CN114514477A

CN114514477A - Conducting member for discharge laser

Info

Publication number: CN114514477A
Application number: CN202080070914.9A
Authority: CN
Inventors: A·J·小艾芬伯格; U·尼曼
Original assignee: Cymer LLC
Current assignee: Cymer LLC
Priority date: 2019-10-11
Filing date: 2020-09-25
Publication date: 2022-05-17
Also published as: KR102669702B1; JP2022553502A; TWI759894B; KR20220058956A; JP7381728B2; TW202131585A; WO2021071681A1

Abstract

An excimer laser comprising a discharge chamber (12) and a conducting member (22), the conducting member (22) for conducting a current associated with a discharge in the discharge chamber of the laser, the conducting member comprising at least one channel (26a to 26d), the at least one channel (26a to 26d) being configured for: the current flow path in the end portions (32,34) of the conductive member is increased relative to the current flow path in the central portion (34) of the conductive member, the conductive member being configured for connecting the laser to a voltage source (24) and being configured to provide an interface between the voltage source and a discharge chamber of the laser.

Description

Conducting member for discharge laser

Cross Reference to Related Applications

This application claims priority from U.S. application No.62/914,359 entitled "connecting component FOR DISCHARGE LASER," filed on 11/10/2019, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a conducting member, associated apparatus, system and method for conducting current associated with a discharge in a discharge chamber of a laser.

Background

A lithographic apparatus is a machine that is configured to apply a desired pattern onto a substrate. Lithographic apparatus can be used, for example, in the manufacture of Integrated Circuits (ICs). For example, a lithographic apparatus may project a pattern (also often referred to as a "design layout" or "design") of a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) disposed on a substrate (e.g., a wafer).

As semiconductor manufacturing processes continue to advance, the size of circuit elements continues to decrease, while the number of functional elements (such as transistors) per device has steadily increased over the past few decades, following a trend commonly referred to as "moore's law". To keep pace with moore's law, the semiconductor industry is pursuing technologies that are able to create smaller and smaller features. To project a pattern on a substrate, the lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features to be patterned on the substrate. The lowest wavelength enables the production of smaller features on the substrate. Typical wavelengths currently used are 365nm (i-line), 248nm, 193nm and 13.5 nm. Lithographic apparatus using Deep Ultraviolet (DUV) radiation may operate at a wavelength of 193 or 248nm, while lithographic apparatus using Extreme Ultraviolet (EUV) radiation may operate at a wavelength in the range 4nm to 20nm (e.g. 6.7nm or 13.5 nm).

Gas discharge lasers may be used to generate DUV radiation. In such lasers, the cathode and anode are typically disposed in a spaced relationship in the cavity of the laser. When a discharge is generated between the cathode and the anode, a current may flow from the cathode to the anode. The current may cause corrosion of the cathode and/or anode, and the corrosion may be non-uniform. Uneven corrosion of the cathode and/or anode may lead to reduced lifetime of the cathode and/or anode and hence of the cavity of the laser.

Disclosure of Invention

According to an aspect of the invention, there is provided a conducting member for conducting current associated with a discharge in a discharge chamber of a laser, the conducting member comprising at least one channel configured for: increasing a current flow path in a portion of the conductive member relative to a current flow path in another portion of the conductive member, the conductive member configured to connect the laser to a voltage source and configured to provide an interface between the voltage source and a discharge chamber of the laser. By increasing the current flow path in the portion of the conductive member relative to the current flow path in other portions of the conductive member, the current density or uniformity of current flow delivered through the conductive member may be increased. It has been found that this in turn may lead to an improved uniformity of the current distribution in the discharge chamber. The improved uniformity of the current distribution in the discharge cell provides for more uniform erosion of the cathode and anode, which can result in increased lifetime of the cathode, anode and/or discharge cell of the laser.

The conductive member may include a plurality of channels. Each of the channels may be associated with a portion of a conductive member. Each of the channels may be configured to: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

The conductive member may include a first end. The first end may include at least one of the channels.

The first end may include a rounded edge. The first end may include at least two of the channels. At least two of the channels may extend longitudinally inward from the first rounded edge.

The conductive member may include a second end portion. The second end may include at least one of the channels.

The second end may include a second rounded edge. The second end may include at least two of the channels. At least two of the channels may extend longitudinally inward from the second rounded edge.

The conductive member may be configured for connection to a plurality of charge storage devices. The conductive member may be configured for connection to a plurality of conductive elements. The conducting member may be configured to conduct current from each of the plurality of charge storage devices to a respective conducting element of the plurality of conducting elements.

The conductive member may include a plurality of first connection points. The conductive member may include a plurality of second connection points. Each of the plurality of first connection points may be configured for connection to a charge storage device of a plurality of charge storage devices. Each of the plurality of second connection points may be configured for connection to a conductive element of a plurality of conductive elements.

The plurality of first connection points may be arranged in a configuration extending longitudinally along the conductive member. The plurality of second connection points may be arranged in a configuration extending longitudinally along the conductive member.

The conductive member may be configured such that each of the channels is disposed between the first connection point and the second connection point.

The conductive member may further include an insulating portion. An insulating portion may be provided in each channel.

The conductive member may be or include a conductive strip.

According to another aspect of the present invention, there is provided a laser comprising a discharge chamber and a conducting member for conducting current associated with a discharge in the discharge chamber, the conducting member comprising at least one channel configured for: the current flow path in one portion of the conductive member is increased relative to the current flow path in another portion of the conductive member, the conductive member configured to connect the laser to a voltage source and configured to provide an interface between the voltage source and a discharge chamber of the laser.

The laser may include a plurality of charge storage devices. The laser may comprise a plurality of conductive elements. The plurality of charge storage devices and the plurality of conductive elements may be connected to a conductive member.

The conductive member may be configured to: a current is conducted from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements.

The plurality of conductive elements may be configured to direct current into the discharge chamber.

The conductive member may include a plurality of channels. The channel in each channel may be associated with a portion of a conductive member. Each of the channels may be configured to: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

The discharge chamber may be configured to hold one or more gases. The one or more gases may include krypton, argon, and/or fluorine.

Any feature of the conductive member of the above aspect may also be applied to or included in the conductive member of the aspect.

According to another aspect of the invention, there is provided a lithographic system comprising: a radiation source comprising a laser comprising a discharge chamber and a conducting member for conducting a current associated with a discharge in the discharge chamber according to any of the above aspects; and a lithographic apparatus.

