Inductively coupled plasma light source with switched power supply.

Abstract

The method and apparatus for generating light includes a chamber having a high-voltage region, a low-voltage region, and a plasma generation region defining a plasma confinement region. A magnetic core is disposed around the chamber and configured to generate plasma within the plasma confinement region. The switching power supply includes a DC power supply and a switched resonant charging circuit, which together generate multiple voltage pulses at an output and apply multiple current pulses to a power delivery section around the magnetic core, thereby establishing at least one plasma loop around the magnetic core that confines the plasma in the plasma confinement region, thereby forming a magnetically confined Z-pinch plasma. Light generated by the Z-pinch plasma propagates from a port in the light source.

Description

[Technical Field]

[0001]

[0001] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described in this application in any way.

[0002]

[0002] Introduction Many commercial and academic applications require high-brightness light in the extreme ultraviolet (EUV) region of the spectrum. For example, EUV light is needed for many industrial applications, including metrology, accelerated testing, photoresist, defect inspection, and microscopy. Other uses of EUV light include microscopy, spectroscopy, areal imaging, and blank mask inspection. These and other applications require EUV sources with high reliability, small physical size, low fixed costs, low operating costs, and low complexity from a critical source of these extreme ultraviolet photons.

[0003]

[0003] Known switching power supplies use magnetic switches that are known in the art to have numerous performance drawbacks, including being relatively slow and physically large, limiting the performance and usefulness of these high-brightness lights in the extreme ultraviolet (EUV) region of the spectrum. New switching power supplies are needed to improve the performance of these high-brightness EUV light sources. Summary of the Invention

[0004] A method and apparatus for generating light includes a chamber having a high voltage region, a low voltage region, and a plasma generation region defining a plasma confinement region. A gas supply port is positioned proximate to the plasma confinement region, and a vacuum pump port is positioned proximate to the plasma confinement region. A magnetic core is positioned around a portion of the chamber and configured to generate a plasma in the plasma generation region that converges to the plasma confinement region.

[0005] The switching power supply is electrically connected between the high voltage region and the low voltage region of the chamber and includes a DC power supply and a switching resonant charging circuit that together generate a plurality of voltage pulses at an output to apply a plurality of current pulses to a power delivery section around the magnetic core, thereby establishing at least one plasma loop around the magnetic core that confines the plasma in a plasma confinement region, thereby forming a magnetically confined Z-pinch plasma. In some configurations, the low voltage region is electrically connected to ground potential.

[0006] The switching power supply includes a charge switch and a discharge switch, which may be solid-state switches, including, for example, metal oxide semiconductor field effect transistors, bimetal oxide semiconductor field effect transistors, insulated gate bipolar transistors, or similar high-voltage semiconductor switches. The switched resonant charging circuit includes at least one inductor and at least one capacitor, configured such that the at least one inductor increases the voltage across the at least one capacitor during operation. The switched resonant charging circuit may be configured to increase the DC voltage generated by the DC power supply to no more than twice the DC voltage generated by the DC power supply. The switched resonant charging circuit may be configured to provide a charging current at the output of the switched power supply sufficient to sustain a plasma during generation of the voltage pulse. A magnetic flux excluder may be positioned proximate to the magnetic core, such that, during operation, at least one plasma loop flows between the magnetic flux excluder and the magnetic core.

[0007] A port is positioned adjacent to the plasma generation region to allow light generated by the Z-pinch plasma to propagate from the light source.

[0008] The present teachings, in accordance with preferred and exemplary embodiments, together with further advantages thereof, are more particularly described in the following detailed description taken in conjunction with the accompanying drawings. Those skilled in the art will understand that the drawings described below are for illustrative purposes only. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the teachings. The drawings are not intended to limit the scope of the applicant's teachings in any way. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a known plasma chamber for producing Z-pinch ultraviolet light. [Figure 2] FIG. 1 illustrates an ultraviolet light source including a solid-state pulsed power supply and power delivery section in accordance with the present teachings. [Figure 3A] FIG. 1 is a schematic diagram of a solid-state pulsed power and delivery system for an ultraviolet light source in accordance with the present teachings. [Figure 3B] 1 is a perspective view of a single substrate solid-state switch subsystem in accordance with the present teachings; [Figure 3C] FIG. 1 illustrates an example of a solid-state switch subsystem including six board power supplies configured radially in parallel. [Figure 4] FIG. 10 illustrates a plot of the current through and voltage across a charging capacitor in a solid-state switch subsystem in a power supply in accordance with the present teachings. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0015] The present teachings will now be described in more detail with reference to exemplary embodiments thereof as illustrated in the accompanying drawings. While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those skilled in the art. Those skilled in the art with access to the teachings herein will recognize additional implementations, modifications, and embodiments, as well as other fields of use, that are within the scope of the present disclosure as described herein.

