Debris trap, extreme ultraviolet light generator, and method for manufacturing electronic devices

Abstract

It was necessary to extend the maintenance interval of the debris trap, suppress the narrowing of the flow path upstream of the debris trap, and create a structure that could collect debris in the downstream area as well. [Solution] A debris trap is arranged in an exhaust path including a gas inlet into which a gas containing debris flows from a chamber and a gas exhaust port for exhausting the gas, comprising a first multi-tube and a second multi-tube, each arranged along a first direction which is the flow direction of the gas from the gas inlet to the gas exhaust port, wherein each of the first multi-tube and the second multi-tube comprises a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction, the second multi-tube is arranged downstream of the first multi-tube in the first direction, and the number of tubes constituting the second multi-tube is greater than the number of tubes constituting the first multi-tube.

Description

Technical Field

[0001] The present disclosure relates to a debris trap, 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 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, development of a semiconductor exposure apparatus combining an apparatus for generating extreme ultraviolet (EUV) light having a wavelength of about 13 nm and a reduction projection reflective optical system has been expected.

[0003] As an EUV light generating apparatus, development of a Laser Produced Plasma (LPP) 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] A debris trap according to one aspect of the present disclosure is a debris trap disposed in an exhaust path including a gas inlet through which gas containing debris flows from a chamber and a gas outlet for exhausting the gas, and includes a first multi-tube and a second multi-tube respectively disposed along a first direction which is a flow direction of the gas proceeding from the gas inlet to the gas outlet, each of the first multi-tube and the second multi-tube includes a plurality of tubes having different maximum outer dimensions in a second direction perpendicular to the first direction, the second multi-tube is disposed on the downstream side in the first direction than the first multi-tube, and the number of tubes constituting the second multi-tube is larger than the number of tubes constituting the first multi-tube.

[0006] A method for manufacturing an electronic device according to another aspect of the present disclosure includes: a chamber in which plasma is generated by irradiating a target material with laser light; an exhaust path including a gas inlet into which a gas containing debris flows from the chamber and a gas exhaust port for exhausting the gas; and a debris trap disposed in the exhaust path, the debris trap comprising a first multitube and a second multitube, respectively, disposed along a first direction which is the direction of gas flow from the gas inlet to the gas exhaust port, each of the first multitube and the second multitube comprising a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction, the second multitube being disposed downstream of the first multitube in the first direction, and the number of tubes constituting the second multitube being greater than the number of tubes constituting the first multitube, generating extreme ultraviolet light with an extreme ultraviolet light generator, outputting the extreme ultraviolet light to an exposure apparatus, and exposing a photosensitive substrate to extreme ultraviolet light in the exposure apparatus in order to manufacture an electronic device.

[0007] A method for manufacturing an electronic device according to another aspect of the present disclosure includes: a chamber from which a plasma is generated by irradiating a target material with laser light; an exhaust path including a gas inlet from which a gas containing debris flows in from the chamber and a gas exhaust port for exhausting the gas; and a debris trap disposed in the exhaust path, wherein the debris trap comprises a first multitube and a second multitube, respectively, arranged along a first direction which is the direction of gas flow from the gas inlet to the gas exhaust port, each of the first multitube and the second multitube comprises a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction, the second multitube being located downstream of the first multitube in the first direction, and the number of tubes constituting the second multitube being greater than the number of tubes constituting the first multitube, and includes irradiating a mask with extreme ultraviolet light generated by an extreme ultraviolet light generator to inspect the mask for defects, selecting a mask using the inspection results, and exposing and transferring a pattern formed on the selected mask 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 shows a schematic configuration of an LPP-type EUV light generation system. [Figure 2] Figure 2 schematically shows the configuration of an EUV light generation apparatus equipped with a debris trap according to a comparative example. [Figure 3] Figure 3 is a perspective view of the debris trap according to the comparative example. [Figure 4] Figure 4 is a schematic cross-sectional view showing the configuration of a debris trap placed in the exhaust path. [Figure 5] Figure 5 is a cross-sectional view of the debris trap after a certain period of use. [Figure 6] Figure 6 is a schematic cross-sectional view showing the configuration of the debris trap according to Embodiment 1. [Figure 7] Figure 7 is a front view of the coaxial cylindrical traps from the first to the second stage of the debris trap, viewed in the direction of gas flow. [Figure 8] Figure 8 is a cross-sectional view of the debris trap after a certain period of use. [Figure 9] Figure 9 is a cross-sectional view showing a modified example 1 of the debris trap. [Figure 10] Figure 10 is a perspective view of the stay applied to the debris trap shown in Figure 9. [Figure 11] Figure 11 is a cross-sectional view showing a modified example 2 of the debris trap. [Figure 12] Figure 12 is a schematic cross-sectional view showing the configuration of a debris trap according to Embodiment 2. [Figure 13] Figure 13 is a front view of the coaxial rectangular tube traps from the first to the second stage of the debris trap, viewed in the direction of gas flow. [Figure 14] Figure 14 schematically shows the configuration of the exposure apparatus connected to the EUV light generator. [Figure 15] Figure 15 schematically shows the configuration of the inspection device connected to the EUV light generator. Embodiment

[0009] -Contents- 1. Explanation of Terms 2. Overall Description of EUV Light Generation System 2.1 Composition 2.2 Operation 3. EUV Light Generation Device According to Comparative Example 3.1 Composition 3.2 Operation 4. Debris Trap According to Comparative Example 4.1 Composition 4.2 Problems 5. Embodiment 1 5.1 Composition 5.2 Operation 5.3 Functions and Effects 5.4 Variation 1 5.5 Variation 2 6. Embodiment 2 6.1 Composition 6.2 Operation 6.3 Functions and Effects 7. Method for Manufacturing Electronic Device 8. About Processor 9. Others

[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 compositions and operations described in each embodiment are essential as the compositions and operations of the present disclosure. Note that the same reference numerals are assigned to the same components, and duplicate explanations are omitted.