According to another aspect of the present invention, there is provided a method for operating a laser, the laser comprising: a laser having a laser discharge chamber; and a conducting member for conducting current associated with a discharge in the discharge chamber, the conducting member comprising at least one channel configured for: the current flow path in one portion of the conductive member is increased relative to the current flow path in another portion of the conductive member, the conductive member connecting the laser to a voltage source and providing an interface between the voltage source and a discharge chamber of the laser. The method comprises the following steps: a voltage is applied to the conductive member to induce a discharge in the discharge cell such that a current associated with the discharge flows through the conductive member to enter the discharge cell.

The laser may include a plurality of charge storage devices. The laser may comprise a plurality of conductive elements. A plurality of charge storage devices and a plurality of conductive elements may be connected to the conductive member.

The conductive member may be configured to: a current is conducted from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements. The plurality of conductive elements is configured to direct current into the discharge chamber.

Applying a voltage to the conductive member may cause current to flow from the plurality of charge storage devices to the plurality of conductive elements via the conductive member such that a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in a portion of the conductive member is longer than a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in other portions of the conductive member.

Applying a voltage to the conductive members may cause a current to flow from the plurality of conductive elements into the discharge chamber.

The step of applying a voltage to the conductive member may include: a negative potential is applied to the conductive member.

The conductive member may include a plurality of channels. Each channel may be associated with a portion of a conductive member. Each channel may be configured to: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

The conductive member may further include an insulating portion disposed in each channel.

Various aspects and features of the present invention set forth above or below may be combined with various other aspects and features of the present invention as would be apparent to one of ordinary skill in the art.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which:

FIG. 1 depicts a schematic overview of a lithographic system including a radiation source and a lithographic apparatus;

FIG. 2 depicts a cross-sectional view of a portion of a laser that may be used in the lithography system of FIG. 1;

FIGS. 3A and 3B depict an exemplary embodiment of a conducting member for use with the laser of FIG. 2;

FIG. 4A depicts a plan view of the conductive member of FIG. 3A;

FIG. 4B depicts a first end of the embodiment of the conductive member of FIG. 4A;

FIG. 4C depicts a first end of another exemplary conductive member for use with the laser of FIG. 2;

FIG. 5 depicts a partially exploded view of a laser chamber including a portion of the laser of FIG. 2;

FIG. 6 depicts a cross-sectional view of a portion of the laser of FIG. 5;

FIG. 7 depicts a portion of the laser of FIG. 5; and

fig. 8 depicts a flowchart outlining the steps of a method for operating a laser.

Detailed Description

FIG. 1 schematically depicts a lithography system. The lithographic system comprises a radiation source SO and a lithographic apparatus LA. The lithographic apparatus LA includes: an illumination system (also referred to as an illuminator) IL configured to condition a radiation beam B (e.g. UV radiation, DUV radiation or EUV radiation); a mask support (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device MA in accordance with certain parameters; a substrate support (e.g. a wafer table) WT constructed to hold a substrate (e.g. a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate support in accordance with certain parameters; and a projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W.

In operation, the illumination system IL receives a radiation beam from a radiation source SO, for example, via a beam delivery system BD. The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic and/or other types of optical components, or any combination thereof, for directing, shaping, and/or controlling radiation. The illuminator IL may be used to condition the radiation beam B to have a desired spatial and angular intensity distribution in cross-section at the plane of the patterning device MA.

The term "projection system" PS as used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, anamorphic, magnetic, electromagnetic and/or electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, and/or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term "projection lens" herein may be considered as synonymous with the more general term "projection system" PS.

The lithographic apparatus LA may be of the following type: wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the projection system PS and the substrate W, also referred to as immersion lithography. More information on immersion techniques is given in US6,952,253, which is incorporated herein by reference.

The lithographic apparatus LA may also be of a type having two or more substrate supports WT (also referred to as a "dual stage"). In such "multiple stage" machines the substrate supports WT may be used in parallel, and/or steps in preparation for subsequent exposure of a substrate W may be performed on a substrate W positioned on one of the substrate supports WT while another substrate W on the other substrate support WT is being used to expose a pattern on the other substrate W.

In addition to the substrate support WT, the lithographic apparatus LA may include a measurement table. The measuring table is arranged to hold the sensor and/or the cleaning device. The sensor may be arranged to measure a property of the projection system PS or a property of the radiation beam B. The measurement station may hold a plurality of sensors. The cleaning device may be arranged to clean a part of the lithographic apparatus, for example a part of the projection system PS or a part of the system in which the immersion liquid is provided. The measurement table may be moved under the projection system PS while the substrate support WT is away from the projection system PS.

In operation, the radiation beam B is incident on the patterning device (e.g., mask) MA, which is held by the mask support MT, and is patterned by a pattern (design layout) present on the patterning device MA. After passing through the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position measurement system IF, the substrate support WT can be moved accurately, e.g. so as to position different target portions C in the path of the radiation beam B in focus and alignment. Similarly, the first positioner PM and possibly another position sensor (which is not explicitly depicted in fig. 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B. Patterning device MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although substrate alignment marks P1, P2 are shown to occupy dedicated target portions, they may be located in spaces between target portions. When substrate alignment marks P1, P2 are located between target portions C, they are referred to as scribe-lane alignment marks.

Fig. 2 shows a portion of a laser 10 for use in a lithography system, such as, for example, the lithography system shown in fig. 1. The laser 10 may be part of or included in the radiation source SO. The laser 10 may be provided in the form of a gas discharge laser, such as for example an excimer laser. The laser 10 includes a discharge chamber 12. The laser 10 includes a first electrode 14, and the first electrode 14 may be a cathode. The laser 10 includes a second electrode 16, and the second electrode 16 may be an anode. A cathode 14 and an anode 16 are disposed in the discharge chamber 12. The cathode 14 and the anode 16 are disposed in spaced relation and opposite one another. The anode 16 may be disposed on the support member 16b opposite the cathode 14. The support member 16b may be provided in the form of an anode support rod. Other arrangements for positioning the first and second electrodes may be used in other embodiments.

The discharge chamber 12 may be configured to hold one or more gases 18, such as, for example, a gas mixture. The gas 18 may include a noble gas (such as, for example, argon, krypton, or xenon) and a reactive gas (such as, for example, fluorine or chlorine).