[0011]

[0016] References herein to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present teachings. The appearances of the phrase "in one embodiment" in various places in the specification do not necessarily all refer to the same embodiment.

[0012]

[0017] It should be understood that the individual steps of the methods of the present teachings can be performed in any order and / or simultaneously so long as the present teachings remain operable. Furthermore, it should be understood that the apparatus and methods of the present teachings can include any number or all of the described embodiments so long as the present teachings remain operable.

[0013]

[0018] Extreme ultraviolet (EUV) light sources play a key role in many optical metrology and exposure applications. It is desirable for these light sources to be configured to address a multitude of use cases. One challenge is to generate high-power, high-brightness EUV light in a configuration that is flexible enough to enable integration with a multitude of applications and also exhibits high stability and reliability.

[0014]

[0019] Extreme ultraviolet radiation is referred to in many ways by those skilled in the art. Some also refer to extreme ultraviolet radiation as high-energy ultraviolet radiation, which may be abbreviated as XUV. Extreme ultraviolet radiation generally refers to electromagnetic radiation that is part of the electromagnetic spectrum, nominally spanning wavelengths from 124 nm to 10 nm. There is some overlap between extreme ultraviolet radiation and what is considered the optical spectrum. One particular EUV wavelength of interest is 13.5 nm because that wavelength is commonly used in lithography. Extreme ultraviolet radiation sources according to the present teachings are not limited to the production of EUV radiation. As is known in the art, plasmas can be used to generate photons in a wide spectral range. For example, plasmas generated according to the present teachings can also be used to generate soft X-ray photons (SXR), which includes, for example, photons having wavelengths less than 10 nm.

[0015]

[0020] So-called Z-pinch plasmas with axial current flow have been shown to be effective in generating EUV and SXR light. However, most known light sources employ electrodes to direct the high discharge current into the plasma. These electrodes are typically in contact with the high-temperature plasma and can melt, creating significant debris, which is highly undesirable as it can significantly shorten the useful life of the light source.

[0016]

[0021] An electrodeless approach to EUV generation is desirable and fills a significant market need. Such sources are available, for example, from Energetiq, a Hamamatsu Company located in Wilmington, Massachusetts. These sources are based on a Z-pinch plasma, but completely avoid electrodes by inductively coupling current into the plasma. The plasma in these EUV sources is magnetically confined from the source walls, minimizing heat load, reducing debris, providing excellent open-loop spatial stability, and stable, repeatable output. One challenge with known Z-pinch sources is that their performance, particularly in brightness, is limited by their power supply, due to the use of magnetic switches, which are highly undesirable and neither flexible nor easily scalable.

[0017]

[0022] One feature of the EUV light sources of the present teachings is that they are versatile and support a variety of applications with high brightness. In particular, the EUV light sources of the present teachings improve upon known Z-pinch designs because they can be optimized for the peak power and / or peak brightness required by the user for a particular application. Furthermore, the EUV sources of the present teachings have a more compact physical footprint and more flexible component layout.

[0018]

[0023] 1 shows a known plasma chamber 100 for generating Z-pinch ultraviolet light. See, for example, commonly assigned U.S. patent application Ser. No. 17 / 676,712, entitled "Inductively Coupled Plasma Light Source," the entire contents of which are incorporated herein by reference.

[0019]

[0024] The chamber 100 includes an interface 102 that delivers a feed gas 104 into the chamber 100. A pump 106 is used to evacuate a chamber region 108 to a desired operating pressure and / or control gas flow within the chamber 100 using a butterfly valve 107 or other means of controlling conductance. A port 110 is provided to allow EUV radiation 112 generated by the EUV plasma to pass through.