[0011] 1. Explanation of Terms "Target" is the object irradiated with the laser light introduced into the chamber. The target irradiated with the laser light is converted into plasma and emits EUV light.

[0012] "Droplet" is a form of the target supplied into the chamber. "DL" is an abbreviation meaning droplet.

[0013] "Plasma light" is synchrotron radiation emitted from a plasma-like target. This synchrotron radiation includes EUV light.

[0014] Stannan is a compound of tin and hydrogen, and is a gas. (Sn + 2H2 → SnH4) "Debris" is a general term for the target material supplied into the chamber, including the portion that did not contribute to plasma generation, as well as the ions, atoms, vapor, particles, and microdroplets of the target material generated during plasma generation.

[0015] 2. Overall description of the EUV light generation system 2.1 Configuration Figure 1 schematically shows the configuration of the LPP-type EUV light generation system 11. The EUV light generation device 1 is used together with the laser device 3. In this disclosure, the system including the EUV light generation device 1 and the laser device 3 is referred to as the EUV light generation system 11.

[0016] The EUV light generator 1 includes a chamber 2 and a target supply unit 26. The chamber 2 is a sealable container. The target supply unit 26 supplies the target material into the chamber 2. The target material may include tin, terbium, gadolinium, lithium, xenon, or any combination of two or more of these.

[0017] The wall of chamber 2 is provided with a through-hole. This through-hole is covered by a window 21, and pulsed laser light 32 output from the laser device 3 passes through the window 21. Inside chamber 2, an EUV focusing mirror 23 with a spheroidal reflective surface is positioned. The EUV focusing mirror 23 has a first focal point and a second focal point. A multilayer reflective film is formed on the surface of the EUV focusing mirror 23, in which molybdenum and silicon are alternately layered. The EUV focusing mirror 23 may be positioned such that its first focal point is located in the plasma generation region 25 and its second focal point is located in the intermediate focal point 292. A through-hole 24 is provided in the center of the EUV focusing mirror 23, and pulsed laser light 33 passes through the through-hole 24.

[0018] The EUV light generator 1 includes a processor 5, a target sensor 4, and the like. The target sensor 4 detects at least one of the following: the presence, trajectory, position, and velocity of the target 27. The target sensor 4 may also have an imaging function.

[0019] Furthermore, the EUV light generator 1 includes a connecting section 29 that connects the inside of the chamber 2 to the inside of the exposure apparatus 6. Inside the connecting section 29 is a wall 291 in which an aperture 293 is formed. The wall 291 is positioned such that the opening of the aperture 293 is located at the second focal point of the EUV focusing mirror 23.

[0020] Furthermore, the EUV light generation device 1 includes a laser light transmission device 34, a laser light focusing mirror 22, a target retrieval device 28 for retrieving the target 27, and the like. The laser light transmission device 34 includes an optical element for defining the transmission state of the laser light and an actuator for adjusting the position, orientation, etc., of this optical element.

[0021] 2.2 Operation Referring to Figure 1, the operation of the EUV light generation system 11 will be explained. The pulsed laser light 31 output from the laser device 3 passes through the laser light transmission device 34 and enters the chamber 2 as pulsed laser light 32, passing through the window 21. The pulsed laser light 32 travels through the chamber 2 along the laser light path, is reflected by the laser light focusing mirror 22, and is irradiated onto the target 27 as pulsed laser light 33.

[0022] The target supply unit 26 outputs a target 27 formed from the target material toward the plasma generation region 25 inside the chamber 2. The target 27 is irradiated with pulsed laser light 33. The target 27 irradiated with pulsed laser light 33 becomes plasma, and synchrotron radiation 251 is emitted from the plasma. The EUV light 252 contained in the synchrotron radiation 251 is selectively reflected by the EUV focusing mirror 23. The EUV light 252 reflected by the EUV focusing mirror 23 is focused at an intermediate focusing point 292 and output to the exposure apparatus 6. Note that multiple pulses contained in the pulsed laser light 33 may be irradiated onto a single target 27.

[0023] The processor 5 is configured to oversee the control of the entire EUV light generation system 11. The processor 5 processes image data of the target 27 captured by the target sensor 4, etc. The processor 5 also performs at least one of the following: control of the timing of the output of the target 27 and control of the output direction of the target 27. Furthermore, the processor 5 performs at least one of the following: control of the oscillation timing of the laser device 3, control of the direction of propagation of the pulsed laser light 32, and control of the focusing position of the pulsed laser light 33. The various controls described above are merely examples, and other controls may be added as needed.

[0024] 3. EUV light generation apparatus related to the comparative example 3.1 Configuration The configuration of the EUV light generation apparatus 1 in the comparative example will be explained using Figure 2. The comparative example in this disclosure is a form that the applicant recognizes as being known only to the applicant, and is not a prior art example acknowledged by the applicant.

[0025] The EUV light generator 1 comprises a chamber 2, a target generator 260, a laser focusing optical system 220, an EUV focusing mirror 23, a gas supply unit 40, a debris trap 50, and an exhaust pump 46. The target generator 260 includes a tank 261, a nozzle 262, a piezoelectric element 263, a heater 264, and a pressure regulator 265. The target material 267 is contained inside the tank 261.