When a voltage is applied between the cathode 14 and the anode 16, a discharge is generated in the discharge region 20 between the cathode 14 and the anode 16. The electrical discharge may ionize the gas 18 in the chamber 12, which may cause chemical reactions between the gases. For example, an argon and fluoride gas mixture may chemically produce excited molecular argon fluoride, which exists only in an excited state and may decay very rapidly. The excited molecule can release its excess energy by emitting a photon, thereby returning to its ground state, where it dissociates back to a free atom. Photons generated during the discharge may then be reflected in the chamber by one or more optical components (not shown) and then directed from the laser 10 as laser pulses. It should be understood that in other embodiments, another gas mixture may be used, such as, for example, a krypton and fluoride gas mixture.

In some embodiments, the gas mixture 18 may be pre-ionized to produce a desired electron density prior to discharge. The laser may include a pre-ionization device 21, which pre-ionization device 21 may be configured to generate ultraviolet radiation for ionizing the gas mixture 18 prior to discharge.

The laser 10 may include a plurality of insulating sections or components 19. The insulating portion or component 19 may comprise a ceramic material, such as, for example, alumina (Al)₂O₃Or AlO₂). Alternatively, the insulating portion or assembly 19 may comprise a plastic material, which may comprise a polymer or a polymer compound, such as, for example, polytetrafluoroethylene or the like. The insulating portion or assembly 19 may be variously disposed in the discharge chamber, for example, to electrically insulate the cathode 14 and anode 16 from other portions of the discharge chamber 12.

It should be understood that the laser 10 may include other components for supplying one or more of the gases, circulating the gases within the discharge chamber, adjusting the temperature within the discharge chamber, etc., which are not shown in fig. 2 for clarity.

The laser 10 includes a conducting member 22 for conducting current associated with a discharge in the discharge chamber 12. In other words, when a discharge is present in the discharge chamber, current may flow through the conductive member 22. Current may flow through the conductive member 22 to enter the discharge chamber 12. For example, electrical current may flow through the conductive member 22 to the cathode 14, and from the cathode 14 to the anode 16, as will be described below. The conductive member 22 is configured for connecting the laser 10 to a voltage source 24 and is configured to provide an interface between the voltage source 24 and the discharge chamber 12 of the laser 10. In other words, a voltage may be applied to the cathode 14 and/or the anode 16 through the conductive member 22. The conductive member 22 may be provided in the form of a conductive strip. The conductive member 22 may comprise a metal, such as, for example, aluminum. The conductive member 22 may include a coating. The coating may include a fluorine-resistant material. For example, the coating may include a transition metal, such as, for example, nickel.

Fig. 3A and 3B illustrate an exemplary embodiment of a conductive member 22 for use with a laser, such as, for example, the laser 10 shown in fig. 2. The conductive member 22 includes at least one channel 26, the channel 26 configured for: the current flow path in the first portion 28 of the conductive member 22 is increased relative to the current flow path in the second portion 30 of the conductive member 22. The channel 26 may alternatively or additionally be configured for: the current flow path in the third portion 32 of the conductive member 22 is increased relative to the current flow path in the second portion 30 of the conductive member 22. In other words, the channel 26a may be configured to force the current to take a longer flow path in the first portion 28 of the conductive member 22 relative to the flow path of the current in the second portion 30 of the conductive member 22. This may result in an increase in the current density or uniformity of current flow in the conductive member 22. It has been found that this in turn may lead to an improved uniformity of the current distribution in the discharge chamber 12. The term "current distribution" may be considered to encompass current flow and/or current density along cathode 14 and/or anode 16 (e.g., along the length of cathode 14 and/or anode 16). The improved uniformity of the current distribution in the discharge cell may provide more uniform erosion of the cathode and anode, which may result in an increased lifetime of the cathode, anode and/or discharge cell of the laser.

The conducting member 22 includes a plurality of channels 26 a-26 d, four of which are shown in fig. 3A and 3B. However, it should be understood that the number of channels may be selected based on a desired or required current distribution in the discharge chamber 12 and/or a desired or required current density in the conductive member 22. It should also be understood that in other embodiments, the conductive member may include more or less than four channels.

Each of the channels 26 a-26 d may be associated with the first portion 28 or the third portion 32 of the conductive member 22. Each of the channels 26 a-26 d is configured for: the current flow path in the associated portion of the conductive member 22 is increased relative to the current flow path in the other portion of the conductive member (i.e., the second portion 30). In the embodiment shown in fig. 3A and 3B, two channels 26a, 26B are associated with the first portion 28 of the conductive member 22. Each of the two

channels

26a, 26b may be configured for: the current flow path in the first portion 28 of the conductive member 22 is increased relative to the current flow path in the second portion 30 of the conductive member 22. The other two

channels

26c, 26d may be associated with the third portion 32 of the conductive member 22. Again, each of the two

further channels

26c, 26d may be configured for: the current flow path in the third portion 32 of the conductive member 22 is increased relative to the current flow path in the second portion 30 of the conductive member 22. The first, second and

third portions

28, 30, 32 are indicated by dashed lines in fig. 3A and 3B.

The conductive member 22 may be configured such that two channels 26a, 26B extend parallel to each other and/or such that two

further channels

26c, 26d extend parallel to each other, as shown in fig. 3A and 3B. Each of the two

channels

26a, 26b and/or each of the other two

channels

26c, 26d may be arranged to extend along an axial or longitudinal direction a of the conductive member 22.

Parameters such as the size and configuration of the

channels

26a, 26b and the other two

channels

26c, 26d may be selected based on the desired current distribution in the discharge chamber 12 or the desired current density in the conductive member 22. The parameters may include the length L and width W of each

channel

26a, 26b and each

further channel

26c, 26d, as indicated in fig. 3A. In some embodiments, the length of each

channel

26a, 26b and/or each

additional channel

26c, 26d may be in the range of about 3 to 20cm, although other dimensions may be used in other embodiments. In some embodiments, the width of each

channel

26a, 26b and/or each

additional channel

26c, 26d may be in the range of about 0.5 to 1.3cm, although other dimensions may be used in other embodiments. Each of the respective channels 26 a-26 d may have all of the same dimensional parameters, or they may be different.

The conductive member 22 may include a first end 34. The first portion 28 of the conductive member 22 may define or be part of the first end 34 of the conductive member 22. In this embodiment, the first end 34 includes two

channels

26a, 26 b. It should be understood that in other embodiments, the first end may include fewer or more than two channels. The first end 34 may include a first rounded edge 34 a. The conductive member 22 may be configured such that the two

channels

26a, 26b extend longitudinally inward from the first rounded edge 34 a.

