monitor the plasma generation region AR or its vicinity via the gas inlet 33f.

[0073] In this embodiment, a partition wall 37 having an opening 37a is provided between the gas supply port 6a and the light-gathering mirror 10 in the second space S2. The partition wall 37 has the same configuration as the partition wall 34 in the first embodiment and is a narrowing member that constricts the gas flow from the gas supply port 6a through the gas inlet 33a toward the main gas exhaust port 33b.

[0074] As described above, in this embodiment, the chamber 3 is formed symmetrically with respect to the plane P, except for the partition wall 37. The other configurations of the chamber 3 are the same as in the first embodiment.

[0075] 3.2 Operation The operation of the EUV light generator 2 according to this embodiment is the same as in the first embodiment, except for the gas flow within the chamber 3. In this embodiment, the gas supplied from the gas supply port 6a to the second space S2 within the chamber 3 flows into the first space S1 from the gas inlet 33a via the focusing mirror 10. The gas supplied from the gas supply port 6b to the second space S2 within the chamber 3 flows into the first space S1 from the gas inlet 33f via the auxiliary plate 90. Thus, in this embodiment, the gas flow within the chamber 3 is basically symmetrical with respect to the plane P.

[0076] 3.3 Effects In this embodiment, similar to the first embodiment, the gas passing through the opening 37a of the partition wall 37 is rectified and its flow velocity is improved, thereby suppressing the entry and diffusion of debris from the opening 37a to the external device 100. This suppresses the intrusion of debris into the external device 100. Therefore, according to this embodiment, the partition wall 33, acting as a debris shield, can suppress the adhesion of debris to the focusing mirror 10, and the partition wall 37, acting as a constricting member, can suppress the intrusion of debris into the external device 100. Furthermore, since the gas flow in the chamber 3 is symmetrical with respect to the plane P, it is possible to suppress the target TG from moving out of the plasma generation region AR due to fluctuations in the gas flow associated with plasma generation.

[0077] 3.4 Variations Next, various modifications of the second embodiment will be described. The first and second modifications described below differ from the second embodiment only in the configuration of the constricting member.

[0078] 3.4.1 First Variation Figure 11 schematically shows the configuration of the EUV light generator 2 according to the first modified example of the second embodiment. This modified example differs from the second embodiment only in that a partition wall 38 is provided in addition to the partition wall 37. The partition wall 38 is provided between the inner wall of the chamber 3 and the partition wall 33 so as to separate the region in the second space S2 where the gas supply port 6a and gas inlet 33a are formed from the region where the gas supply port 6b and gas inlet 33f are formed. The partition wall 38 separates the gas flow supplied from the gas supply port 6a from the gas flow supplied from the gas supply port 6b.

[0079] In this modified example, a partition wall 38 is provided to separate the two gas flows supplied into the chamber 3, thereby suppressing the influence of the gas flow from the gas supply port 6b on the area on the focusing mirror 10 side.

[0080] 3.4.2 Second Variation Figure 12 schematically shows the configuration of the EUV light generator 2 according to a second modification of the second embodiment. In this modification, a cylindrical structure 39 is provided instead of the partition wall 37. The cylindrical structure 39 has the same configuration as the cylindrical structure 35 according to the first modification of the first embodiment. The cylindrical structure 39 is connected to the end of the connecting pipe 32. The cylindrical structure 39 may be integrally molded with the connecting pipe 32.

[0081] The cylindrical structure 39 may be configured such that the cross-sectional area of ​​its internal space decreases as it approaches the differential exhaust chamber 80.

[0082] Furthermore, similar to the second modification of the first embodiment, the constricting member may be made of a block instead of the partition wall 37. The block may be made up of multiple members.