[0026] A heater 264 is placed on the outer wall of the tank 261, and the target substance 267 inside the tank 261 is heated by the heater 264, thereby melting the target substance 267. The target substance 267 is, for example, tin.

[0027] The pressure regulator 265 is connected to the tank 261 via piping. The pressure regulator 265 regulates the pressure inside the tank 261. The pressure regulator 265 contains internal solenoid valves for supplying and exhausting air, pressure sensors, etc. The pressure regulator 265 is connected to a gas cylinder (not shown) filled with an inert gas such as helium or argon. The inert gas is supplied from the gas cylinder to the tank 261 via the pressure regulator 265. The pressure regulator 265 can increase or decrease the pressure inside the tank 261 by supplying gas into the tank 261 or exhausting gas from the tank 261.

[0028] The nozzle 262 is in communication with the tank 261, and the molten target material 267 is discharged from the nozzle hole of the nozzle 262. The plasma generation region 25 inside the chamber 2 is located on the extension of the central axis of the nozzle 262.

[0029] The target generator 260 forms droplets, for example, by a continuous jet method. In the continuous jet method, the nozzle 262 is vibrated to impart standing waves to the jet-like flow of target 27, thereby periodically separating the target 27. The separated target 27 can form droplets by creating free interfaces due to their own surface tension.

[0030] A piezoelectric element 263, which serves as a means for vibrating the nozzle 262, is fixed to the outer side surface of the pipe-shaped nozzle 262. The flow of target material 267 ejected in a jet-like manner from the nozzle 262 is periodically interrupted by the vibration of the piezoelectric element 263, forming droplets. The target generator 260 is an example of a target supply unit 26 (Figure 1).

[0031] The target generator 260 is positioned in the chamber 2 via a stage 266. The stage 266 is a mechanism that adjusts the position of the target generator 260 so that the target 27 output from the target generator 260 is supplied to the plasma generation region 25. The stage 266 may be, for example, a two-axis stage with actuators that can move the target generator 260 in two mutually orthogonal axes.

[0032] The laser focusing optical system 220 is an optical system that focuses pulsed laser light 32 introduced into the chamber 2 through the window 21 onto the plasma generation region 25. The laser focusing optical system 220 is located inside the chamber 2. The laser focusing optical system 220 includes a high-reflectivity off-axis parabolic mirror 222, a high-reflectivity planar mirror 223, and a plate 224.

[0033] The high-reflectivity off-axis parabolic mirror 222 and the high-reflectivity planar mirror 223 are each held in a mirror holder and fixed to the plate 224. The optical elements are arranged so that the focusing position of the laser focusing optical system 220 substantially coincides with the plasma generation region 25. The high-reflectivity off-axis parabolic mirror 222 and the high-reflectivity planar mirror 223 are examples of laser beam focusing mirrors 22 (Figure 1).

[0034] The EUV focusing mirror 23 is held in an EUV light focusing mirror holder 231 and fixed to a plate 232. The plate 232 is fixed to the inner wall of the chamber 2. The plate 232 is provided with through holes 233 for allowing pulsed laser light 33 reflected by the laser focusing optical system 220 to pass towards the plasma generation region 25.

[0035] A plasma emitting EUV light 252 is generated by focusing pulsed laser light 32 output from the laser device 3 onto a target 27 supplied to the chamber 2 by the target generator 260 through the window 21 and the laser focusing optical system 220.

[0036] The EUV light 252 is collected by the EUV focusing mirror 23 and output to an external device such as the exposure apparatus 6 via the intermediate focusing point 292. Of the targets 27 output into the chamber 2 from the target generator 260, those targets 27 that were not irradiated with the pulsed laser light 33 are recovered by the target recovery device 28.

[0037] Chamber 2 is connected to a gas supply unit 40 and an exhaust pump 46. The gas supply unit 40 supplies etching gas that reacts with debris floating in Chamber 2 and debris adhering to the inside of Chamber 2. If the target material 267 is tin, the etching gas may be hydrogen gas. The exhaust pump 46 exhausts the reaction product of the debris and etching gas, as well as unreacted etching gas, to the outside of Chamber 2. A vacuum pump may be used as the exhaust pump 46. A detoxification device (not shown) may be connected to the output of the exhaust pump 46.

[0038] The exhaust path 47, which is a gas passage between the exhaust pump 46 and the chamber 2, includes a gas inlet 48 into which gas containing debris flows from the chamber 2 and a gas exhaust port 49 for exhausting the gas. The gas exhaust port 49 is connected to the exhaust pump 46, and a debris trap 50 is placed in the middle of the exhaust path 47.

[0039] The debris trap 50 includes a plurality of blades 52 arranged parallel to the direction of gas flow from the gas inlet 48 to the gas exhaust port 49. The blades 52 may be flat plate members, curved plates, or cylindrical members.

[0040] 3.2 Operation The generation operation of EUV light 252 in the EUV light generator 1 is as described in Figure 1. The exhaust pump 46 guides the etching gas and reactants in the chamber 2 to the debris trap 50. When the target 27 is tin and the etching gas is hydrogen gas, the reactants include stannane (SnH4).

[0041] The Stannan decomposes upon contact with Blade 52, causing the target substance, tin, to precipitate. The precipitated tin is then collected by adhering to Blade 52.

[0042] 4. Debris trap related to the comparative example 4.1 Configuration Figure 3 is a perspective view of a debris trap 50 according to a comparative example. Figure 4 is a cross-sectional view of a debris trap 50 located in the exhaust path 47.

