Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/09—Processes or apparatus for excitation, e.g. pumping
  • H01S3/097—Processes or apparatus for excitation, e.g. pumping by gas discharge of a gas laser
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
  • H01S3/22—Gases
  • H01S3/223—Gases the active gas being polyatomic, i.e. containing two or more atoms
  • H01S3/225—Gases the active gas being polyatomic, i.e. containing two or more atoms comprising an excimer or exciplex

Definitions

• the disclosed subject matter relates to an apparatus configured to control or operate an optical source in an idle mode.
• Photolithography is the process by which semiconductor circuitry is patterned on a substrate such as a silicon wafer.
• An optical source generates deep ultraviolet (DUV) light used to expose a photoresist on the wafer.
• DUV light is light having a wavelength from, for example, about 100 nanometers (nm) to about 400 nm.
• the optical source is a laser source (for example, an excimer laser) and the DUV light is a pulsed laser beam.
• the DUV light from the optical source interacts with a projection optical system, which projects the beam through a mask onto the photoresist on the silicon wafer. In this way, a layer of chip design is patterned onto the photoresist.
• the photoresist and wafer are subsequently etched and cleaned, and then the photolithography process repeats.
• an apparatus configured to control an idle mode of an optical source that, during production mode, produces a production light beam for use by an output device.
• the apparatus includes: an instruction unit and an idle unit in communication with the instruction unit and configured to communicate with the optical source.
• the instruction unit is configured to create an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode in which the production light beam is not being produced for use by the output device. Each property in the set can be assigned any value within a continuous range of values.
• the idle unit is configured to: receive, from the instruction unit, the idle plan; store the idle plan; and provide the idle plan to the optical source upon receiving a command related to the idle mode.
• Implementations can include one or more of the following features.
• the optical source can produce a pulsed idle light beam
• the set of coded properties can include a sequence of a plurality of firing patterns, each firing pattern defining the pulsed idle light beam.
• Each firing pattern can include one or more of: a rate at which the idle light beam produces pulses; an energy of the pulses of the idle light beam; a total number of bursts of the pulses of the idle light beam; a number of pulses within each burst; an interval between bursts; and pauses that extend the interval between bursts.
• the set of coded properties can include one or more of: a voltage, a discharge timing target between two or more chambers; one or more properties or settings within the optical source; and one or more signals provided to actuators within the optical source.
• the idle unit can be configured to receive the command related to the idle mode from one or more of: the output device and an entity other than the output device.
• the idle unit can be configured to receive the command related to the idle mode during production mode, during idle mode, or during a time other than the production mode and the idle mode.
• the apparatus can include a metrology unit configured to sense one or more conditions of the optical source.
• the instruction unit can be in communication with the metrology unit, the instruction unit being configured to create the idle plan based on an analysis of one or more of the sensed conditions from the metrology unit.
• the instruction unit can be configured to create the idle plan based on input from a user.
• the instruction unit can be configured to create the idle plan based on an analysis of a prior state of the optical source.
• the instruction unit can be configured to create the idle plan based on an analysis that seeks to optimize or improve a performance of one or more of the optical source and the output device.
• the instruction unit can be configured to create the idle plan based on an analysis that includes determining a sensitivity of the optical source to changes in the values of one or more of the coded properties.
• the changes in the values of one or more of the coded properties can include one or more of: changes to the pauses that extend an interval between bursts of pulses of the idle light beam; changes to the rate at which the idle light beam produces pulses; changes to the energy of the pulses of the idle light beam; changes to the total number of bursts of the pulses of the idle light beam; and changes to the number of pulses within each burst.
• the sensitivity of the optical source to the changes in the values of one or more of the coded properties can be determined by analyzing data collected from a metrology unit during operation of the optical source in a prior idle mode, in a prior production mode, or in both a prior idle mode and a prior production mode.
• the optical source can be configured to produce an idle light beam or to produce no light beam.
• the optical source can produce a pulsed idle light beam that does not fall within a set of production properties that are required by the output device.
• an apparatus includes: an optical source; a production unit configured to communicate with the optical source; and an idle unit configured to communicate with the optical source.
• the optical source is configured to be in one of a plurality of modes of operation including: a production mode in which a production light beam is produced for use by an output device; and an idle mode in which the production light beam is not produced for use by the output device.
• the production unit is configured to operate the optical source during the production mode.
• the idle unit is configured to: receive, at any moment in time including during any operating mode of the optical source, an idle plan that includes a set of coded properties that together define operation of the optical source in the idle mode; and upon receiving a command, provide the idle plan to the optical source to thereby operate the optical source during the idle mode.
• a light beam can be a pulsed light beam and the set of coded properties can include a sequence of a plurality of firing patterns, each firing pattern defining the idle pulsed light beam.
• Each firing pattern can include one or more of: a rate at which the idle light beam produces pulses; an energy of the pulses of the idle light beam; a total number of bursts of the pulses of the idle light beam; a number of pulses within each burst; an interval between bursts; and pauses that extend the interval between bursts.
• the set of coded properties can include one or more of: a voltage, a discharge timing target between two or more chambers; one or more properties or settings within the optical source; and one or more signals provided to actuators within the optical source.
• the idle unit can be configured to receive the command related to the idle mode from one or more of: the output device and an entity other than the output device.
• the idle unit can be configured to receive the command related to the idle mode during production mode, during idle mode, or during a time other than the production mode or the idle mode.
