Dust management in gas discharge chambers

Abstract

A dust collector for a gas discharge chamber of a light source includes an inlet port, an outlet port, and a passive dust trap. The inlet port is in fluid communication with the cavity of the gas discharge chamber. The outlet port is in fluid communication with an active dust trap such that an outflow passage outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port. The passive dust trap is configured to define a second flow path that extends across the outflow passage and at least partially along a second direction different from the outflow direction to a collection pocket defined within the collector body of the passive dust trap.

Description

Technical Field

[0001] (Cross - reference to Related Applications)

[0001] This application claims the priority of U.S. Application No. 63 / 488,821 filed on March 7, 2023 and U.S. Application No. 63 / 627,854 filed on February 1, 2024, which are hereby incorporated by reference in their entirety.

[0002]

[0002] The disclosed subject matter relates to dust management in a gas discharge chamber of a light source.

Background Art

[0003]

[0003] One type of gas discharge light source used in photolithography is called an excimer light source or laser. Typically, an excimer laser uses a combination of one or more noble gases that may include argon, krypton, or xenon, and a reactive gas that may include fluorine or chlorine as the gain medium. An excimer laser can generate an excimer (or exciplex), which is a pseudo - molecule, under appropriate electrical stimulation (supply energy) and high - pressure conditions (of the gas mixture), and the excimer exists only in an excited state. The excited - state excimer produces amplified light in the ultraviolet region. An excimer light source can use a single gas discharge chamber or multiple gas discharge chambers. When the excimer light source is operating, it generates a deep ultraviolet (DUV) light beam. The DUV light can include wavelengths, for example, from about 100 nanometers (nm) to about 280 nm. Energy can be supplied to the gain medium through electrodes, but the electrodes can corrode during operation and generate metal fluoride (or metal chloride) dust particles.

[0004]

[0004] The DUV light beam may be directed to a photolithography exposure apparatus or scanner, which is a machine that applies a desired pattern to a target portion of a substrate (such as a silicon wafer). The DUV light beam interacts with a projection optical system that projects the DUV light beam onto the photoresist of the wafer through a mask. In this way, one or more layers of the chip design are patterned on the photoresist, after which the wafer is etched and cleaned. [Overview of the Initiative]

[0005]

[0005] In some common embodiments, a dust collector for a gas discharge chamber of a light source includes an inlet port, an outlet port, and a baffle. The inlet port is in fluid communication with the cavity of the gas discharge chamber. The outlet port is in fluid communication with an active dust trap such that an outflow passage outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port. The baffle is configured to define a second flow path that extends across the outflow passage and at least partially along a second direction different from the outflow direction to a collection pocket defined within the collector body.

[0006]

[0006] In other common embodiments, a dust collector for a gas discharge chamber of a light source includes an inlet port, an outlet port, and a passive dust trap. The inlet port is in fluid communication with the cavity of the gas discharge chamber. The outlet port is in fluid communication with an active dust trap such that an outflow passage outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port. The passive dust trap is configured to define a second flow path that extends across the outflow passage and at least partially along a second direction different from the outflow direction to a collection pocket defined within the collector body of the passive dust trap.

[0007]

[0007] The embodiment may include one or more of the following features. For example, the passive dust trap may include a baffle. The baffle may extend laterally across the outflow passage. The baffle may be configured to capture dust particles in a collection pocket. The second flow path may have a narrower cross-sectional area compared to the cross-sectional area of ​​the outflow passage. The baffle may extend along an angle of 75° to 105° or 85° to 95° with respect to the outflow direction. The baffle may also define a third flow path extending toward the outflow passage on the way from the second flow path toward the active dust trap, such that a curved flow path extends around the baffle between the second and third flow paths. The collector body may include a projection extending toward the tip of the baffle, and a constricted region of the second flow path may be defined near the tip of the baffle between the projection and the baffle. The constricted region may have a smaller cross-sectional area than the cross-sectional area of ​​the outflow passage. The baffle may not have sharp edges or sharp corners. The baffle's properties along the flow path are smooth. The baffle's tip may have a curved shape with a radius of gyration of less than 1 inch, less than 0.5 inches, or less than 0.25 inches. The baffle may extend across the outflow passage along its cross-section, and the extent of the baffle along its transverse direction may be greater than or equal to the extent of the outflow passage. The baffle may be rigid. The baffle may be made of nickel-plated metal, ingot, copper, brass, nickel-copper alloy, copper alloy, or Monel.

[0008]

[0008] The passive dust trap can be configured to capture dust particles in a collection pocket. The interior of the collector body can be defined as a cylindrical region and a conical region. The second flow path can form a spiral shape extending through the cylindrical region and the conical region to the collection pocket. The spiral flow can extend along the third flow path so as to return from the collection pocket to the outflow passage, with the spiral flow path extending between the second and third flow paths.

[0009]

[0009] The collector body may be removable from the rest of the passive dust trap. The passive dust trap may be removable from the outflow passage.

[0010]

[0010] In other common embodiments, a dust collector for a gas discharge chamber of a light source includes an inlet port, an outlet port, and a collector. The inlet port is in fluid communication with the cavity of the gas discharge chamber. The outlet port is in fluid communication with an active dust trap such that an outflow passage outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port. The collector is along the outflow passage. The collector includes a collector body that defines a second flow path extending along a second direction different from the outflow direction, extending from the outflow passage to a collection pocket.

[0011]

[0011] Embodiments may include one or more of the following features. For example, the second channel may be configured to capture dust particles in a collection pocket. The second channel may extend at least partially along an angle of 75° to 105° or 85° to 95° with respect to the outflow direction. The collector body may further define a third channel that extends from the second channel around a bend and toward the outflow passage on its way toward the active dust trap. The second channel may extend within a defined structure without sharp ends or corners. The second channel may be defined between a baffle extending laterally across the outflow passage and a projection of the collector body extending toward the tip of the baffle. The collector body may further define a third channel that extends from the second channel toward the outflow passage and the active dust trap such that the bend extends at least partially around the tip of the baffle with a turning radius of less than 1 inch, less than 0.5 inches, or less than 0.25 inches.

[0012]

[0012] The second channel may have a narrower cross-sectional area compared to the cross-sectional area of ​​the outflow channel. The second channel may extend to a cylindrical and conical region defined within the collector body between the outflow channel and the collection pocket, and may form a cyclone extending to the collection pocket. The cyclone flow may extend along the third channel so as to return from the collection pocket towards the outflow channel, with the cyclone channel extending between the second and third channels. The collector may be removable from the outflow channel.

[0013]

[0013] In other common embodiments, a dust control device for a gas discharge chamber of a light source includes a cavity of the gas discharge chamber, an active dust trap in fluid communication with the cavity of the gas discharge chamber via an outflow passage outside the cavity of the gas discharge chamber, and a dust collector located between the active dust trap and the cavity of the gas discharge chamber along the outflow passage. The dust collector includes a baffle extending across the outflow passage and configured to define a second flow path extending at least partially along a second direction different from the outflow direction to a collection pocket defined in the collector body.