[0043] The debris trap 50 is a coaxial cylindrical trap having a multi-tube structure in which multiple cylindrical blades 52 of different diameters are arranged concentrically. "Tube" is synonymous with "cylinder."

[0044] The debris trap 50 may include a housing 54 that houses multiple blades 52 and constitutes part of the exhaust path 47. The housing 54 functions as a container for housing multiple blades 52 and also functions as a flow channel for the exhaust path 47. Note that the housing 54 is omitted in Figure 3. Each blade 52 is arranged such that the side surface of the circular tube extends along the direction of gas flow. The direction of gas flow in the exhaust path 47 is called the "gas flow direction," and the direction perpendicular to the gas flow direction is called the "gas flow perpendicular direction."

[0045] Multiple blades 52 are positioned and fixed in place by rod-shaped stays 56a and 56b located before and after the gas flow direction. The stays 56a and 56b may have notches for fixing each blade 52. The stays 56a and 56b before and after the blades 52 may be held by a shaft 58. Alternatively, the blades 52 may be welded to the stays 56a and 56b. Alternatively, multiple spacers may be arranged parallel to the radial direction of the blades 52 to fix each blade 52, and the blades 52 may be fixed to the spacers.

[0046] The debris trap 50 is positioned in the exhaust path 47 piping in a section where the temperature of the gas flowing into the debris trap 50 is between 20°C and 70°C. Alternatively, the EUV light generator 1 is operated under operating conditions such as adjusting the laser output so that the temperature of the gas flowing into the debris trap 50 is between 20°C and 70°C.

[0047] The debris trap 50 has neither a heater nor a temperature sensor. The temperature of the blade 52 depends on the temperature of the gas flowing into the debris trap 50 and is between 20°C and 70°C. If it is anticipated that some of the target material attached to the blade 52 will detach, a target material recovery section may be provided below the blade 52 in the direction of gravity. The recovery section may be configured as a space outside the gas flow path. The recovery section does not need to be equipped with a heater.

[0048] 4.2 Challenges Figure 5 is a cross-sectional view of the debris trap 50 after a certain period of use. Figure 5 shows a cross-section without the stays 56a and 56b. By depositing metallic tin 60 on the surface of the blades 52 of the debris trap 50, tin in the exhaust gas is collected. In addition, metallic tin 60 also adheres to the shaft 58 and stays 56a.

[0049] Therefore, if the EUV light generator 1 is operated for a long period of time, the metallic tin 60 deposited on the surface of the blade 52 will eventually narrow the exhaust path 47. When the exhaust path 47 narrows, the exhaust resistance increases, which may make it difficult to maintain the pressure inside the chamber 2 at a predetermined value. When the pressure inside the chamber 2 increases, the transmittance of the EUV light 252 decreases, which may result in insufficient output.

[0050] The thickness of the metallic tin 60 adhering to the blade 52 begins to increase upstream, and when the flow path upstream of the blade 52 narrows, cleaning or replacement of the debris trap 50 becomes necessary. At this time, the downstream side of the blade 52 often still has an area where metallic tin can be collected. In other words, as shown in the area enclosed by the dashed line in Figure 5, a lot of metallic tin 60 adheres to the upstream tip of the blade 52, and the gas flow path tends to narrow.

[0051] In order to extend the operating time of the EUV light generator 1, it was necessary to extend the maintenance interval of the debris trap 50, and a structure was needed that could suppress the narrowing of the flow path upstream of the blade 52 and collect tin in the downstream region as well.

[0052] 5. Embodiment 1 5.1 Configuration Figure 6 is a schematic cross-sectional view showing the configuration of the debris trap 100 according to Embodiment 1. The debris trap 100 has a multi-stage trap structure in which a plurality of coaxial cylindrical traps 101, 102, 103, 104, and 105 are arranged at intervals in the direction of gas flow. Although Figure 6 shows an example of a five-stage trap structure, the number of trap stages is not limited to five, and can be designed to any number of stages from two to five. In order to sufficiently remove debris, it is desirable to have three or more trap stages.

[0053] Each of the coaxial cylindrical traps 101, 102, 103, 104, and 105 has a multi-tube structure in which multiple cylindrical blades 521, 522, 523, 524, and 525 of different diameters are arranged concentrically. The outer circumference shape of the cylindrical blade is an example of "cylindrical" in this disclosure.

[0054] Figure 6 shows an example where the first stage coaxial tube trap 101 has a double-bladed tube, the second stage coaxial tube trap 102 has a triple-bladed tube, the third stage coaxial tube trap 103 has a quadruple-bladed tube, the fourth stage coaxial tube trap 104 has a quintuple-bladed tube, and the fifth stage coaxial tube trap 105 has a sextuple-bladed tube, starting from the upstream side in the gas flow direction. However, the number of blades (number of layers of multi-tube) constituting each stage trap is not limited to the example in Figure 6. Coaxial tube trap 101 is an example of the "first multi-tube" in this disclosure, and coaxial tube trap 102 is an example of the "second multi-tube" in this disclosure. Coaxial tube traps 103, 104, and 105 are each examples of the "third multi-tube" in this disclosure. Blades 521, 522, 523, 524, and 525 are each examples of the "tube" in this disclosure. The gas flow direction from top to bottom in Figure 6 is an example of the “first direction” in this disclosure, and the direction perpendicular to the gas flow is an example of the “second direction” in this disclosure.

[0055] The multiple blades 521, 522, 523, 524, and 525 that constitute the coaxial cylindrical traps 101, 102, 103, 104, and 105 of each stage may be held by stays 561, 562, 563, 564, and 565. The stays 561, 562, 563, 564, and 565 may be held by a shaft 58.