[0083] 4. Methods for manufacturing electronic devices Figure 13 schematically shows the configuration of the exposure apparatus 100a connected to the EUV light generator 2. In Figure 13, the exposure apparatus 100a, as an external device 100, includes a mask irradiation unit 102 and a workpiece irradiation unit 104. The mask irradiation unit 102 illuminates the mask pattern on the mask table MT via a reflective optical system with EUV light 20 incident from the EUV light generator 2. The workpiece irradiation unit 104 images the EUV light 20 reflected by the mask table MT onto a workpiece (not shown) placed on the workpiece table WT via a reflective optical system. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 100a exposes the workpiece with EUV light 20 reflecting the mask pattern by synchronously moving the mask table MT and the workpiece table WT in parallel. By transferring a device pattern to a semiconductor wafer through the exposure process described above, an electronic device can be manufactured.

[0084] Figure 14 schematically shows the configuration of the inspection device 100b connected to the EUV light generator 2. In Figure 14, the inspection device 100b, as an external device 100, includes an illumination optical system 110 and a detection optical system 112. The EUV light generator 2 outputs EUV light 20 to the inspection device 100b as an inspection light source. The illumination optical system 110 reflects the EUV light 20 incident from the EUV light generator 2 and irradiates the mask 116 placed on the mask stage 114. The mask 116 here includes mask blanks before a pattern is formed. The detection optical system 112 reflects the EUV light 20 from the illuminated mask 116 and images it onto the light-receiving surface of the detector 118. The detector 118, having received the EUV light 20, acquires an image of the mask 116. The detector 118 is, for example, a TDI (Time Delay Integration) camera. The image of the mask 116 obtained through the above process is used to inspect for defects in the mask 116, and the inspection results are used to select a mask suitable for manufacturing electronic devices. Then, the pattern formed on the selected mask is exposed and transferred onto a photosensitive substrate using the exposure apparatus 100a, thereby enabling the manufacture of electronic devices.

[0085] The above description is intended to be illustrative, not restrictive. It will be apparent to those skilled in the art that modifications can be made to the embodiments of this disclosure without departing from the claims. Terms used herein and throughout the claims should be construed as “non-restrictive” unless otherwise specified. For example, terms such as “includes,” “has,” “equip,” and “possesses” should be construed as “not excluding the existence of components other than those described.” Also, the modifier “one” should be construed as “at least one” or “one or more.” Furthermore, the term “at least one of A, B, and C” should be construed as “A,” “B,” “C,” “A+B,” “A+C,” “B+C,” or “A+B+C,” and should also be construed as including combinations of them with anything other than “A,” “B,” and “C.”

Claims

1. A chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light, A focusing mirror is placed inside the chamber and reflects the EUV light toward an external device, A differential exhaust chamber is provided on the optical path of the EUV light reflected by the aforementioned focusing mirror, A gas supply port for supplying gas to the space between the differential exhaust chamber and the light-gathering mirror, A first partition wall is disposed between the plasma generation region and the focusing mirror, and the first partition wall is provided with a gas inlet through which gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side, and through which the EUV light traveling from the plasma generation region toward the focusing mirror passes. A main gas exhaust port for exhausting gas that has flowed from the concentrating mirror side through the gas inlet to the plasma generation region side, A narrowing member is positioned between the gas supply port and the concentrating mirror, allowing the EUV light reflected by the concentrating mirror to pass through, and narrowing the gas flow from the gas supply port toward the gas inlet, An EUV light generator equipped with [a specific feature].

2. An EUV light generation apparatus according to claim 1, The constricting member is a second partition wall having an opening through which the EUV light passes.

3. An EUV light generation apparatus according to claim 2, The second partition wall rectifies the gas flow at the opening and directs it toward the concentrating mirror.

4. An EUV light generation apparatus according to claim 2, The second partition intersects with the optical path of the EUV light and separates the area on the focusing mirror side from the area on the external device side.

5. An EUV light generation apparatus according to claim 2, The opening is similar in shape to the cross-sectional shape of the EUV light in the second partition wall.

6. An EUV light generation apparatus according to claim 2, The size of the opening is larger than the size of the cross-section of the EUV light in the second partition wall.