• the apparatus can include a metrology unit configured to sense one or more conditions of the optical source.
• the apparatus can include an instruction unit in communication with the idle unit and the metrology unit, the instruction unit configured to create the idle plan.
• Each property in the set of coded properties of the idle plan can be assigned any value within a continuous range of values.
• the optical source can be configured to accept, process, and execute the provided idle plan including executing associated firing patterns within the provided idle plan.
• the production unit can be a component within the output device.
• an apparatus includes: a plurality of optical sources, at least one optical source being in service relative to an output device; a production unit; and an idle unit.
• Each in service optical source is configured to be in one of a plurality of modes of operation including: a production mode in which a production light beam is produced for use by the output device; and an idle mode in which the production light beam is not being produced for use by the output device.
• the production unit is configured to communicate with the in service optical source and to operate the in service optical source during the production mode.
• the idle unit is configured to: receive, at any moment in time, an idle plan that includes a set of coded properties that together define operation of one or more in service optical sources in the idle mode; and upon receiving a command, provide the idle plan to the optical source in service to thereby operate the in service optical source during the idle mode.
• the idle plan can include a set of coded properties that together define operation of a plurality of in service optical sources in the idle mode.
• the idle unit can be configured to provide the idle plan to each of the in service optical sources of the plurality to thereby operate the in service optical sources during respective idle modes.
• the idle unit can be configured to provide the idle plan to each of the in service optical sources of the plurality to thereby operate the in service optical sources during respective idle modes at different moments in time or at the same time or at overlapping moments in time.
• the in service optical source can produce a pulsed idle light beam
• the set of coded properties can include a sequence of a plurality of firing patterns, each firing pattern defining the pulsed idle light beam.
• the idle unit can be configured to receive the command related to the idle mode from one or more of: the output device and an entity other than the output device.
• the apparatus can include an instruction unit configured to create the idle plan based on a set of programmable instructions.
• a method for controlling a mode of an optical source.
• the method includes enabling operation of the optical source in either a production mode in which the optical source is producing a production light beam for use by an output device or an idle mode in which the production light beam is not being produced for use by the output device.
• the method includes receiving, at any moment in time including while operating the optical source in the production mode or in the idle mode, an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode.
• the method also includes, upon receipt of a command related to the idle mode, providing the idle plan to the optical source.
• the idle plan can be provided to the optical source by one or more of: beginning operating the optical source in idle mode based on the provided idle plan after halting operating the optical source in production mode; and continuing operating the optical source in idle mode based on the provided idle plan.
• the method can include storing the idle plan.
• the method can include instructing the optical source to operate in idle mode including instructing the optical source to produce an idle light beam that does not fall within a set of production properties that are required by the output device or to produce no light beam.
• the method can include creating the idle plan based on one or more of: an analysis of one or more sensed conditions of the optical source, an input from a user, an analysis of a prior state of the optical source, an analysis that seeks to optimize or improve a performance of one or more of the optical source and the output device, and a sensitivity of the optical source to changes in values of one or more of the coded properties.
• the idle plan can be provided to the optical source by providing the idle plan to the optical source until the command is no longer received.
• a method is performed for controlling a mode of an optical source. The method includes enabling operation of the optical source in either a production mode in which the optical source is producing a production light beam for use by an output device or in an idle mode in which the production light beam is not being produced for use by the output device. The method includes receiving an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode. Each property in the set can be assigned any value within a range and not limited to a set of discrete values. The method includes, upon receipt of a command related to the idle mode, providing the idle plan to the optical source.
• the idle plan can be provided to the optical source by: beginning operating the optical source in idle mode based on the provided idle plan after halting operating the optical source in production mode; and continuing operating the optical source in idle mode based on the provided idle plan.
• the method can include storing the idle plan.
• the method can include instructing the optical source to operate in idle mode including instructing the optical source to produce an idle light beam that does not fall within a set of production properties that are required by the output device or to produce no light beam.
• the method can include creating the idle plan based on one or more of: an analysis of one or more sensed conditions of the optical source, an input from a user, an analysis of a prior state of the optical source, an analysis that seeks to optimize or improve a performance of one or more of the optical source and the output device, and a sensitivity of the optical source to changes in values of one or more of the coded properties.
• Fig. 1 is a block diagram of an apparatus including an instruction unit and an idle unit, the apparatus configured to control or operate an optical source in an idle mode, the optical source providing a production light beam to an output device when operating in production mode;
• FIG. 2 A is a block diagram of the apparatus of Fig. 1, in which the optical source is operating in production mode;
• Fig. 2B is a block diagram of the apparatus of Fig. 1, in which the optical source is operating in true idle mode;
• Fig. 2C is a block diagram of the apparatus of Fig. 1, in which the optical source is operating in warm idle mode;
• FIG. 3 is a schematic illustration of an implementation of an idle plan created by the apparatus and provided to the optical source, the idle plan providing instructions on operation in idle mode;
• Fig. 4 is a block diagram of an implementation of the optical source and also includes a production unit and a metrology unit, one or more of which can be in communication with the apparatus;
• Fig. 5 is a block diagram of an implementation of a generic unit (which can correspond to the instruction unit, the idle unit, the production unit, or the metrology unit), the generic unit including one or more modules;
• Fig. 6 is a block diagram of an implementation of the optical source and the output device, in which the optical source is a dual-stage optical source;
• FIG. 7 is a block diagram of an implementation of an apparatus that includes the instruction unit of Fig. 1 and a plurality of optical source systems, with each optical source system including a respective optical source arranged relative to a respective output device;
• Fig. 8 is a flow chart of a procedure performed by the apparatus of Fig. 1, the apparatus of Fig. 7, or any one of the optical source systems of Fig. 7 in conjunction with a procedure performed by any one of the optical sources of Figs. 1, 4, 6, and 7; and
• Fig. 9 is a block diagram of an implementation of the apparatus of Fig. 1 operating in warm idle mode.