[0014]

[0014] Embodiments may include one or more of the following features. For example, the dust control device may further include an exhaust fan configured to direct dust and fluid from the cavity of the gas discharge chamber to the outflow passage within the cavity of the gas discharge chamber. The velocity of the dust and fluid flow through the outflow passage may increase as it passes through the dust collector. The baffle may extend laterally across the outflow passage. The baffle may be configured to trap dust particles in collection pockets. The second flow path may have a narrower cross-sectional area compared to the cross-sectional area of ​​the outflow passage. The collector body may include a projection extending toward the tip of the baffle, and the constricted region of the second flow path may be defined near the tip of the baffle between the projection and the baffle. The baffle may not have sharp ends or corners. The surface shape of the baffle may have smooth characteristics. The baffle may extend across the outflow passage along its cross-section, and the extent of the baffle along its transverse direction may be greater than or equal to the extent of the outflow passage.

[0015]

[0015] In other common embodiments, a method for collecting dust from a cavity of a gas discharge chamber of a light source includes: discharging a fluid containing dust particles from the cavity toward an active dust trap toward an outflow passage outside the cavity; redirecting at least a portion of the fluid containing dust particles toward a second flow path that extends at least partially toward a second direction different from the direction of the outflow passage; increasing the velocity of the redirected fluid containing dust particles by passively compressing the redirected fluid containing dust particles; and collecting the dust particles in a collection pocket while allowing the redirected fluid to return to the outflow passage on its way toward the active dust trap.

[0016]

[0016] Embodiments may include one or more of the following features. For example, a fluid containing dust particles may be discharged from the cavity by operating an exhaust fan in the cavity of the gas discharge chamber, configured to direct the dust and fluid from the cavity of the gas discharge chamber to the outlet passage. At least a portion of the fluid may be redirected from the outlet passage to a second passage by preventing the fluid from moving directly toward the active dust trap with a baffle extending across the outlet passage and defining a second passage. The redirected fluid may be passively compressed by pushing the redirected fluid out of a constricted region of the second passage, which is defined between a baffle extending across the outlet passage and a projection defining a collection pocket of the collector body. The velocity of the redirected fluid may be increased by increasing the velocity of the redirected fluid to at least twice the velocity of the fluid being discharged from the cavity to the outlet passage.

[0017]

[0017] Details of one or more embodiments will be made apparent in the accompanying drawings and the following description. Other features will be apparent from the description and drawings, as well as from the claims. [Brief explanation of the drawing]

[0018] [Figure 1A]

[0018] This is a block diagram of a dust collector configured to remove dust particles from the cavity of a gas discharge chamber, the dust collector being positioned between the cavity and an active dust trap. [Figure 1B]

[0019] This is a block diagram of a close-up section showing details of the dust collector, including a baffle extending across an outflow passage defined between the cavity and the active dust trap. [Figure 1C]

[0020] Figures 1A and 1B are close-up side cross-sectional views of the baffle. [Figure 2]

[0021] Perspective view of the baffle from FIGS. 1A to 1C. [Figure 3]

[0022] Perspective view of an embodiment of the dust collector of FIGS. 1A and 1B, the dust collector including a collector body including a baffle body and a neck body between the baffle body and the collector body. [Figure 4A]

[0023] Perspective view of the dust collector of FIG. 3 showing cross-section 4A along the XZ plane. [Figure 4B]

[0024] Perspective view of the dust collector of FIG. 3 showing cross-section 4B along the XY plane. [Figure 5A]

[0025] Notch cross-sectional view obtained from cross-section 4A of FIG. 4A. [Figure 5B]

[0026] Notch cross-sectional view obtained from cross-section 4B of FIG. 4B. [Figure 6]

[0027] Block diagram of an embodiment of a dust management device configured for the cavity of a gas discharge chamber, the dust management device including an active dust trap which is an embodiment of the active dust trap of FIG. 1A and a dust collector which is an embodiment of the dust collector of FIG. 1A. [Figure 7]

[0028] Block diagram of an embodiment of a two-stage light source including an embodiment of a gas discharge chamber. [Figure 8]

[0029] Flowchart of a procedure for collecting and removing dust particles from a cavity, for example, performed by the dust collector of FIG. 1A. [Figures 9A-9E]

[0030] Shows different embodiments of the baffle that can be used in any of the dust collectors of FIGS. 1A to 7. [Figure 10A-10C]

[0031] Shows different embodiments of the collector body of the dust collectors of FIGS. 1A to 7. [Figure 11A]

[0032] This is a block diagram of another embodiment of a dust collector configured to remove dust particles from the cavity of a gas discharge chamber, the dust collector being positioned between the cavity and an active dust trap. [Figure 11B]

[0033] Figure 11A is a perspective view of the dust collector. [Figure 12]

[0034] This is a perspective view of an embodiment of a dust collector, which includes a collector body, a main body, and a neck body located between the main body and the collector body, wherein the collector body is removable from the rest of the dust collector. [Figure 13]

[0035] This is a perspective view of an embodiment of a dust collector that includes a collector body, a main body, and a neck body located between the main body and the collector body, wherein the collector body, the main body, and the neck body are removable from the outflow passage. [Modes for carrying out the invention]

[0019]

[0036] Referring to Figures 1A to 1C, the dust collector 100 is configured to remove dust particles (or simply "dust") 131 from a cavity 130 defined within the gas discharge chamber 132 of the light source. During steady operation, the gas discharge chamber 132 is configured to generate a light beam 133 used by an external device or output device 179 (also shown in Figures 6 and 7). The output device 179 may be, for example, a photolithography exposure apparatus. The dust collector 100 is located outside the gas discharge chamber 132 in an outflow passage 140, which extends from the cavity 130 to an active dust trap 145.

[0020]

[0037] Conventionally, the active dust trap 145 is configured to clean components within the cavity 130 of the gas discharge chamber. For example, the active dust trap 145 is configured to remove dust 131 from such components within the cavity 130. To this end, the active dust trap 145 receives the dust 131 from within the cavity 130 (through the outflow passage 140) along with a fluid (such as gas), and then captures the dust 131 while allowing the fluid to return to the cavity 130 along a return passage 150 separate from the outflow passage 140. This return fluid entering the cavity 130 along the return passage 150 can be used as a clean fluid (gas) stream for purging components (such as optical elements) in the gas discharge chamber 132. Such optical components within or at least partially defining the cavity 130 may interact with the light beam 133 or the precursor light beam forming the light beam 133. An example of a cleanable optical element is an optical window formed in the wall of the chamber 132, which allows the light beam 133 (or precursor light beam) to enter and exit the cavity 130. Purge such components can keep them clean and prevent dust accumulation on them. The active dust trap 145 includes, in particular among other possible mechanisms, an active element 146 such as an electrostatic precipitator or other non-passive elements that capture dust 131 in the fluid flowing through it.

