Reducing energy consumption of gas discharge chamber blower

Abstract

A control device for a light source includes a plurality of gas discharge chambers, wherein a blower is disposed in each gas discharge chamber. The control device comprises: a fault monitoring module configured to monitor one or more operating conditions of the light source at regular use intervals of the light source, and for each monitored operating condition, determine a fault state and a fault type, the fault type is related to which blower of the gas discharge chamber affects the monitored operating condition; and a control module configured to receive the determined fault state and the determined fault type from the fault monitoring module; selecting at least one gas discharge chamber; and sending an instruction to the blower in the selected at least one gas discharge chamber, the instruction being based on the determined fault state and the determined fault type.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Application No. 63 / 411,452, filed on September 29, 2022, and incorporated herein by reference in its entirety. Technical Field

[0003] The disclosed subject matter relates to controlling a blower disposed in a gas discharge chamber of a light source to thereby reduce energy consumed by the blower during operation of the light source. Background Art

[0004] A gas discharge light source used in lithography is called an excimer light source or laser. Typically, an excimer laser uses a combination of one or more inert gases (which may include argon, krypton or xenon) and a reactive gas (which may include fluorine or chlorine). An excimer laser can create excimers under appropriate conditions of electrical simulation (the energy provided) and high pressure (of the gas mixture), and the excimers only exist in the powered state. The excimers in the powered state produce amplified light in the ultraviolet range. An excimer light source can use a single gas discharge chamber or multiple gas discharge chambers. When the excimer light source is being performed, the excimer light source produces a deep ultraviolet (DUV) beam. The DUV light may include a wavelength of, for example, from about 100 nanometers (nm) to about 400nm.

[0005] The DUV beam can be directed to a lithography exposure device or scanner, which is a machine that applies the desired pattern to a target portion of a substrate, such as a silicon wafer. The DUV beam interacts with a projection optical system, which projects the DUV beam onto the photoresist of the wafer with the aid of a mask. In this way, one or more layers of the chip design are patterned onto the photoresist, and the wafer is then etched and cleaned. Summary of the invention

[0006] In some general aspects, a control device is configured for a light source. The light source includes a plurality of gas discharge chambers, wherein a blower is arranged in each gas discharge chamber. The control device includes: a fault monitoring module, the fault monitoring module is configured to monitor one or more operating conditions of the light source, and for each monitored operating condition, determine a fault state and a fault type, the fault type being related to which blower of the gas discharge chamber affects the monitored operating condition; and a control module, the control module is configured to receive the determined fault state and the determined fault type from the fault monitoring module; select at least one gas discharge chamber; and send instructions to the blower in the selected at least one gas discharge chamber, the instructions being based on the determined fault state and the determined fault type.

[0007] Implementations may include one or more of the following features. For example, the fault monitoring module may be configured to determine, for each monitored operating condition, a priority associated with the monitored operating condition; and the control module may be configured to select at least one gas discharge chamber based on the determined priority. The fault monitoring module may be configured to monitor one or more operating conditions of the light source at a periodic usage interval of the light source, and the control module may be configured to select at least one gas discharge chamber based on a gas discharge chamber selected by the control module during a most recent previous usage interval. The plurality of gas discharge chambers may include a master oscillator gas discharge chamber and a power amplifier gas discharge chamber, the power amplifier gas discharge chamber being optically connected in series with the master oscillator gas discharge chamber, and the fault type may be selected from a set of possible fault types, the set of possible fault types including a power amplifier fault type, a master oscillator fault type, and a common fault type.

[0008] Each of the one or more operating conditions may be defined by a performance metric that is related to the light source or a light beam produced by the light source. The one or more performance metrics may include: a wavelength histogram associated with the light beam; an energy dose error associated with the light beam; an energy error associated with the light beam; a bandwidth error associated with the light beam; an operating point of a master oscillator gas discharge chamber; an operating point of a power amplifier gas discharge chamber; a spectral characteristic accuracy associated with the light beam; and an actuator operating point of the light source.

[0009] The fault status determined for the monitored operating condition can be: flagged if the performance metric associated with the monitored operating condition is not within a threshold range of the performance metric; or cleared if the performance metric associated with the monitored operating condition is within a threshold range of the performance metric. The fault monitoring module can be configured to determine an overall fault status based on the determined fault status of each monitored operating condition, and the control module is configured to select at least one gas discharge chamber and send instructions to the blower in the selected at least one gas discharge chamber. The control module can include decoding the overall fault status to analyze the determined fault status of each monitored operating condition.

[0010] The control module is configured to select at least one gas discharge chamber and send instructions to the blower in the selected at least one gas discharge chamber, which may include: the control module is configured to operate in an active mode if all of the determined fault states are cleared, and to operate in a risk mode if any of the determined fault states is marked. In the active mode, the control module may be configured to send instructions to reduce the operating speed of the blower in the selected at least one gas discharge chamber by a decreasing speed step, and in the risk mode, the control module may be configured to send instructions to increase the operating speed of the blower in the selected at least one gas discharge chamber by an increasing speed step, the increasing speed step being greater than the decreasing speed step. The increasing speed step may be less than or equal to 40 revolutions per minute (rpm), and the decreasing speed step may be approximately one-half, one-third, one-quarter, or one-fifth of the increasing speed step. In the active mode, the control module can be configured to: select one of the gas discharge chambers; and if the reduced operating speed is higher than the baseline speed, send an instruction to reduce the operating speed of the blower arranged in the selected gas discharge chamber to the reduced operating speed. The control module can be configured to send an instruction to increase the operating speed of the blower arranged in the selected gas discharge chamber if the current operating speed of the blower arranged in the selected gas discharge chamber is lower than the baseline speed, and if the current operating speed of the blower arranged in the selected gas discharge chamber is at the baseline speed, send an instruction to maintain the operating speed of the blower arranged in the selected gas discharge chamber. The control device can also include a baseline module, the baseline module is configured to control the baseline speed of each blower of each gas discharge chamber, and the control of the baseline speed of a specific blower is related to the age of the gas discharge chamber containing the blower. The fault monitoring module can be configured to determine the fault priority for each monitored operating condition. In risk mode, the control module can be configured to: analyze the fault state of each monitored operating condition to determine which one or more fault states are marked; if multiple fault states are marked, select one of the marked fault states based on the determined fault priority, and if a single fault state is marked, select the single marked fault state; select a gas discharge chamber based on a fault type associated with the selected fault state; and send an instruction to increase the operating speed of the blower of the selected gas discharge chamber. The fault type can be associated with a single gas discharge chamber or can be associated with multiple gas discharge chambers. In risk mode, the control module is configured to select a gas discharge chamber based on the fault type associated with the selected fault state, which may include: selecting a single gas discharge chamber associated with the fault type or selecting a gas discharge chamber from multiple gas discharge chambers associated with the fault type.In risk mode, after the operating speed of the blower of the selected gas discharge chamber has been increased, the control module can be configured to: enter a holding state; after the holding state ends: receive the next determined fault state and fault type from the fault monitoring module for each monitored operating condition; analyze the fault state of each monitored operating condition to determine which one or more fault states are marked; if any fault state of one or more fault states is marked, then: if multiple fault states are marked, select one of the marked fault states based on the determined fault priority, and if a single fault state is marked, select the single marked fault state; select a gas discharge chamber based on the fault type associated with the selected fault state; and send an instruction to increase the operating speed of the blower of the selected gas discharge chamber; and if no fault state of one or more fault states is marked, exit the risk mode and wait for the next determined fault state and fault type from the fault monitoring module.

[0011] The fault monitoring module may be configured to monitor one or more operating conditions of the light source at a regular use interval of the light source, and the regular use interval of the light source may be measured as a number of pulses of a light beam generated by the light source. The regular use interval may include a first regular use interval and a second regular use interval, the second regular use interval being greater than the first regular use interval. The fault monitoring module may be configured to operate using the second regular use interval after determining a flagged fault condition using the first regular use interval and then determining a zero flagged fault condition in a next use interval.

[0012] In other general aspects, a method is configured to control a plurality of blowers, each blower being arranged in a gas discharge chamber of a light source. The method includes: monitoring one or more operating conditions of the light source at regular intervals of use of the light source; for each monitored operating condition, determining a fault state and a fault type, the fault type being related to which blower of the gas discharge chamber affects the monitored operating condition; selecting at least one gas discharge chamber; and sending instructions to the blowers in the selected at least one gas discharge chamber, the instructions being based on the determined fault state and the determined fault type.

[0013] Implementations may include one or more of the following features. For example, the method may further include: for each monitored operating condition, determining a priority associated with the monitored operating condition. At least one gas discharge chamber may be selected by selecting at least one gas discharge chamber based on the determined priority. At least one gas discharge chamber may be selected by selecting at least one gas discharge chamber based on a gas discharge chamber selected during a recent previous use interval. The fault state determined for the monitored operating condition may be: marked if the performance metric associated with the monitored operating condition is not within a threshold range of the performance metric; or cleared if the performance metric associated with the monitored operating condition is within a threshold range of the performance metric. The method may further include determining an overall fault state based on the determined fault state of each monitored operating condition. By decoding the overall fault state to analyze the determined fault state of each monitored operating condition, at least one gas discharge chamber may be selected and instructions may be sent to the blower in the selected at least one gas discharge chamber.

[0014] At least one gas discharge chamber may be selected and instructions may be sent to the blower in the selected at least one gas discharge chamber by operating in an active mode if all of the determined fault states are cleared, and operating in a risk mode if any of the determined fault states is marked. In the active mode, the instructions may be sent to the blower by sending an instruction to reduce the operating speed of the blower in the selected at least one gas discharge chamber by a decreasing speed step, and in the risk mode, the instructions may be sent to the blower by sending an instruction to increase the operating speed of the blower in the selected at least one gas discharge chamber by an increasing speed step, the increasing speed step being greater than the decreasing speed step. In the active mode: at least one gas discharge chamber may be selected by selecting one of the gas discharge chambers; and the instructions to the blower may be sent by: if the reduced operating speed is higher than the baseline speed, sending an instruction to reduce the operating speed of the blower arranged in the selected gas discharge chamber to the reduced operating speed. The instruction may be sent to the blower by sending an instruction to increase the operating speed of the blower arranged in the selected gas discharge chamber if the current operating speed of the blower arranged in the selected gas discharge chamber is at or below the baseline speed. The instruction may be sent to the blower by sending an instruction to maintain the operating speed of the blower arranged in the selected gas discharge chamber if the current operating speed of the blower arranged in the selected gas discharge chamber is within a threshold range of the baseline speed. The method may also include controlling the baseline speed of each blower of each gas discharge chamber, and controlling the specific blower baseline speed is related to the life of the gas discharge chamber housing the blower. The method may also include determining a fault priority for each monitored operating condition. Furthermore, operating in the risk mode may include analyzing the fault state of each monitored operating condition to determine which one or more fault states are marked; if multiple fault states are marked, selecting one of the marked fault states based on the determined fault priority, and, if a single fault state is marked, selecting the single marked fault state; selecting a gas discharge chamber based on a fault type associated with the selected fault state; and sending an instruction to increase the operating speed of the blower of the selected gas discharge chamber. The fault type may be associated with a single gas discharge chamber or may be associated with multiple gas discharge chambers; and operating in the risk mode may include selecting a gas discharge chamber based on the fault type associated with the selected fault state, selecting a gas discharge chamber based on the fault type associated with the selected fault state includes selecting a single gas discharge chamber associated with the fault type or selecting a gas discharge chamber from a plurality of gas discharge chambers associated with the fault type.

[0015] Operating in risk mode may include: after the operating speed of the blower of the selected gas discharge chamber has been increased: entering a hold state; after the hold state ends: analyzing the next determined fault state of each monitored operating condition to determine which one or more fault states are marked; if any fault state of one or more fault states is marked, then: if multiple fault states are marked, selecting one of the marked fault states based on the determined fault priority, and, if a single fault state is marked, selecting the single marked fault state; selecting a gas discharge chamber based on the fault type associated with the selected fault state; and sending an instruction to increase the operating speed of the blower of the selected gas discharge chamber; and if no fault state of one or more fault states is marked, exiting risk mode and waiting for the next determined fault state and fault type.

[0016] In other general aspects, a control device is configured for a light source, the light source including a first gas discharge chamber and a second gas discharge chamber, the second gas discharge chamber being optically connected in series with the first gas discharge chamber. The control device includes: a fault monitoring module, the fault monitoring module being configured to monitor one or more operating conditions of the light source at regular intervals and to determine a fault state for each monitored operating condition; and a control module, the control module being configured to send a first instruction to a first blower in the first gas discharge chamber and a second instruction to a second blower in the second gas discharge chamber, the first instruction and the second instruction being related to a speed of the first blower and a speed of the second blower, respectively, and the first instruction and the second instruction being based on the determined fault state. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a block diagram of an ultraviolet light source that generates a light beam for use in a lithographic exposure apparatus, the light source comprising: a light generating device having one or more gas discharge chambers, each gas discharge chamber including a blower; and a device configured at least in part to control the speed of the blower;

[0018] Figure 2 yes Figure 1 A block diagram of an implementation of a device, Figure 1 The device includes a monitoring module, a decrementing module and an incrementing module, and an optional baseline module;

[0019] Figure 3 The invention shows how to determine the overall fault state of a light source based on one or more operating conditions of the light source for providing Figure 1 and Figure 2 Schematic diagram of the use of the device;

[0020] FIG. 4A to FIG. 4Cis an exemplary graph showing how the baseline velocity varies with respect to the life of the discharge chamber for different discharge chambers;

[0021] Figure 5 is a diagram of a state machine representing an implementation of the device, the state machine comprising a monitoring state (performed by a monitoring module), a decrementing state (performed by a decrementing module), and an incrementing state (performed by an incrementing module);

[0022] Fig. 6A is a flow chart of a program executed by the decrement module while the state machine is in the decrement state;

[0023] Figure 6B is a flow chart of a program executed by the monitoring module while the state machine is in the monitoring state;

[0024] Figure 6C is a flow chart of a program executed by the baseline module while the state machine is in the baseline state;

[0025] Fig.6D is a flow chart of a program executed by the increment module while the state machine is in the increment state;

[0026] Fig. 7A is used to control Figure 1 and Figure 2 A flowchart of a procedure executed by a device for controlling the speed of a blower of a light source;

[0027] Figure 7B can be included in Fig. 7A additional steps in the procedure;

[0028] Figure 8 is a block diagram of an implementation of a light source in which the light generating means comprises two gas discharge chambers in a master oscillator-power amplifier arrangement;

[0029] Fig. 9A is a block diagram of an implementation of a light source and an implementation of a lithography exposure apparatus, in which the light source, the light generating device includes a plurality of gas discharge chambers;

[0030] Fig. 9B yes Fig. 9A A block diagram of an implementation method of a projection optical system of a lithography exposure device;

[0031] Fig.10 A light source comprising a plurality of gas discharge chambers is implemented and Figure 1 A block diagram of an implementation of an apparatus for controlling the speed of each blower in each gas discharge chamber based on a fault state and a fault type;

[0032] Fig.11is an exemplary table showing fault type and fault priority for each performance metric being monitored;

[0033] Fig.12 Is Fig.10 A flowchart of a program executed by a device for controlling a plurality of blowers, each blower being arranged at Fig.10 In a gas discharge chamber of a light source;

[0034] Fig.13 Is Fig.10 Device combination Fig.12 A flowchart of the active program executed by the program;

[0035] Fig.14 Is Fig.10 Device combination Fig.12 A flowchart of the risk procedures to be performed by the program; and

[0036] Fig.15 is a graph showing the relationship between blower speed and Fig.10 A diagram showing the use of light sources and Fig.10 The status of the device and Fig.10 A diagram of the light sources used.