7. An EUV light generation apparatus according to claim 2, The differential exhaust chamber is a space sandwiched between a first orifice plate and a second orifice plate located on the external device side of the first orifice plate. The first orifice plate has a first orifice formed on the optical path of the EUV light, The second orifice plate has a second orifice formed on the optical path of the EUV light, The differential exhaust chamber is connected to a gas exhaust port for exhausting gas.

8. An EUV light generation apparatus according to claim 7, The diameter of the first orifice is larger than the diameter of the second orifice.

9. An EUV light generation apparatus according to claim 8, The diameter of the opening is larger than the diameter of the second orifice.

10. An EUV light generation apparatus according to claim 2, The second partition wall is positioned between the gas supply port and the concentrating mirror, on the side closer to the gas supply port than to the concentrating mirror.

11. An EUV light generation apparatus according to claim 2, The second bulkhead is positioned between the differential exhaust chamber and the concentrating mirror, on the side closer to the differential exhaust chamber than to the concentrating mirror.

12. An EUV light generation apparatus according to claim 1, The constricting member is a cylindrical structure through which the EUV light passes through its internal space.

13. An EUV light generation apparatus according to claim 12, The gas supply port is positioned to supply gas to the internal space of the cylindrical structure.

14. An EUV light generation apparatus according to claim 12, The cross-sectional area of ​​the internal space of the cylindrical structure decreases along the direction of propagation of the EUV light.

15. An EUV light generation apparatus according to claim 1, The aforementioned narrowing member is a block that surrounds the optical path of the EUV light.

16. An EUV light generation apparatus according to claim 15, The aforementioned block is composed of multiple members.

17. A method for manufacturing electronic devices, A chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light, A focusing mirror is placed inside the chamber and reflects the EUV light toward an external device, A differential exhaust chamber is provided on the optical path of the EUV light reflected by the aforementioned focusing mirror, A gas supply port for supplying gas to the space between the differential exhaust chamber and the light-gathering mirror, A first partition wall is disposed between the plasma generation region and the focusing mirror, and the first partition wall is provided with a gas inlet through which gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side, and through which the EUV light traveling from the plasma generation region toward the focusing mirror passes. A main gas exhaust port for exhausting gas that has flowed from the concentrating mirror side through the gas inlet to the plasma generation region side, A narrowing member is positioned between the gas supply port and the concentrating mirror, allowing the EUV light reflected by the concentrating mirror to pass through, and narrowing the gas flow from the gas supply port toward the gas inlet, The EUV light generated by the EUV light generator is output to the exposure device. To manufacture an electronic device, expose a photosensitive substrate to EUV light in the exposure apparatus. A method for manufacturing electronic devices including

18. A method for manufacturing electronic devices, A chamber that generates EUV light by irradiating a target supplied to an internal plasma generation region with laser light, A focusing mirror is placed inside the chamber and reflects the EUV light toward an external device, A differential exhaust chamber is provided on the optical path of the EUV light reflected by the aforementioned focusing mirror, A gas supply port for supplying gas to the space between the differential exhaust chamber and the light-gathering mirror, A first partition wall is disposed between the plasma generation region and the focusing mirror, and the first partition wall is provided with a gas inlet through which gas supplied from the gas supply port flows from the focusing mirror side to the plasma generation region side, and through which the EUV light traveling from the plasma generation region toward the focusing mirror passes. A main gas exhaust port for exhausting gas that has flowed from the concentrating mirror side through the gas inlet to the plasma generation region side, A narrowing member is positioned between the gas supply port and the concentrating mirror, allowing the EUV light reflected by the concentrating mirror to pass through, and narrowing the gas flow from the gas supply port toward the gas inlet, The EUV light generated by the EUV light generator is irradiated onto the mask to inspect for defects in the mask. Using the results of the above inspection, select a mask. The pattern formed on the selected mask is exposed and transferred onto a photosensitive substrate. A method for manufacturing electronic devices including

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