• an apparatus 100 is configured to control or operate an optical source 140 in an idle mode.
• the optical source 140 operates in a production mode in which the optical source 140 produces a production light beam 160 for use by and as needed by an output device 165.
• the apparatus operates the optical source 140 in the idle mode in which the production light beam 160 is not being produced for use by the output device 165.
• Figs. 2B and 2C show two possible configurations for idle mode operation. In Fig.
• the optical source 140 operating in idle mode does not produce any light beam, and this mode can be referred to as a true idle mode. While in Fig. 2C, the optical source 140 operating in idle mode produces an idle light beam 162, and this mode can be referred to as a warm idle mode.
• the idle light beam 162 has properties that can vary and at various times such properties may not correspond to or could be outside the scope of a set of production properties that are required by the output device 165.
• the optical source 140 is in standby and ready to switch back to production mode as quickly as possible upon an instruction to do so.
• the apparatus 100 is configured to operate the optical source 140 in idle mode in a manner that reduces wear and deterioration of the optical source 140 as much as possible.
• the apparatus 100 is configured to operate the optical source 140 in idle mode in a manner that keeps the optical source 140 in a state that enables a faster recovery from idle mode. That is, the apparatus 100 enables the optical source 140 to more rapidly transition from the idle mode to the production mode but still reduce deterioration of the optical source 140.
• the apparatus 100 can prevent unscheduled downtime of the optical source 140, and can also improve dose stability that might otherwise be degraded after long periods of non-use or downtime of the optical source 140.
• the apparatus 100 includes an instruction unit 110 configured to create an idle plan 115 that includes a set of coded properties that together define operation of the optical source 140 in the idle mode.
• the apparatus 100 includes an idle unit 120 in communication with the instruction unit 110, the idle unit 120 being configured to communicate with the optical source 140.
• the idle unit 120 is configured to receive, from the instruction unit 110, the idle plan 115; and to store the idle plan 115 for later use.
• one or more of the idle unit 120 and the instruction unit 110 are distinct from the optical source 140 and the output device 165. In other implementations, one or more of the idle unit 120 and the instruction unit 110 are integrated within the output device 165.
• the instruction unit 110 can provide the idle plan 115 to the idle unit 120 at any appropriate time, as long as it is provided before the optical source 140 needs to execute the idle plan 115. As shown in Figs. 2B and 2C, the instruction unit 110 has provided or is providing the idle plan 115 to the idle unit 120, and the idle unit 120 provides the idle plan 115 to the optical source 140 upon receiving a command 105 related to the idle mode.
• the idle unit 120 is configured to receive the command 105 related to the idle mode from one or more of: the output device 165 and an entity other than the output device 165. For example, a human operator or another computer (such as within the output device 165 or the instruction unit 110) can provide the command 105 to the idle unit 120.
• the idle unit 120 is configured to receive the command 105 related to the idle mode during production mode, during idle mode, or during a time other than the production mode and the idle mode.
• the optical source 140 can be a pulsed optical source that produces a pulsed production light beam 160.
• Operating the optical source 140 in production mode causes wear on components within the optical source 140 due at least in part to the requirements for operating at high repetition rates and intense pulse powers. Accordingly, operation of the optical source 140 in the production mode also uses substantial resources within the optical source 140.
• the output device 165 no longer requires the production light beam 160, it makes sense to reduce the usage of the optical source 140 to prevent the optical source 140 from wearing out too rapidly.
• it may not be practical to completely shut down the optical source 140 at this time because doing so makes it much more time consuming to restart the optical source 140 (to return to the production mode) after a period of inactivity.
• This time that is lost performing a restart from a complete shutdown of the optical source 140 means that time is lost operating the output device 165, which causes a loss of efficiency in operation of the output device 165.
• the optical source 140 is more likely to suffer from transient effects (surges or spikes in operating parameters) when transitioning from a full production mode to a complete shutdown or transitioning from a period of inactivity to a full production mode. Because of this, the apparatus 100 operates the optical source 140 in the idle mode in a manner that reduces resources used, reduces transient effects, expands the life of the optical source 140, and also maintains the optical source 140 in a state that requires less time to restart, that is, to return to production mode and ready for production of the production light beam 160.
• Transient effects are often highly variable, different between one optical source 140 and another, change over time, and depend on the specifics and history of the usage of that particular optical source 140. Manifestations of the transient effects can be variable as well. With reference also to Figs.
• transient effects include, for example, changes in efficiency of the excitation mechanism 441 (such as a voltage efficiency), variation in the shape and size of energy burst transients in one or more chambers that house the gain medium 442, transients in spectral bandwidth of the production light beam 160, variations in wavelength of the production light beam 160, variations in other properties of the production light beam 160 such as pointing, divergence, and beam profile, variable sensitivity to changes in the pulse repetition rate of the production light beam 160, and thermal or temperature transients.