[0037] Implementation method

[0038] refer to Figure 1 , the ultraviolet light source 100 includes a light generating device 105 and a device 110, wherein the light generating device 105 includes one or more gas discharge chambers 104. Figure 1 In the example of FIG. 1 , the light generating device 105 includes one discharge chamber 104, but it may include a plurality of discharge chambers 104 (such as Figure 8 and Fig. 9A104i). The gas discharge chamber 104 is configured to hold a gas mixture 107 including a gain medium within an internal cavity 104i of the gas discharge chamber 104, accommodating an energy source 106, which is configured to supply energy to the gas mixture 107, thereby generating the light beam 102. The gain medium of the gas mixture 107 is configured to emit deep ultraviolet (DUV) light in response to a voltage signal being applied to the energy source 106. The energy source 106 can be configured to supply energy to the gas mixture 107 in short (e.g., nanosecond) current pulses using high voltage discharges interspersed with energy-free periods. When energy from the energy source 106 is provided to the gas mixture 107, the gas mixture 107 generates pulses of the light beam 102 from population inversion occurring in the gain medium of the gas mixture 107 by stimulated emission. Therefore, the light beam 102 is a pulsed light beam that includes light pulses centered at a wavelength in the DUV range, for example, a wavelength of 248 nanometers (nm) or 193 nm. For a DUV light source, the gas gain medium of the gas mixture 107 may include, for example, argon fluoride (ArF), krypton fluoride (KrF), or xenon chloride (XeCl). The light beam 102 is directed along a path toward the lithography exposure apparatus 101. The light beam 102 is used to pattern microelectronic features on a substrate or wafer received in the lithography exposure apparatus 101. The size of the microelectronic features patterned on the wafer is related to the wavelength of the pulsed light beam 102, wherein a lower wavelength results in a smaller minimum feature size or critical dimension. For example, when the wavelength of the pulsed light beam 102 is 248 nm or 193 nm, the minimum size of the microelectronic features may be, for example, 50 nm or less.

[0039] Specifically, the energy source 106 may include a cathode and an anode, and the potential difference between the cathode and the anode forms an electric field in the gas mixture 107. The electric field provides energy to the gain medium within the gas mixture 107, and such energy is sufficient to cause a population inversion and enable the generation of light pulses via stimulated emission. Repeated creation of such a potential difference forms a sequence of light pulses, which ultimately constitute the light beam 102. A "discharge event" is the application of a voltage, which forms a potential difference sufficient to cause a discharge in the gain medium of the gas mixture 107 and the emission of a light pulse.

[0040] When light pulses are generated from a gas mixture 107 close to the energy source 106, there is a period of time during which the molecules within the gas mixture 107 are recycled. This recycling time is longer than the time between pulses of the energy source 106. In addition, if another energy pulse is supplied to the recycled gas mixture 107, which is still closest to the energy source 106, the output quality of the resulting light pulses of the light beam 102 will be reduced and may cause failure of the light generating device 105. To address this problem, the gas discharge chamber 104 maintains a blower 108, which is fixed to the walls 103A, 103B of the gas discharge chamber 103. In various implementations, the blower 108 may include a rotating structure such as a fan. See, for example, U.S. Patent No. 6,765,946, issued on July 20, 2004 and named after Partlo et al., which is incorporated herein by reference in its entirety. The blower 108 is configured to periodically displace a portion of the recycled gas mixture 107 from the energy source 106 within the gas discharge chamber 104 to allow fresh gas mixture 107 to interact with the energy source 106 before the next pulse of the energy source 106 is generated. If the speed of the blower 108 is too slow, arcing, shedding, and inefficiencies may occur in the gas discharge chamber 104, and the gas discharge chamber 104 may malfunction when the blower 108 is unable to adequately clear the portion of the recycled gas mixture 107. Another consideration is that the rotation or movement of the blower 108 may cause vibrations within the gas discharge chamber 104, which may affect one or more spectral properties of the beam 102 and the dose performance of the beam 102 at the lithographic exposure apparatus 101.

[0041] During operation of the light source 100, the operating speed of the blower 108 (i.e., the speed or rate at which the blower 108 rotates around the rotation axis of the blower 108) can be maintained constant at a preconfigured speed. Specifically, the operating speed of the blower 108 can be maintained at a maximum blower speed so that the operating speed 108 of the blower does not change over time and does not change with the operation of the light source 100. Under such conditions, the blower 108 can consume a substantially constant amount of energy over time, or in other words, require constant power as the light source 100 operates, which may be at least expensive and cost inefficient. Therefore, as discussed herein, the operating speed of the blower 108 is changed or adjusted over time (as the light source 100 operates) by the device 110 based on the fault state of one or more operating conditions of the light source 100 and the baseline speed of the blower 108 (which is the minimum allowed speed of the blower 108). The operating speed of the blower 108 is changed or adjusted by adjusting the operating speed set point of the blower 108. In this way, the device 110 acts as a blower controller that controls the operating speed of the blower 108 by adjusting the operating speed between a minimum blower speed and a maximum blower speed, the minimum blower speed and the maximum blower speed together defining a safe blower speed range for the blower 108 during operation of the light source 100. In other words, as the light source 100 operates, the device 110 adjusts the operating speed of the blower 108 within the safe blower speed range, within which no failure and / or problem occurs in the light source 100, and the device 100 also adjusts the operating speed of the blower 108 so that the blower 108 saves more energy, and therefore, the light source 100 consumes less energy. Detailed information on the device 110 is provided next. The device 110 performs analysis and sends instructions related to the operating speed of the blower 108 at regular usage intervals of the operation of the light source 100. The usage interval can be based on the number of pulses of the light beam 102 generated by the light generating device 105. Thus, for example, the device 110 may perform analysis and send instructions per 5 million pulses of the light beam 102. At some time, depending on the current performance status of the light source 100, the usage interval may be increased to, for example, 10 million pulses of the light beam 102.

[0042] refer to Figure 2 The device 110 (or the blower controller) includes a monitoring module 112 and a control module 115 , and the control module 115 also includes a decrementing module 114 and an incrementing module 116 .

[0043] Typically, the monitoring module 112 is configured to monitor a fault condition associated with one or more operating conditions of the light source 100. For example, each of the one or more operating conditions can be defined by a performance metric associated with the light source 100 or the light beam 102 generated by the light source 100. If at least one of the associated performance metrics is not within a threshold range for the performance metric, the fault condition can be considered marked, and if all of the associated performance metrics are within their respective threshold ranges, the fault condition can be considered cleared. Therefore, as the light source 100 operates, the monitoring module 112 can monitor one or more operating conditions of the light source 100 by monitoring one or more associated performance metrics.

[0044] Typically, the decrement module 114 is configured to reduce the operating speed of the blower 108 if the fault condition associated with one or more operating conditions of the light source 100 is cleared and if the reduced operating speed would be at or above the baseline speed of the blower 108, which is the minimum allowable speed of the blower 108. For example, the decrement module 114 can be configured to reduce the operating speed of the blower 108 by the decrement speed step size.

[0045] Typically, the incrementing module 116 is configured to increase the operating speed of the blower 108 if a fault state of one or more operating conditions of the light source 100 is marked. The incrementing module 116 can be configured to increase the operating speed of the blower 108 by an incremental speed step. In one example, the incremental step can be, for example, less than or equal to 25 revolutions per minute (rpm). In this example, the incremental speed step is greater than the decremental speed step, and the decremental speed step is approximately one-half, one-third, one-quarter, or one-fifth of the incremental speed step. In some implementations, the incremental step can be less than or equal to 40 rpm.

[0046] The apparatus 110 may also include a baseline module 118 configured to increase the operating speed of the blower 108 if the operating speed of the blower 108 is below a baseline speed.

[0047] As the light source 100 operates, the operating speed of the blower 108 is adjusted within a blower speed range defined by a minimum blower speed and a maximum blower speed by the increment module 114 and the decrement module 116 as well as the baseline module 118. The blower speed range is a safe range within which the light source 100 has no problems and / or failures and operates correctly. In this way, the device 110 controls the operating speed of the blower 108 by adjusting the operating speed within the safe blower speed range so that the blower 108 consumes minimal energy and the energy consumed by the light source 100 is reduced.

[0048] The modules 112, 114, 116, 118 of the device 110 may be implemented in a control system that communicates with the blower 108 to control the blower 108. Thus, the control system of the blower controller 108 is configured to monitor the fault state of one or more operating conditions of the light source 100, reduce the operating speed of the blower 108 in a decreasing state if the fault state associated with the one or more operating conditions of the light source 100 is cleared and if the reduced operating speed will be at or above the baseline speed, and increase the operating speed of the blower 108 in an increasing state if the fault state associated with the one or more operating conditions of the light source 100 is flagged. The control system of the blower controller 110 may also be configured to increase the operating speed of the blower 108 in an increasing state if the reduced operating speed of the blower 108 is below the baseline speed.

[0049] The device 110 may include, for example, a computer-readable memory module, and one or more electronic processors coupled to the computer-readable memory module. Each of the modules 112, 114, 116, 118 may communicate with the memory module and may be controlled by one or more electronic processors. For example, each module 112, 114, 116, 118 may include or access one or more programmable processors and may each execute a program of instructions to perform a desired function by operating on input data and generating appropriate outputs. Each module 112, 114, 116, 118 may be implemented in any of digital electronic circuitry, computer hardware, firmware, or software. In another implementation, each module 112, 114, 116, 118 accesses a memory within a memory module, which is also configured to store information output from one or more of the modules 112, 114, 116, 118, information from the discharge chamber 104, or information related to other aspects of the light generating device 105, such information can be used for various purposes of the modules 112, 114, 116, 118 during operation of the device 110. The memory within the memory module can be a read-only memory and / or a random access memory, and can provide a storage device suitable for tangibly embodying computer program instructions and data. The device 110 may also include one or more input devices (such as a keyboard, a touch device, an audio input device) and one or more output devices (such as an audio output or a video output).

[0050] In the example where the device 110 acts as a blower controller, the fault state associated with one or more operating conditions can be defined (by the control system) using binary representation. Specifically, if the fault state is cleared, the fault state can be assigned a value of zero (0), and if the fault state is marked, the fault state can be assigned a value of one (1). Detailed information about the fault state associated with one or more operating conditions of the light source 100 is provided below.

[0051] refer to Figure 3 , an overall fault state 327 of the light source 100 is determined by the device 110 at each iteration based on one or more operating conditions of the light source 100. Each of the one or more operating conditions is defined by a performance metric 320_1 to 320_N related to the light source 100 or the light beam 102 generated by the light source 100. The fault state 327 of the device 110 for controlling the blower 108 should be based on system parameters, metrics, and signals that are significantly affected by changes in the speed of the blower 108.

[0052] exist Figure 3 In the example, one or more performance metrics 320_1 to 320_N include a spectral characteristic accuracy associated with the light beam 102, an energy dose error associated with the light beam 102, an energy error associated with the light beam 102, an actuator operating point of the light generating device 105 within the light source 100, and a gas discharge chamber dropout rate.

[0053] The spectral characteristic accuracy represents the stability and accuracy of the spectral characteristic (such as wavelength) of the light beam 102 generated by the light source 100. Specifically, the spectral characteristic accuracy related to wavelength is based on the average value and standard deviation of the wavelength error of the light beam 102 calculated within a moving window of M pulses of the light beam 102, where M is an integer equal to or greater than 1. The value of the spectral characteristic accuracy can be directly measured / calculated, or it can be estimated based on other measurement data.

[0054] The energy dose error represents the difference between the expected dose or target dose at the wafer received in the lithography exposure apparatus 107 and the actual dose at the wafer. The dose at the wafer is the amount of optical energy delivered per unit area within the exposure time or a specific number of pulses of the light beam 102 at the wafer. Although the energy dose error can be directly measured / calculated, it can alternatively be estimated based on other measurement data.

[0055] The energy error represents the standard deviation of the measured energy of the beam 102. Specifically, the energy error can be considered as the difference between the amount of energy in a pulse of the beam 102 and a target energy. Although the energy error can be measured directly, it can alternatively be estimated from other data.

[0056] The actuator operating point of the light generating device 105 characterizes the position at which the actuator within the light generating device 105 is operating within a range of possible settings, values, or conditions. In some implementations, as described below with respect to Figure 8 As discussed, the actuator may be a timing module connected to a first stage including a first discharge chamber 804A (the first stage constituting a master oscillator) and a second stage including a second discharge chamber 804B of a light generating device 805 (the second stage constituting a power amplifier). Such a timing module controls the relative timing between a first trigger signal of a first energy source 806A sent to the first discharge chamber 804A and a second trigger signal of a second energy source 806B sent to the second discharge chamber 804B. This relative timing may be referred to as differential timing. In these implementations, a measure of the actuator operating point for the light generating device 805 may quantify the shift of the actual relative timing from the peak efficiency differential timing (Tpeak), where Tpeak is the value of the relative timing when the light generating device 805 generates a light beam 802, and the light beam 802 has a maximum energy at a specific input energy applied to the light generating device 805 (via the energy sources 806A, 806B). This metric for the actuator operating point may be calculated or estimated based on the voltage or energy supplied to the energy sources 806A, 806B, the output energy of the light beam 802, and the differential timing.

[0057] The gas discharge chamber dropout rate quantifies a failure mechanism in which the blower 108 is unable to adequately clear portions of the recycled gas mixture 107 , and therefore the gas mixture is not moved through the gas discharge chamber 104 quickly enough, resulting in arcing and energy loss in the gas discharge chamber 104 .

[0058] In some implementations, as described above, one or more of the performance metrics 320_1 to 320_N related to the light source 100 may be unavailable at certain times during operation or within certain systems, and the device 110 may estimate the value of the unavailable performance metric to determine the fault state 327 based on other available data. To calculate the overall fault state 327, the device 110 receives the performance metrics 320_1, 320_2, ..., 320_N.