The conductive member 22 may include a second end 36. The third portion 32 of the conductive member 22 may define or be part of the second end 36 of the conductive member 22. In this embodiment, the second end 36 includes two

additional channels

26c, 26 d. It should be understood that in other embodiments, the second end may include more or less than two additional channels. Second end 36 may include a second rounded edge 36 a. The conductive member 22 may be configured such that the other two

channels

26c, 26d extend longitudinally inward from the second rounded edge 36 a. One or all of channels 26 a-26 d may extend longitudinally inward from one of first rounded edge 34a and second rounded edge 36 a. Conductive member 22 is configured such that first rounded edge 34a and second rounded edge 36a are disposed opposite each other.

Experiments have shown that, for example, in use, increased current may flow in the first end 34 and/or the second end 36 relative to current flowing in the remainder of the conductive member 22 (if not for the channels 26 a-26 d). In other words, in use, the current density in the first end 34 and/or the second end 36 may be higher relative to the current density in the remainder of the conductive member 22. By providing the

channels

26a, 26b as part of the first end 34 of the conductive member 22 and/or providing the

additional channels

26c, 26d as part of the second end 36 of the conductive member 22, the current or current density flowing in the first end 34 and/or the second end 36 may be reduced. This may result in an increase in the uniformity of the current or current density flowing through the conductive member 22. This in turn may lead to a more uniform corrosion of the cathode and/or anode, which may lead to an increased lifetime of the cathode, anode and/or discharge chamber.

Fig. 3A shows an exemplary conductive member 22 that may be used with the discharge chamber 12 holding an argon fluoride gas mixture, but may also be used in combination with other gas mixtures. As described above, the conductive member 22 may be configured to conduct a current associated with a discharge in the discharge chamber 12. One or more dimensions of the conductive member 22 may be selected based on the current distribution that may be needed or desired in the discharge chamber 12. Additionally or alternatively, in use, the dimensions of the conductive member 22 may be selected to minimize or reduce the inductance of the conductive member 22, for example, when current flows through the conductive member 22. It should be understood that the dimensions may alternatively or additionally be selected based on one or more dimensions of the discharge chamber 12 and/or other portions of the laser 10. In this embodiment, the conductive member 22 may have a thickness T in the range of 20 to 50mm, such as, for example, about 30mm, although other thicknesses may be used in other embodiments. The conductive member 22 also includes two recessed portions 35a having a thickness less than the thickness T. The conductive member 22 may have a length L1 and a width W1 selected in conjunction with the size of the discharge laser, and the length L1 and width W1 may vary in various embodiments.

Fig. 3B shows an exemplary conductive member 22 such as may be used with a discharge chamber 12 containing a gas mixture, such as krypton fluoride gas mixture, although the exemplary conductive member 22 of fig. 3B may also be used in combination with other gas mixtures. The conductive member 22 shown in fig. 3B is similar to the conductive member shown in fig. 3A. However, it can be seen that the conductive member 22 shown in fig. 3B is thinner than the conductive member 22 shown in fig. 3A. In this embodiment, the conductive member 22 may have a thickness in the range of 2 to 5mm, such as, for example, about 3mm, although other thicknesses may be used in other embodiments. The length L1 and width W1 of the conductive member 22 shown in FIG. 3B will be selected in conjunction with the size of the discharge laser, and this may vary in various embodiments.

Fig. 4A illustrates a plan view of the exemplary conductive member 22 shown in fig. 3A. However, it should be understood that any of the features described below may also be applied to the conductive member 22 shown in fig. 3B. The conductive member 22 is configured for connection to a voltage source 24. The conductive member 22 may be configured to receive a portion of a connection arrangement for connecting a voltage source to a laser (not shown in fig. 4A). The conductive member 22 may include two recessed portions 35 a. The two recessed portions 35a may be considered to be recessed downward into the plane of fig. 4A. The two recessed portions 35a can be seen more clearly in fig. 3A. In some embodiments, the recessed portion 35a may be configured to receive at least a portion of the connection arrangement. Two recessed portions 35a are disposed in a central or middle portion 37 of the conductive member 22. The intermediate portion 37 of the conductive member 22 may be part of the second portion 30 of the conductive member 22 or included in the second portion 30 of the conductive member 22. Each of the recessed portions 35a may be arranged to extend along an axial or longitudinal direction a. The width W2 of the center or middle portion 37 may be greater than the width W1 (shown in fig. 3A) of the remainder of the conductive member 22. The central or intermediate portion 37 may be configured to allow a seal to be formed between the conductive member 22 and another portion of the laser 10.

The conductive member 22 may be configured for connection to a plurality of charge storage devices and a plurality of conductive elements. Each charge storage device may be provided in the form of a capacitor as shown in fig. 5, for example. However, it should be understood that other means for storing charge may be used. Each conductive element may be provided in the form of a feed-through element, although in other embodiments, other conductive elements may be used. The conducting members 22 may be configured to conduct electrical current from each capacitor to a respective feedthrough.

Referring to fig. 4A, the conductive member 22 may include a plurality of first connection points 38. Each first connection point 38 may be configured for connection to a charge storage device, such as a capacitor. Each first connection point 38 may be provided in the form of a hole. The first connection point 38 is arranged along an axial or longitudinal direction a of the conductive member 22. The first connection point 38 may be disposed near an outer edge or perimeter of the conductive member 22. The first connection points 38 may be arranged in two

rows

38a, 38b on opposite sides of the conducting member 22. As shown in fig. 4A, some of the first connection points 38 may be disposed in the recessed portion 35 a.

The conductive member 22 may include a plurality of second connection points 40. Each second connection point 40 may be configured for connection to a feed-through element. Each first connection point 38 is provided in the form of a further hole. The second connection point 40 may be linearly arranged along the axial or longitudinal direction a of the conductive member 22, although other arrangements may be used in other embodiments. The second connection point 40 may be arranged between two

rows

38a, 38b of the first connection points 38. Each second connection point 40 may be associated with a pair of first connection points 38. Each second connection point 40 may be disposed between an associated pair of first connection points 38.