• Some of these manifestations exhibit asymptotic behavior as the optical source 140 resumes the production mode and reaches steady state operation. And, the asymptotic behavior of each manifestation can converge at a rate that is distinct from the others.
• the apparatus 100 enables an efficient idle mode and more rapid return to production mode at least in part by using an idle plan 115 in which each property in the set of coded properties can be assigned any value within a continuous range of values.
• the set of coded properties can be considered infinitely programmable within the continuous range of values, and each property can be adjusted or modified over time.
• each property is not limited to a set of distinct values and each property can take on any value that can be programmed, where the only limitations are that of practical limits and not theoretical limits.
• the set of coded properties can include any number of firing patterns, the properties can be arranged in any order, sequences of firing patterns can be changed at any time, properties or firing patterns can be repeatable.
• the idle plan 315 including a sequence 316 of firing patterns 317i, where i is any positive integer.
• Each firing pattern 317i includes a set of the coded properties that together define the pulsed idle light beam 162.
• the sequence 316 begins with the following firing patterns: [FP1] : [FP2] : [FP1] : [FP3] : [FP3] : [FP1].
• the sequence of the idle plan 115 can be re-entrant, meaning that the sequence can be interrupted while being executed and then it can be restarted at the point in the sequence at which it was stopped.
• the sequence in the idle plan 115 can be restarting, meaning that is starts from the beginning each time the idle mode is entered.
• Each firing pattern 317i includes, for example, one or more of: a rate at which the idle light beam produces pulses; an energy of the pulses of the idle light beam; a total number of bursts of the pulses of the idle light beam; a number of pulses within each burst; an interval between bursts; and pauses that extend the interval between bursts.
• a firing pattern FPi can be given by these coded properties: [CPI, CP2, CP3, CP4, CP5, CP6], where CPI corresponds to a total number of bursts of pulses of the idle light beam 162, CP2 corresponds to the repetition rate at which pulses of the idle light beam 162 are produced, CP3 corresponds to the total number of pulses within each burst of the idle light beam 162, CP4 corresponds to the interval between bursts, CP5 corresponds to a target energy of the idle light beam 162, and CP6 corresponds to pauses in time that extend beyond the inter-burst interval.
• CPI corresponds to a total number of bursts of pulses of the idle light beam 162
• CP2 corresponds to the repetition rate at which pulses of the idle light beam 162 are produced
• CP3 corresponds to the total number of pulses within each burst of the idle light beam 162
• CP4 corresponds to the interval between bursts
• the set of coded properties includes one or more of: a voltage applied to an excitation mechanism of the optical source 140 (such as the excitation mechanism 441 of the optical source 440), a discharge timing or differential timing target between two or more chambers of the optical source 140 (such as in the optical source 640 of Fig. 6); one or more properties or settings within the optical source 140; and one or more signals provided to actuators within the optical source 140 (such as the actuator signals 445 provided to the optical source 440).
• the apparatus 100 can enable creation of the idle plan 115 at any time, even while the optical source 140 is in production mode (Fig. 2A). Additional features and characteristics of the apparatus 100 will be discussed in greater detail below after a discussion of the structure of the optical source 140 and the output device 165.
• the optical source 440 includes an excitation mechanism 441 and a gain medium 442 operationally controlled by the excitation mechanism 441.
• the optical source 440 is configured to produce a pulsed production light beam 460 during production mode.
• An excitation signal 443 is applied to the optical source 440 and excites the excitation mechanism 441 when the optical source 440 is in the production mode.
• the optical source 440 operates in the idle mode in which the idle unit 120 provides the idle plan 115 to the optical source 440 and the production light beam 460 is not produced for use by the output device 165, as discussed above with respect to Figs.
• the excitation signal 443 is either not applied to the optical source 440 and the excitation mechanism 441 is not excited (such as the idle mode shown in Fig. 2B) or the excitation signal 443 is applied under control of the idle plan 115 (such as the idle mode shown in Fig. 2C).
• the excitation signal 443 is generated by the idle unit 120 and while in the production mode, the excitation signal 443 is generated by a production unit 450.
• the excitation signal 443 is any type of signal that is sufficient to cause the optical source 440 to generate the production light beam 460 (and also the idle light beam 162 when operating in idle mode).
• the excitation mechanism 441 excites the gain medium 442 in response to the excitation signal 443.
• the gain medium 442 is any medium suitable for producing a production light beam 160 at the wavelength, energy, and bandwidth required for the application at the output device 165.
• the gain medium 442 can be a fluid such as a gas or a liquid, a crystal, a glass, or a semiconductor.
• the excitation mechanism 441 is any mechanism capable of exciting the gain medium 442.
• the excitation mechanism 441 can be a plurality of electrodes that produce an electric discharge in a volume bounded by the electrodes, such electric discharge exciting the gain medium 442.
• the excitation signal 443 can be, for example, an electrical signal (such as a voltage signal) or a command signal that causes an additional element (such as a voltage or current source) to generate an electrical signal that is provided to the excitation mechanism 441.
• the excitation signal 443 can be a time-varying direct current (DC) electrical signal or an alternating current (AC) electrical signal, such as a sine wave voltage signal or a square wave voltage signal.