[0059] Each of the one or more performance metrics 320_1 to 320_N is associated with a corresponding value 321_1 to 321_N, which is passed through a corresponding filter 322_1 to 322_N to eliminate the effects of noise or temporary performance problems that may occur during operation. For example, each of the filters 322_1 to 322_N can be a low-pass filter or a weighted sum filter, so that a fault state 327 related to one or more operating conditions 320_1 to 320_N of the light source 100 is determined using the filter 322_1 to 322_N (including a low-pass filter or a weighted sum filter). In addition, each of the filters 322_1 to 322_N can have a configurable transfer function to filter the values ​​321_1 to 321_N of the performance metrics 320_1 to 320_N.

[0060] The filtered values ​​323_1 to 323_N of the performance metrics 320_1 to 320_N are output from each of the corresponding filters 322_1 to 322_N. To determine the corresponding fault state 325_1 to 325_N associated with each of the performance metrics 320_1 to 320_N (and thus the operating condition), each of the filtered values ​​323_1 to 323_N is compared with the corresponding threshold range 324_1 to 324_N associated with the corresponding performance metric 320_1 to 320_N. If it is determined that the corresponding performance metric 320_1 to 320_N is not within the threshold range 324_1 to 324_N of the performance metric 320_1 to 320_N, the fault state 325_1 to 325_N of the performance metric 320_1 to 320_N is marked. If the corresponding performance metric 320_1 to 320_N is determined to be within the threshold range 324_1 to 324_N of the performance metric 320_1 to 320_N, the fault state 325_1 to 325_N of the performance metric 320_1 to 320_N is cleared. As described above, if the fault state 325_1 to 325_N is cleared, the fault state 325_1 to 325_N can be assigned a value of zero (0), and if the fault state 325_1 to 325_N is marked, the fault state 325_1 to 325_N can be assigned a value of one (1).

[0061] Each fault state 325_1 to 325_N is input into a fault state module 326 (which may be a controller), which determines an overall fault state 327 of the light source 100 based on the fault states 325_1 to 325_N of the performance metrics 320_1 to 320_N related to the light source 100. For example, in some implementations, if any one of the fault states 325_1 to 325_N is marked (or has a value of 1), then the overall fault state 327 of the light source 100 is marked (or has a value of 1). Also, if all of the fault states 325_1 to 325_N are cleared (or have a value of 0), then the overall fault state 327 of the light source 100 is cleared (or has a value of 0). In this way, the overall fault state 327 of the light source 100 can be determined, and the device 110 can control the blower 108 based on the fault state 327 of the light source 100, thereby reducing the energy consumption of the blower 108 during operation. In other implementations, the fault status module 326 may be configured to flag the overall fault status 325 only when multiple fault statuses 325_1 to 325_N are flagged.

[0062] Details of the baseline speed of the blower 108 are provided below.

[0063] refer to FIG. 4A to FIG. 4C , the baseline speed of the blower 108 can be related to the life of the gas discharge chamber 104. FIG. 4A to FIG. 4C In the examples of , the baseline speed changes as the gas discharge chamber 104 ages over time. In other words, the baseline speed changes as the number of pulses of the light beam 102 generated by the gas discharge chamber 104 increases over time (and as the gas discharge chamber 104 ages). In these examples, the device 110 adjusts the baseline speed of the blower 108 between a minimum baseline speed bmin and a maximum baseline speed bmax. Any of the modules 114, 116, 118 or another module of the device 110 can perform the adjustment. Typically, as the gas discharge chamber 104 ages and performance faults, problems, and / or errors occur more frequently in the aged light source 100 (and in the gas discharge chamber 104), it is desirable to increase the baseline speed of the blower 108. By increasing the baseline speed of the gas discharge chamber 104 as the discharge chamber 104 ages, performance faults, problems, and / or errors that may occur in the aged light source 100 are reduced or mitigated.

[0064] exist Figure 4AIn the example of , the device 110 adjusts the baseline speed from the maximum baseline speed bmax to the minimum baseline speed bmin at time t1a. Then, at time t1a, the device 110 begins to gradually increase the baseline speed. As the gas discharge chamber 104 ages over time (or as pulses of the light beam 102 are generated by the gas discharge chamber 104), the baseline speed of the blower 108 increases at a constant rate 429a (or slope). The baseline speed of the blower 108 increases or increments from the minimum baseline speed bmin to the maximum baseline speed bmax, such that the baseline speed reaches the maximum baseline speed bmax at time t2a at the end of the useful life of the gas discharge chamber 104.

[0065] exist Figure 4B In the example of FIG. 1 , the device 110 adjusts the baseline speed from the maximum baseline speed bmax to the minimum baseline speed bmin at time t1b. Although the gas discharge chamber 104 remains young in life for the amount of time dL between time t1b and t2b, the baseline speed of the blower 108 does not change and remains constant at the minimum baseline speed bmin. Because the gas discharge chamber 104 is young in life between time t1b and t2b, in this example, there is no need to increase the baseline speed to reduce or mitigate performance issues within the light source 100.

[0066] At time t2b, the device 110 begins to increase or increment the baseline speed. As the gas discharge chamber 104 ages and degrades over time (and as pulses of the light beam 102 are generated by the gas discharge chamber 104), the baseline speed of the blower 108 increases at a constant rate 429b (or slope). The baseline speed of the blower 108 increases or increments from a minimum baseline speed bmin to a maximum baseline speed bmax, such that the baseline speed reaches the maximum baseline speed bmax at time t3b at the end of the useful life of the gas discharge chamber 104.

[0067] Figure 4C An example similar to Figure 4B , except that the baseline speed of the blower 108 remains constant for a shorter amount of time dS and the baseline speed increases at a rate 429c that is slower than the rate 429b. After the baseline speed is decreased to a minimum baseline speed bmin at time t1c and maintained at the minimum baseline speed bmin for time dS, as the gas discharge chamber 104 ages and degrades over time, at time t2c, the baseline speed increases at a constant rate 429c until the baseline speed of the blower 108 reaches a maximum baseline speed bmax at time t3c at the end of the useful life of the gas discharge chamber 104.

[0068] refer to Figure 5 , device 110( Figure 2) is represented as a state machine 510 for light source 100. In this representation of state machine 510, monitoring module 112 is represented by monitoring state 512, decrementing module 114 is represented by decrementing state 514, and incrementing module 116 is represented by incrementing state 516. State machine 510 may also include baseline state 518, which represents baseline module 118 ( Figure 2 ). Additionally, in this implementation, the state machine 510 includes a passive state 511 in which there are no commands or instructions from the state machine 510 to change or adjust the operating speed of the blower 108.

[0069] If the number of pulses of the light beam 102 generated from the gas discharge chamber 104 is above a threshold, or after the state machine 510 has been in the passive state 511 for a threshold period of time, the state machine 510 transitions from the passive state 511 to the decrementing state 514T(PD). Typically, the decrementing state 514 is configured to reduce the operating speed of the blower 108 if the fault state 327 associated with one or more operating conditions of the light source 100 is cleared and if the reduced operating speed will be at or above the baseline speed.

[0070] Specifically, and with reference to Fig. 6A , in the decrement state 514, the decrement module 114 determines whether the fault state 327 of the light source 100 is cleared (e.g., at 0) (532). If the fault state 327 is not cleared (and is therefore marked or has a value of 1) (532), the decrement module 114 exits the decrement state 514 and the state machine 510 transitions from the decrement state 514 to the increment state 516T (DI), so that the operating speed of the blower 108 is incremented to a safe operating speed, at which no problems and / or faults will occur in the light source 100.

[0071] If the fault state is cleared (or has a value of 0) (532), the decrement module 114 determines whether the operating speed of the blower 108 is greater than the baseline speed (533). If the operating speed of the blower 108 is not greater than the baseline speed (which means that it is equal to or less than or below the baseline speed of the blower 108), the decrement module 114 exits the decrement state 514 and the state machine 510 transitions from the decrement state 514 to the baseline state 518T (DB), so that the operating speed of the blower 108 is incremented to a safe operating speed that is above the baseline speed and at which problems and / or faults will not occur in the light source 100.

[0072] If the operating speed of the blower 108 is greater than the baseline speed (533), the decrement module 114 determines whether the proposed new blower speed will be greater than the baseline speed (534). The proposed new blower speed is the operating speed 108 of the blower minus the decrement speed step size. If the proposed new speed of the blower 108 is not greater than the baseline speed (i.e., the proposed new blower speed will be at or less than the baseline speed) (534), the decrement module 114 exits the decrement state 514 and the state machine 510 transitions from the decrement state 514 to the monitoring state 512T (DM) so that one or more operating conditions of the light source 100 and the operating speed of the blower 108 can be monitored.

[0073] On the other hand, if the proposed new blower speed will be greater than the baseline speed (534), the decrement module 114 determines whether the number of pulses of the light beam 102 generated by the gas discharge chamber 104 since the last time the blower speed was changed is greater than a threshold number of pulses (541). The threshold number of pulses can be preset to a positive integer to reduce the frequency of blower speed changes. For example, the frequency of blower speed changes can be set to ensure that the light generating device 105 and the performance metric have sufficient time to adjust to the effects of the blower speed change. In addition, it is possible to operate in the decrement state 514 without performing this step 541.

[0074] If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is not greater than the threshold number of pulses (thus, it is equal to or less than the threshold number of pulses) (541), the decrement module 114 returns to step 532 and repeats steps 532, 533, 534. If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is greater than the threshold number of pulses (541), the decrement module 114 instructs the blower 108 to reduce or decrement its operating speed (542). For example, the decrement state 514 can decrement the operating speed of the blower 108 by the decrement speed step size.

[0075] After decreasing the operating speed of the blower 108 in the decrement state 514 (542), the decrement module 114 returns to query whether the fault state 327 associated with one or more operating conditions of the light source 100 is clear (eg, has a value of 0) (532).

[0076] Thus, in summary, if there are no faults (532), if the speed of the blower 108 is greater than the baseline speed (533), if the proposed new blower speed will be greater than the baseline speed (534), and if a certain number of pulses of the light beam 102 have been produced (541) since the last change in the blower speed, the decrement module 114 decreases (524) the speed of the blower 108. In this way, the energy consumed by the blower 108 is significantly reduced, particularly during the beginning of the useful life of the light source 100 and the gas discharge chamber 104.

[0077] Also refer to Figure 5 And as mentioned above Fig. 6A As discussed, if the proposed new speed of the blower 108 will not be greater than the baseline speed (i.e., the new blower speed will be at or less than the baseline speed) (534), the decrement module 114 exits the decrement state 514 and the state machine 510 transitions from the decrement state 514 to the monitoring state 512T (DM) so that one or more operating conditions of the speed light source 100 and the operating speed of the blower 108 can be monitored.

[0078] Generally, in the monitoring state 512, the monitoring module 112 is configured to monitor the exit criteria and remain in the monitoring state 512 while there are no faults, the blower speed is greater than the baseline speed, and no exit criteria events have occurred. Figure 6B In the monitoring state 512, the monitoring module 112 determines whether the fault state 327 related to one or more operating conditions of the light source 100 is cleared (e.g., has a value of 0) (537). If the fault state 327 is not cleared (and therefore marked) (537), the state machine 510 transitions from the monitoring state 512 to the increment state 516T (MI), so that the operating speed of the blower 108 is increased to a safe operating speed at which problems and / or failures will not occur in the light source 100.

[0079] If the fault condition is cleared (or has a value of 0) (537), the monitoring module 112 determines whether the operating speed of the blower 108 is greater than the baseline speed (538). If the operating speed of the blower 108 is less than or below the baseline speed (538), the state machine 510 transitions from the monitoring state 512 to the baseline state 518T(MB), so that the operating speed of the blower 108 is increased to a safe operating speed at which problems and / or failures will not occur within the light source 100. If the operating speed of the blower 108 is greater than the baseline speed (538), the monitoring module 112 determines whether one or more exit criteria are met (536). For example, the exit criteria can be based on one or more of the baseline speed, the number of pulses of the light beam 102 generated by the light source 100, and an event that results in an improvement in the performance of the light source 100. If the exit criteria are met, the state machine 510 transitions from the monitoring state 512 to the decrement state 514 (because the light source 100 is determined to be in a safe condition to reduce the operating speed of the blower 108)T(MD). If the exit criteria are not met, the monitoring module 112 returns to determine whether the fault state 327 related to one or more operating conditions of the light source 100 is cleared (e.g., has a value of 0) (537). One possible exit criterion that can be evaluated at step 536 is to determine whether the speed of the blower 108 is greater than the baseline speed plus a lower threshold (such as, 200rpm). In this case, it seems more appropriate to reduce the blower speed (via the decrement state 514). Another possible exit criterion that can be evaluated at step 536 is to determine whether the number of pulses generated by the current of the light beam 102 is greater than a predetermined threshold, such as 100 million pulses. Alternatively, instead of evaluating the exit criteria set at step 536 based on the number of pulses generated by the light beam 102, the monitoring module 112 can evaluate whether certain performance improvement events have occurred. For example, a performance improvement event can be a gas refill or injection in which the gas mixture 107 is at least partially or completely replaced. Such an event can result in improved performance of the light source 100.

[0080] Reference again Figure 5 And as mentioned above Fig. 6A As discussed, if the operating speed of the blower 108 is equal to or less than the baseline speed (533), the decrement module 114 exits the decrement state 514, and the state machine 510 transitions from the decrement state 514 to the baseline state 518T(DB), so that the operating speed of the blower 108 is incremented to a safe operating speed that is higher than the baseline speed and does not cause problems and / or failures in the light source 100. Figure 6C100 . The state machine 510 may be configured to increase the operating speed of the blower 108 by 516T (BI) from the baseline state 518. In general, if the operating speed of the blower 108 is at or below the baseline speed, the baseline state 518 is configured to increase the operating speed of the blower 108. The baseline module 118 determines whether the fault state 327 of the light source 100 is cleared (e.g., equal to 0) (539). If the fault state 327 is not cleared (and is therefore marked or has a value of 1) (539), the state machine 510 transitions from the baseline state 518 to the increment state 516T (BI) so that the operating speed of the blower 108 is incremented to a safe operating speed at which problems and / or failures will not occur within the light source 100.

[0081] If the fault condition is cleared (or has a value of 0) (539), the baseline module 118 determines whether the operating speed of the blower 108 is less than the baseline speed (540). If the operating speed of the blower 108 is not less than the baseline speed (540), the state machine 510 transitions from the baseline state 518 to the monitoring state 512 (because no operating speed increase is required) T(BM). On the other hand, if the operating speed of the blower 108 is less than the baseline speed (540), the baseline module 118 determines whether the number of pulses of the light beam 102 generated by the gas discharge chamber 104 since the last change in the blower speed is greater than a threshold number of pulses (548). As described above, the threshold number of pulses can be preset to a positive integer to reduce the frequency of changes in the blower speed. If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is not greater than the threshold number of pulses (548), the baseline module 118 continues to query whether the number of pulses of the light beam 102 generated by the gas discharge chamber 104 since the last change in the blower speed is greater than the threshold number of pulses (548).