[0056] Multiple coaxial cylindrical traps 101, 102, 103, 104, and 105 are arranged coaxially with their respective central axes aligned. The spacing between the coaxial cylindrical traps 101, 102, 103, 104, and 105 is such that even if metallic tin adheres to the upstream tip of the blades 521, 522, 523, 524, and 525 in the gas flow direction of each trap, it will not come into contact with the blades 521, 522, 523, 524, and 525 before and after it in the gas flow direction. For example, the spacing between the coaxial cylindrical traps 101, 102, 103, 104, and 105 may be 10 mm.

[0057] The number of blades may be increased as you move downstream in the direction of the gas flow; for example, one blade may be added per stage, as shown in Figure 6. Also, consecutive stages of traps with the same number of blades are permitted.

[0058] The number of blades 521, 522, 523, 524, and 525 on each of the coaxial circular tube traps 101, 102, 103, 104, and 105 increases with each downstream trap, and the spacing between blades within each trap (the gap between the tubes that make up the multi-layered circular tube) is denser with each downstream trap.

[0059] Focusing on the first-stage coaxial tube trap 101 and the second-stage coaxial tube trap 102, the distance between the closest blades among the multiple blades 522 constituting the second-stage coaxial tube trap 102, which is downstream, is smaller than the distance between the closest blades among the multiple blades 521 constituting the first-stage coaxial tube trap 101. A similar relationship exists between the relatively upstream traps and downstream traps for the third stage and beyond. The distance between the closest blades among the multiple blades 521 constituting the coaxial tube trap 101 is an example of "the distance between the closest pipes among the multiple pipes constituting the first multi-tube" in this disclosure, and the distance between the closest blades among the multiple blades 522 constituting the coaxial tube trap 102 is an example of "the distance between the closest pipes among the multiple pipes constituting the second multi-tube" in this disclosure.

[0060] Furthermore, even if each blade 521, 522, 523, 524, and 525 is extended axially, it will not overlap with the other blades upstream and downstream. In other words, the diameters of each blade 521, 522, 523, 524, and 525 are different so that their axial projections do not overlap. Here, "diameter" may refer to the outer diameter of a cylindrical blade. "Outer diameter" is an example of the maximum outer dimension perpendicular to the gas flow.

[0061] The thickness (wall thickness) and length in the gas flow direction of each of the multiple blades 521, 522, 523, 524, and 525 are not particularly limited. The thickness of each blade 521, 522, 523, 524, and 525 may be, for example, 0.1 mm or more and 2.0 mm or less. The thicknesses of each blade 521, 522, 523, 524, and 525 may all be the same, or there may be a mixture of blades with different thicknesses.

[0062] The lengths of blades 521, 522, 523, 524, and 525 in the gas flow direction may be the same for each stage, or blades of different lengths may be used for each stage.

[0063] Figure 7 is a front view of the first and second stages of coaxial cylindrical traps 101 and 102 of the debris trap 100, as seen in the direction of gas flow. The first stage coaxial cylindrical trap 101 has a structure in which two cylindrical blades 521a and 521b of different diameters are arranged coaxially. The second stage coaxial cylindrical trap 102 has a structure in which three cylindrical blades 522a, 522b and 522c of different diameters are arranged coaxially. Each of the cylindrical blades 521a and 521b corresponds to blade 521 in Figure 6, and each of the cylindrical blades 522a, 522b and 522c corresponds to blade 522 in Figure 6. The coaxial cylindrical trap 101 is an example of the "multiple pipes" of the first multi-tube system in this disclosure, and the coaxial cylindrical trap 102 is an example of the "multiple pipes" of the second multi-tube system in this disclosure.

[0064] In each stage, the cylindrical blades 521a, 521b, 522a, 522b, and 522c have smaller diameter blades nested inside larger diameter blades. The outer diameter of the outermost cylindrical blade 522c in the second stage is larger than the outer diameter of the outermost cylindrical blade 521b in the first stage. The outer diameter of the innermost cylindrical blade 522a in the second stage is smaller than the outer diameter of the innermost cylindrical blade 521a in the first stage. The spacing between the blades of the cylindrical blades 522a, 522b, and 522c in the second stage is narrower than the spacing between the blades of the cylindrical blades 521a and 521b in the first stage. The blade spacing of the circular pipe blades 521a and 521b is an example of the "spacing between adjacent pipes of multiple pipes constituting the first multi-tube" in this disclosure, and the blade spacing of the circular pipe blades 522a, 522b, and 522c is an example of the "spacing between adjacent pipes of multiple pipes constituting the second multi-tube" in this disclosure. The circular pipe blade 521b is an example of the "first outermost pipe" in this disclosure, and the circular pipe blade 522c is an example of the "second outermost pipe" in this disclosure. The circular pipe blade 521a is an example of the "first innermost pipe" in this disclosure, and the circular pipe blade 522a is an example of the "second innermost pipe" in this disclosure.

[0065] Figure 7 shows only the coaxial cylindrical traps 101 and 102 from the first to the second stage, but the same relationships exist between the traps in front of and behind each other in the third stage and beyond.

[0066] Each of the coaxial tube traps 101, 102, 103, 104, and 105 in each stage may be configured to be replaceable individually, or they may be configured to be replaced as a whole. Each of the coaxial tube traps 101, 102, 103, 104, and 105 is made of a metal such as stainless steel, aluminum, nickel, or copper.

[0067] In the EUV light generator 1, a debris trap 100 is used instead of the debris trap 50 shown in Figures 3 and 4.