[0020]

[0025] In various systems, the port 110 is configured to be user-adaptable for attachment to an application system (not shown) through which EUV radiation passes directly through the port 110. The plasma generation region 114 defines a plasma confinement region 116. The plasma confinement region 116 is formed by magnetic induction when a pulse-forming and power delivery system 118 provides a current that actively and passively interacts with the magnetic cores 120, 121. A high-voltage region 122 is attached to the plasma generation region 114. The low-voltage region 124 has an outer surface coupled to a low-voltage potential, which in some embodiments is ground 126, as shown in FIG. 1. A pulsed power supply 119 using a magnetic switch is electrically coupled to the power delivery system 118. The chamber 100 also includes a region 128 between the inner and outer magnetic cores 121, 120, through which current carried by the inductively coupled plasma flows. During operation of the Z-pinch plasma in this known chamber 100, the feed gas in the plasma generating region 114 is compressed by an electrical pulse generated by the pulsed power supply 119, followed by expansion of the gas after the pulse.

[0021]

[0026] FIG. 2 illustrates an ultraviolet light source 200 including a solid-state pulsed power supply 250 and a power delivery section 252 according to the present teachings. The light source 200 is an inductively coupled design that uses magnetic confinement of the plasma within a plasma confinement region 238, where a Z-pinch is created away from the chamber 204 components, to provide high reliability and stability. A magnetic flux eliminator 206 is used to increase the confinement of the magnetic flux within the power delivery section, thus reducing inductance. During operation, one or more plasma loops flow through the magnetic flux eliminator region 206 and the plasma generation region 202, forming a plasma loop around the inner magnetic core 208. The plasma loops themselves do not produce significant EUV light.

[0022]

[0027] A target gas 210 enters the chamber 204 through an interface 212. In some embodiments, the target gas is xenon. A pump 214 is used to evacuate a chamber region 216 to a desired operating pressure. A valve, such as a butterfly valve 215, is used to control the pressure within the chamber region 216. A transparent port 218 is provided to allow EUV radiation, i.e., plasma-generated EUV light 220, to pass through. This port 218 can be, for example, any of the various types of ports described in connection with port 110 of FIG. 1 .

[0023]

[0028] A solid-state pulsed power supply (PPS) 250 is used to drive current through a power delivery section 252 to a low voltage region to generate the plasma. In one particular embodiment, the low voltage region is grounded. However, it should be understood that the low voltage region is not necessarily at ground potential. The solid-state pulsed power supply 250 is connected to the power delivery section 252 on a high voltage side 268 and a low voltage side 270. In some configurations, the diameter of the plasma confinement region 238 is smaller than the diameter of the high voltage region electrically coupled to the high voltage side 268. The pulsed power system 250 produces a DC voltage (V DC ) is coupled to the output of DC power supply 254. Resonant charging subsystem 256, having a charging switch 258 and an inductor 260, is configured to approximately double the voltage provided by DC power supply 254 at capacitor 266. This is accomplished using inductive energy storage by inductor 260, which effectively doubles the voltage provided by DC power supply 254 at capacitor 266. In other words, resonant charging subsystem 256 and capacitor 266 form a resonant charging circuit.

[0024]

[0029] The solid-state pulsed power supply 250 also includes a solid-state switch subsystem 262, which includes a discharge switch 264 and at least one capacitor 266 that generates the current necessary to form the plasma. The at least one capacitor is typically a plurality of capacitors, as described in connection with FIG. 3B. FIG. 3A shows a schematic diagram of a solid-state pulsed power and delivery system 300 for an ultraviolet light source in accordance with the present teachings. The system 300 includes a resonant charging subsystem 302, a solid-state switch subsystem 304, and a transmission line system 306 that couples the resonant charging subsystem 302 and the solid-state switch subsystem 304. The resonant charging subsystem 302 includes a DC power supply 308 that generates a high voltage in the range of approximately 500 V to 1 kV, which in one particular embodiment may be a 1 kV power supply. Other embodiments may have a DC power supply 308 that operates in the multi-kV range. The DC power supply 308 provides the DC voltage to a charging switch 310, which in many embodiments includes a high-power solid-state switch that switches the output voltage of the DC power supply 308. In recent years, there have been significant advances in the performance of high-power solid-state device technologies. For example, heterojunction bipolar transistors (HBTs), insulated gate bipolar transistors (IGBTs), silicon carbide metal-oxide-semiconductor field-effect transistors (SiCFETs), and bimetal-oxide-semiconductor field-effect transistors (BiMOSFETs) are examples of robust, high-power, fast-switching solid-state switches that are useful in power supplies according to the present teachings. BiMOSFET devices combine the strengths of MOSFET devices with the strengths of IGBT devices to achieve V ce (voltage difference between the collector and emitter) and V f BiMOSFET devices are particularly useful because they achieve a positive temperature coefficient of resistance (forward voltage). BiMOSFET devices also preferably feature low conduction losses, making them particularly suitable for high frequency and / or high power density applications.