• DC direct current
• AC alternating current
• one or more coded properties in the idle plan 115 can correspond to properties of the excitation signal 443, such properties including a maximum amplitude of the time-varying signal, an average amplitude of the time-varying signal, a frequency of the time- varying signal, a duty cycle of the time-varying signal, and/or any other property related to the time-varying signal.
• the optical source 440 is a dual-stage source (such as shown in Fig. 6)
• one or more coded properties of the idle plan 115 can further correspond to the relative timing between these two excitation signals 442.
• the optical source 440 can also include a set 444 of optical elements, the set 444 including one or more optical devices for interacting with, forming, and adjusting the light beam produced by the gain medium 442.
• Such optical elements can include, for example, a spectral feature selection apparatus, which is configured to adjust at least one spectral feature (such as the wavelength or bandwidth) of the light beam 460.
• the spectral feature selection apparatus includes optical components such as prisms, mirrors, and diffractive elements.
• One or more actuator signals 445 can be provided to actuators associated with the optical elements within the set 444 to thereby control operation (for example, motion, geometric arrangement, or other physical aspects) of the optical elements.
• the production unit 450 can supply the actuator signals 445 to the actuators.
• one or more coded properties in the idle plan 115 can correspond to properties of the actuator signals 445.
• An implementation 400 of the apparatus 100 is shown that further includes a metrology unit 451.
• the metrology unit 451 is configured to sense one or more conditions of the optical source 440.
• the instruction unit 110 is in communication with the metrology unit 451.
• the instruction unit 110 is configured to create the idle plan 115 based on an analysis of one or more of the sensed conditions from the metrology unit 451, as discussed further below. Additionally, the metrology unit 451 can also communicate with the production unit 450.
• each unit 525 which can correspond to the instruction unit 110, the idle unit 120, the production unit 450, or the metrology unit 451, can include any of the following modules: an electronic processing module 526, a computer-readable memory module 527, and an input/output module 528.
• the electronic processing module 526 includes one or more processors suitable for execution of a computer program such as a general or special purpose microprocessor, and any one or more processors of any kind of digital computer.
• an electronic processor receives instructions and data from a read-only memory, a random-access memory (RAM), or both.
• the electronic processing module 526 can include any type of electronic processor, which executes instructions and accesses data stored in the memory module 527.
• the electronic processor is also capable of writing data to the memory module 427.
• the memory module 527 can be volatile memory, such as RAM, or non-volatile memory. In some implementations, the memory module 527 includes non-volatile and volatile portions or components.
• the memory module 527 can store data and information that is used in the operation of the unit 525. For example, the memory module 527 within the idle unit 120 can store the idle plan 115 received from the instruction unit 110. As another example, the memory module 527 within the production unit 450 can store information received from the optical source 440 and/or the output device 165.
• the input/output module 528 is any kind of interface that allows the unit 525 to exchange data and signals with an operator, the optical source 440, the other units, and/or an automated process running on another electronic device.
• the instruction unit 110 can receive data relating to the idle plan 115 through the input/output module 528 of the instruction unit 110.
• the instruction unit 110 can receive data from the optical source 440 and/or the output device 165.
• the input/output module 528 can include one or more of a visual display, a keyboard, and a communications interface, such as a parallel port, a Universal Serial Bus (USB) connection, and or any type of network interface, such as, for example, Ethernet.
• the input/output module 528 also can allow communication without physical contact through, for example, an IEEE 802.11, Bluetooth, or a near-field communication (NFC) connection.
• NFC near-field communication
• the unit 525 is coupled to other units, the optical source 440, and/or the output device 165 through respective data connections.
• These data connections can be a physical cable or other physical data conduit (such as a cable that supports transmission of data based IEEE 802.3), a wireless data connection (such as a data connection that provides data via IEEE 802.11 or Bluetooth), or a combination of wired and wireless data connections.
• each unit 525 (idle unit 120, instruction unit 110, production unit 450, metrology unit 451) is shown as being a separate entity, it is possible, in some implementations, for one or more of the units 525 to be implemented as a part of other components (such as the optical source 440 or output device 165) or other units 525.
• the production unit 450 is a component within or associated with the output device 165.
• an implementation 640 of the optical source 140 and an implementation 600 of the apparatus 100 is shown as a part of a photolithography system 670.
• the optical source 640 produces a pulsed production light beam 660, which is provided to an output device 165 that is a lithography exposure apparatus 665.
• the optical source 640 is, for example, an excimer optical source that outputs the pulsed production light beam 660 (which can be a laser beam).
• the pulsed production light beam 660 enters the lithography exposure apparatus 665, it is directed through a projection optical system 675 and projected onto a wafer 676 to form one or more microelectronic features on a photoresist on the wafer 676.
• the photolithography system 670 also includes an implementation 650 of the production unit 350.
• the production unit 650 is connected to components of the optical source 640 and the lithography exposure apparatus 665.
• the production unit 650 can receive data related to the pulsed production light beam 660 or other information from the lithography exposure apparatus 665 and/or can send commands to the lithography exposure apparatus 665.
• the production unit 650 can receive data related to the optical source 640 from the metrology unit 651. In other examples, the production unit 650 is connected only to the optical source 640.
• the optical source 640 is a two-stage laser system that includes a master oscillator (MO) 643A that provides a seed light beam 645 to a power amplifier (PA) 643B.