[0068] 5.2 Operation Figure 8 is a cross-sectional view of the debris trap 100 after a certain period of use. Figure 8 shows a cross-section without stays 561, 562, 563, 564, and 565. As the exhaust gas from chamber 2 passes through the debris trap 100 in the exhaust path 47, metallic tin 60 is deposited in the upstream trap before flowing into the downstream trap, so the density of tin in the exhaust gas decreases towards the downstream side.

[0069] Therefore, the tin deposit thickness per unit time on each coaxial cylindrical trap 101, 102, 103, 104, and 105 is larger for traps located upstream in the gas flow direction and smaller for traps located downstream.

[0070] In each coaxial cylindrical trap 101, 102, 103, 104, and 105, the arrangement density of blades 521, 522, 523, 524, and 525 is sparser upstream and denser downstream. As a result, the narrowing of the flow path (reduction in flow path cross-sectional area) progresses generally uniformly between the upstream traps with larger blade spacing and the downstream traps with smaller blade spacing.

[0071] 5.3 Action and Effects According to the debris trap 100 of Embodiment 1, the narrowing of the flow path progresses almost uniformly between the upstream trap and the downstream trap, thereby suppressing the occurrence of narrowing only on the upstream side.

[0072] Furthermore, since the axial projections of each blade 521, 522, 523, 524, and 525 do not overlap, the downstream blades have less overlap with the low-tin-density region behind the upstream blades. As a result, tin can be effectively collected in the downstream trap as well.

[0073] As described above, the debris trap 100 according to Embodiment 1 extends the time until the pressure loss caused by the debris trap 100 affects the operation of the EUV light generator 1, thereby extending the maintenance interval of the debris trap 100.

[0074] 5.4 Variation 1 Figure 9 is a cross-sectional view showing a modified example 1 of the debris trap 100, and Figure 10 is a perspective view of the stay 566 applied to the debris trap 100 shown in Figure 9. Instead of the stays 561, 562, 563, 564, and 565 shown in Figure 6, a stay 566 consisting of a combination of lattice-shaped members 567a and 567b as shown in Figure 10 may be used. In this case, the shaft 58 may be omitted.

[0075] 5.5 Variation 2 Figure 11 is a cross-sectional view showing a modified example 2 of the debris trap 100. Instead of the stays 561, 562, 563, 564, and 565 shown in Figure 6, plate-shaped stays 661, 662, 663, 664, 665, and 666 as shown in Figure 11 may be used. That is, the stays 661, 662, 663, 664, 665, and 666 may be composed of plate-shaped members having a predetermined width W, and may be configured to hold the front and rear blades 521, 522, 523, 524, and 525 by a plurality of plate-shaped stays 661, 662, 663, 664, 665, and 666.

[0076] Each of the plate-shaped stays 661, 662, 663, 664, 665, and 666 is positioned so that the side surface of the plate, which has a width W, is parallel to the direction of gas flow. In this case, the shaft 58 may also be omitted.

[0077] 6. Embodiment 2 6.1 Configuration Figure 12 is a schematic cross-sectional view showing the configuration of the debris trap 120 according to Embodiment 2. Figure 13 is a front view of the first and second stage coaxial rectangular tube traps 121 and 122 of the debris trap 120 as seen in the gas flow direction. The differences between the debris trap 120 and the debris trap 100 according to Embodiment 1 will be explained. The shape of the blades constituting the multi-stage trap structure is not limited to circular tubes. For example, instead of circular tube blades, polygonal tube blades, where the outer circumference of the cross-section perpendicular to the gas flow direction is polygonal, may be used. The outer circumference shape of the polygonal tube blade is an example of a "polygonal tubular shape" in this disclosure.

[0078] The cross-sectional shape of the rectangular tube may be a polygon that matches the cross-sectional shape of the exhaust path 47. For example, if the cross-sectional shape of the exhaust path 47 is a square, the cross-sectional shape of the rectangular tube may be a square. The term "polygon" includes shapes that can be considered polygons in practical terms. The same applies to the term "square." For example, a rounded square, which is a square with rounded corners, may be included in the concept of a square.

[0079] The debris trap 120 includes coaxial rectangular tube traps 121, 122, 123, 124, and 125 instead of the coaxial circular tube traps 101, 102, 103, 104, and 105 shown in Figure 6. Each of the coaxial rectangular tube traps 121, 122, 123, 124, and 125 has a multi-tube structure in which multiple rectangular tube-shaped blades 531, 532, 533, 534, and 535, each with a different maximum external dimension perpendicular to the gas flow, are arranged coaxially. In the case of a rectangular tube with a square cross-sectional shape perpendicular to the gas flow direction, the external dimension in the diagonal direction of the square cross-sectional shape can be the "maximum external dimension perpendicular to the gas flow direction".

[0080] The blades 531, 532, 533, 534, and 535 that make up the coaxial rectangular tube traps 121, 122, 123, 124, and 125 may be held at equal intervals from each other by a stay 566. If a stay 566 like the one in Figure 10 is used, the shaft 58 may be omitted. Instead of the stay 566, stays 561, 562, 563, 564, and 565 shown in Figure 6, or stays 661, 662, 663, 664, 665, and 666 shown in Figure 11 may be used.

[0081] The debris trap 120 includes a housing 55 that forms part of the exhaust path 47, instead of the housing 54 in Figure 6. The housing 55 has a rectangular cross-sectional shape in the cross section perpendicular to the gas flow direction.