[0021]

[0038] As the lifespan of the gas discharge chamber 132 increases (due to improvements in the manufacturing of the gas discharge chamber 132 and its components), the gas discharge chamber 132 generates more dust 131 during operation than the current active dust trap 145 can hold. Therefore, over time and with use, the active dust trap 145 may become saturated with dust 131 and no longer be able to remove it from the cavity 130 of the chamber 132. Thus, the active dust trap 145 eventually becomes unable to properly return clean fluid to the cavity 130 via the return passage 150. In such a case, the dust 131 is no longer removed, and the return fluid in the return passage 150 is not properly flushed, resulting in the components in the cavity 130 not being properly cleaned or purged. Consequently, such components may be damaged and the gas discharge chamber 132 may fail before the actual lifespan of the gas discharge chamber 132 is reached. Furthermore, if the components of the gas discharge chamber 132 are damaged, the characteristics of the light beam 133 may be adversely affected, potentially rendering the light beam 133 unusable or failing to meet the requirements for use by the output device 179.

[0022]

[0039] The dust collector 100 is positioned between the cavity 130 of the gas discharge chamber 132 and the active dust trap 145. The dust collector 100 is designed to delay the saturation of dust 131 within the active dust trap 145. Because the dust collector 100 is positioned along the outflow passage 140, the active dust trap 145 can operate efficiently for the lifetime of the gas discharge chamber 132.

[0023]

[0040] The dust collector 100 includes a collector body 108 that defines an inlet port 102i that fluidly communicates with the cavity 130 of the gas discharge chamber 132, and an outlet port 102o that fluidly communicates with the active dust trap 145. The outflow passage 140 is located outside the cavity 130 of the gas discharge chamber 132 and is defined along the outflow direction from the inlet port 102i to the outlet port 102o.

[0024]

[0041] The dust collector 100 operates by blocking the dust-filled fluid flow along the outflow passage 140 and abruptly changing the direction of the dust-filled fluid flow so that it moves away from the outflow passage 140 and into the second flow path 142. Normally, the fluid flow abruptly changes direction after the dust particles 131 in the fluid have flowed out of the fluid due to their own inertia and momentum, and are returned to the outflow passage 140 along the third flow path 143. Specifically, the dust particles 131 have momentum along the direction of the second flow path 142. Then, when the fluid changes direction and returns towards the outflow passage 140 along the third flow path 143, these particles 131 instead continue to travel along the path of the second flow path 142 without turning back towards the outflow passage 140, and are captured or collected in the collector body 108.

[0025]

[0042] The dust collector 100 includes a baffle 105 extending across the outflow passage 140. The baffle 105 (together with the collector body 108) is configured to define a second flow path 142 that extends at least partially along a second direction different from the outflow direction. The second flow path 142 extends to a collection pocket 107 defined within the collector body 108 of the collector 100. The collection pocket 107 is a three-dimensional cavity or space defined within the wall of the collector body 108. Thus, dust particles 131 continue to travel along the second flow path 142 into the collection pocket 107 and remain trapped there. The baffle 105 has an elongated, rounded triangular body 106 extending from the base 111 (Figures 1B and 1C) along the baffle direction 105d (Figure 1C). The base 111 coincides with the inner wall 140w of the collector body 108, and the inner wall 140w at least partially defines the outflow passage 140 (see Figures 1A and 1B). In the local XYZ coordinate system of the baffle 105, the triangular body 106 (specifically, the baffle direction 105d, Figure 1C) extends along the X direction relative to the base 111, and the base 111 lies in a vertical plane including the Z direction. The Z direction may indicate the direction of the outflow passage 140. (In embodiments where the outflow passage 140 follows a curved trajectory, the Z direction may be considered the direction in which the outflow passage collides with the baffle 105.) Also, the redirected fluid containing the dust particles 131 is passively compressed as it travels along the second flow path 142, and this compression increases the velocity of the redirected fluid containing the dust particles 131 relative to the velocity of the fluid containing the dust particles 131 exiting the cavity 130. For example, the velocity of the redirected fluid containing the dust particles 131 may be at least twice the velocity of the fluid containing the dust particles 131 being discharged from the cavity 130 into the outflow passage 140.

[0026]

[0043] Referring to Figure 2, an embodiment 205 of the baffle 105 is shown in perspective. The baffle 205 has an elongated, rounded, substantially triangular body 206 extending from the base 211 along the baffle direction 205d. The base 211 coincides with the inner wall 140w (see Figures 1A and 1B) that at least partially defines the outflow passage 140. In the local XYZ coordinate system of the baffle 205, the triangular body 206 (specifically the baffle direction 205d) extends along the X direction relative to the base 211 (which is in the YZ plane or in a plane containing the Z direction). The baffle 205 is positioned within the outflow passage 140 such that the triangular body 206 extends laterally across the outflow passage 140 (see Figures 1A and 1B). That is, the baffle direction 205d extends laterally with respect to the direction of the outflow passage 140. Therefore, in the examples shown in Figures 1A to 1C, the baffle direction 205d of the triangular body 206 is lateral or approximately perpendicular to the outflow passage 140, and the Z direction is along the outflow passage 140.

[0027]

[0044] In other embodiments, the baffle direction 205d of the triangular body 206 may extend along a direction within 5° from the X direction (or baffle direction 205d), within 10° from the X direction, or within 15° from the X direction, while the base 211 remains in the YZ plane. Similarly, the baffle direction 205d of the triangular body 206 may be constructed to extend along an angle within 5° from the perpendicular to the Z direction, within 10° from the perpendicular to the Z direction, or within 15° from the perpendicular to the Z direction when fixed within the outflow passage 140. An example of this embodiment is shown in Figure 9E.

[0028]

[0045] As shown in Figures 1A to 1C and Figure 2, the baffles 105 and 205 (specifically the triangular body 206) do not have any sharp ends or corners extending into the outflow passage 140. This rounded, smooth characteristic of the triangular body 206 facilitates the fluid flow around the triangular body 206 of the baffles 105 and 205, and allows the dust particles 131 to continue moving along the second flow path 142 to the collection pocket 107. As shown in the close-up in Figure 1C, the tip 109 of the baffle 105 has a rounded or curved shape along the flow path, i.e., the second flow path 142 and the third flow path 143. If the range (width) L140 of the outflow passage 140 (along the X direction of the baffle 105, see Figure 1B) is approximately 1 inch (such as 1 inch, 0.5 inches, or a value between 0.5 and 1.0 inches), then the tip 109 of the baffle 105 may have a radius of rotation or bending R105 of less than 1 inch, less than 0.5 inches, or less than 0.25 inches. Also, the range or length L105 of the baffle 105 along the X direction (or the direction perpendicular to the outflow passage 140) (Figure 1C) is at least the length of the range L140 of the outflow passage 140 along the X direction (Figure 1B). In the above example, if the range L140 of the outflow passage 140 along the X direction is 1 inch, then the length L105 of the baffle 105 is at least 1 inch. Or, if the range of the outflow passage 140 along the X direction is 0.5 inches, then the length L105 of the baffle 105 is at least 0.5 inches. In various embodiments, the baffle 105 may have a length L105 in the X direction of approximately 0.5 inches, 0.8 inches, 1 inch, 1.5 inches, 2 inches, 4 inches, 5 inches, or 6 inches. The baffle 105 may have a length in the Y direction of approximately 0.5 inches, 0.8 inches, 1 inch, 1.5 inches, 2 inches, 4 inches, 5 inches, or 6 inches. The baffle 105 may have a base 211 with a length in the Z direction of approximately 0.5 inches, 0.8 inches, 1 inch, 1.5 inches, 2 inches, 4 inches, 5 inches, or 6 inches.