[0025]

[0030] When charging switch 310 is closed, the voltage generated by DC power supply 308 is applied to inductor 312, which stores energy for the pulse. Inductor 312 is one or more inductors coupled in series to provide a large inductance value. For example, in some systems, the total inductance value of inductor 312 may be on the order of 1 to 10 micro-H, or more, in some embodiments.

[0026]

[0031] Diodes D1 314 and D2 316 prevent the current passed by charge switch 310 from reversing and provide a charging current that pre-ionizes the plasma, thereby maintaining the plasma loop. Resonant charging subsystem 302 is configured to approximately double the voltage provided by the DC power supply at capacitor 318. Note that resonant charging subsystem 302, transmission line 306, and capacitor 318 form a resonant charging circuit.

[0027]

[0032] The transmission line system 306 couples the voltage generated by the resonant charging subsystem 302 to the solid-state switch subsystem 304. The solid-state switch subsystem 304 includes a capacitor 318 and a solid-state discharge switch 320. In many embodiments, the capacitor 318 is a bank of multiple parallel-connected capacitors that provide a relatively high capacitance value with a relatively low inductance. For example, in one particular embodiment, the total capacitance value of the capacitor 318 may be on the order of 3,000 nF. In the particular embodiment described, the peak pre-pulse current is in the range of 380 amps, and the half-sine charge time is in the range of 15 to 20 microseconds.

[0028]

[0033] The schematic diagram of the solid-state pulse power and delivery system 300 shows the power delivery section 252 (FIG. 2) as the primary side 324 of a transformer 322 and the plasma as the secondary side 326. The current pulses generated by the solid-state switch subsystem 304 are applied to the primary side 324 of the transformer 322 via the power delivery section 252. The plasma itself is modeled as the secondary side 326 of the transformer 322, which has both an inductive component 328 and a resistive component 330.

[0029]

[0034] Pulsed operation of the solid-state pulsed power and delivery system 302 is achieved by switching through two solid-state switches: a charge switch 310 in the resonant charging subsystem 302 and a discharge switch 320 in the solid-state switch subsystem 350. The charge switch 310 in the resonant charging subsystem 302 applies a high-voltage pulse across a capacitor 318 or capacitor bank in the solid-state switch subsystem 304. When the charge switch 310 is closed, current flows through the resonant charging subsystem 302, charging the capacitor 318. Diodes D1 314 and D2 316 are configured to ensure the desired direction of current flow and are also configured to provide a charging current that pre-ionizes the plasma, thereby maintaining the plasma loop between pulses. The charging voltage, including the maximum charging voltage, can be expressed as follows:

number

number

[0030]

[0035] Preionization is important because Z-pinch operation requires a sustained plasma loop, as it requires continuously ionized gas for proper function. Discharge switch 320 is closed when the maximum voltage across capacitor 318 is reached.

[0031]

[0036] 2 and 3A , the resulting discharge causes capacitor 318 to drive current through high-voltage side 268 and low-voltage side 270 of power delivery section 252. As a result, inner magnetic core 208 couples the current pulse to the plasma loop, resulting in a large current pulse in the plasma that forms a loop that flows through flux ejector region 206 and plasma confinement region 202, forming a loop around inner magnetic core 208. In some embodiments, at least three inductively coupled plasma loops converge into plasma confinement region 202 to form a magnetically confined Z-pinch. Plasma confinement region 202 generates and emits nearly 100% of the EUV radiation generated by the plasma. As a result, light source 200 produces high-quality EUV light 236 from well-defined and stable pinch plasma confinement region 202. Importantly, light source 200 is a very compact source compared to other known light sources for generating stable pinch plasma suitable for light source applications. These features are enabled by the solid-state switching power supply of the present teachings.