[0082] As shown in Figure 13, the first stage coaxial rectangular tube trap 121 has a structure in which two rectangular tube blades 531a and 531b with different maximum external dimensions in the direction perpendicular to the gas flow are arranged coaxially. The second stage coaxial rectangular tube trap 122 has a structure in which three rectangular tube blades 532a, 532b, and 532c with different maximum external dimensions in the direction perpendicular to the gas flow are arranged coaxially. In each stage, the rectangular tube blades 531a, 531b, 532a, 532b, and 532c are arranged in a nested manner, with blades with smaller maximum external dimensions inside blades with larger maximum external dimensions. Rectangular tube blades 531a and 531b are blades 531 in Figure 12, and rectangular tube blades 532a, 532b, and 532c are blades 532 in Figure 12.

[0083] The outer circumferential shapes of the cross-sections of the rectangular tube blades 531a, 531b, 532a, 532b, and 532c perpendicular to the gas flow direction may be similar to each other. Also, the outer circumferential shapes of the cross-sections of the rectangular tube blades 531a, 531b, 532a, 532b, and 532c perpendicular to the gas flow direction may be similar to the shape of the flow path cross-section of the exhaust path 47. That is, the outer circumferential shapes of the cross-sections of each rectangular tube blade 531a, 531b, 532a, 532b, and 532c perpendicular to the gas flow direction may be similar to the inner circumferential shape of the cross-section perpendicular to the gas flow direction of the housing 55. The same applies to the third and subsequent coaxial rectangular tube traps 123, 124, and 125. The other configurations are the same as in Embodiment 1.

[0084] 6.2 Operation The operation of the debris trap 120 is the same as that of the debris trap 100.

[0085] 6.3 Action and Effects According to Embodiment 2, the same effects as in Embodiment 1 can be obtained. By designing the shape of each trap and blade to match the cross-sectional shape of the exhaust path 47, as in the debris trap 120, the space utilization rate of the exhaust path 47 is improved, making it possible to realize a compact debris trap 120.

[0086] 7. Methods for Manufacturing Electronic Devices Figure 14 schematically shows the configuration of the exposure apparatus 6a connected to the EUV light generator 1. The EUV light generator 1 is equipped with a debris trap 100 or a debris trap 120. In Figure 14, the exposure apparatus 6a as an external device includes a mask irradiation unit 68 and a workpiece irradiation unit 69. The mask irradiation unit 68 illuminates the mask pattern on the mask table MT via a reflective optical system using EUV light incident from the EUV light generator 1. The workpiece irradiation unit 69 images the EUV light 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 6a exposes the workpiece to EUV light reflecting the mask pattern by synchronously moving the mask table MT and the workpiece table WT in parallel. By transferring a device pattern onto a semiconductor wafer through the exposure process described above, an electronic device can be manufactured.

[0087] Figure 15 schematically shows the configuration of the inspection device 6b connected to the EUV light generator 1. In Figure 15, the inspection device 6b, as an external device, includes an illumination optical system 63 and a detection optical system 66. The illumination optical system 63 reflects the EUV light incident from the EUV light generator 1 and irradiates the mask 65 placed on the mask stage 64. The mask 65 here includes mask blanks before a pattern is formed. The detection optical system 66 reflects the EUV light from the illuminated mask 65 and forms an image on the light-receiving surface of the detector 67. The detector 67, having received the EUV light, acquires an image of the mask 65. The detector 67 is, for example, a TDI (Time Delay Integration) camera. Based on the image of the mask 65 acquired through the above process, defects in the mask 65 are inspected, and the results of the inspection are used to select a mask suitable for the manufacture of an electronic device. Then, the pattern formed on the selected mask can be exposed and transferred onto a photosensitive substrate using an exposure device 6a to manufacture an electronic device.

[0088] 8. About the processor Processors such as Processor 5 may be physically configured in hardware form to perform the various processes included in this disclosure. For example, the processor may be a computer that includes a memory storing a control program that defines the various processes, and a processing unit that executes the control program. The control program may be stored in a single memory, or it may be stored in multiple physically separate memories, and the various processes may be defined by the control program as a collection of these memories. The processing unit may be a general-purpose processing unit such as a CPU (Central Processing Unit), or a purpose-specific processing unit such as a GPU (Graphics Processing Unit).

[0089] Furthermore, the processor may be programmed in software form to perform the various processes included in this disclosure. For example, the processor may have functions for performing the various processes implemented in a dedicated device such as an ASIC (Application Specific Integrated Circuit) or a programmable device such as an FPGA (Field Programmable Gate Array).

[0090] The various processes included in this disclosure may be performed by one computer, one dedicated device, or one programmable device, or by the cooperation of multiple computers, multiple dedicated devices, or multiple programmable devices located physically separately. The various processes may be performed by at least two combinations of one or more computers, one or more dedicated devices, and one or more programmable devices.

[0091] 9. Other The above description is intended to be illustrative and not restrictive. Therefore, 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. It will also be apparent to those skilled in the art that the embodiments of this disclosure can be used in combination.

[0092] Terms used in this specification and throughout the claims should be interpreted as "non-limiting" unless otherwise specified. For example, terms such as "includes," "have," "equip," and "possess" should be interpreted as "not excluding the existence of components other than those described." Also, the modifier "one" should be interpreted as "at least one" or "one or more." Furthermore, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." In addition, it should be interpreted as including combinations of these with anything other than "A," "B," and "C."

Claims

1. A debris trap is positioned in an exhaust path that includes a gas inlet into which a gas containing debris flows from a chamber and a gas exhaust port for exhausting the gas, The system comprises a first multi-tube and a second multi-tube, respectively, arranged along a first direction which is the flow direction of the gas from the gas inlet to the gas exhaust port. Each of the first and second multi-tubes comprises a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction. The second multi-tube is positioned downstream of the first multi-tube in the first direction. The number of tubes constituting the second multi-tube is greater than the number of tubes constituting the first multi-tube. Debris trap.