[0029]

[0046] The baffles 105 and 205 may be rigid members and may be monolithic (made from a single main material). The baffles 105 and 205 are made of a material that does not react with the dust particles 131 and the fluid from the cavity 130 of the gas discharge chamber 132. For example, the baffles 105 and 205 may be made of nickel-plated metal, ingot, copper, brass, nickel-copper alloy, copper alloy, or Monel™.

[0030]

[0047] Referring to Figure 1B, the second channel 142 is defined within a constricted region 141, where the cross-sectional area is narrower compared to the cross-sectional area of ​​the outflow passage 140 (taken along a direction substantially perpendicular to the fluid flow along the second channel 142). In other words, the range L142 of the second channel 142 is smaller than the range L140 of the outflow passage 140. By pushing the dust-filled fluid passing through the outflow passage 140 into the second channel 142, which has a much smaller cross-sectional area and is bent in a direction different from the outflow direction, the fluid's velocity increases as it crosses the second channel 142, and due to the inertia of the dust particles 131, these dust particles are propelled along the second channel 142 toward the collection pocket 107. The fluid can then return along the third channel toward the outflow passage 140 and thus toward the active dust trap 145. A bent channel 144 is formed between the second channel 142 and the third channel 143, adjacent to the tip 109 of the baffle 105, and connects the second channel 142 and the third channel 143. Channels 142, 143, 144 and the outflow passage 140 are all openings through which fluid can pass. They can have various cross-sectional shapes. For example, the outflow passage 140 may have a circular cross-sectional shape (along the direction perpendicular to the direction of fluid flow). Other geometric shapes are also possible; for example, the outflow passage 140 may have a square, rectangular, or elliptical cross-sectional shape.

[0031]

[0048] To increase the constriction of the second flow path 142, the collector body 108 may include a projection 103 extending toward the tip 109 of the baffle 105, as shown in Figure 1B. In this case, the constriction region 141 is defined between the projection 103 and the elongated body 106 / tip 109 of the baffle 105.

[0032]

[0049] Referring to Figure 3, an embodiment 300 of the dust collector 100 is shown. The dust collector 300 includes a baffle body 301, a collector body 308, and a collector body 308 including a neck body 304 between the baffle body 301 and the collector body 308. An outflow passage 340 extends through the baffle body 301 and is defined from an inlet port 302i (fluidly communicating with the cavity 130 of the gas discharge chamber 132) to an outlet port 302o (fluidly communicating with the active dust trap 145). The inlet port 302i may be defined within an inlet body 302Bi, and the outlet port 302o may be defined within an outlet body 302Bo. The inlet body 302Bi is physically fixed to the gas discharge chamber 132 to provide an airtight seal to prevent leakage of fluid and dust particles from the inlet port 302i. The outlet body 302Bo is physically fixed to the active dust trap 145 to provide an airtight seal to prevent leakage of fluid (and dust particles escaping from the dust collector 300) from the outlet port 302o. The relative lengths of the inlet body 302Bi and the outlet body 302Bo along the Z direction may differ from those shown in Figure 3; for example, the length of the outlet body 302Bo along the Z direction may be shorter than shown, or may be similar to or shorter than the length of the inlet body 302Bi along the Z direction. The baffle body 301, neck body 304, and collector body 308 can be formed as a single rigid member and can be made of a material that does not react with the fluid and dust particles from the cavity 130 of the gas discharge chamber 132. In some embodiments, the baffle body 301, neck body 304, and collector body 308 are made of metals such as nickel-plated metal, ingot metal, copper, brass, nickel-copper alloy, copper alloy, or Monel.

[0033]

[0050] Figure 5A shows a cross-sectional perspective view along the XZ plane shown in Figure 4A, and Figure 5B shows a cross-sectional plan view along the XY plane shown in Figure 4B. As shown in Figures 5A and 5B, the dust collector 300 includes a baffle 305 that is partially housed within a baffle body 301 and extends into a neck body 304. The inlet port body 302Bi has a cylindrical inner surface 302Si (Figure 5A) that defines an inlet cavity 302Ci with a circular cross-section along the XY plane, and the outlet port body 302Bo has a cylindrical inner surface 302So that defines an outlet cavity 302Co with a circular cross-section along the XY plane. The collector body 308 is redirected from the outflow passage 340 to a second flow path 342 and defines a collection pocket 307 that receives the flow of fluid and dust particles 131 pushed between the baffle 305 and the neck body 304 along the second flow path 342. Most of the fluid flows along the bent channel 344 around the tip 309 of the baffle 305 (see Figure 5B) into the third channel 343 and returns to the outflow channel 340 on its way to the active dust trap 145.

[0034]

[0051] Referring to Figure 6, the dust control device 660 is configured for the cavity 630 of the gas discharge chamber 632 of the light source 665. The light source 665 generates a light beam 666 from a light beam 633 supplied by the gas discharge chamber 632. The light beam 666 is supplied to the output device 679. The dust control device 660 is configured to remove dust particles 131 from the cavity 630. For this purpose, the dust control device 660 includes an active dust trap 645, which is an embodiment of an active dust trap 145 (Figure 1A), and a dust collector 600, which is an embodiment of a dust collector 100 (Figure 1A). The dust collector 600 is positioned along the outflow passage 640 between the cavity 630 of the gas discharge chamber 632 and the active dust trap 645. The dust control device 660 also includes an exhaust fan 634 within the cavity 630 of the gas discharge chamber 632. The exhaust fan 634 is configured to push the dust particles 131 and fluid from the cavity 630 into the outflow passage 640. The velocity of the dust particles 131 and fluid from the cavity 630 increases as they flow through the dust collector 600, which may be designed similarly to the dust collectors 100, 300. This velocity increase occurs when the dust particles 131 and fluid pass through second passages 142, 342, which have a narrower cross-sectional area compared to the cross-sectional area of ​​the outflow passage 640. As discussed above, the active dust trap 645 is configured to remove (or prevent accumulation of) dust particles 131 from components within the cavity 630. For example, in some embodiments, the cavity 630 may house a pair of electrodes 634a, 634b, at least two optical elements 635a, 635b which may include windows that transmit the wavelength of a light beam 633, a light reflector, and / or an output coupler.