• MO master oscillator
• PA power amplifier
• the MO 643 A and the PA 643B can be considered to be subsystems of the optical source 640 or systems that are part of the optical source 640.
• the power amplifier 643B receives the seed light beam 645 from the master oscillator 643A and amplifies the seed light beam 645 to generate the production light beam 660 for use in the lithography exposure apparatus 665.
• the master oscillator 643A can emit a pulsed seed light beam 645, with seed pulse energies of approximately 1 milliJoule (mJ) per pulse, and these seed pulses can be amplified by the power amplifier 643B to about 10 to 15 mJ.
• mJ milliJoule
• the master oscillator 643A includes a discharge chamber 646A having two elongated electrodes 641A (which constitute the excitation mechanism 341), a gain medium 642A that is a gas mixture, and a fan for circulating gas between the electrodes 641 A.
• a resonator is formed between beam turner 647 A (that can constitute a line narrowing module) on one side of the discharge chamber 646A and an output coupler 648A on a second side of the discharge chamber 646A.
• the line narrowing module 647 A can include a diffractive optic such as a grating that finely tunes the spectral output of the discharge chamber 646A.
• the optical source 640 also includes a beam coupling optical system 649 that modifies the size or shape of the output light beam as needed to form the seed light beam 645.
• the metrology unit 651 can include a line center analysis module that receives an output light beam (the seed light beam 645 from the output coupler 648 A).
• the line center analysis module is a measurement system that can be used to measure or monitor a spectral feature such as the wavelength of the seed light beam 645.
• the line center analysis module can be placed at other locations in the optical source 640, or it can be placed at the output of the optical source 640.
• the power amplifier 643B includes a beam coupling optical system 648B that receives the seed light beam 645 from the master oscillator 643A and directs the seed light beam through a discharge chamber 646B, and to a beam turning optical element 647B, which modifies or changes the direction of the seed light beam 645 so that it is sent back into the discharge chamber 646B.
• the discharge chamber 646B includes a pair of elongated electrodes 64 IB, a gain medium 642B that is a gas mixture, and a fan for circulating the gas mixture between the electrodes 641B.
• the gas mixture of the gain media 642 A, 642B used in respective discharge chamber 646 A, 646B can be any gas suitable for producing a light beam at the wavelength and bandwidth required for the application at the output device (the lithography exposure apparatus 665).
• the gas mixture can contain a noble gas (rare gas) such as, for example, argon or krypton, a halogen, such as, for example, fluorine or chlorine and traces of xenon apart from helium and/or neon as buffer gas.
• the gas mixture examples include argon fluoride (ArF), which emits light at a wavelength of about 193 nm, krypton fluoride (KrF), which emits light at a wavelength of about 248 nm, or xenon chloride (XeCl), which emits light at a wavelength of about 351 nm.
• the excimer gain medium (the gas mixture) is pumped with short (for example, nanosecond) current pulses in a high- voltage electric discharge by application of a voltage 643 (the excitation signal 343) to the respective elongated electrodes 641 A, 64 IB.
• the metrology unit 651 can also include a bandwidth analysis module 652, where various parameters (such as spectral features of bandwidth and/or wavelength) of the light beam 660 can be measured.
• the output light beam 660 can also be directed through a beam preparation system 653.
• the beam preparation system 653 can include, for example, a pulse stretcher, where each of the pulses of the output light beam 660 is stretched in time, for example, in an optical delay unit, to adjust for performance properties of the light beam that impinges the lithography exposure apparatus 665.
• the beam preparation system 653 also can include other components that are able to act upon the beam 660 such as, for example, reflective and or refractive optical elements (such as, for example, lenses and mirrors), filters, and optical apertures (including automated shutters).
• the production light beam 660 is a pulsed light beam and can include one or more bursts of pulses that are separated from each other in time. Each burst can include one or more pulses of light.
• a burst includes hundreds of pulses, for example, 100-400 pulses.
• the gain medium 642A (or 642B) is pumped by applying voltage 643 A to the electrodes 641 A, the gain medium 642A emits light.
• the voltage 643 A is applied to the electrodes 641 A in pulses, the light emitted from the gain medium 642A is also pulsed.
• the repetition rate of the pulsed production light beam 660 is determined by the rate at which voltage 643 A is applied to the electrodes 641 A, with each application of voltage 643 A producing a pulse of light.
• the pulse of light propagates through the gain medium 642A and exits the chamber 646A through the output coupler 648A.
• a train of pulses is created by periodic, repeated application of voltage 643A to the electrodes 641 A.
• the repetition rate of the pulses can range between about 500 Hz and 6,000 Hz. In some implementations, the repetition rate is be greater than 6,000 Hz, and can be, for example, 12,000 Hz or greater.
• the signals from the production unit 650 can also be used to control the application of energy to the electrodes 641A, 641B within the master oscillator 643A and the power amplifier 643B, respectively, for controlling the respective pulse energies of the master oscillator 643A and the power amplifier 643B, and thus, the energy of the production light beam 660.
• the amount of delay can influence properties of the production light beam 660, such as the amount of coherence in the production light beam 660 or the bandwidth of the production light beam 660.
• the pulsed production light beam 660 can have an average output power in the range of tens of watts, for example, from about 50 W to about 130 W.
• the irradiance (that is, the average power per unit area) of the light beam 660 at the output may range from 60 W/cm 2 to 80 W/cm 2 .