Fig. 4B illustrates the first end 34 of the conductive member shown in fig. 4A. The conductive member 22 may be configured such that each

channel

26a, 26b extends between a first connection point 38 and a second connection point 40, and current may flow from the associated first connection point 38 to the second connection point 40. In the exemplary embodiment shown in fig. 4A, each

channel

26a, 26b extends generally between two first connection points 38 and two second connection points 40. In use, when the conductive member 22 is connected to a capacitor and a feed-through element, the conductive member 22 may conduct electrical current from one or a pair of capacitors to the associated feed-through element. The current flow paths in the first and

second portions

28, 30 of the conductive member are indicated by arrows in fig. 4B. As shown in fig. 4B, the flow path of the current in the first portion 28 of the conductive member 22 is longer than the flow path of the current in the second portion 30. In other words, the

channels

26a, 26b may be configured to force current on a longer flow path in the first portion 28 of the conductive member 22 than the flow path of current in the second portion 30 of the conductive member 22. This may result in an increase in the uniformity of the current flowing through the conductive member 22 or the current density in the conductive member 22. This, in turn, may result in a more uniform current or current density along the cathode 14 and/or anode 14, which may result in more uniform corrosion of the cathode and anode. This may result in an increased lifetime of the cathode, anode and/or discharge chamber.

Fig. 4C illustrates the first end 34 of another exemplary embodiment of the conductive member 22. The conductive member shown in fig. 4C is similar to the conductive member 22 described above. In this embodiment, the conductive member 22 includes an insulating portion 42. At least a portion of the insulating portion 42 may be disposed in each of the two

channels

26a, 26 b. The insulating portion 42 may be configured to prevent current from flowing across each

channel

26a, 26b or across both

channels

26a, 26 b. The insulating portion 42 may be configured based on parameters of each

channel

26a, 26b and/or the distance D between the two

channels

26a, 26 b. In this embodiment, the insulating portion 42 includes a U-shape. It should be appreciated that in other embodiments, the insulating portion may have a different shape, for example, depending on the parameters of each channel and/or the distance between two channels. In other embodiments, the insulating portion may include two separate prongs 42a, the two separate prongs 42a not being coupled together to form a single piece. The insulating portion 42 may include two prongs 42a and/or a portion 42b connecting the two prongs 42 a. The length L3 and/or width W3 of each prong 42a may be selected based on the length L and/or width W of each

channel

26a, 26 b. In other words, the length L3 and/or width W3 of each prong 42a may be selected to largely correspond to the length L and/or width W of each

channel

26a, 26 b. The insulating portion 42 may be disposed on the conductive member 22, for example, such that each of the prongs 42a is disposed in each of the two

channels

26a, 26 b. When each prong 42a of the insulating portion 42 is disposed in each of the two

channels

26a, 26b, the portion 42b may cover the portion 34b of the first rounded edge 34 a. A portion 34b of the first rounded edge 34a may extend between the two

channels

26a, 26 b.

The insulating portion may be formed of an insulating material. For example, the insulating material may comprise a plastic material. The plastic material may comprise a polymer or a polymer compound, such as, for example, polytetrafluoroethylene or the like. Alternatively, insulating materialThe material may comprise a ceramic material, such as, for example, alumina (Al)₂O₃Or AlO₂). As described above, an insulating portion 42 may be disposed in each

channel

26a, 26b to prevent arcing or arcing from forming in each

channel

26a, 26b and/or between the two

channels

26a, 26 b. It should be understood that the conductive member 22 may include additional insulative portions. The additional insulating portion may include any of the features of insulating portion 42. The further insulating portion may be arranged in each

further channel

26c, 26 d. The conductive member 22 may include an insulating portion disposed in one or more of the channels 26 a-26 d. One or all of the channels 26 a-26 d may include an insulating portion disposed therein.

Fig. 5 is a cross-sectional view illustrating an exemplary embodiment of laser 10. The laser 10 comprises a portion of the laser shown in fig. 2. Thus, any of the features described above with respect to fig. 2 may also be applied to the laser 10 shown in fig. 5.

Fig. 5 shows an outer portion 12a of the discharge chamber 12 shown in fig. 2. The outer portion 12a of the discharge cell 12 may be disposed on the outside of the discharge cell 12 in the form of a recess. As described above, the laser 10 includes the conductive member 22. The conductive member 22 is configured to be attached to the outer portion 12a of the discharge chamber. The conductive member 22 shown in fig. 5 is the same as the conductive member 22 shown in fig. 4A and 4B. As such, any of the features described above with respect to fig. 4A and 4B may also be applied to the conductive member 22 shown in fig. 5.

The laser 10 comprises a plurality of charge storage devices 44, the plurality of charge storage devices 44 being provided in the form of a plurality of capacitors. Each capacitor 44 may have a capacitance in the range of 200 to 800pF, although other capacitances may be used in other embodiments. The arrangement of the capacitors 44 may correspond to the arrangement of the first connection points 38 of the conductive members 22. In other words, the capacitor 44 may be arranged along the axial or longitudinal direction B of the laser 10. The capacitors 44 may be arranged in two

rows

44a, 44b on opposite sides of the outer portion 12a of the discharge chamber 12. The capacitor 44 may be connected to the conductive member 22, for example, using a plurality of conductive fasteners 46a (e.g., screws, pins, bolts, etc.), one of the plurality of conductive fasteners 46a being shown in fig. 5. Each fastener 46a may be inserted into the first connection point to connect the capacitor to the conductive member 22.

The laser 10 includes a plurality of conductive elements 48, the plurality of conductive elements 48 being provided in the form of a plurality of feed-through elements. The arrangement of the feed-through element 48 may correspond to the arrangement of the second connection points 40 of the conductive member 22. In other words, feed-through elements 48 may be linearly arranged along an axial or longitudinal direction B of laser 10, such as shown in fig. 5. Other arrangements may be used in other embodiments. The feed-through element 48 may be arranged between the two

rows

44a, 44b of capacitors 44. The feedthrough element 48 may be connected to the conductive member 22, for example, using a plurality of additional conductive fasteners 46b (such as screws, pins, bolts, etc.), one of which is shown in fig. 5. Each additional fastener 46b may be inserted into the second connection point to connect the feed-through element 48 to the conductive member 22, although other fastening means may also be used.