[0035]

[0052] During the operation of the gas discharge chamber 632, the gain medium contained within the cavity 630 is placed within an optical resonator (which may be formed from one or more partial reflection mirrors or windows 635a, 635b). This gain medium is excited by short (e.g., nanosecond) current pulses in a high-voltage discharge from an energy source (e.g., a pair of electrodes 634a, 634b), thereby generating a plasma that results in optical amplification. A light beam 633 (the amplified light beam) having a wavelength in the ultraviolet region (e.g., deep ultraviolet, i.e., the DUV region) is generated and output from the gas discharge chamber 632. The gain medium within the cavity 630 is typically a gas mixture containing a noble gas (e.g., argon, krypton, or xenon), a halogen (e.g., fluorine or chlorine), and a buffer gas. Therefore, for example, the gain medium may contain argon and fluorine, krypton and fluorine, or xenon and chlorine. If the gain medium contains argon and fluorine, the light source 665 may be an argon fluoride (ArF) laser with an amplified light beam 633 having a wavelength of approximately 193 nm. Electrodes 634a and 634b can be made of, for example, brass. Fluorine in the gain medium may chemically interact with the material of electrodes 634a and 634b (e.g., brass), and such interactions may result in corrosion, potentially generating metallic fluoride (or metallic chloride if the chloride is halogen) particles. Such particles generated by corrosion are called dust particles 131, but are sometimes simply referred to as particles.

[0036]

[0053] The active dust trap 645 supplies a cleaning purge gas along the return passage 150, and such cleaning purge gas is configured to push the purge gas along the path toward the components (windows 635a, 635b and / or electrodes 634a, 634b) to prevent or reduce the possibility of dust particles 131 coming into contact with such components. For example, the active dust trap 645 may be a metal fluoride trap (MFT) and may use a filter such as a mechanical mesh and an active dust collector that uses electrostatic force to capture metal fluoride dust particles 131 or other particles. In some embodiments, as a portion of the gas discharge gain medium (or fluid) passes through the MFT, metal fluoride dust particles in the contaminated gas discharge gain medium may be adsorbed by the filter in the MFT, and the remaining particles may be collected by an electrostatic precipitator. For example, certain MFTs are already described in U.S. Patent No. 6,240,117 issued on May 29, 2001, and U.S. Patent No. 7,819,945 issued on October 26, 2010, and these patents are incorporated herein by reference in their entirety.

[0037]

[0054] However, even with the active dust trap 645, there are situations in which dust particles 131 can still be recirculated to the cavity 630 via the return passage 150 and reach (and contaminate) the components of the gas discharge chamber 632. For example, contamination may occur during gas replenishment procedures (replacement or replenishment of the gain medium). Another example is when the active dust trap 645 leaks dust particles 131 or becomes full of dust particles 131, which can cause contamination during normal operation of the gas discharge chamber 632. If a large amount of dust particles 131 accumulates on a component in the gas discharge chamber 632, that component may be damaged. If the component is an optical element that interacts with the light beam 633 (or a precursor of the light beam 633), dust particles 131 on the surface of such an optical element may also absorb energy from the light beam 633, causing the dust particles 131 on the surface of such an optical element to heat up and potentially interact with the surface of the optical element or be welded to the surface of the optical element. Surface damage to the optical elements within the cavity 630 can be a significant issue, particularly in relation to extending the lifespan of the gas discharge chamber 632 and the need to increase the energy of the light beam 633. The dust control device 660 can help extend the lifespan of the active dust trap 645 by redirecting the dust particles 131 to the dust collector 600, where they are captured and never reach the active dust trap 645.

[0038]

[0055] Referring to Figure 7, the light source 665 may be a two-stage light source 765. The light source 765 includes a first-stage main oscillator 770A and a second-stage power amplifier 770B. The main oscillator 770A includes a main oscillator gas discharge chamber 732A, and the power amplifier 770B includes a power amplifier gas discharge chamber 732B. The main oscillator gas discharge chamber 732A includes two elongated electrodes 734Aa and 734Ab as an energy source, providing a pulsed energy source to the gain medium 771A in the cavity 730A of the chamber 732A. The power amplifier gas discharge chamber 732B includes two elongated electrodes 734Ba and 734Bb as an energy source, providing a pulsed energy source to the gain medium 771B in the cavity 730B of the chamber 732B.

[0039]

[0056] The main oscillator 770A supplies a pulsed amplified optical beam (called a seed beam) 773 to the power amplifier 770B. The main oscillator gas discharge chamber 732A houses the gain medium 771A in which amplification occurs, and the main oscillator 770A includes an optical feedback mechanism such as an optical resonator. The optical resonator is formed between the spectral optics 774A on one side of the main oscillator gas discharge chamber 732A and the output coupler 775A on the second side of the main oscillator gas discharge chamber 732A. The power amplifier gas discharge chamber 732B houses the gain medium 771B in which amplification occurs when the seed beam 773 from the main oscillator 770A is seeded. If the power amplifier 770B is designed as a regenerative ring resonator, it is called a power ring amplifier, in which case sufficient optical feedback can be provided from the ring design. The power amplifier 770B may also include a beam return (such as a reflector) 774B that returns the light beam (e.g., by reflection) to the power amplifier gas discharge chamber 732B, forming a circulating loop path (the input to the ring amplifier intersects with the output from the ring amplifier), and an output coupler 775B for inputting a seed light beam 773 and outputting an amplified light beam 776. The working light beam 766 supplied to the output device 779 may correspond to the amplified light beam 776 output from the power amplifier 770B and further modulated by other optical components 777 such as beam induction and re-induction optics and pulse stretch optics.

[0040]

[0057] The gain media 771A and 771B used in the respective gas discharge chambers 732A and 732B may be combinations of gases suitable for generating an amplified light beam of approximately the required wavelength, bandwidth, and energy. For example, as discussed above, the gain media 771A and 771B may contain argon fluoride (ArF) emitting light at a wavelength of approximately 193 nm, or krypton fluoride (KrF) emitting light at a wavelength of approximately 248 nm.

[0041]

[0058] The gas discharge chambers 732A and 732B include components such as windows 735Aa, 735Ab, and 735Ba and 735Bb, respectively. Windows 735Aa, 735Ab, 735Ba, and 735Bb are made of materials compatible with the gain media 771A and 771B, respectively. Furthermore, windows 735Aa, 735Ab, 735Ba, and 735Bb are made of materials that can transmit the light that will be generated by the gain media 771A and 771B. Therefore, in this example, since the generated light is in the DUV region, windows 735Aa, 735Ab, 735Ba, and 735Bb must transmit light having wavelengths in the DUV region. In some embodiments, windows 735Aa, 735Ab, 735Ba, and 735Bb are made of a crystalline structure. For example, windows 735Aa, 735Ab, 735Ba, and 735Bb may be made from calcium fluoride, magnesium fluoride, or fused silica.