• the instruction unit 110 creates the idle plan 115, and provides the created idle plan 115 to the idle unit 120 which is associated with the optical source 140.
• the idle unit 120 Upon receipt of the command 105, the idle unit 120 provides the idle plan 115 to the optical source 140 to thereby operate the optical source 140 in idle mode, as shown in Figs. 2B and 2C.
• the idle plan 115 that is created can be applied to a plurality of distinct optical sources. An implementation of such an arrangement is shown in Fig. 7. In Fig.
• an apparatus 778 includes the instruction unit 110 and three optical source systems 778A, 778B, 778C, with each optical source system 778A, 778B, 778C including a respective optical source 740A, 740B, 740C. While three optical source systems 778A, 778B, 778C are shown in the apparatus 778, it is possible for the idle plan 115 to be applied to only one or two or more than three optical source systems.
• Each optical source 740A, 740B, 740C can be in service relative to its respective output device 765A, 765B, 756C at any time.
• each optical source 740A, 740B, 740C is configured to be in one of a plurality of modes of operation including: a production mode in which a production light beam is produced for use by the output device 765 A, 765B, 765C; and an idle mode in which the production light beam is not being produced for use by the output device 765 A, 765B, 765C.
• the optical sources 740A, 740C are operating in idle mode and producing a respective idle light beam 762A, 762C, while the optical source 740B is operating in production mode under control of the production unit 750B and producing the production light beam 760B.
• the instruction unit 710 supplies the idle plan 715 to each respective idle unit 720A, 720B, 720C (prior to the idle plan 715 being implemented by an optical source). Moreover, the idle units 720A, 720C have received respective commands 705 A, 705C to provide the idle plan 715 to the respective optical source 740A, 740C.
• the idle plan 715 can be provided to an optical source 740 A, 740B, 740C at any time (after it has been received by the respective 720A, 720B, 720C). For example, it can be provided at the same time to two or more optical sources such as shown in Fig. 7 to optical sources 740A, 740C. Or, it can be provided at distinct times such as shown in Fig. 7 in which the idle plan 715 is not being provided to the optical source 740B but is being provided to the optical source 740A, 740C. In this way, the idle plan 715 is modular.
• the optical source 740A, 740B, 740C can share some properties in common, while some properties can be distinct.
• an idle plan 715 that specifies firing pulse repetition rates up to 6000 Hz can only be applied to an optical source capable of 6000 Hz operation and not to optical sources capable of repetition rates no greater than 4000 Hz.
• Some other properties between the optical sources 740A, 740B, 740C may need to be shared in order for the modularity of the idle plan 715 to work between all three optical sources 740A, 740B, 740C.
• a procedure 880 is performed by the apparatus 100 (or the apparatus 400) for controlling the operating mode of the optical source 140 (or any of the optical sources 440, 640, 740A, 740B, 740C).
• the procedure 880 is performed in conjunction with a procedure 890 performed by the optical source 140.
• the procedure 880 includes creating the idle plan 115 (881), the idle plan 115 including the set of coded properties that together define operation of the optical source 140 in the idle mode.
• the procedure 880 also includes determining whether the command 105 is received (882), and providing the idle plan 115 to the optical source 14 if the command 105 has been received (883).
• the procedure 890 includes operating the optical source 140 in the production mode, in which the optical source 140 is producing the production light beam 160 for use by the output device 165 (891).
• the procedure 890 includes determining whether an idle command is received (892).
• the idle command is a command instructing the optical source 140 to operate in the idle mode in which the production light beam 160 is not being produced for use by the output device 165.
• idle command is provided by an external entity such as the production unit 450 or a manual user. In order for the optical source 140 to be able to enter idle mode upon receipt of the idle command (892), the provision of the idle plan 115 (883) needs to occur prior to the receipt of the idle command (892).
• the optical source 140 executes the provided idle plan 115 (893) upon receipt of the idle command (892). Specifically, the optical source 140 operates in idle mode based on the provided idle plan 115 (893). Additionally, the procedure 890 can also include halting operation of the optical source 140 in production mode before beginning operation in idle mode. For example, upon receipt of the idle command at 892, the optical source 140 can halt operation in production mode. While operating in idle mode (893), the optical source 140 determines whether an instruction or command (such as from the production unit 450 or a user) to end operation in idle mode is received (894), and if such an instruction is received (894), the optical source determines whether an instruction is received to enter production mode of operation (895). If an instruction is received to enter the production mode of operation (895), then the optical source operates in production mode (891). Otherwise, the procedure 890 ends.
• an instruction or command such as from the production unit 450 or a user
• the optical source 140 can be enabled to operate in production mode (891) under control of the production unit 450.
• the optical source 140 can be enabled to operate in idle mode (893) under control of the idle unit 120.
• the idle plan 115 can be sent to the idle unit 120 and stored by the idle unit 120 until the command 105 is received (882) at the idle unit 120.
• the idle unit 120 can receive the command 105 (882) from one or more of: the output device 165 and an entity (such as a user or another computer or machine) other than the output device 165.
• the idle unit 120 can receive the command 105 (882) from the instruction unit 110.
• the idle unit 120 can receive the command 105 (882) while the optical source 140 is operating in production mode, while the optical source 140 is operating in idle mode, or during a time other than operation in the production mode and the idle mode, or at any time during the procedure 890.