[0082] If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is greater than the threshold number of pulses (548), the baseline module 118 increases or increments the operating speed of the blower 108 (549). For example, the baseline module 118 may increment the operating speed of the blower 108 by an incremental speed step size. For example, the incremental speed step size may be approximately 5 revolutions per minute (rpm). After increasing the operating speed of the blower 108, the baseline module 118 again returns to step 439 to determine whether the fault state 327 of the light source 100 is cleared (e.g., equal to 0).

[0083] Reference again Figure 5 And as mentioned above FIG. 6A to FIG. 6CAs discussed, the state machine 510 may transition to the increment state 516 from any of the decrement state 514, the monitoring state 512, and the baseline state 518. For example, in the decrement state 514, if the fault state 327 is not cleared (and therefore marked or has a value of 1) (532), the decrement module 114 exits the decrement state 514 and the state machine 510 transitions from the decrement state 514 to the increment state 516T(DI). Generally, in the increment state 516, the operating speed of the blower 108 is increased to a safe operating speed that will not cause problems and / or failures within the light source 100. Next, reference will be made to Fig.6D The increment state 516 is discussed with reference to the implementation shown in FIG.

[0084] Specifically, in the increment state 516, the increment module 116 determines whether the fault state 327 of the light source 100 is cleared (e.g., 0) (544). If the fault state 327 is not cleared (e.g., if the fault state is 1) (544), the increment module 116 sets a new target speed for the blower 108 (545). The new target speed of the blower 108 can be equal to the operating speed of the blower 108 plus a large incremental speed step (such as, for example, 100rpm). The idea is to significantly increase the speed of the blower 108 when a fault occurs. After the new target speed for the blower 108 is set (545) or after the increment module 116 determines that the fault state is cleared (e.g., the fault state is 0) (544), the increment module 116 determines whether the operating speed of the blower 108 is less than the new target speed (535). If the operating speed of blower 108 is not less than the new target speed (535), meaning that the operating speed of blower 108 is greater than or equal to the new target speed (535), state machine 510 transitions from increment state 516 to monitor state 512T(IM).

[0085] If the operating speed of the blower 108 is less than the target speed (535), the incrementing module 116 determines whether the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is greater than a threshold number of pulses (546). If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is not greater than the threshold number of pulses, the incrementing module 116 continues to query whether the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is greater than the threshold number of pulses (546). If the number of pulses of the light beam 102 generated by the gas discharge chamber 104 is greater than the threshold number of pulses, the incrementing module 116 increases or increments the operating speed of the blower 108 by a regular amount (547). For example, the incrementing module 116 may increment the operating speed of the blower 108 by an incremental speed step such as 25 rpm. After increasing the operating speed of the blower 108 (547), the incrementing module 116 returns to step 535 to determine whether the increased operating speed of the blower 108 is less than the target speed (535).

[0086] More generally and in reference Fig. 7A When the device 110 executes the program 760 to control the blower 108. The program 760 can be relative to the light source 100 ( Figure 1 ) is performed, the light source 100 includes a device 110 ( Figure 2 ) and the blower 108 in the gas discharge chamber 104. The program 760 can also be relative to the state machine 510 ( Figure 5 ) is performed. In the following, the procedure 760 is described with respect to the light source 100 including the blower 108.

[0087] Procedure 760 includes monitoring one or more operating conditions of a light source for a fault condition (761). For example, as described above with reference to Figure 6B As discussed, the monitoring module 112 monitors the fault state 327 ( Figure 3 )(537).

[0088] Next, if the fault condition associated with one or more operating conditions of the light source 100 clears and if the reduced operating speed will be at or above the baseline speed, the device 110 decrements the operating speed of the blower 108 (763). Fig. 6A , if the fault state 327 related to one or more operating conditions of the light source 100 is cleared (532) and if the reduced operating speed of the blower 108 will be above the baseline speed (534), the decrement module 114 decrements the operating speed of the blower 108 (542). Decrementing the operating speed of the blower 108 may include decreasing the operating speed of the blower 108 by the decrement speed step size. Additionally, decrementing the operating speed of the blower 108 may include reducing an amount of vibration within the light source 100 caused by movement of the blower 108.

[0089] On the other hand and again referring to Fig. 7A If a fault condition associated with one or more operating conditions of the light source is flagged, the device 110 increments the operating speed of the blower 108 (765). Fig.6D , if the fault state 327 of the light source 100 is marked, the incrementing module 116 increments the operating speed of the blower 108 (547). Increasing the operating speed of the blower 108 may include increasing the operating speed of the blower 108 by the incremental speed step size. In this way, the incrementing module 116 prevents the blower 108 from operating at an operating speed that may cause problems and / or failures in the light source 100.

[0090] Also refer to Figure 7BIf the reduced operating speed of the blower is below the baseline speed, routine 760 may also include increasing the operating speed of the blower (767). Figure 6C If the baseline module 118 determines that the reduced operating speed of the blower 108 (which was reduced by the decrement module 114) is below the baseline speed (540), the baseline module 118 increases or increments the operating speed of the blower 108 (549). Thus, similar to the increment module 116, the baseline module 118 prevents the blower 108 from operating at an operating speed that could cause problems and / or failures within the light source 100.

[0091] In one example, decreasing and increasing the operating speed of the blower 108 may include adjusting the operating speed of the blower 108 within a blower speed range defined by a minimum blower speed and a maximum blower speed. In other words, the operating speed of the blower 108 is adjusted between the minimum blower speed and the maximum blower speed by the increasing module 114 and the decreasing module 116 (as well as the baseline module 118). As described above, the blower speed range is a safe range in which the light source 100 has no problems and / or failures and operates correctly. Therefore, the device 110 can control the operating speed of the blower 108 by adjusting the operating speed within the safe blower speed range, so that the blower 108 consumes minimal energy and the energy consumed by the light source 100 is reduced.

[0092] In some implementations, the procedure 760 further includes determining an incremental speed step size and a decremental speed step size for the blower 108, each speed step size being dependent on a fault state 327 associated with one or more operating conditions of the light source 100. Specifically, one or more studies of the light source 100 may be performed, for example, by a user, to determine a maximum incremental speed step size and a maximum decremental speed step size that both maintains stability of the light source 100 and does not adversely affect the performance of the light source 100 (and keeps the fault state 327 of the light source 100 clear). In addition, the procedure 760 may further include determining a blower speed range for the blower 108, the blower speed range being dependent on the fault state 327 of one or more operating conditions of the light source 100. Similarly, one or more studies of the light source 100 may be performed, for example, by a user, to determine a minimum blower speed and a maximum blower speed (and thus a blower speed range) such that when the blower 108 is operated within the blower speed range, the performance of the light source 100 is not adversely affected (and keeps the fault state 327 of the light source 100 clear).

[0093] Return to reference Figure 3In some implementations, at least one of the operating conditions of the light source 100 (associated with the corresponding performance metrics 320_1 to 320_N) is active and at least one of the operating conditions is passive or risk responsive. Specifically, for the active operating condition, before the value 323_1 to 323_N of the associated performance metric 320_1 to 320_N is not within the threshold range 324_1 to 324_N of the performance metric 320_1 to 320_N, the operating speed of the blower 108 is adjusted (e.g., by the increment module 116 or the decrement module 114). For the passive operating condition, after the value 323_1 to 323_N of the associated performance metric 320_1 to 320_N is not within the threshold range 324_1 to 320_N of the performance metric 320_1 to 324_N, the operating speed of the blower 108 is adjusted (e.g., by the increment module 116 or the decrement module 114). Additionally, in some implementations, each active operating condition is associated with a limited threshold range that is tighter than the actual threshold range 324_1 to 324_N of the performance metrics 320_1 to 320_N, and the operating speed of the blower 108 is adjusted (e.g., by the increment module 116 or the decrement module 114) by determining a fault state 325_1 to 325_N of the active operating condition based on the limited threshold range until the value 323_1 to 323_N of the associated performance metric 320_1 to 320_N is not within the actual threshold range 324_1 to 324_N.

[0094] refer to Figure 8 , light source 100( Figure 1 ) includes a light generating device 805, the light generating device 805 includes two gas discharge chambers 804A, 804B, and the light generating device 805 generates a pulsed output beam 802, which is directed to a lithography exposure device 801. The pulsed output beam 802 has a wavelength in the ultraviolet range (for example, in the deep ultraviolet range) and is used by the lithography exposure device 801 to pattern a semiconductor substrate or wafer 870. Figure 8 In the example of FIG. 8 , the gas discharge chamber 804A is part of a master oscillator configured to generate a seed beam 802s, and the gas discharge chamber 804B is part of a power amplifier configured to generate an output beam 802 from the seed beam 802s. Each of the discharge chambers 804A, 804B includes a respective blower 808A, 808B, and each of the blowers 808A, 808B is configured to displace a respective gas mixture 807A, 807B including a gain medium from a respective energy source 806A, 806B within the respective gas discharge chamber 804A, 804B. Figure 8In the example of , the device 110 is configured as a device 810, which is configured to control the operating speed of two blowers 807A, 807B. Specifically, the device 810 controls the blowers 807A, 807B to consume the least amount of energy or power during the operation of the light source 800, while ensuring that problems and / or failures do not occur (or at least are reduced) in the light source 800. Other implementations of the light source 800 are also possible.

[0095] Each discharge chamber 804A, 804B is configured to hold a respective gas mixture 807A, 807B in a respective internal cavity 873A, 873B. The gas mixture 807A, 807B used in the respective discharge chamber 804A, 804B may be a combination of suitable gases for generating the respective light beams 802s, 802 around the desired wavelength, bandwidth, and energy. For example, the gas mixture 807A, 807B may include argon fluoride (ArF), which emits light at a wavelength of approximately 193 nm. Each discharge chamber 804A, 804B is defined by a respective chamber wall 803A_1, 803A_2, 803B_1, 803B_2, which is configured to hold a respective blower 808A, 808B, and in this implementation, a respective optical assembly 875A, 876A, 877A, 875B, 876B, 877B. Each discharge chamber 804A, 804B accommodates a respective energy source 806A, 806B, which is configured to supply energy to a gas mixture 807A, 807B in each internal cavity 873A, 873B. For example, each energy source 806A, 806B may include an electrode pair that forms a potential difference and excites a gain medium of the gas mixture 807A, 807B in operation.

[0096] Each discharge chamber 804A, 804B may include one or more optical components. For example, the discharge chamber 804A includes optical components 875A, 876A associated with the internal cavity 873A of the discharge chamber 804A. The optical components 875A, 876A may include windows that allow light beams to enter and exit the internal cavity 873A of the discharge chamber 804A. The optical component 875A may be a partially reflective / partially transmissive optical coupler that allows the seed beam 802s to leave the discharge chamber 804A. In addition, the light source 800 may also include other optical components outside the discharge chamber 804A, such as an optical component 877A corresponding to a spectral feature selection module that selects the wavelength and / or bandwidth of the seed beam 802s output from the discharge chamber 804A. For example, the spectral feature selection module 877A may include one or more of a beam expansion prism or a beam splitter. In this example, optical component 875A is held within chamber wall 803A_1 and optical component 876A is held within chamber wall 803A_2.

[0097] The discharge chamber 804B includes an optical assembly 875B associated with the interior cavity 873B of the discharge chamber 804B. The optical assemblies 875B, 876B may include windows that allow light beams (such as the seed beam 802s and the light beam 802) to enter and exit the interior cavity 873B of the discharge chamber 804B. In addition, the light source 800 may also include other optical assemblies outside the discharge chamber 804B, such as an optical assembly 877B corresponding to a beam reverser or redirector that is configured to direct the light beam 802 back through the discharge chamber 804B. Figure 8 In the example of FIG. 803B , optical component 875B is held within chamber wall 803B_1 and optical component 876B is held within chamber wall 803B_2 .

[0098] During the operation use of the light source 800, the device 810 controls the respective operating speeds of the two blowers 807A and 807B. In some implementations, the control of the operating speed of the blower 807A can be independent of the control of the operating speed of the blower 807B. In some implementations, each blower 808A and 808B is independently controlled by a dedicated device (810A and 810B). In addition, the device 810B is designed to be different from the device 810A to take into account the differences between the parameters of how the discharge chambers 804A and 804B affect the output beam. In addition, although in these implementations, the control of the blowers 808A and 808B is not coupled, their simultaneous control by the devices 810A and 810B may be different in performance from when only one blower is controlled, because each blower 808A and 808B drives the vibrations in the frame of the chambers 804A and 804B in different ways.

[0099] In other implementations, control of the operating speed of blower 807A and / or blower 807B may be dependent on a performance metric associated with light generating device 805, and thus control of the two blowers 807A, 807B may be coupled.

[0100] In some implementations, a single device 810 can be configured to control the blower 810A of the first discharge chamber 804A, but the device 810 is not used to control the blower 810B of the second discharge chamber 804B.

[0101] Specifically, in Figure 8 In the example of FIG. 8 , the device 810 includes a monitoring module (such as Figure 2 The monitoring module 112 of the device 110 in the embodiment is configured to monitor the fault state of one or more operating conditions of the light source 800. In addition, the device 810 includes a decrement module (such as Figure 2 The decrement module 114 of the device 110 in the embodiment of the present invention is configured to reduce the operating speed of the appropriate blower 808A, 808B if the fault state related to one or more operating conditions of the light source 800 is cleared and if the reduced operating speed of the corresponding blower 808A, 808B will be at or above the baseline speed. The device 810 also includes an incrementing module (such as Figure 2 The device 110 of the embodiment of the present invention is configured to increase the operating speed of the appropriate blower 808A, 808B if a fault condition is marked related to one or more operating conditions of the light source 800. In this way, the device 810 controls the blowers 808A, 808B to consume a minimum amount of energy or power during operation of the light source 800, so that problems and / or faults within the light source 800 are reduced or mitigated based on the fault condition of the light source 800 and the baseline speed of the blowers 808A, 808B.