In some embodiments, laser 10 may include an optional connecting member 45. The connection member 45 may be provided in the form of a connection plate or an interconnection plate. The connecting plate 45 may be configured to be flexible. For example, the connecting plate 45 may have a thickness of less than 1mm, but other thicknesses are used in other embodiments. The connection plate 45 may include a conductive material. The conductive material may comprise a metal or metal alloy, such as, for example, copper or brass. Connection plate 45 may be disposed between conductive member 22 and capacitor 44 and feed-through element 48. The connection plate 45 may have the same or similar shape and configuration as the conductive member 22 including the channel. In fig. 5, two channels 45a and 45b are visible that correspond to the two channels in the conducting member 22. It should be understood that the number of channels in the connecting plate 45 may correspond to the number of channels in the conductive member 22. The connection plate 45 may be arranged to ensure contact between the conductive member 22, the capacitor 44 and the feed-through element 48. The connection plate 45 may include a plurality of yet additional holes 45a, for example, to allow the capacitors 44 and the feed-through elements 48 to be connected to the conductive member 22 through the connection plate 45.

The laser 10 may comprise a connection arrangement 47 for connecting a voltage source (not shown in fig. 5) to the laser 10, e.g. the conductive member 22. The connection arrangement 47 comprises at least two connection elements 47 a. Each connecting element 47 may comprise a conductive material, such as for example a metal. Each connecting element 47a may be disposed in a respective recessed portion 35a of the conductive member 22. The connecting element 47a may be secured to the conductive member 22 by yet another plurality of fasteners 47b, such as, for example, screws, pins, bolts, or the like. The connection arrangement 47 may comprise at least two further connection elements 47 c. The two further connecting elements 47c may each be provided in the form of a resilient and/or flexible element, such as a spring or a helical spring, etc. Each further connecting element 47c may be arranged in a recess 47d of each connecting element 47 a. The connection element 47a and the further connection element 47c may comprise a conductive material. The conductive material may include a metal or metal alloy such as, for example, tin, brass, copper, or the like. The connection arrangement 47 may comprise at least two sealing elements 47e, such as for example two gaskets. Each sealing element 47e may be arranged to surround the connection element 47a and/or the further connection element 47 c. In other words, each sealing element 47e may be arranged between the conductive member 22 and the connection element 47a and/or the further connection element 47 c. A connection arrangement 47 may be provided to ensure contact between the voltage source and the conductive member 22. It should be understood that in other embodiments, any of a variety of other components for coupling a voltage source to a conductive member may be used.

Fig. 6 shows a cross-sectional view of a portion of the laser 10 along the line B in fig. 5. The cathode 14 and anode 16 of the laser 10 may be configured to extend along an axial or longitudinal direction of the laser 10. The anode 16 is attached to the support member 16b by a plurality of fastening elements 16c, which fastening elements 16c may be provided in the form of screws, pins, bolts or the like. Feed-through elements 48 (three of which are shown in fig. 6) may be configured to direct current into discharge chamber 12. For example, feed-through element 48 may be connected to cathode 14 of laser 10. Each feed-through element 48 may be arranged to extend from an outer portion 12a of discharge chamber 12 into discharge chamber 12. This may allow for the application of a voltage to the cathode 14 through the conductive member 22 and the feed-through element 48, as will be described below. Each of the feed-through elements 48 may be configured to seal at least a portion of the discharge chamber 12, e.g., to prevent gas 18 from leaking from the interior of the discharge chamber 12. Each feed-through element 48 may include a fluorine-resistant material. The fluorine-resistant material may comprise a metal alloy, such as for example brass.

Fig. 7 shows a portion of the laser 10 shown in fig. 5. As described above, current may flow through one or more portions of laser 10 when a discharge is present between cathode 14 and anode 16. The flow paths of the current are indicated by arrows in fig. 7.

As described above, the voltage source 24 may be connected to the conductive member 22. In use, a voltage may be applied to the conductive member 22 to induce an electrical discharge in the discharge chamber such that a current associated with the electrical discharge flows through the conductive member 22 to enter the discharge chamber 12. The voltage applied to the conductive member 22 may be in the range of 500 to 1500V.

Conductive member 22 may be connected to capacitor 44 and feed-through element 48. Each capacitor 44 may be charged when a voltage is applied to the conductive member 22. The charging of each capacitor 44 may result in an increase in the voltage between cathode 14 and anode 16. This voltage may be applied to cathode 14 via feed-through element 48. For example, a negative potential may be applied to the conductive member 22, which causes the feed-through element 48 and the cathode 14 to be negatively charged. The negative potential applied to the conductive member 22 may also negatively charge at least a portion of each capacitor 44. This in turn may create an electric field between cathode 14 and anode 16, with anode 16 being connected to ground. It should be understood that in other embodiments, a positive potential may be applied to the anode. The electric field may ionize the gas mixture 18 between the cathode 14 and the anode 16. When the gas mixture 18 is sufficiently ionized, gas breakdown may occur and a discharge may be generated in the discharge region 20 of the discharge chamber 12. This may result in a voltage V across each of the capacitors 44_CPAnd the voltage across cathode 14 and anode 16 drops. Current may flow from capacitor 44 to feed-through element 48 via conductive member 22. Current may flow from feed-through element 48 into discharge chamber 12, e.g., to cathode 14 and across discharge region 20 to anode 16. As described above, by mixingThe conductive member 22 is configured to include at least one channel that may increase the current density or uniformity of current flow in the conductive member 22. This, in turn, may result in an increase in the uniformity of the current or current density along cathode 14 and anode 16 (e.g., along the length of cathode 14 and/or anode 16). This increased uniformity of current or current density may result in more uniform erosion of the cathode and anode, which may result in an increase in the lifetime of the cathode, anode and/or discharge cell of the laser. Current may flow from anode 16 to ground (not shown), for example, using current return element 54. The current return element 54 may be configured to ground the anode 16.

Fig. 8 is a flow chart summarizing the steps of a method for operating a laser, such as the laser 10 described above. In step 105, the method includes the step of providing a discharge laser and voltage source having a conductive member 22 as described above.

In step 110, the method comprises: a voltage source is used to apply a voltage to the conductive member. A voltage is applied to cause a discharge in a discharge cell of the laser to operate the laser to generate a laser beam, as described above.

In step 115, a voltage applied to the conductive member causes a current to flow from a charge storage device (e.g., capacitor 44) of the laser to a conductive element (e.g., feed-through element 48) of the laser via the conductive member.

In step 120, a voltage applied to the conductive member causes current to flow from the feed-through element 48 into the discharge chamber. For example, current may flow from the conductive element to a first electrode of the laser, such as the cathode 14. Current may flow from a first electrode of the laser (e.g., across the discharge region 20) to a second electrode of the laser, e.g., the anode 16.