[0032]

[0037] Another feature of the present teachings is that the pulse forming and power delivery section 300 of the solid-state pulse power system can be constructed with power supply components on multiple circuit boards, allowing the power supply to be constructed in a relatively small area compared to known switching power supply technologies.

[0033]

[0038] FIG. 3B illustrates a perspective view of a single-board solid-state switch subsystem 350 in accordance with the present teachings. The solid-state switch subsystem 350 includes a bank of capacitors 320 configured in parallel to provide a relatively large capacitance. For example, in one particular embodiment suitable for commercial production, such a solid-state switch subsystem 350 may include 24 capacitors 320 on a single board providing a capacitance of approximately 528 nF. The solid-state switch 322, in this particular embodiment, is a BiMOSFET switch integrated into the single-board subsystem 350 and configured with diodes that protect the components 310, 314, 316, 320, and 322 from voltage reversals, as described in connection with FIG. 3A . Referring again to FIG. 3A , the subsystem 350 also includes a connector 352 that couples the solid-state switch subsystem 350 to the charging cable 306 that couples to the charging subsystem 302. Additionally, a fiber coupler 354 is shown for coupling an optical fiber from a controller to the solid-state switch subsystem 350, the optical fiber being used for fast triggering of the switch 322.

[0034]

[0039] Figure 3C shows an example of a solid-state switch subsystem 370 including six board power supplies configured radially in parallel with 24 capacitors 320 per board having a total capacitance in the range of, for example, 3000 nF, as described in connection with Figure 3B. Other embodiments may include any number of capacitors 320 per board having a total capacitance in the range of a few microfarads. Referring to all of Figures 3A, 3B, and 3C, the capacitors 320 are charged by a resonant charging subsystem.

[0035]

[0040] The radial configuration of the solid-state switch subsystem 370 has very efficient thermal management. In some configurations, a cooling ring 372, supplied with a cooling fluid such as water via a fluid inlet 374 and a fluid outlet 376, is disposed around the solid-state switch subsystem 370 to provide temperature control.

[0036]

[0041] The radial configuration of solid-state switch subsystem 370 is also very compact. To make the overall pulsed power supply more compact, a fiber optic cable can be coupled to fiber coupler 354 and used to trigger discharge switch 322 at peak voltages by triggering switch 322, as described in connection with FIG. 3B.

[0037]

[0042] 4 shows a plot 400 of the current through and voltage across a charging capacitor in a solid-state switch subsystem in a power supply in accordance with the present teachings. Plot 402 represents the voltage across the charging capacitor in volts as a function of time in microseconds. Plot 404 represents the current through the charging capacitor in kAmps as a function of time in microseconds. Plot 400 shows that when the elapsed time reaches approximately 20 microseconds, a large voltage pulse is established, which may be on the order of approximately 1.3 kKV with an associated peak current pulse of approximately 6.8 kA.

[0038]

[0043] Thus, one important feature of the present teachings is that the solid-state charge switch 310 and the solid-state discharge switch 320 can be conveniently located within the power supply unit itself because they do not suffer from magnetic saturation, as in known power supplies for generating Z-pinch inductively coupled plasmas. This allows the designer to place the switching devices next to the capacitor 320 on the switch board itself, which has the advantage of minimizing inductance. This is possible, at least in part, because the FET switching devices themselves are compact, especially when compared to magnetic switches. Such a configuration is not possible in known systems that use coupled-core magnetic circuits, because simplicity and space requirements make such a configuration impractical for commercial use.

[0039]

[0044] Pulse formation and power delivery by a solid-state pulse power system according to the present teachings has many advantages. One advantage is that by using a pulse power system according to the present teachings to drive and contain the plasma, the plasma source 200 (FIG. 2) operates without the use of electrodes that are typically used in known systems to direct the discharge current to the plasma.