[0102] refer to Fig. 9A , light source 100( Figure 1 ) includes an implementation 900 of a light generating device 905, the light generating device 905 including: a plurality of optical oscillators 909-1 to 909-N, a plurality of optical oscillators 904-1 to 904-N each including a corresponding gas discharge chamber 904-1 to 904-N, and generating a pulsed light beam 902 directed to a lithography exposure device 901; and a control system 950. The light source 900 is configured to generate an output light beam 902 in the ultraviolet range for use by, for example, the lithography exposure device 901 to pattern a semiconductor substrate or wafer 970. Specifically, the lithography exposure device 901 utilizes a shaped exposure beam 902' to expose the wafer 970, and the shaped exposure beam 902' is formed by passing the light beam 902 (which is an exposure beam in this example) through a projection optical system 995. Fig. 9A In the example shown, the light generating device 905 includes N optical oscillators 909-1 to 909-N, and therefore includes N gas discharge chambers 904-1 to 904-N, where N is an integer greater than 1. Each of the gas discharge chambers 904-1 to 904-N is configured to emit a corresponding light beam 978-1 to 978-N toward the beam combiner 993. In the example shown, the control system 950 is connected to the light generating device 905 and the lithography exposure device 901. Other implementations of the light source 900 are also possible.

[0103] Each of the gas discharge chambers 904-1 to 904-N includes a respective blower 908-1 to 908-N, each of the blowers 908-1 to 908-N being configured to displace a respective gas mixture 907-1 to 907-N including a gain medium from a respective energy source 906-1 to 906-N within the respective gas discharge chamber 904-1 to 904-N. Fig. 9A In the example of , device 910 (which is an implementation of device 110) is included as part of control system 950. Device 910 is configured as a blower controller to control the operating speed of blowers 908-1 to 908-N. Specifically, device 910 controls each blower 908-1 to 908-N to consume a minimum amount of energy or power during operation of light source 900 while ensuring that problems and / or failures do not occur (or at least are reduced) within light source 900.

[0104] Details of optical oscillator 909-1 are discussed below. The other N-1 optical oscillators in light generating device 905 include the same or similar features.

[0105] The optical oscillator 909-1 includes a gas discharge chamber 904-1, which contains an energy source 906-1, which may include, for example, a cathode and an anode, and a blower 908-1. The discharge chamber 904-1 also contains a gas mixture 907-1 including a gain medium. The resonator is formed between a spectral feature selection module 977-1 on one side of the discharge chamber 904-1 and an output coupler 980-1 on a second side of the discharge chamber 904-1. The spectral feature selection module 977-1 may include a diffractive optical element, such as, for example, a grating and / or a prism, which can fine-tune the spectral output of the discharge chamber 904-1. In some implementations, the spectral feature selection module 977-1 includes a plurality of diffractive optical elements. For example, the spectral feature selection module 977-1 may include four prisms, some of which are configured to control the central wavelength of the light beam 978-1, and other of which are configured to control the spectral bandwidth of the light beam 978-1.

[0106] In some implementations, the spectral signature selection module 977-1 may include or communicate with a spectral signature control system that is configured to control, for example, various components within the spectral signature selection module 977-1. In these implementations, the device 910 includes a decrement module (similar to the decrement module 114) and an increment module (similar to the increment module 116). The decrement module and the increment module of the device 910 together can be configured to avoid interfering with the operating speed of the blower at which the aliased frequency of the second harmonic of the blower 908-1 interferes with the spectral signature control system associated with the light source 900. For example, the interfering blower operating speed can depend on the repetition frequency of the light beam generated by the light source 900 (including the light beam 902 or the exposure beam 902' in this example).

[0107] The optical oscillator 909-1 also includes a line center analysis module 981-1 that receives the output beam from the output coupler 980-1. The line center analysis module 981-1 is a measurement system that can be used to measure or monitor the wavelength of the beam 978-1. The line center analysis module 981-1 can provide data to the control system 950, and the control system 950 can determine metrics related to the beam 978-1 based on the data from the line center analysis module 981-1. For example, the control system 950 can determine a beam quality metric or a spectral bandwidth based on the data measured by the line center analysis module 981-1.

[0108] The light generating device 905 also includes a gas supply system 990, which is fluidically coupled to the interior of the discharge chamber 904-1 via a fluid conduit 998. The fluid conduit 998 is any conduit capable of conveying a gas or other fluid without or with minimal fluid loss. For example, the fluid conduit 998 can be a pipe made of a material that does not react with one or more fluids conveyed in the conduit 998 or a pipe coated with the material. The gas supply system 990 includes a chamber 991, which contains and / or is configured to receive a supply of one or more gases used in the gas mixture 907-1. The gas supply system 990 also includes equipment (such as a pump, a valve, and / or a fluid switch) that enables the gas supply system 990 to remove gas from the discharge chamber 904-1 or inject gas into the discharge chamber 904-1. The gas supply system 990 is coupled to the control system 950. The gas supply system 990 can be controlled by the control system 950 to perform, for example, a refilling procedure.

[0109] The other N-1 optical oscillators are similar to optical oscillator 904-1 and have similar or identical components and subsystems. For example, each optical oscillator in optical oscillators 909-1 to 909-N includes an energy source similar to energy source 906-1, a spectrum feature selection module similar to spectrum feature selection module 977-1, and an output coupler similar to output coupler 980-1. Optical oscillators 909-1 to 909-N can be tuned or configured so that all of the beams in beams 978-1 to 978-N have the same properties or optical oscillators 909-1 to 909-N can be tuned or configured so that at least some of the optical oscillators have at least some properties different from other optical oscillators. For example, all of the beams in beams 978-1 to 978-N can have the same central wavelength, or the central wavelength of each beam 978-1 to 978-N can be different. The central wavelength generated by a specific optical oscillator in optical oscillators 909-1 to 909-N can be set using a corresponding spectrum feature selection module.

[0110] The light generating device 905 further includes a beam control device 992 and a beam combiner 993. The beam control device 992 is between the gas mixture of the optical oscillators 909-1 to 909-N and the beam combiner 993. The beam control device 992 determines which of the beams 978-1 to 978-N are incident on the beam combiner 993. The beam combiner 993 forms the exposure beam 902 according to one or more beams incident on the beam combiner 993. In the example shown, the beam control device 992 is represented as a single element. However, the beam control device 992 can be implemented as a collection of separate beam control devices. For example, the beam control device 992 can include a collection of shields, one of which is associated with each optical oscillator 909-1 to 909-N.

[0111] The light generating device 905 may include other components and systems. For example, the light generating device 905 may include a beam preparation system 994, which includes a bandwidth analysis module that measures various properties of the light beam (such as bandwidth or wavelength). The beam preparation system 994 may also include a pulse stretcher (not shown) that temporally stretches each pulse that interacts with the pulse stretcher. The beam preparation system 994 may also include other components capable of acting on light, such as, for example, reflective and / or refractive optical elements (such as, for example, lenses and mirrors), and / or filters. In the example shown, the beam preparation system 994 is positioned in the path of the exposure beam 902. However, the beam preparation system 994 can be placed at other locations within the light source 900. In addition, other implementations are possible. For example, the light generating device 905 may include N instances of the beam preparation system 994, each instance being placed to interact with one of the beams 978-1 to 978-N. In another example, the light generating device 905 may include an optical element (such as a mirror) that redirects the light beams 978 - 1 to 978 -N to the beam combiner 993 .

[0112] The photolithography exposure apparatus 901 may be a liquid immersion system or a dry system. The photolithography exposure apparatus 901 includes: a projection optical system 995 through which the exposure beam 902 passes before reaching the wafer 970; and a sensor system or a measurement system 997. The wafer 970 is held or received on a wafer holder 996. Fig. 9B , the projection optical system 995 includes a slit 995a, a mask 995b and a projection objective lens, and the projection objective lens includes a lens system 995c. The lens system 995c includes one or more optical elements. The exposure beam 902 enters the photolithography exposure device 901 and impinges on the slit 995a, and at least some of the beam 902 passes through the slit 995a to form a shaped exposure beam 902'. Fig. 9A and Fig. 9B In the example of , slit 995a is rectangular and shapes exposure beam 902 into an elongated rectangular shaped beam, which is shaped exposure beam 902'. Mask 995b includes a pattern that determines which portions of the shaped beam are transmitted by mask 995b and which portions are blocked by mask 995b. Microelectronic features are formed on wafer 970 by exposing a layer of radiation-sensitive photoresist material on wafer 970 with exposure beam 902'. The design of the pattern on the mask is determined by the specific microelectronic circuit characteristics desired.

[0113] As mentioned above Figure 8 and Fig. 9AAs described above, the device 810 / 910 is configured to operate using the corresponding light generating device 805 / 905 of the corresponding light source 800 / 900. Fig.10 , an implementation 1010 of the device 810 or 910 is illustrated using a light generating device 1005 of a light source 1000, the light source 1000 generating a light beam 1002, the light beam 1002 being a pulsed light beam. The light source 1000 may correspond to the light source 800 including the light generating device 805 or the light source 900 including the light generating device 905. The light generating device 1005 includes a plurality of gas discharge chambers 1004i, where i is a set of integers from 1 to greater than 1. For example, the gas discharge chambers 1004i may correspond to the gas discharge chambers 804A and 804B of the light generating device 805, or the gas discharge chambers 1004i may correspond to the gas discharge chambers 904-1 to 904-N of the light generating device 905. Each gas discharge chamber 1004i includes or holds a blower 1008i.

[0114] The device 1010 includes a fault monitoring module 1012 and a control module 1015. The fault monitoring module 1012 is similar in some general respects to the monitoring module 112, and the control module 1015 is similar in some general respects to the control module 115. In addition, the fault monitoring module 1012 and the control module 1015 have some additional features that further improve how the device 1010 controls, adjusts, or changes the operating speed of the blower 1008i.

[0115] The fault monitoring module 1012 is configured to monitor one or more operating conditions 1030k of the light source 1000 at regular intervals of use of the light source 1005, where k is 1 (if one operating condition is monitored) or a set of integers from 1 to greater than 1. The fault monitoring module 1012 is configured to determine, for each monitored operating condition 1030k, a fault state 1025 and a fault type 1055, the fault type 1055 being related to which blower 1008i of one of the gas discharge chambers 1004i within the light source 1000 affects the monitored operating condition 1030k. The fault monitoring module 1012 may also be configured to determine, for each monitored operating condition 1030k, a fault priority 1056 associated with or related to the monitored operating condition 1030k. The fault priority 1056 indicates a level of importance or urgency associated with clearing the flagged fault state 1025 of the particular monitored operating condition 1030k. In clearing any flagged faults, some monitored operating conditions 1030k have a higher priority than other monitored operating conditions 1030k. The control module 1015 receives the determined fault state 1025 and the determined fault type 1055 from the fault monitoring module 1012. The control module 1015 is configured to select at least one of the gas discharge chambers 1004i. The control module 1015 is configured to send instructions 1031 to the blower 1008i in the selected gas discharge chamber 1004i. The instructions 1031 are based on the determined fault state 1025 and the determined fault type 1055.

[0116] As described above, each of the one or more operating conditions 1030k of the light source 1000 is defined by a performance metric 1020k (where k is again a set of integers from 1 to a number greater than 1) that is related to the light source 1005 or the light beam 1002 generated by the light source 1005. The performance metric 1020k may be affected by the speed of one or more blowers 1008i associated with the corresponding gas discharge chamber 1004i. For example and with reference to Figure 8, a performance metric 1020k related to the wavelength performance of the light beam 1002 is more likely to be affected by the speed of the blower 808A in the gas discharge chamber 804A. As another example, a performance metric 1020k related to the bandwidth performance of the light beam 1002 is more likely to be affected by the speed of the blower 808A in the gas discharge chamber 804A. As another example, a beam parameter (which is a parameter of the light beam 1002) is more likely to be affected by the speed of the blower 808B in the gas discharge chamber 804B. As another example, a parameter associated with the energy performance in the light beam 1002 may be affected by the speed of the two blowers 808A, 808B in the two gas discharge chambers 804A, 804B. Similar to the device 110, the device 1010 adjusts or changes the operating speed of one or more blowers 1008i based on one or more fault conditions 1025 of these one or more operating conditions 1030k. Additionally, the device 1010 adjusts or changes the operating speed of one or more blowers 1008i based on the fact that the failure of a particular operating condition 1030k is affected by a particular gas discharge chamber 1004i. The device 1010 is able to select which blowers 1008i to adjust or maintain by considering the failure type 1055 of each failure.

[0117] refer to Fig.11 As shown in Table 1180, Figure 8In the example of a light source 800 of FIG. 1 , where there are two gas discharge chambers 804A, 804B, there are three fault types 1155 associated with each fault state 1025 for each operating condition 1030i defined by a performance metric 1120k. In addition, as described below, each fault state 1025 may have an associated fault priority 1156 indicating the level of importance of clearing any associated flagged fault state 1025. In this example, the three fault types 1155 may be: master oscillator (or MO) for the first gas discharge chamber 804A, power amplifier (PA) for the second gas discharge chamber 804B, and common (Comm.) for faults affected by both gas discharge chambers 804A, 804B. An example of a performance metric 1120k that may be monitored by the device 1010 is also shown in table 1180. The listed performance metrics 1120k are: PADropout, MODropout, EnergySigmaMax, EnergyDoseMax, EnergyDoseMin, WLHistoMax, WLHistoMin, BWFault, H / VDivergence. For example, as described above, the dropout performance metric 1120k (PADropout or MODropout) corresponds to the dropout rate, which quantifies the failure mechanism in which the blower of the gas discharge chamber is unable to adequately clear a portion of the recycled gas mixture and therefore the gas mixture is not moved through the gas discharge chamber quickly enough, which results in arcing and energy loss in the gas discharge chamber. The EnergySigmaMax performance metric 1120k corresponds to the maximum standard deviation of the energy in the beam 1002. The EnergyDoseMax / Min performance metric 1120k corresponds to the maximum / minimum moving average of the error in the energy of the beam 1002. The WLHistoMax / Min performance metrics 1120k correspond to the wavelength ±3σ average (respectively) of the beam 1002. The BWFault performance metric 1120k corresponds to a bandwidth out-of-range for the light beam 1002. The H / VDivergence performance metric 1120k is a measure of the divergence of the light beam 1002.

[0118] from Fig.11As can be seen in the exemplary table 1180 of FIG. 1180 , the fault state 1025 marked as being associated with the PADropout performance metric 1120k has a fault type 1155PA. Therefore, assuming that there is only one fault state 1025 in the current usage interval, the device 1010 selects PA (gas discharge chamber 804B) and any instructions related to speed will be sent to the blower 808B of the gas discharge chamber 804B. On the other hand, the device 1010 will not change the speed of the blower 808A of the gas discharge chamber 804A (MO chamber) because the fault type 1155 associated with the PADropout performance metric 1120k is not an MO fault type. In contrast, the fault state 1025 marked as being associated with the MODropout performance metric 1120k has a fault type 1155MO. Thus, assuming that there is only one fault state 1025 in the current usage interval, the device 1010 selects MO (gas discharge chamber 804A) and any speed-related instructions 1031 will be sent by the control module 1015 to the blower 808A of the gas discharge chamber 804A (while the speed of the blower 808B remains unchanged). As another example, the fault state 1025 labeled as being associated with the EnergyDoseMax metric 1120k has a fault type 1155 Comm (for Common). This means that the fault associated with EnergyDoseMax is affected by both gas discharge chambers 804A and 804B.