[0042]

[0059] The light source 765 may also include a controller 778 configured to control the operation of the light source 765 and can communicate with an output device 779.

[0043]

[0060] One or more of the gas discharge chambers 732A, 732B may be configured to include corresponding dust control devices 760A, 760B, respectively. Each dust control device 760A, 760B is designed similarly to the dust control device 660 in Figure 6. Thus, each dust control device 760A, 760B includes corresponding active dust traps 745A, 745B communicating with corresponding cavities 730A, 730B and corresponding outflow passages 740A, 740B located outside the cavities 730A, 730B, and corresponding dust collectors 700A, 700B. The dust collectors 700A, 700B are located along the outflow passages 740A, 740B, between the corresponding active dust traps 745A, 745B and the corresponding chambers 730A, 730B. Dust collectors 700A and 700B are designed similarly to dust collectors 100, 300, or 600, and active dust traps 745A and 745B are designed similarly to active dust traps 145 and 645.

[0044]

[0061] Referring to Figure 8, procedure 880 is performed to collect and remove dust particles 131 from cavity 130 (or any of cavities 630, 730A, or 730B). For consideration of procedure 880, refer to dust collector 100 in Figure 1A, but procedure 880 can also be performed by dust collectors 300, 700A, or 700B. Procedure 880 includes discharging the fluid containing the dust particles 131 from cavity 130 to an outflow passage 140 outside cavity 130 toward an active dust trap 145 (881). At least a portion of the fluid containing the dust particles 131 is redirected from the outflow passage 140 to a second flow path 142 that extends at least partially along a second direction different from the direction of the outflow passage 140 (882). The redirected fluid containing the dust particles 131 is passively compressed, causing its velocity to increase (883). The dust particles 131 are then collected in the collection pocket 107, while the redirected fluid can return to the outflow passage 140 on its way to the active dust trap 145 (884). Referring to Figure 6, the fluid containing the dust particles 131 can be discharged from the cavity 630 by operating the exhaust fan 634 in the cavity 630, which is configured to push the dust 131 and fluid from the cavity 630 to the outflow passage 640 (881).

[0045]

[0062] Referring again to Figure 7, the output device 779 may correspond to a photolithography exposure apparatus or scanner, which is a machine that applies a desired pattern to a target portion of a substrate S (such as a silicon wafer). The light beam 766 (which may have wavelengths in the deep ultraviolet (DUV) region) interacts with a projection optical system PS that projects the DUV light beam 766 onto the photoresist of the wafer S via a mask MA. In this way, one or more layers of the chip design are patterned on the photoresist, after which the wafer S is etched and cleaned. The photolithography exposure apparatus 779 utilizes a stable light source 765 to ensure accurate and error-free manufacturing of nanoscale integrated circuits using the wafer S. The stable illumination of the light beam 766 allows for predictable illumination radiation onto the photoresist of the wafer S. On the other hand, unstable illumination of the light beam 766 may not adequately develop the photoresist, potentially causing printing errors. Dust particles 131 (Figure 1A) present inside both gas discharge chambers 732A and 732B can adversely affect the intensity of the light beam 766 and potentially cause dose errors in wafer S. Dust collectors 700A and 700B and dust management devices 760A and 760B reduce the amount of dust particles 131 in the corresponding gas discharge chambers 732A and 732B by extending the lifespan of the active dust traps 745A and 745B.

[0046]

[0063] Other embodiments, such as those listed below, are also within the scope of the claims.

[0047]

[0064] For example, the baffle 105 may have a shape different from that shown in Figures 1A to 1C, or from that of embodiment 205 in Figure 2. For example, other embodiments 905A, 905B, 905C, and 905D of the baffle 105 / 205 are shown in Figures 9A, 9B, 9C, and 9D, respectively, when mounted on the inner wall 140w of the collector body 108. As mentioned above, in other embodiments, the baffle direction 205d of the triangular body 206 may extend along a direction within 5° from the X direction, within 10° from the X direction, or within 15° from the X direction, while the base 211 remains in a plane including the Z direction. Figure 9E shows an embodiment in which the baffle direction 905dE is oriented at an angle of about 7° from the X direction.

[0048]

[0065] Referring to Figures 10A to 10C, in other embodiments, the projections 103 of the collector body 108 may have a different geometric shape than those shown in Figures 1A and 1B. For example, Figure 10A shows an embodiment 1003A of the projection 103 having a rounded or circular cross-section, Figure 10B shows an embodiment 1003B of the projection 103 having a rectangular cross-section, and Figure 10C shows an embodiment 1003C of the projection 103 having an oblique edge. In any case, to increase the constriction of the second flow path 142, the projections 1003A, 1003B, and 1003C extend toward the body or side wall of the baffle 105, forming constricted regions 1041A, 1041B, and 1041C, respectively. Figures 10A to 10C show an example where the projections 103 have a symmetrical structure, but other configurations are also possible. For example, a protruding body 1003A having a circular structure may be placed on the inlet side of the collector body 108, while a protruding body 1003B having a rectangular structure may be placed on the outlet side of the collector body 108.

[0049]

[0066] Referring to Figures 11A and 11B, Embodiment 1100 of the dust collector 100 includes a collector body 1108 designed as a spiral trap positioned at a tangential angle to the outflow passage 1140. The dust collector 1100 defines an inlet port 1102i and an outlet port 1102o. The collector body 1108 includes a cylindrical portion 1108-1, a conical portion 1108-2 extending from the cylindrical portion 1108-1, and a collection pocket 1107. The conical portion 1108-2 is fluidly coupled to the collection pocket 1107 for collecting dust particles 131. A central cylinder 1105 extends within the cylindrical portion 1108-1.

[0050]

[0067] At the inlet port 1102i, the central cylinder 1105, in conjunction with the inner wall of the cylindrical section 1108-1, blocks the fluid flow along the outflow passage 1140, causing the fluid to spiral around the central cylinder 1105 along the second flow path 1142 toward the cone section 1108-2. The dust particles 131 have momentum and travel along the spiral path into the cone section 1108-2, where they are captured in the collection pocket 1107, while the fluid (shown by the dashed line) bounces off the inner wall of the cone section 1108-2 and exits through the internal passage of the central cylinder 1105 through the outflow port 1102o toward the active dust trap 145.

[0051]

[0068] Referring to Figure 12, in another embodiment 1200 of the dust collector 100, the collector body 1208 is detachable from the rest of the dust collector 1200. Specifically, the collector body 1208 can be detached from the body 1201 (which may be the same as the baffle body 301) in the neck region 1204. In this way, the collector body 1208 (in which the dust particles 131 are captured) can be replaced with an empty new collector body 1208, or it can be emptied of the dust particles 131, cleaned, and replaced.