[0040]

[0045] Another advantage of the solid-state pulse power system of the present teachings is that the resonant charging with inductive energy storage and voltage doubling described herein allows for much higher frequency operation compared to prior art systems. For example, when using solid-state switching devices for switches 310 and 320, operating frequencies in the 10 KHz range are easily achievable, allowing for significantly higher frequency operation. Furthermore, when using solid-state switching devices, a wide range of pulse energies can be obtained. For example, in commercially available devices, pulse energies can be in the range of several joules. As a result, higher operating frequencies and higher pulse energies allow for much higher brightness to be achieved with light sources using the solid-state pulse power system of the present teachings.

[0041]

[0046] Yet another advantage of the solid-state pulse power system of the present teachings is that the power supply can generate a controllable amount of charging current pulse that can be used to generate a pre-ionization current sufficient to obtain the desired Z-pinching condition. The solid-state pulse power system of the present teachings is highly adjustable to generate a wide range of pre-ionization pulse conditions. Suitable pre-ionization pulses are much smaller than the pulses primarily used to generate plasma. Typically, pre-pulses have maximum currents in the sub-kiloampere range, while main pulses have maximum currents of 5-10 kA. However, these power systems can generate highly adjustable pulses to provide flexible operation.

[0042]

[0047] Thus, another feature of the power supplies of the present teachings is their ability to generate pulses with highly adjustable dwell times. Dwell time refers to the delay after charge time and before main capacitor discharge. One measure of charge time is the time that switch 310 in resonant charging subsystem 302 is closed. In one particular embodiment, the dwell time is controllable from less than 1 microsecond to more than 50 microseconds to provide a variety of more desirable operating conditions.

[0043]

[0048] As described herein, preionization is necessary to obtain favorable Z-pinch plasma generation conditions. Also as described herein, preionization according to the present teachings is achieved by generating a prepulse from current leakage for charging, the amplitude of the prepulse being much smaller than the main pulse that generates the Z-pinch plasma. The dwell time, which is the approximate time between the prepulse and the main pulse, is selected to provide the desired Z-pinching conditions.

[0044]

[0049] Those skilled in the art will appreciate that there are numerous methods for generating ultraviolet light in accordance with the present teachings. These methods generally provide a feed gas to the plasma confinement region 202 within the plasma chamber 204 (FIG. 2). Some methods also apply the feed gas or a second gas to ports located at one or more of a variety of locations. A high voltage region 268 connected to the plasma confinement region 202 within the plasma chamber 204 is pulsed with a high voltage relative to a low voltage region 270.

[0045]

[0050] A voltage pulse train is generated by a solid-state pulsed power supply 300 and applied to at least one capacitor 318 electrically connected across a power delivery section 304 surrounding an inner magnetic core 208 disposed around the plasma confinement region 202. The voltage pulse train charges the at least one capacitor 318 until a voltage maximum is reached, and a solid-state discharge switch 320 is closed, causing the at least one capacitor to discharge, causing the inner magnetic core 208 to couple a current pulse into the plasma confinement region 202, forming a plasma within the loop. The plasma is maintained between voltage pulses by the charging current, which causes pre-ionization as described herein. The resulting plasma produces ultraviolet light, which propagates through a transparent port 218 disposed adjacent to the plasma confinement region 202.

[0046]

[0051] It should be appreciated that there are numerous performance advantages inherent in a solid-state switched pulse power system according to the present teachings used to drive current pulses. The system allows for flexibility beyond conventional magnetic switching systems, which are limited by eddy current and hysteresis losses in the magnetic switch core region. Importantly, the frequency of the current pulses can be significantly increased compared to known systems using magnetic switching power supplies. Also, the energy per pulse can be significantly increased compared to known systems using magnetic switching power supplies. The result of these enhancements is increased production of EUV radiation and much more flexible operation.

[0047]

[0052] equivalent While the applicant's teachings are described in conjunction with various embodiments, it is not intended that the applicant's teachings be limited to such embodiments. On the contrary, the applicant's teachings encompass various alternatives, modifications, and equivalents, which can be made without departing from the spirit and scope of the teachings, as will be appreciated by those skilled in the art.