[0119] In this manner, the device 1010 is able to manage the blower speeds of multiple gas discharge chambers by considering not only the fault state 1025 but also the fault type 1155 .

[0120] In addition, and again refer to Fig.10, the device 1010 may also consider a fault priority 1056 associated with the monitored operating state 1030k. Whenever a fault state 1025 is marked for a plurality of operating conditions 1030k in the current use interval, the fault priority 1056 may be considered and analyzed. In this example, the fault monitoring module 1012 is configured to determine, for each monitored operating state 1030k, a fault priority 1056 associated with the monitored operating state 1030k. The control module 1015 receives the fault priority 1056 and further additionally selects a gas discharge chamber 1004i based on the fault priority 1056. In this manner, the device 1010 determines instructions and selects at least one of the gas discharge chambers 1004k based on the fault state 1025, the fault type 1055, and the fault priority 1056 during the current use interval. If during the current usage interval, two or more operating conditions have marked fault states 1025, the device 1010 can compare the fault priority 1056 of each of these fault states 1025 (which are marked) and select the gas discharge chamber 1004i associated with the performance metric 1120k having the higher fault priority 1056 (and send the instruction 1031 to the blower 1008i of the selected gas discharge chamber 1004i).

[0121] For example, refer to Fig.11 1030k, a fault priority 1156 is assigned to each of the performance metrics 1120k (each performance metric is associated with an operating condition 1030k). The fault priority 1156 of the PADropout performance metric 1120k is 1, which means that the PADropout performance metric 1120k has the highest priority and the fault priority 1156 of the MODropout performance metric 1120k is 2, which means that the MODropout performance metric 1120k has the second highest priority, but is lower than the priority of the PADropout performance metric 1120k. Thus, if the fault states 1025 of both the PADropout performance metric 1120k and the MODropout performance metric 1120k are marked during the current usage interval, the control module 1015 may select the gas discharge chamber 804B (PA gas discharge chamber) and send an instruction 1031 to the blower 808B of the gas discharge chamber 804B because the PADropout performance metric 1120k (and operating conditions) has a higher priority (to clear any faults) and the fault type 1155 of the PADropout performance metric 1120i is a PA fault type (associated with the PA gas discharge chamber).

[0122] As another example and with reference to Fig.111180 , Dropouts (both PA and MO) have a higher fault priority 1156 (1 and 2 respectively) than the H / VDivergence performance metric 1120i (which has a fault priority 1156 of 9).

[0123] As described above, if the performance metric 1020k associated with the monitored operating condition 1030k is not within the threshold range of the performance metric 1020k, the fault state 1025 determined by the fault monitoring module 1012 for the operating condition 1030k is marked, or if the performance metric 1020k associated with the monitored operating condition 1030k is within the threshold range of the performance metric 1020k, the fault state 1025 determined by the fault monitoring module 1012 for the operating condition 1030k is cleared. Only when the fault state 1025 is marked, the control module 1015 selects the gas discharge chamber 1004i.

[0124] As described above, control module 1015 is similar to control module 115 in at least some general respects. Thus, control module 1015 may include increment module 1014, decrement module 1016, and optional baseline module 1018. Modules 1014, 1016, and 1018 may be configured with additional components or systems as detailed above and discussed relative to modules 114, 116, and 118. As described above, increment module 1014 is configured to increase the operating speed of a particular blower 1008i and decrement module 1016 is configured to decrease the operating speed of a particular blower 1008i. As described above, baseline module 1018 is configured to adjust the baseline speed of a particular blower 1008i.

[0125] As described above, for each monitored operating condition 1030k, the fault monitoring module 1012 determines the fault state 1025, the fault type 1055, and the fault priority 1056. The fault information is then received by the control module 1015, which selects at least one gas discharge chamber 1004i accordingly and sends the instruction 1031 to the corresponding blower 1008i. According to the instruction 1031, the increment module 1014 and the decrement module 1016 can be configured to adjust the operating speed of the selected blower 1008i. Also according to the instruction 1031, the baseline module 1018 can be configured to adjust the baseline speed of the selected blower 1008i. For example, if the operating speed of the selected blower 1008i is determined to be lower than the baseline speed, the baseline module 1018 can be used to increase or increment the operating speed of the blower 1008i.

[0126] The baseline module 1018 can also be configured to adjust the baseline speed of one or more blowers 1008i based on other parameters, including the lifespan or operating time of the gas discharge chamber 1004i of a given blower 1008i. For example, the baseline speed of a blower 1008i of a gas discharge chamber 1004i with a longer operating time can be increased more by the baseline module 1018 than the baseline speed of a blower 1008i of a gas discharge chamber 1004i with a shorter operating time.

[0127] refer to Fig.12 , device 1010 (which is an implementation of device 110, 810 or 910) executes program 1260 to control multiple blowers (such as blower 1008i), each of which is arranged in a gas discharge chamber (such as gas discharge chamber 1004i) of light source 1000.

[0128] The procedure 1260 includes monitoring one or more operating conditions 1030k of the light source 1000 (1261). For example, as described above with reference to Fig.10 As discussed, the fault monitoring module 1012 monitors one or more operating conditions 1030k of the light source 1000 at regular intervals of use of the light source 1000 (and the light generating device 1005). As described above, if a single operating condition 1030k is monitored, then k is 1, or if there are multiple operating conditions 1030i being monitored, then k is a set of integers from 1 to greater than 1. For each monitored operating condition 1030k (1261), the device 1010 (e.g., the fault monitoring module 1012) determines a fault state 1025 and a fault type 1055 (1262). As described above, the fault type 1055 is related to which blower 1008i of the gas discharge chamber 1004i affects the monitored operating condition 1030k. Specifically, the fault type 1055 can be related to the blower 1008i in the gas discharge chamber 1004i that has the greatest impact on the monitored operating condition 1030k. In some implementations, the device 1010 (specifically, the fault monitoring module 1012 ) may also determine the fault priority 1056 at 1262 .

[0129] Next, the device 1010 (e.g., the control module 1015, once it receives the fault status 1025 and the fault type 1055 from the fault monitoring module 1012) selects at least one gas discharge chamber 1004i (1264). As described above, the control module 1015 can select at least one gas discharge chamber 1004i (1264) based on the determined fault status 1025 and the determined fault type 1055. For example and with reference to Figure 8 and Fig.11, if the operating condition with only the fault state 1025 marked corresponds to the PADropout performance metric 1120k, then the PA gas discharge chamber 804B may be selected at 1264 because the fault type for this performance metric 1120k is PA 1155 ( Fig.11 ).

[0130] The device 1010 (via the control module 1015) sends an instruction 1031 to the blower 1008i (1266) of the selected at least one gas discharge chamber 1004i, the instruction 1031 being based on the determined fault state 1025 and the determined fault type 1055. The instruction 1031 may result in an adjustment or change in the operating speed (or baseline speed) of the blower 1008i. Fig.13 and Fig.14 Instructions 1031 to adjust or change the operating speed of the blower 1008i based on the determined fault state 1025 and fault type 1055 are discussed in further detail. After the instructions 1031 are sent at 1266, the process 1260 proceeds to the next usage interval and returns to step 1261. In some implementations, the usage interval is a constant value. In other implementations, the usage interval is generally a constant value, but can be adjusted or reset to a different value depending on one or more actions taken at step 1266.

[0131] refer to Fig.13 If the control module 1015 determines that no fault status is marked in the fault status 1025 (determined at step 1262), then an active mode or state is entered. In the active state, routine 1314 is executed by the control module 1015. The active state may include Fig. 6A The decreasing state of 514 and Figure 6C On the other hand, and with reference to Fig.14 If the control module 1015 determines that one or more of the fault conditions 1025 (determined at step 1262) are marked, a risk mode or state is entered. In the risk state, procedure 1416 is performed by the control module 1015. The risk state may include Fig.6D The following discussion will focus on the incremental state 516. Fig.13 The active state program 1314, followed by Fig.14 Risk Status Procedure 1416.

[0132] refer to Fig.13 , in the active state procedure 1314, the blower 1008i of at least one discharge chamber 1004i is selected at 1264 ( Fig.12 The selected operating speed of the blower 1008i is determined and instructions 1031 are sent accordingly by the control module 1015 to accomplish the following: Fig.12 For example, the gas discharge chamber blower 1008i may be selected at 1364 based on the gas discharge chamber blower 1008i selected during the most recent previous usage interval. Figure 8 , if during the most recent previous usage interval, blower 808A in gas discharge chamber 804A was selected for further analysis at 1364, then blower 808B in gas discharge chamber 804B may be selected during the current usage interval at 1364. Thus, in this example, the analysis alternates between blowers 808A and 808B for each usage interval.

[0133] The control module 1015 (e.g., via the decrement module 1014) determines whether the operating speed of the selected blower 1008i is greater than the baseline speed (1333). If the operating speed of the selected blower 1008i is not greater than the baseline speed (1333) (which means that it is equal to, less than, or below the baseline speed of the selected blower 1008i), the control module 1015 sends a command 1031 ( Fig.10 ) to increase the operating speed of the selected blower 1008i (1349). A new set point for the blower speed can be calculated by adding, for example, the incremental speed step size to the current blower speed. For example, the incremental speed step size can be 5 rpm. In addition, if appropriate, the control module 1015 can also reset the usage interval at this time. For example, the usage interval can be set to 10,000,000 pulses of the light beam 1002.

[0134] If the operating speed of the selected blower 1008i is greater than the baseline speed (1333), the control module 1015 determines whether the proposed new blower speed will be greater than the baseline speed (1334). The proposed new blower speed corresponds to the current operating speed of the selected blower 1008i minus the decreasing speed step size. If the proposed new speed of the selected blower 1008i will not be greater than the baseline speed (i.e., at 1334, the proposed new blower speed will be at or less than the baseline speed), the control module 1015 sends an instruction 1031 to maintain the operating speed of the selected blower 1008i (1312). Essentially, this corresponds to Figure 5 The state machine 510 in transitions from the decrement state 514 to the monitoring state 512.

[0135] If the proposed new blower speed will be greater than the baseline speed (1334), the control module 1015 sends an instruction 1031 to reduce or decrement the operating speed of the selected blower 1008i (1342). The control module 1015 can calculate the new operating speed of the selected blower 1008i by subtracting the decrement speed step size (STEP) from the current operating speed of the selected blower 1008i. For example, the decrement speed step size can be 5 rpm.

[0136] The operating speed of the selected blower 1008i is reduced by a decreasing speed step size (1342). On the other hand, the operating speed of the selected blower 1008i is increased by an increasing speed step size (1349). The increasing speed step size can be greater than the decreasing speed step size. For example, the increasing speed step size can be 5 revolutions per minute (rpm), and the decreasing speed step size can be 5rpm. In some implementations, the increasing speed step size can be any value less than or equal to 25rpm, and the decreasing speed step size can be less than this value. Therefore, if the increasing speed step size is 20rpm, the decreasing speed step size can be 5rpm or 10rpm.

[0137] In addition, the control module 1015 can also control the baseline speed of each blower 1008i in each gas discharge chamber 1004i in the light generating device 1005. The control of the baseline speed of a particular blower 1008i can be based on the life of the gas discharge chamber 1004i that houses the particular blower 1008i. This is described above with reference to FIG. 4A to FIG. 4C A discussion was held.

[0138] refer to Fig.14 , in the risk state procedure 1416, at 1262, the control module 1015 has determined that at least one fault state 1025 has been marked. Next, the control module 1015 executes procedure 1464 to select the gas discharge chamber 1004i. Initially, the control module 1015 decodes the fault state (1443). Specifically, the control module 1015 analyzes the fault state of each monitored operating condition to determine which one or more fault states are marked (1443). The control module 1015 determines whether more than one fault state 1025 has been marked (1444). If the control module 1015 determines that only a single fault state 1025 has been marked (1444), it selects the single fault state (1445B). If the control module 1015 determines that there are multiple marked fault states 1025 (1444), it selects a fault state 1025 for further action based on the determined fault priority 1056 (1445A). For example, as described above, and with reference to Fig.111445A, the control module 1015 may select a single fault state 1025 for further action by selecting the fault state 1025 associated with the performance metric 1120k having the highest priority 1156. In the table 1180, a lower number in the priority 1156 column corresponds to a higher priority 1156. Thus, in the table 1180, the PADropout performance metric 1120k has the highest priority 1156 and the H / VDivergence performance metric 1120k has the lowest priority 1156. Next, the control module 1015 selects a gas discharge chamber 1004i based on the fault type associated with the selected fault state 1025 (1446). Once the gas discharge chamber 1004i is selected at 1446, the control module 1015 sends an instruction 1031 to increase the operating speed of the blower 1008i in the selected gas discharge chamber 1004i (1466).

[0139] As mentioned above and with reference to Fig.11 , some faults (associated with some performance metrics 1120k) are affected by more than one gas discharge chamber 1004i. In this case, the control module 1015 may select a gas discharge chamber 1004i based on the fault type 1055Common associated with the fault state 1025 selected at step 1446 by considering other factors. For example, the control module 1015 may select a different gas discharge chamber 1004i in the current use interval than the gas discharge chamber 1004i selected at step 1446 in the most recent previous use interval. Thus, if the speed of the blower 808B of the gas discharge chamber 804B was increased at step 1466 (e.g., by 25 rpm) during the most recent previous use interval ( Fig.14 ), and during the current usage interval, Common fault type 1055 is associated with the marked fault state 1025 ( Fig.14 ), the speed of the blower 808A of the gas discharge chamber 804A can be in the current use interval, in step 1466 ( Fig.14 As another example, in other implementations, if the speed of the blower 808B of the gas discharge chamber 804B was increased at step 1342 (e.g., by 25 rpm) during the most recent prior use interval, Fig.13 ) and during the current use interval, Common fault type 1055 is associated with the marked fault state 1025, the speed of the blower 808A of the gas discharge chamber 804A can be reduced at step 1466 ( Fig.14) (e.g., increase by 25 rpm). On the other hand, in some other implementations, the control module 1015 can select the gas discharge chamber 1004i in the current use interval if the Common fault type 1044 is associated with the marked fault state 1025 ( Fig.14 ), the marked fault state 1025 is the same as the gas discharge chamber 1004i selected at step 1342 ( Fig.13 )). If during the most recent prior usage interval, the speed of the gas discharge chamber blower 808B was at step 1342 ( Fig.13 ) and during the current use interval, the Common fault type 1055 is associated with the marked fault state 1025, then the speed of the blower 808B of the gas discharge chamber 804B can be reduced at step 1466 ( Fig.14 ) (for example, increase by 25 rpm).