[0052]

[0069] Referring to Figure 13, in yet another embodiment 1300 of the dust collector 100, the entire dust collector 1300 (including the collector body 1308, body 1301, and neck region 1304) can be removed from the outflow passage 340.

[0053]

[0070] In both the dust collector 1200 and the dust collector 1300, the replaceable section can be separated from the rest of the dust collector or the outflow passage 340 using an appropriate fluid mechanism such as a valve or shut-off valve. In particular, the mechanism enabling separation is configured to prevent the captured dust from re-entering the outflow passage 340. For example, a separate seal or shut-off mechanism can be placed or operated between the body 1301 and the collector body 1308 before the body 1301 is separated from the outflow passage 340 (to prevent dust particles 131 or air in the collector body 1308 from re-entering the outflow passage 340). The seal / shut-off mechanism can be operated within the neck region 1304.

[0054]

[0071] These interchangeable designs allow the dust collectors 1200 and 1300 to be replaced throughout the entire lifespan of the chamber 132.

[0055]

[0072] The examples can be further described using the following clauses. 1. A dust collector for a gas discharge chamber of a light source, The cavity of the gas discharge chamber and the inlet port that is in fluid communication with it, An outlet port, which is in fluid communication with an active dust trap, such that the outflow passage located outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port, A dust collector comprising a passive dust trap extending across an outflow passage, configured to define a second flow path extending at least partially along a second direction different from the outflow direction to a collection pocket defined in the collector body of the passive dust trap. 2. A dust collector according to Clause 1, with a passive dust trap including a baffle. 3. A dust collector according to Clause 2, in which the baffle extends laterally across the outflow passage. 4. The dust collector according to clause 2, wherein the second flow path has a cross-sectional area narrower than the cross-sectional area of ​​the outflow passage. 5. A dust collector according to Clause 2, wherein the baffle extends along an angle of 75° to 105° or 85° to 95° with respect to the direction of outflow. 6. The dust collector of Clause 2, wherein the baffle also defines a third channel extending toward the outflow passage on its way from the second channel toward the active dust trap, such that the bent channel extends around the baffle between the second channel and the third channel. 7. The dust collector according to Clause 2, wherein the collector body includes a projection extending toward the tip of the baffle, the projection having a constricted region of a second flow path defined between the projection and the baffle near the tip of the baffle. 8. A dust collector according to Clause 7, wherein the constricted region has a cross-sectional area smaller than the cross-sectional area of ​​the outflow passage. 9. The baffle has no sharp edges and no sharp corners, and the dust collector is as specified in Clause 2. 10. The dust collector of Clause 2 has smooth characteristics along the flow path of the baffle. 11. A dust collector of Clause 2, wherein the tip of the baffle has a curved shape with a turning radius of less than 1 inch, less than 0.5 inches, or less than 0.25 inches. 12. A dust collector according to Clause 2, wherein the baffle extends across the outflow passage along its cross-section, and the extent of the baffle along its cross-section is greater than or equal to the extent of the outflow passage. 13. The baffle is rigid, and the dust collector is as per clause 2. 14. The dust collector of Clause 2, whose baffle is made of nickel-plated metal, ingot, copper, brass, nickel-copper alloy, copper alloy, or Monel. 15. A dust collector according to Clause 1, wherein a passive dust trap is configured to capture dust particles within a collection pocket. 16. The dust collector according to Clause 1, wherein the inside of the collector body defines a cylindrical region and a conical region, and a second flow path forms a spiral shape extending through the cylindrical region and the conical region to a collection pocket. 17. A dust collector according to Clause 16, wherein the spiral flow extends along the third flow path, returning from the collection pocket towards the outflow passage, such that the spiral flow path extends between the second and third flow paths. 18. A dust collector according to Clause 1, wherein the collector body is detachable from the rest of the passive dust trap. 19. A dust collector according to Clause 1, wherein the passive dust trap is removable from the outflow passage. 20. A dust collector for a gas discharge chamber of a light source, The cavity of the gas discharge chamber and the inlet port that is in fluid communication with it, An outlet port, which is in fluid communication with an active dust trap, such that the outflow passage located outside the cavity of the gas discharge chamber is defined along the outflow direction from the inlet port to the outlet port, A dust collector comprising a collector body that defines a second flow path extending from the outflow passage to a collection pocket, along a second direction different from the outflow direction. 21. A dust collector according to clause 20, wherein a second flow path is configured to capture dust particles within a collection pocket. 22. A dust collector according to clause 20, wherein the second flow path extends at least partially along an angle of 75° to 105° or 85° to 95° with respect to the outflow direction. 23. The dust collector of clause 20, wherein the collector body further defines a third flow path that extends toward the outflow passage, passing through a bend from the second flow path and proceeding toward the active dust trap. 24. A dust collector of Clause 20, wherein the second flow path extends within a defined structure without sharp ends or corners. 25. A dust collector according to clause 20, wherein a second flow path is defined between a baffle extending laterally across the outflow passage and a projection of the collector body extending toward the tip of the baffle. 26. Dust collector of Clause 25, wherein the collector body further defines a third flow path extending from the second flow path toward the outflow passage and active dust trap, such that the bent flow path extends at least partially around the tip of the baffle with a turning radius of less than 1 inch, less than 0.5 inches, or less than 0.25 inches. 27. A dust collector according to clause 20, wherein the second flow path has a narrower cross-sectional area compared to the cross-sectional area of ​​the outflow passage. 28. A dust collector according to clause 20, wherein the second flow path extends to a cylindrical and conical region defined within the collector body between the outflow passage and the collection pocket, forming a cyclone that extends to the collection pocket. 29. Dust collector of Clause 28, wherein the cyclone flow extends along the third channel so as to return from the collection pocket toward the outflow passage, such that the cyclone flow path extends between the second and third channels. 30. A dust collector according to Clause 20, wherein the collector is removable from the outflow passage. 31. Dust control device for a gas discharge chamber of a light source, The gas discharge chamber cavity and the active dust trap, which is in fluid communication with the gas discharge chamber cavity via an outflow passage outside the gas discharge chamber cavity, A dust control device comprising a dust collector located between an active dust trap and a cavity of a gas discharge chamber along an outflow passage, the dust collector including a baffle configured to define a second flow path extending across the outflow passage and at least partially along a second direction different from the outflow direction to a collection pocket defined within the collector body. 32. The dust control device of Clause 31, further comprising an exhaust fan configured to direct dust and fluid from the cavity of the gas discharge chamber to an outflow passage, located within the cavity of the gas discharge chamber. 33. A dust control device according to Clause 32, wherein the velocity of the dust and fluid flow through the outflow passage increases as it passes through the dust collector. 34. Dust control device according to Clause 31, wherein the baffle extends laterally across the outflow passage. 35. A dust control device according to Clause 31, wherein the baffle is configured to trap dust particles in a collection pocket. 36. A dust control device according to Clause 31, wherein the second flow path has a cross-sectional area narrowed compared to the cross-sectional area of ​​the outflow passage. 37. The dust control device of clause 31, wherein the collector body includes a projection extending toward the tip of the baffle, and a constricted region of the second flow path is defined near the tip of the baffle between the projection and the baffle. 38. The dust control device of Clause 31, which has no sharp edges or corners on the baffle. 39. A dust control device according to Clause 31, wherein the surface shape of the baffle has the characteristic of being smooth. 40. A dust control device according to Clause 31, wherein the baffle extends across the outflow passage along its cross-section, and the extent of the baffle along its cross-section is greater than or equal to the extent of the outflow passage. 41. A method for collecting dust from the cavity of a gas discharge chamber of a light source, Discharging a fluid containing dust particles from the cavity to an outflow passage outside the cavity, towards an active dust trap. To redirect at least a portion of the fluid containing dust particles from the outflow passage to a second flow path that extends at least partially along a second direction different from the direction of the outflow passage, By passively compressing the diverted fluid containing dust particles, the velocity of the diverted fluid containing dust particles is increased, and A method comprising collecting dust particles into a collection pocket while allowing a redirected fluid to return to the outflow channel on its way to an active dust trap. 42. The method of Clause 41, wherein discharging a fluid containing dust particles from a cavity includes operating an exhaust fan within the cavity of a gas discharge chamber, configured to direct the dust and fluid from the cavity of the gas discharge chamber to an outflow passage. 43. The method of Clause 41, wherein at least a portion of the fluid is redirected from the outflow passage to a second flow path, and the fluid is prevented from moving directly toward the active dust trap by a baffle extending across the outflow passage and defining the second flow path. 44. The method of Clause 41, wherein passively compressing the redirected fluid includes pushing the redirected fluid out of a constricted region of a second flow path, which is defined between a baffle extending across the outflow passage and a projection defining a collection pocket of the collector body. 45. The method of Clause 41, wherein increasing the velocity of the redirected fluid includes increasing the velocity of the redirected fluid to at least twice the velocity of the fluid being discharged from the cavity into the outlet passage.