The step of applying a voltage may include charging a charge storage device (e.g., capacitor 44) and/or a conductive element. For example, as described above, a negative potential may be applied to the conductive member. This can result in at least a portion of the conductive member, the conductive element, and each charge storage device being negatively charged. This in turn may cause the first electrode (e.g., cathode) of the laser to be negatively charged.

The method can comprise the following steps: for example, a step of pre-ionizing the gas mixture in a discharge chamber of the laser before the discharge.

It should be understood that any of the features described above, for example with respect to fig. 7, may be applied to the method or portions of the method.

As described above, by forming the channels in the conductive member, uneven corrosion of the cathode and/or anode may be reduced or prevented. Since the conducting member may be connected to the discharge chamber on the outer portion, it may not be exposed to fluorine gas when the conducting member is detached from and/or (re) attached to the outer portion of the discharge chamber. Additionally, as described above, the formation of the channels may have no or reduced impact on one or more structural or thermal properties of the conductive member.

The term "channel" may be considered to encompass an elongated recess or an elongated hollow space or portion.

It should be understood that the terms "current flow path" and "flow path of current" may be used interchangeably.

It should be understood that reference to multiple features may be used interchangeably with reference to a singular form of such features, such as, for example, "at least one" and/or "each". The singular forms of features (such as, for example, "at least one" or "each") may be used interchangeably.

In this document, the terms "radiation" and "beam" are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g. having a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (extreme ultraviolet radiation, e.g. having a wavelength in the range of about 5 to 100 nm).

The terms "reticle", "mask" or "patterning device" used herein should be broadly interpreted as referring to a general purpose patterning device that can be used to impart an incident radiation beam with a patterned cross-section corresponding to a pattern to be created in a target portion of the substrate. The term "light valve" may also be used herein. Examples of other such patterning devices, in addition to classical masks (transmissive or reflective, binary, phase-shifting, hybrid, etc.), include programmable mirror arrays and programmable LCD arrays.

Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications. Possible other applications include the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, Liquid Crystal Displays (LCDs), thin film magnetic heads, etc.

Although specific reference may be made in this text to embodiments of the invention in the context of lithographic apparatus, embodiments of the invention may be used in other apparatus or systems. Embodiments of the invention may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus that measures or processes an object such as a wafer (or other substrate) or a mask (or other patterning device). These devices are commonly referred to as lithographic tools. Such a lithography tool may use vacuum conditions or ambient (non-vacuum) conditions.

Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention is not limited to optical lithography and may be used in other applications, for example imprint lithography, where the context allows.

Other aspects of the invention are set forth in the following numbered clauses.

1. A conducting member for conducting current associated with an electrical discharge in a discharge chamber of a laser, the conducting member comprising:

at least one channel configured to: the current flow path in one portion of the conductive member is increased relative to the current flow path in another portion of the conductive member, the conductive member is configured to connect the laser to a voltage source, and the conductive member is configured to provide an interface between the voltage source and a discharge chamber of the laser.

2. The conductive member according to clause 1, wherein the conductive member comprises a plurality of channels.

3. The conductive member according to clause 2, wherein each of the channels is associated with a portion of the conductive member and is configured for: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

4. The conductive member according to any one of the preceding clauses wherein the conductive member includes a first end portion including at least one of the channels.

5. The conductive member according to clause 4, wherein the first end includes a first rounded edge, the first end including at least two of the channels extending longitudinally inward from the first rounded edge.

6. The conductive member according to any of clauses 4 or 5, wherein the conductive member includes a second end portion including at least one of the channels.

7. The conductive member according to clause 6, wherein the second end includes a second rounded edge, the second end including at least two of the channels extending longitudinally inward from the second rounded edge.

8. The conductive member according to any one of the preceding clauses, wherein the conductive member is configured for connection to a plurality of charge storage devices and a plurality of conductive elements.

9. The conductive member according to clause 8, wherein the conductive member is configured for: a current is conducted from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements.

10. The conductive member according to clause 8 or 9, wherein the conductive member comprises a plurality of first connection points and a plurality of second connection points, and wherein each of the plurality of first connection points is configured for connection to a charge storage device of the plurality of charge storage devices, and each of the plurality of second connection points is configured for connection to a conductive element of the plurality of conductive elements.

11. The conductive member according to clause 10, wherein the plurality of first connection points and/or the plurality of second connection points are each arranged in a configuration extending longitudinally along the conductive member.

12. The conductive member according to clause 10 or 11, wherein the conductive member is configured such that each of the channels is disposed between the first connection point and the second connection point.

13. The conductive member according to any one of the preceding clauses, further comprising an insulating portion disposed in each channel.

14. The conductive member according to any one of the preceding clauses wherein the conductive member comprises a conductive strip.

15. A laser, comprising:

a discharge chamber; and

a conducting member for conducting current associated with a discharge in the discharge chamber, the conducting member comprising:

16. The laser according to clause 15, wherein the laser comprises a plurality of charge storage devices and a plurality of conductive elements, the plurality of charge storage devices and the plurality of conductive elements being connected to the conductive member.

17. The laser of clause 16, wherein the conductive member is configured for: a current is conducted from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements.

18. The laser according to clause 16 or 17, wherein the plurality of conductive elements are configured to: current is directed into the discharge chamber.

19. The laser according to any of clauses 15 to 18, wherein the conducting member comprises a plurality of channels, each of the channels being associated with a portion of the conducting member and configured for: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

20. The laser according to any of clauses 15 to 19, wherein the discharge chamber is configured to hold one or more gases comprising krypton, argon and/or fluorine.

21. A lithography system, comprising:

a radiation source comprising a laser, the laser comprising:

a discharge chamber; and

conducting means for conducting an electrical current associated with an electrical discharge in the discharge chamber according to any of clauses 1-14; and

a lithographic apparatus.

22. A method for operating a laser, the laser comprising:

a laser having a laser discharge chamber; and

a conducting member for conducting current associated with a discharge in the discharge chamber, the conducting member comprising at least one channel configured for: increasing a current flow path in a portion of a conductive member relative to a current flow path in another portion of the conductive member, the conductive member connecting the laser to a voltage source and providing an interface between the voltage source and a discharge chamber of the laser, the method comprising:

a voltage is applied to the conductive member to induce a discharge in the discharge cell such that a current associated with the discharge flows through the conductive member to enter the discharge cell.