[0140] In some implementations, the control module 1015 enters a hold state (1411) after sending the instruction 1031 to the blower 1008i of the selected gas discharge chamber 1004i. The hold state may correspond to a hold use interval, such as, for example, 10,000,000 pulses of the light beam 1002. During the hold state (1411), the control module 1015 does not perform any actions. The purpose of the hold state (1411) is to avoid taking actions in response to transient conditions during the next use interval (a transient condition may be displayed as a marked fault in step 1262 during the next use interval). The control module 1015 also determines whether any fault state 1025 is still marked (1436). If any of the fault states 1025 is still marked at 1436, the control module 1015 repeats the risk state procedure 1416. If all fault conditions in the fault state 1025 are cleared at 1436 (and not flagged), the control module 1015 may therefore exit the risk state procedure 1416 and return to monitoring one or more operating conditions 1030k (1261) of the light source 1000. The control module 1015 may also reset the length of the use interval before exiting the risk state procedure 1416. For example, the use interval may be reset to 100,000,000 pulses of the light beam 1002.

[0141] In summary, during the risk state procedure 1416, since the fault state 1025 is marked, any blower in the blowers 1008i should not be decremented until the control module 1015 determines that all faults are cleared at 1436; only the blowers 1008i in the gas discharge chamber 1004i associated with the fault type 1055 need to be incremented at 1466, and if there are multiple marked fault states 1025 occurring simultaneously, the control module 1015 resolves the fault type 1055 that is most detrimental to the performance of the light source 1000 by selecting the marked fault state 1025 with the highest priority 1056 at 1445A.

[0142] refer to Fig.15 , graph 1581 is shown aligned with graph 1585. Graphs 1581 and 1585 correspond to a simulation showing how device 1010 responds based on the health of light source 1000 (as determined based on monitored operating conditions 1030k). In this simulation, it is assumed that PA fault type 1055 has a higher fault priority 1056 than Common fault type 1055. In discussing graphs 1581 and 1585, reference is made to Fig.10 The device 1010 and Figure 8 Light source 800.

[0143] In graph 1581, the speed set point of blower 1008i is tracked relative to the usage of light source 800. The speed set point of blower 808A of gas discharge chamber 804A is shown by a solid line (which is represented by 1582A), and the speed set point of blower 808B of gas discharge chamber 804B is shown by a double line (which is represented by 1582B). Fault state 1025 is shown by a dashed line. Usage can be represented by the number of pulses of light beam 1002 generated by light source 1000, and in this example, it is given in millions of pulses of light beam 1002. Therefore, a value of 5 on the horizontal axis of graph 1581 corresponds to 0 to 5,000,000 million pulses of light beam 1002.

[0144] In graph 1585, states of device 1010 are depicted along the vertical axis. Additionally, each state depicted is categorized as either an event 1586A associated with blower 808A of gas discharge chamber 804A or an event 1586B associated with blower 808B of gas discharge chamber 804B.

[0145] 1155 . From 0 to 5 usage units, the fault state 1025 is zero (0), which means that no faults are marked. From 5 to 9 usage units, the fault state 1025 is two (2), which means that two faults are marked. In addition, the fault types 1055 of two of these marked faults are PA fault types 1155. From 9 to 15 usage units, the fault state 1025 is 28, which means that 28 faults are marked. In addition, the fault types 1055 of these marked faults include a mixture of PA fault types 1155 and Common fault types 1155. From 16 to 24 usage units, the fault state 1025 is 26, and the fault types 1055 of these marked faults are only Common fault types 1155.

[0146] At the beginning of the simulation, from 0 to 5 units of use, there are no faults marked because the fault state 1025 is zero (0). During this time, the device 1010 operates in the active state, in which the device 1010 executes procedures 1260 and procedures 1314. Each time procedure 1260 is executed, the control module 1015 alternates between the two gas discharge chambers. Initially, the gas discharge chamber 804A is selected at step 1264, and the operating speed of the blower 808A is decreased at step 1342 (as indicated by the decrease in line 1582A of the graph 1581 and the "MO Decrease" state of the graph 1585). Thereafter, the gas discharge chamber 804B is selected at step 1264 (after the use interval has passed), and the operating speed of the blower 808B is decreased at step 1342 (as indicated by the decrease in line 1582B of the graph 1581 and the "PA Decrease" state of the graph 1585). Gas discharge chamber 804A is then selected again at step 1264 (after a usage interval) and the operating speed of blower 808A is decremented at step 1342 (as indicated by the decrease in line 1582A of graph 1581 and the "MO Decrease" state of graph 1585).

[0147] From 5 to 15 units of use, there is a marked fault. The value of the fault state 1025 is about 28 in the chart 1581, and as described above, the control module 1015 decodes the value and determines which one or more fault states are marked (at 1443). The control module 1015 determines that the marked fault states include fault states with PA fault type 1155 (from 5 to 9 units of use) and fault states with Common fault type 1155 (from 9 to 15 units of use). Therefore, the device 1010 operates in a risk state in which the device 1010 executes the program 1260 and the program 1416. As described above, in this simulation, it is assumed that the PA fault type 1155 has a higher fault priority 1056 than the Common fault type 1155. Therefore, at all times during this use frame (5-15 units of use), the control module 1015 selects the gas discharge chamber 804B at step 1446 and sends instructions 1031 to increase the operating speed of the blower 808B at each use interval. This is shown by the steps in double line 1582B of graph 1581 and also by the “PA Increment Fault” state of graph 1585 .

[0148] From 16 to 24 units of use, the fault state 1025 is 26 (as indicated by the graph 1581), and the fault type 1055 of these marked faults is only the Common fault type 1155. Therefore, the device 1010 operates in a risk state where the device 1010 executes the procedure 1260 and the procedure 1416. Because the only fault type is the Common fault type 1155, the control module 1010 alternates and selects the gas discharge chamber 804A at step 1446, and sends the instruction 1031 to increase the operating speed of the blower 808A at the next use interval. This is shown by the step in the single line 1582A of the graph 1581 and is also shown by the "MO Increment Fault" state of the graph 1585. In general, the control module 1010 alternates between increasing the operating speed of the blower 808A and the operating speed of the blower 808B within each use interval. After the operating speed of blower 808A is increased at use unit 18, control module 1010 resets the use interval to a larger value moving forward. Therefore, the next action is taken at use unit 22, where control module 1010 sends instruction 1031 to increase the operating speed of blower 808B, as shown by the steps in double line 1582B of graph 1581 and also shown by the "PA Increment Fault" state of graph 1585.

[0149] The implementation can be further described using the following terms:

[0150] 1. A control device for a light source, the light source comprising a plurality of gas discharge chambers, wherein a blower is arranged in each gas discharge chamber, the control device comprising:

[0151] a fault monitoring module configured to monitor one or more operating conditions of the light source and, for each monitored operating condition, determine a fault state and a fault type related to which blower of the gas discharge chamber affects the monitored operating condition; and

[0152] A control module, the control module being configured to receive the determined fault state and the determined fault type from the fault monitoring module; select at least one gas discharge chamber; and send instructions to the blower in the selected at least one gas discharge chamber, the instructions being based on the determined fault state and the determined fault type.

[0153] 2. A control device according to clause 1, wherein:

[0154] The fault monitoring module is configured to determine, for each monitored operating condition, a priority level associated with the monitored operating condition; and

[0155] The control module is configured to select the at least one gas discharge chamber based on the determined priority.

[0156] 3. According to the control device described in claim 1, the fault monitoring module is configured to monitor the one or more operating conditions of the light source at regular usage intervals of the light source, and the control module is configured to select at least one gas discharge chamber based on the gas discharge chamber selected by the control module during the most recent previous usage interval.

[0157] 4. A control device according to claim 1, wherein the multiple gas discharge chambers include a master oscillator gas discharge chamber and a power amplifier gas discharge chamber, the power amplifier gas discharge chamber is optically connected in series with the master oscillator gas discharge chamber, and the fault type is selected from a set of possible fault types, the set of possible fault types including a power amplifier fault type, a master oscillator fault type and a common fault type.

[0158] 5. A control device according to clause 1, wherein each of the one or more operating conditions is defined by a performance metric, the performance metric being related to the light source or the light beam generated by the light source.

[0159] 6. A control device according to clause 5, wherein the one or more performance metrics include:

[0160] a wavelength histogram associated with the light beam;

[0161] an energy dosage error associated with the beam;

[0162] an energy error associated with the beam;

[0163] a bandwidth error associated with the beam;

[0164] The operating point of the master oscillator gas discharge chamber;

[0165] The operating point of the power amplifier gas discharge chamber;

[0166] an accuracy of a spectral characteristic associated with the light beam; and

[0167] The actuator operating point of the light source.

[0168] 7. A control device according to clause 1, wherein the fault state determined for the monitored operating condition is:

[0169] is flagged if a performance metric associated with the monitored operating condition is not within a threshold range for that performance metric; or

[0170] Cleared if a performance metric associated with the monitored operating condition is within the threshold range for the performance metric.

[0171] 8. A control device according to claim 1, wherein the fault monitoring module is configured to determine an overall fault state based on the determined fault state of each monitored operating condition, and the control module is configured to select at least one gas discharge chamber and send the instruction to the blower in the selected at least one gas discharge chamber, including: the control module decodes the overall fault state to analyze the determined fault state of each monitored operating condition.

[0172] 9. A control device according to clause 1, wherein the control module is configured to select at least one gas discharge chamber and send the instruction to the blower in the selected at least one gas discharge chamber, including: the control module is configured to operate in an active mode if all fault states among the determined fault states are cleared, and to operate in a risk mode if any one of the determined fault states is marked.

[0173] 10. A control device according to claim 9, wherein, in active mode, the control module is configured to send instructions to reduce the operating speed of the blower in at least one selected gas discharge chamber by a decreasing speed step, and, in risk mode, the control module is configured to send instructions to increase the operating speed of the blower in at least one selected gas discharge chamber by an increasing speed step, wherein the increasing speed step is greater than the decreasing speed step.

[0174] 11. A control device according to clause 10, wherein the increasing speed step size is less than or equal to 40 revolutions per minute (rpm) and the decreasing speed step size is approximately one-half, one-third, one-quarter or one-fifth of the increasing speed step size.

[0175] 12. The control device according to clause 9, wherein, in active mode, the control module is configured to:

[0176] selecting one of the gas discharge cells; and

[0177] If the reduced operating speed is above the baseline speed, a command is sent to reduce the operating speed of the blower disposed in the selected gas discharge chamber to the reduced operating speed.

[0178] 13. A control device according to claim 12, wherein the control module is further configured to send an instruction to increase the operating speed of the blower arranged in the selected gas discharge chamber if the current operating speed of the blower arranged in the selected gas discharge chamber is lower than the baseline speed, and to send an instruction to maintain the operating speed of the blower arranged in the selected gas discharge chamber if the current operating speed of the blower arranged in the selected gas discharge chamber is at the baseline speed.

[0179] 14. The control device according to clause 12 further includes a baseline module, which is configured to control the baseline speed of each blower of each gas discharge chamber, and the control of the baseline speed of a specific blower is related to the life of the gas discharge chamber containing the blower.

[0180] 15. A control device according to clause 9, wherein:

[0181] The fault monitoring module is further configured to determine a fault priority for each monitored operating condition; and

[0182] In risk mode, the control module is configured to:

[0183] analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged;

[0184] If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition;

[0185] selecting a gas discharge chamber based on the fault type associated with the selected fault state; and

[0186] A command is sent to increase the operating speed of the blower of the selected gas discharge chamber.

[0187] 16. A control device according to clause 15, wherein:

[0188] The fault type is associated with a single gas discharge chamber or is associated with a plurality of gas discharge chambers; and

[0189] In the risk mode, the control module is configured to select the gas discharge chamber based on the fault type associated with the selected fault state, including: selecting the single gas discharge chamber associated with the fault type or selecting a gas discharge chamber from the plurality of gas discharge chambers associated with the fault type.

[0190] 17. A control device according to clause 15, wherein, in risk mode, after the operating speed of the blower of the selected gas discharge chamber has been increased, the control module is configured to:

[0191] Enter hold mode;

[0192] After the hold state ends:

[0193] receiving, for each monitored operating condition, a next determined fault state and fault type from the fault monitoring module;

[0194] analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged;

[0195] If any of the one or more fault conditions is flagged, then:

[0196] If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition;

[0197] selecting a gas discharge chamber based on the fault type associated with the selected fault state; and

[0198] sending a command to increase the operating speed of the blower of the selected gas discharge chamber; and

[0199] If none of the one or more fault conditions is flagged, then the risk mode is exited and the next determined fault condition and fault type from the fault monitoring module is awaited.

[0200] 18. A control device according to claim 1, wherein the fault monitoring module is configured to monitor the one or more operating conditions of the light source at a regular usage interval of the light source, and the regular usage interval of the light source is measured as the number of pulses of the light beam generated by the light source.

[0201] 19. A control device according to claim 18, wherein the periodic use interval includes a first periodic use interval and a second periodic use interval, the second periodic use interval is greater than the first periodic use interval, and the fault monitoring module is configured to operate using the second periodic use interval after determining the marked fault state using the first periodic use interval and then determining the zero-marked fault state in the next use interval.

[0202] 20. A method for controlling a plurality of blowers, each blower being arranged in a gas discharge chamber of a light source, the method comprising:

[0203] monitoring one or more operating conditions of the light source at regular intervals of use of the light source;

[0204] for each monitored operating condition, determining a fault state and a fault type, the fault type being related to which blower of the gas discharge chamber affects the monitored operating condition;

[0205] selecting at least one gas discharge chamber; and

[0206] Instructions are sent to the blower in the selected at least one gas discharge chamber, the instructions being based on the determined fault state and the determined fault type.

[0207] 21. The method of clause 20, further comprising: for each monitored operating condition, determining a priority associated with the monitored operating condition; and

[0208] The selecting the at least one gas discharge chamber comprises: selecting the at least one gas discharge chamber based on the determined priority.

[0209] 22. The method of clause 20, wherein selecting the at least one gas discharge chamber comprises selecting the at least one gas discharge chamber based on the gas discharge chamber selected during a most recent previous usage interval.

[0210] 23. The method of clause 20, wherein the fault condition determined for the monitored operating condition is:

[0211] is flagged if a performance metric associated with the monitored operating condition is not within a threshold range for the performance metric; or,

[0212] Cleared if the performance metric associated with the monitored operating condition is within the threshold range of the performance metric.

[0213] 24. The method of clause 20, further comprising: determining an overall fault state based on the determined fault state of each monitored operating condition,

[0214] Wherein selecting at least one gas discharge chamber and sending the instruction to the blower in the selected at least one gas discharge chamber includes decoding the overall fault status to analyze the determined fault status of each monitored operating condition.