2. A debris trap according to claim 1, The aforementioned debris is tin. Debris trap.

3. A debris trap according to claim 1, The distance between the closest tubes among the multiple tubes constituting the second multi-tube is smaller than the distance between the closest tubes among the multiple tubes constituting the first multi-tube. Debris trap.

4. A debris trap according to claim 1, The aforementioned plurality of tubes are arranged in a nested manner. Debris trap.

5. A debris trap according to claim 1, Each of the aforementioned plurality of tubes is circular or polygonal in shape. Debris trap.

6. A debris trap according to claim 1, The central axes of the first multi-tube and the second multi-tube coincide. Debris trap.

7. A debris trap according to claim 1, The outer circumferential shapes of the cross-sections of each of the plurality of tubes perpendicular to the first direction are similar to each other. Debris trap.

8. A debris trap according to claim 1, The outer circumferential shape of the cross-section of each of the plurality of pipes perpendicular to the first direction is similar to the shape of the flow path cross-section of the exhaust path. Debris trap.

9. A debris trap according to claim 1, The device comprises a housing that accommodates the first multi-tube and the second multi-tube, Debris trap.

10. A debris trap according to claim 9, The housing constitutes a part of the flow path pipe of the exhaust path. Debris trap.

11. A debris trap according to claim 9, The outer circumferential shape of the cross-section of each of the plurality of tubes perpendicular to the first direction is similar to the inner circumferential shape of the cross-section of the housing perpendicular to the first direction. Debris trap.

12. A debris trap according to claim 1, The first multi-tube and the second multi-tube are arranged with an interval between them in the first direction. Debris trap.

13. A debris trap according to claim 1, The projected image obtained by projecting the multiple tubes constituting the first multi-tube in the axial direction does not overlap with the projected image obtained by projecting the multiple tubes constituting the second multi-tube in the axial direction. Debris trap.

14. A debris trap according to claim 1, The spacing between adjacent tubes in the multiple tubes constituting the first multi-tube is greater than the spacing between adjacent tubes in the multiple tubes constituting the second multi-tube. Debris trap.

15. A debris trap according to claim 1, The maximum external dimensions in the second direction of the first outermost tube, which is the outermost of the multiple tubes constituting the first multi-tube, are smaller than the maximum external dimensions in the second direction of the second outermost tube, which is the outermost of the multiple tubes constituting the second multi-tube. The maximum external dimension in the second direction of the first innermost tube, which is the innermost of the multiple tubes constituting the first multi-tube, is greater than the maximum external dimension in the second direction of the second innermost tube, which is the innermost of the multiple tubes constituting the second multi-tube. Debris trap.

16. A debris trap according to claim 1, The system includes a stay that holds the plurality of pipes, Debris trap.

17. A debris trap according to claim 1, The third multi-tube further comprises a plurality of tubes arranged along the first direction and having different maximum external dimensions in the second direction, The third multi-tube is positioned downstream of the second multi-tube in the first direction, and the number of tubes constituting the third multi-tube is greater than the number of tubes constituting the second multi-tube. Debris trap.

18. A chamber in which plasma is generated by irradiating a target material with laser light, An exhaust path including a gas inlet into which gas containing debris flows from the chamber and a gas exhaust port for exhausting the gas, A debris trap according to claim 1, which is arranged in the exhaust path, An extreme ultraviolet light generating device equipped with [a specific feature].

19. A method for manufacturing electronic devices, A chamber in which plasma is generated by irradiating a target material with laser light, An exhaust path including a gas inlet into which gas containing debris flows from the chamber and a gas exhaust port for exhausting the gas, The exhaust path includes a debris trap, The aforementioned debris trap is The system comprises a first multi-tube and a second multi-tube, respectively, arranged along a first direction which is the flow direction of the gas from the gas inlet to the gas exhaust port. Each of the first and second multi-tubes comprises a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction. The second multi-tube is positioned downstream of the first multi-tube in the first direction. The number of tubes constituting the second multi-tube is greater than the number of tubes constituting the first multi-tube, and extreme ultraviolet light is generated by an extreme ultraviolet light generating device. The aforementioned extreme ultraviolet light is output to the exposure device, To manufacture an electronic device, the process involves exposing a photosensitive substrate to extreme ultraviolet light in the exposure apparatus, A method for manufacturing electronic devices.

20. A method for manufacturing electronic devices, A chamber in which plasma is generated by irradiating a target material with laser light, An exhaust path including a gas inlet into which gas containing debris flows from the chamber and a gas exhaust port for exhausting the gas, The exhaust path includes a debris trap, The aforementioned debris trap is The system comprises a first multi-tube and a second multi-tube, respectively, arranged along a first direction which is the flow direction of the gas from the gas inlet to the gas exhaust port. Each of the first and second multi-tubes comprises a plurality of tubes, each having different maximum external dimensions in a second direction perpendicular to the first direction. The second multi-tube is positioned downstream of the first multi-tube in the first direction. The number of tubes constituting the second multi-tube is greater than the number of tubes constituting the first multi-tube, and the mask is irradiated with extreme ultraviolet light generated by an extreme ultraviolet light generator to inspect for defects in the mask. Using the results of the above inspection, select a mask. This includes exposing and transferring the pattern formed on the selected mask onto a photosensitive substrate. A method for manufacturing electronic devices.

Images