Claims

1. a light source, a) a chamber comprising a high voltage region, a low voltage region, and a plasma generation region defining a plasma confinement region; b) a magnetic core disposed about a portion of the chamber, the magnetic core configured to generate a plasma in the plasma generation region that converges to the plasma confinement region; c) a switching power supply having an output electrically connected between the high voltage region and the low voltage region of the chamber, the switching power supply comprising a DC power supply and a switched resonant charging circuit, the DC power supply and the switched resonant charging circuit together generating a plurality of voltage pulses at the output that cause a plurality of current pulses to be applied to a power delivery section about the magnetic core, thereby establishing at least one plasma loop about the magnetic core that confines plasma to the plasma confinement region, thereby forming a magnetically confined Z-pinch plasma; d) a port disposed adjacent to the plasma generation region for propagating light generated by the Z-pinch plasma out of the light source; A light source comprising:

2. The light source of claim 1 , wherein the switching power supply comprises a charge switch and a discharge switch.

3. The light source of claim 2 , wherein at least one of the charge switch and the discharge switch comprises a solid-state switch.

4. The light source of claim 2 , wherein at least one of the charge switch and the discharge switch comprises a field effect transistor (FET).

5. 3. The light source of claim 2, wherein at least one of the charge switch and the discharge switch comprises a bimetal oxide semiconductor field effect transistor (BiMOSFET) device.

6. 3. The light source of claim 2, wherein at least one of the charge switch and the discharge switch comprises an insulated gate bipolar transistor (IGBT).

7. 10. The light source of claim 1, wherein the switched resonant charging circuit is configured to provide a charging current to the output of the switched power supply sufficient to maintain the at least one plasma loop during generation of the voltage pulse.

8. 10. The light source of claim 1, further comprising a magnetic flux excluder disposed proximate to said magnetic core, whereby during operation said at least one plasma loop flows between said magnetic flux excluder and said magnetic core.

9. The light source of claim 1 , wherein the low voltage region is electrically connected to ground potential.

10. The light source of claim 1 , wherein the switched resonant charging circuit is configured to increase the DC voltage produced by the DC power supply.

11. 10. The light source of claim 1, wherein the switched resonant charging circuit is configured to increase the DC voltage generated by the DC power supply to no more than twice the generated DC voltage.

12. 10. The light source of claim 1, wherein the switched resonant charging circuit comprises at least one inductor and at least one capacitor, the at least one inductor configured to increase a voltage across the at least one capacitor during operation.

13. 10. The light source of claim 1, wherein the switched resonant charging circuit comprises a capacitor bank including a plurality of parallel-connected capacitors.

14. The light source of claim 1 further comprising a gas supply port located proximate to the plasma confinement region.

15. The light source of claim 1 further comprising a vacuum pumping port located proximate to said plasma confinement region.

16. 1. A method for generating an inductively coupled Z-pinch plasma, comprising: a) constructing a chamber having a high voltage region and a low voltage region, the high voltage region defining a plasma confinement region within a plasma generation region; b) surrounding a portion of the chamber with a magnetic core configured to focus the plasma within the plasma confinement region; c) generating a direct current (DC) voltage; d) generating a plurality of voltage pulses from the generated DC voltage using resonant charging and discharging of a solid-state switch; e) applying the generated voltage pulses between the high voltage region and the low voltage region of the chamber to apply current pulses to a power delivery section around the magnetic core, thereby establishing at least one plasma loop around the magnetic core that confines plasma to the plasma confinement region, thereby forming a magnetically confined Z-pinch plasma; A method comprising:

17. The method of claim 16 further comprising electrically coupling the low voltage region to ground.

18. 17. The method of claim 16, wherein the switched resonant charging circuit increases the DC voltage produced by the DC power supply.

19. 17. The method of claim 16, wherein the switched resonant charging circuit increases the DC voltage generated by the DC power source to no more than twice the generated DC voltage.

20. The method of claim 16 , further comprising applying a current to the power delivery section around the magnetic core that maintains the at least one plasma loop during generation of the voltage pulse.

21. 17. The method of claim 16, wherein the current applied to the power delivery section about the magnetic core that maintains the at least one plasma loop during generation of the voltage pulses is applied during times between the voltage pulses.

22. 17. The method of claim 16, further comprising increasing magnetic flux confinement within the plasma confinement region using a magnetic flux excluder positioned proximate to the magnetic core.

23. The method of claim 16 , further comprising providing a feed gas proximate to the plasma confinement region.

24. The method of claim 16 further comprising pumping a gas adjacent to the plasma confinement region.

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