[0056]

[0073] The above embodiments and other embodiments fall within the scope of the following claims.

Claims

1. A dust collector for a gas discharge chamber of a light source, The cavity of the gas discharge chamber and the inlet port that is in fluid communication with it, An outlet port, wherein the outlet passage located outside the cavity of the gas discharge chamber is fluidly connected to an active dust trap such that the outflow passage is defined along the outflow direction from the inlet port to the outlet port, A dust collector comprising a passive dust trap extending across the aforementioned outflow passage, configured to define a second flow path extending at least partially along a second direction different from the outflow direction to a collection pocket defined in the collector body of the passive dust trap.

2. The dust collector according to claim 1, wherein the passive dust trap comprises a baffle extending laterally across the outflow passage.

3. The dust collector according to claim 1, wherein the inside of the collector body defines a cylindrical region and a conical region, and the second flow path has a spiral shape that extends through the cylindrical region and the conical region to the collection pocket.

4. The dust collector according to claim 3, wherein the spiral flow extends along the third flow path so as to return from the collection pocket toward the outflow passage, such that the spiral flow path extends between the second flow path and the third flow path.

5. The dust collector according to claim 1, wherein the collector body is removable from the other parts of the passive dust trap.

6. The dust collector according to claim 1, wherein the passive dust trap is removable from the outflow passage.

7. A dust collector for a gas discharge chamber of a light source, The cavity of the gas discharge chamber and the inlet port that is in fluid communication with it, An outlet port, wherein the outlet passage located outside the cavity of the gas discharge chamber is fluidly connected to an active dust trap such that the outflow passage is defined along the outflow direction from the inlet port to the outlet port, A dust collector comprising a collector body that defines a second flow path extending from the outflow passage to a collection pocket, along a second direction different from the outflow direction.

8. The dust collector according to claim 7, wherein the second flow path is configured to capture dust particles in the collection pocket.

9. The dust collector according to claim 7, wherein the second flow path extends at least partially along an angle of 75° to 105° or 85° to 95° with respect to the outflow direction.

10. The dust collector according to claim 7, wherein the collector body further defines a third flow path that extends toward the outflow passage, after passing through a bend from the second flow path and proceeding toward the active dust trap.

11. The dust collector according to claim 7, wherein the second flow path extends within a defined structure without sharp ends or corners.

12. The dust collector according to claim 7, wherein the second flow path is defined between a baffle extending laterally across the outflow passage and a projection of the collector body extending toward the tip of the baffle.

13. The dust collector of claim 12, wherein the collector body further defines a third flow path extending from the second flow path toward the outflow passage and the active dust trap, such that the bent flow path extends at least partially around the tip of the baffle with a turning radius of less than 1 inch, less than 0.5 inches, or less than 0.25 inches.

14. The dust collector according to claim 7, wherein the second flow path has a cross-sectional area narrower than the cross-sectional area of ​​the outflow passage.

15. The dust collector according to claim 7, wherein the second flow path extends to a cylindrical region and a conical region defined within the collector body between the outflow passage and the collection pocket, forming a cyclone that extends to the collection pocket.

16. The dust collector of claim 15, wherein the cyclone flow extends along the third flow path so as to return from the collection pocket toward the outflow passage, such that the cyclone flow path extends between the second flow path and the third flow path.

17. The dust collector according to claim 7, wherein the collector is removable from the outflow passage.

18. A method for collecting dust from the cavity of a gas discharge chamber of a light source, Discharging a fluid containing dust particles from the cavity to an outflow passage outside the cavity toward an active dust trap, To redirect at least a portion of the fluid containing the dust particles from the outflow passage to a second flow path that extends at least partially along a second direction different from the direction of the outflow passage, By passively compressing the diverted fluid containing the dust particles, the velocity of the diverted fluid containing the dust particles is increased, and A method comprising collecting dust particles in a collection pocket while allowing the redirected fluid to return to the outflow passage on its way to the active dust trap.

19. The method of claim 18, wherein discharging a fluid containing dust particles from the cavity includes operating a discharge fan within the cavity of the gas discharge chamber, configured to direct the dust and fluid from the cavity of the gas discharge chamber to the outflow passage.

20. The method of claim 18, wherein redirecting at least a portion of the fluid from the outflow passage to the second flow path includes preventing the fluid from moving directly toward the active dust trap by a baffle extending across the outflow passage and defining the second flow path.

21. The method of claim 18, wherein passively compressing the redirected fluid includes pushing the redirected fluid out of a constricted region of the second flow path, which is defined between a baffle extending across the outflow passage and a projection defining the collection pocket of the collector body.

22. The method of claim 18, wherein increasing the velocity of the redirected fluid includes increasing the velocity of the redirected fluid to at least twice the velocity of the fluid being discharged from the cavity into the outflow passage.

Images