23. The method of clause 22, wherein the laser comprises a plurality of charge storage devices and a plurality of conductive elements, the plurality of charge storage devices and the plurality of conductive elements being connected to the conductive member.

24. The method of clause 23, wherein the conductive member is configured for: conducting a current from each of the plurality of charge storage devices to a respective one of a plurality of conductive elements configured to direct the current into the discharge chamber.

25. The method of clause 23 or 24, wherein applying the voltage to the conductive member causes current to flow from the plurality of charge storage devices to the plurality of conductive elements via the conductive member such that a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in a portion of the conductive member is longer than a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in other portions of the conductive member.

26. The method according to clause 25, wherein applying the voltage to the conductive member causes current to flow from the plurality of conductive elements into the discharge chamber.

27. The method according to any of clauses 23 to 26, wherein the step of applying a voltage to the conductive member comprises: a negative potential is applied to the conductive member.

28. The method according to any of clauses 22 to 27, wherein the conductive member comprises a plurality of channels, each of the channels being associated with a portion of the conductive member and configured for: the current flow path in the associated portion of the conductive member is increased relative to the current flow path in other portions of the conductive member.

29. The method according to any of clauses 22-29, wherein the conductive member further comprises an insulating portion disposed in each channel.

While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. The above description is intended to be illustrative and not restrictive. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

Claims

at least one channel configured to: increasing a current flow path in a portion of the conductive member relative to a current flow path in another portion of the conductive member, the conductive member configured to connect the laser to a voltage source, and the conductive member configured to provide an interface between the voltage source and the discharge chamber of the laser.

2. The conducting member according to claim 1, wherein the conducting member comprises a plurality of the channels.

3. The conductive member of claim 2, wherein each of the channels is associated with a portion of the conductive member and is configured to: increasing a current flow path in an associated portion of the conductive member relative to a current flow path in other portions of the conductive member.

4. The conducting member according to claim 1, wherein the conducting member comprises a first end comprising at least one of the channels.

5. The conductive member of claim 4, wherein the first end comprises a first rounded edge, the first end comprising at least two of the channels extending longitudinally inward from the first rounded edge.

6. The conducting member according to claim 4, wherein the conducting member comprises a second end portion comprising at least one of the channels.

7. The conductive member of claim 6, wherein the second end includes a second rounded edge, the second end including at least two of the channels extending longitudinally inward from the second rounded edge.

8. The conductive member of claim 1, wherein the conductive member is configured to connect to a plurality of charge storage devices and a plurality of conductive elements.

9. The conductive member of claim 8, wherein the conductive member is configured to: conducting current from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements.

10. The conductive member according to claim 9, wherein the conductive member comprises a plurality of first connection points and a plurality of second connection points, and wherein each of the plurality of first connection points is configured to connect to a charge storage device of the plurality of charge storage devices and each of the plurality of second connection points is configured to connect to a conductive element of the plurality of conductive elements.

11. The conductive member according to claim 10, wherein the plurality of first connection points and/or the plurality of second connection points are each arranged in a configuration extending longitudinally along the conductive member.

12. The conductive member according to claim 11, wherein the conductive member is configured such that each of the channels is disposed between a first connection point and a second connection point.

13. The conductive member according to claim 2, further comprising an insulating portion disposed in each channel.

14. The conductive member according to claim 3, wherein the conductive member comprises a conductive strip.

15. A laser, comprising:

a discharge chamber; and

a conducting member for conducting current associated with an electrical discharge in the discharge chamber, the conducting member comprising:

16. The laser according to claim 15, wherein the laser comprises a plurality of charge storage devices and a plurality of conductive elements, the plurality of charge storage devices and the plurality of conductive elements being connected to the conductive member.

17. The laser of claim 16, wherein the conducting member is configured to: conducting the current from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements.

18. The laser of claim 16, wherein the plurality of conductive elements are configured to: the current is directed into the discharge chamber.

19. The laser of claim 15, wherein the conducting member comprises a plurality of the channels, each of the channels being associated with a portion of the conducting member and configured to: increasing a current flow path in an associated portion of the conductive member relative to a current flow path in other portions of the conductive member.

20. The laser of claim 18, wherein the discharge chamber is configured to hold one or more gases comprising krypton, argon, and/or fluorine.

21. A lithography system, comprising:

a radiation source comprising a laser, the laser comprising:

a discharge chamber; and

a conducting member for conducting a current associated with a discharge in the discharge chamber of claim 13; and

a lithographic apparatus.

22. A method for operating a laser, the laser comprising:

a laser having a laser discharge chamber; and

a conducting member for conducting current associated with a discharge in the discharge chamber, the conducting member comprising at least one channel configured for: increasing a current flow path in a portion of the conductive member relative to a current flow path in another portion of the conductive member, the conductive member connecting the laser to a voltage source and providing an interface between the voltage source and the discharge chamber of the laser, the method comprising:

applying a voltage to the conductive member to induce a discharge in the discharge chamber such that a current associated with the discharge flows through the conductive member to enter the discharge chamber.

23. The method of claim 22, wherein the laser comprises a plurality of charge storage devices and a plurality of conductive elements, the plurality of charge storage devices and the plurality of conductive elements being connected to the conductive member.

24. The method of claim 23, wherein the conductive member is configured to: conducting the current from each charge storage device of the plurality of charge storage devices to a respective conductive element of the plurality of conductive elements, the plurality of conductive elements configured to direct the current into the discharge chamber.

25. The method of claim 23, wherein applying the voltage to the conductive member causes current to flow from the plurality of charge storage devices to the plurality of conductive elements via the conductive member such that a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in the one portion of the conductive member is longer than a current flow path from a charge storage device of the plurality of charge storage devices to an associated conductive element of the plurality of conductive elements in other portions of the conductive member.

26. The method of claim 25, wherein applying the voltage to the conductive member flows current from the plurality of conductive elements into the discharge chamber.

27. The method of claim 23, wherein the step of applying the voltage to the conductive member comprises: applying a negative potential to the conductive member.

28. The method of claim 23, wherein the conducting member comprises a plurality of the channels, each of the channels being associated with a portion of the conducting member and configured for: increasing a current flow path in an associated portion of the conductive member relative to a current flow path in other portions of the conductive member.

29. The method of claim 22, wherein the conductive member further comprises an insulating portion disposed in each channel.

30. The method of claim 28, wherein the conductive member further comprises an insulating portion disposed in each channel.