[0215] 25. A method according to clause 20, wherein selecting at least one gas discharge chamber and sending the instruction to the blower in the selected at least one gas discharge chamber includes: operating in an active mode if all of the determined fault states are cleared, and operating in a risk mode if any of the determined fault states is marked.

[0216] 26. A method according to clause 25, wherein, in the active mode, sending the instruction to the blower includes: sending an instruction to reduce the operating speed of the blower in at least one selected gas discharge chamber by a decreasing speed step, and, in the risk mode, sending the instruction to the blower includes: sending an instruction to increase the operating speed of the blower in at least one selected gas discharge chamber by an increasing speed step, wherein the increasing speed step is greater than the decreasing speed step.

[0217] 27. A method according to clause 25, wherein in the active mode:

[0218] Selecting at least one gas discharge cell comprises: selecting one of the gas discharge cells; and

[0219] Sending the instruction to the blower includes sending an instruction to reduce the operating speed of the blower disposed in the selected gas discharge chamber to the reduced operating speed if the reduced operating speed is above a baseline speed.

[0220] 28. A method according to clause 27, wherein sending the instruction to the blower includes: if the current operating speed of the blower arranged in the selected gas discharge chamber is at or below the baseline speed, sending an instruction to increase the operating speed of the blower arranged in the selected gas discharge chamber, and if the current operating speed of the blower arranged in the selected gas discharge chamber is within a threshold range of the baseline speed, sending an instruction to maintain the operating speed of the blower arranged in the selected gas discharge chamber.

[0221] 29. The method of clause 27, further comprising controlling the baseline speed of each blower of each gas discharge chamber, wherein control of a particular blower baseline speed is related to the life of the gas discharge chamber in which the blower is housed.

[0222] 30. The method of clause 25, further comprising: determining a fault priority for each monitored operating condition;

[0223] Wherein operating in the risk mode includes:

[0224] analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged;

[0225] If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition;

[0226] selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and

[0227] A command is sent to increase the operating speed of the blower of the selected gas discharge chamber.

[0228] 31. A method according to clause 30, wherein:

[0229] The fault type is associated with a single gas discharge chamber or is associated with a plurality of gas discharge chambers; and

[0230] Operating in the risk mode includes: selecting the gas discharge chamber based on the fault type associated with the selected fault state, and selecting the gas discharge chamber based on the fault type associated with the selected fault state includes: selecting the single gas discharge chamber associated with the fault type or selecting the gas discharge chamber associated with the fault type from multiple gas discharge chambers.

[0231] 32. The method of clause 30, wherein operating in the risk mode comprises: after the operating speed of the blower of the selected gas discharge chamber has been increased:

[0232] Enter hold mode;

[0233] After the hold state ends:

[0234] analyzing a next determined fault condition for each monitored operating condition to determine which one or more fault conditions are flagged;

[0235] If any of the one or more fault conditions is flagged, then:

[0236] If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition;

[0237] selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and

[0238] sending a command to increase the operating speed of the blower of the selected gas discharge chamber; and

[0239] If no fault state among the one or more fault states is marked, the risk mode is exited and the next determined fault state and fault type are awaited.

[0240] 33. A control device for a light source, the light source comprising a first gas discharge chamber and a second gas discharge chamber, the second gas discharge chamber being optically connected in series with the first gas discharge chamber, the control device comprising:

[0241] a fault monitoring module configured to monitor one or more operating conditions of the light source at regular intervals and to determine a fault status for each monitored operating condition; and

[0242] A control module, the control module being configured to send a first instruction to a first blower in the first gas discharge chamber and a second instruction to a second blower in the second gas discharge chamber, the first instruction and the second instruction being related to a speed of the first blower and a speed of the second blower, respectively, and the first instruction and the second instruction being based on the determined fault state.

[0243] The implementations described above and other implementations are within the scope of the following claims.

Claims

1. A control device for a light source, the light source comprising a plurality of gas discharge chambers, wherein a blower is arranged in each gas discharge chamber, the control device comprising: a fault monitoring module configured to monitor one or more operating conditions of the light source and, for each monitored operating condition, determine a fault state and a fault type, the fault type being related to which blower of the gas discharge chamber affects the monitored operating condition; as well as A control module, the control module being configured to receive the determined fault state and the determined fault type from the fault monitoring module; select at least one gas discharge chamber; And sending an instruction to the blower in the selected at least one gas discharge chamber, the instruction being based on the determined fault state and the determined fault type.

2. The control device according to claim 1, wherein: The fault monitoring module is configured to determine, for each monitored operating condition, a priority level associated with the monitored operating condition; and The control module is configured to select the at least one gas discharge chamber based on the determined priority.

3. A control device according to claim 1, wherein the fault monitoring module is configured to monitor the one or more operating conditions of the light source at regular usage intervals of the light source, and the control module is configured to select at least one gas discharge chamber based on the gas discharge chamber selected by the control module during the most recent previous usage interval.

4. The control device according to claim 1, wherein the plurality of gas discharge chambers include a master oscillator gas discharge chamber and a power amplifier gas discharge chamber, the power amplifier gas discharge chamber is optically connected in series with the master oscillator gas discharge chamber, and the fault type is selected from a set of possible fault types, the set of possible fault types including a power amplifier fault type, a master oscillator fault type and a common fault type.

5. A control device according to claim 1, wherein each of the one or more operating conditions is defined by a performance metric related to the light source or a light beam generated by the light source.

6. The control device of claim 5, wherein the one or more performance metrics include: a wavelength histogram associated with the light beam; an energy dosage error associated with the beam; an energy error associated with the beam; a bandwidth error associated with the beam; The operating point of the master oscillator gas discharge chamber; The operating point of the power amplifier gas discharge chamber; an accuracy of a spectral characteristic associated with the light beam; and The actuator operating point of the light source.

7. The control device of claim 1, wherein the fault state determined for the monitored operating condition is: is flagged if a performance metric associated with the monitored operating condition is not within a threshold range for that performance metric; or Cleared if a performance metric associated with the monitored operating condition is within the threshold range for the performance metric.

8. The control device of claim 1, wherein the fault monitoring module is configured to determine an overall fault state based on the determined fault state of each monitored operating condition, and the control module is configured to select at least one gas discharge chamber and send the instruction to the blower in the selected at least one gas discharge chamber comprises: The control module decodes the overall fault status to analyze the determined fault status for each monitored operating condition.

9. The control device according to claim 1, wherein the control module is configured to select at least one gas discharge chamber and send the instruction to the blower in the selected at least one gas discharge chamber, comprising: The control module is configured to operate in an active mode if all of the determined fault conditions are cleared, and to operate in a risk mode if any of the determined fault conditions is flagged.

10. The control device according to claim 9, wherein: In active mode, the control module is configured to send instructions to reduce the operating speed of the blower in at least one selected gas discharge chamber by a decreasing speed step, and, in risk mode, the control module is configured to send instructions to increase the operating speed of the blower in at least one selected gas discharge chamber by an increasing speed step, wherein the increasing speed step is greater than the decreasing speed step.

11. The control device of claim 10, wherein the increasing speed step size is less than or equal to 40 revolutions per minute (rpm), and the decreasing speed step size is approximately one-half, one-third, one-quarter, or one-fifth of the increasing speed step size.

12. The control device according to claim 9, wherein: In active mode, the control module is configured to: selecting one of the gas discharge cells; and If the reduced operating speed is above the baseline speed, a command is sent to reduce the operating speed of the blower disposed in the selected gas discharge chamber to the reduced operating speed.

13. A control device according to claim 12, wherein the control module is further configured to: if the current operating speed of the blower arranged in the selected gas discharge chamber is lower than the baseline speed, send an instruction to increase the operating speed of the blower arranged in the selected gas discharge chamber, and if the current operating speed of the blower arranged in the selected gas discharge chamber is at the baseline speed, send an instruction to maintain the operating speed of the blower arranged in the selected gas discharge chamber.

14. The control device according to claim 12 further includes a baseline module, which is configured to control the baseline speed of each blower of each gas discharge chamber, and the control of the baseline speed of a specific blower is related to the life of the gas discharge chamber containing the blower.

15. The control device according to claim 9, wherein: The fault monitoring module is further configured to determine a fault priority for each monitored operating condition; and In risk mode, the control module is configured to: analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged; If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition; selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and A command is sent to increase the operating speed of the blower of the selected gas discharge chamber.

16. The control device according to claim 15, wherein: The fault type is associated with a single gas discharge chamber or is associated with a plurality of gas discharge chambers; and In the risk mode, the control module is configured to select the gas discharge chamber based on the fault type associated with the selected fault state, including: selecting the single gas discharge chamber associated with the fault type or selecting a gas discharge chamber from the plurality of gas discharge chambers associated with the fault type.

17. The control device according to claim 15, wherein: In risk mode, after the operating speed of the blower of the selected gas discharge chamber has been increased, the control module is configured to: Enter hold mode; After the hold state ends: receiving, for each monitored operating condition, a next determined fault state and fault type from the fault monitoring module; analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged; If any of the one or more fault conditions is flagged, then: If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition; selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and sending a command to increase the operating speed of the blower of the selected gas discharge chamber; and If none of the one or more fault conditions is flagged, then the risk mode is exited and the next determined fault condition and fault type from the fault monitoring module is awaited.

18. A control device according to claim 1, wherein the fault monitoring module is configured to monitor the one or more operating conditions of the light source at a regular usage interval of the light source, and the regular usage interval of the light source is measured as the number of pulses of the light beam generated by the light source.

19. The control device of claim 18, wherein the periodic use interval includes a first periodic use interval and a second periodic use interval, the second periodic use interval being greater than the first periodic use interval, the fault monitoring module being configured to operate using the second periodic use interval after determining a marked fault state using the first periodic use interval and then determining a zero marked fault state in a next use interval.

20. A method for controlling a plurality of blowers, each blower being arranged in a gas discharge chamber of a light source, the method comprising: monitoring one or more operating conditions of the light source at regular intervals of use of the light source; for each monitored operating condition, determining a fault state and a fault type, the fault type being related to which blower of the gas discharge chamber affects the monitored operating condition; selecting at least one gas discharge chamber; as well as Instructions are sent to the blower in the selected at least one gas discharge chamber, the instructions being based on the determined fault state and the determined fault type.

21. The method according to claim 20, further comprising: For each monitored operating condition, determining a priority associated with the monitored operating condition; and The selecting the at least one gas discharge chamber comprises: selecting the at least one gas discharge chamber based on the determined priority.

22. The method of claim 20, wherein selecting the at least one gas discharge chamber comprises: The at least one gas discharge cell is selected based on the gas discharge cell selected during a most recent previous usage interval.

23. The method of claim 20, wherein the fault condition determined for the monitored operating condition is: is flagged if a performance metric associated with the monitored operating condition is not within a threshold range for the performance metric; or, Cleared if the performance metric associated with the monitored operating condition is within the threshold range of the performance metric.

24. The method of claim 20, further comprising: determining an overall fault status based on the determined fault status of each monitored operating condition, Wherein selecting at least one gas discharge chamber and sending the instruction to the blower in the selected at least one gas discharge chamber includes decoding the overall fault status to analyze the determined fault status of each monitored operating condition.

25. The method of claim 20, wherein selecting at least one gas discharge chamber and sending the instruction to the blower in the selected at least one gas discharge chamber comprises: If all of the determined fault states are cleared, operation is performed in the active mode, and if any of the determined fault states is marked, operation is performed in the risk mode.

26. The method according to claim 25, wherein: In the active mode, sending the instruction to the blower includes: sending an instruction to reduce the operating speed of the blower in at least one selected gas discharge chamber by a decreasing speed step, and in the risk mode, sending the instruction to the blower includes: sending an instruction to increase the operating speed of the blower in at least one selected gas discharge chamber by an increasing speed step, and the increasing speed step is greater than the decreasing speed step.

27. The method according to claim 25, wherein: In the active mode: Selecting at least one gas discharge cell comprises: selecting one of the gas discharge cells; and Sending the instruction to the blower includes sending an instruction to reduce the operating speed of the blower disposed in the selected gas discharge chamber to the reduced operating speed if the reduced operating speed is above a baseline speed.

28. The method of claim 27, wherein sending the instruction to the blower comprises: If the current operating speed of the blower arranged in the selected gas discharge chamber is at or below the baseline speed, an instruction is sent to increase the operating speed of the blower arranged in the selected gas discharge chamber, and if the current operating speed of the blower arranged in the selected gas discharge chamber is within the threshold range of the baseline speed, an instruction is sent to maintain the operating speed of the blower arranged in the selected gas discharge chamber.

29. The method of claim 27, further comprising: The baseline speed of each blower of each gas discharge chamber is controlled, and the control of the baseline speed of a particular blower is related to the life of the gas discharge chamber containing the blower.

30. The method of claim 25, further comprising: Determine fault priority for each monitored operating condition; Wherein operating in the risk mode includes: analyzing the fault condition for each monitored operating condition to determine which one or more fault conditions are flagged; If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition; selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and A command is sent to increase the operating speed of the blower of the selected gas discharge chamber.

31. The method of claim 30, wherein: The fault type is associated with a single gas discharge chamber or is associated with a plurality of gas discharge chambers; and Operating in the risk mode includes: selecting the gas discharge chamber based on the fault type associated with the selected fault state, and selecting the gas discharge chamber based on the fault type associated with the selected fault state includes: selecting the single gas discharge chamber associated with the fault type or selecting the gas discharge chamber associated with the fault type from multiple gas discharge chambers.

32. The method of claim 30, wherein: Operating in the risk mode includes: after the operating speed of the blower of the selected gas discharge chamber has been increased: Enter hold mode; After the hold state ends: analyzing a next determined fault condition for each monitored operating condition to determine which one or more fault conditions are flagged; If any of the one or more fault conditions is flagged, then: If multiple fault conditions are marked, selecting one of the marked fault conditions based on the determined fault priority, and if a single fault condition is marked, selecting the single marked fault condition; selecting a gas discharge chamber based on the fault type associated with the selected fault condition; and sending a command to increase the operating speed of the blower of the selected gas discharge chamber; and If no fault state among the one or more fault states is marked, the risk mode is exited and the next determined fault state and fault type are awaited.

33. A control device for a light source, the light source comprising a first gas discharge chamber and a second gas discharge chamber, the second gas discharge chamber being optically connected in series with the first gas discharge chamber, the control device comprising: a fault monitoring module configured to monitor one or more operating conditions of the light source at regular intervals and determine a fault status for each monitored operating condition; as well as A control module, the control module being configured to send a first instruction to a first blower in the first gas discharge chamber and a second instruction to a second blower in the second gas discharge chamber, the first instruction and the second instruction being related to a speed of the first blower and a speed of the second blower, respectively, and the first instruction and the second instruction being based on the determined fault state.

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