• the idle unit 120 can provide the idle plan 115 to the optical source 140 (883).
• the receipt of the idle plan 115 at the optical source 140 can occur at any moment in time including while operating the optical source 140 in the production mode, as long as it occurs prior to receipt of the idle command (892). It is alternatively or additionally possible to receive a new idle plan 115 while operating in the idle mode (893). Moreover, each property in the set of coded properties (of the idle plan 115) can be assigned any value within a range and the value is not limited to a set of discrete values.
• the procedure 880 can also include storing the idle plan 115 (for example, at the idle unit 120) after it is created (881).
• the idle plan 115 can be stored within the memory module 527 of the idle unit 120.
• the idle plan 115 provided to the optical source 140 can be accompanied by the instruction to begin operation in idle mode (892).
• This instruction to the optical source 140 to begin operation in idle mode can include one or more instmctions to produce the idle light beam 162, such idle light beam 162 being a light beam that does not fall within a set of production properties that are required by the output device 140, such as shown in Fig. 2C.
• This instruction to the optical source 140 to begin operation in idle mode (892) can include one or more instructions to produce no light beam at all, such as shown in Fig. 2B.
• the optical source 140 can produce a pulsed light beam as the production light beam 160 and as the idle light beam 162.
• the set of coded properties of the idle plan 115 can include a sequence of firing patterns, with each firing pattern defining the pulsed idle light beam 162, such as shown in Fig. 3.
• a firing pattern FPi includes one or more coded properties.
• Examples of possible coded properties include: a rate at which the idle light beam 162 produces pulses; an energy of the pulses of the idle light beam 162; a total number of bursts of the pulses of the idle light beam 162; a number of pulses within each burst; an interval of time between bursts; and temporal pauses that extend the interval of time between the bursts of the pulses of the idle light beam 162.
• the set of coded properties can include the value of the excitation signal 443 provided to the excitation mechanism 441.
• this excitation signal 443 can be a voltage provided to electrodes and thus, a coded property can include a value or set of values associated with this voltage.
• the set of coded properties can include a target value of a discharge timing between the two or more chambers 646 A, 646B. This discharge timing can correspond to the difference in timing between the occurrence of a pulse produced by the master oscillator 643 A and a pulse produced by the power amplifier 643B.
• the set of coded properties can include one or more properties or settings within the optical source 140.
• the set of coded properties can include one or more signals provided to actuators within the optical source 140.
• the set of coded properties can include one or more signals provided to actuators that control optical elements within the line narrowing module 647 A.
• One of the actuators associated with the line narrowing module 647A can adjust a position or angle of one or more prisms relative to the grating to thereby adjust a spectral property of the seed light beam 645 (and thus, the idle light beam that is produced from the seed light beam 645 during idle mode).
• the instruction unit 110 creates the idle plan 115 (881).
• the instruction unit 110 can create the idle plan 115 (881) based on an analysis of one or more sensed conditions of the optical source 140.
• the sensed conditions of the optical source 140 can be provided to the instruction unit 110 from the metrology unit 451.
• the instruction unit 110 can create the idle plan 115 (881) based on an input from a user, for example, through the input/output module 528 within the instruction unit 110.
• the instruction unit 110 can create the idle plan 115 (881) based on an analysis of a prior state of the optical source 140.
• the instruction unit 110 can create the idle plan 115 (881) based on an analysis that seeks to optimize or improve a performance of one or more of the optical source 140 and the output device 165. [0091]
• the instruction unit 110 can create the idle plan 115 (881) based on an analysis that includes determining a sensitivity of the optical source 140 to changes in values of one or more of the coded properties. For example, the instruction unit 110 can probe the optical source 140 by modifying the values of coded properties and then analyze how sensed conditions of the optical source 140 change (by way of the metrology unit 451). The instruction unit 110 can determine the sensitivity of the optical source 140 to changes to the pauses that extend the interval between bursts of pulses of the idle light beam 162.
• the instruction unit 110 can determine the sensitivity of the optical source 140 to changes to the rate at which the idle light beam 162 produces pulses.
• the instruction unit 110 can determine the sensitivity of the optical source 140 to changes to the energy of the pulses of the idle light beam 162.
• the instruction unit 110 can determine the sensitivity of the optical source 140 to changes to the total number of bursts of the pulses of the idle light beam 162.
• the instruction unit 110 can determine the sensitivity of the optical source 140 to changes to the number of pulses within each burst of the idle light beam 162.
• the instruction unit 110 can determine the sensitivity of the optical source 140 to the changes in the values of one or more of the coded properties by analyzing data collected from the metrology unit 451 during operation of the optical source 140 in a prior idle mode, in a prior production mode, or in both a prior idle mode and a prior production mode.
• the instruction unit 110 can determine how best to create the idle plan 115 (881).
• the procedure 890 can also include one or more queries (that could take place at any time during idle mode operation), each query determining whether an instruction has been received to end idle mode operation (894) and enter production mode operation (895).
• the procedure 890 can switch from operation of the optical source 140 in idle mode to production mode upon receipt of such instruction.
• the idle plan 115 is repeated infinitely by the optical source 140 during operation in idle mode (893).
• the optical source 140 in order to stop operating in idle mode, the optical source 140 would need to receive a command to halt or stop (894).
• the idle plan 115 is repeated a limited number of times, after which the optical source 140 automatically stops operating in idle mode (and enters a true idle mode where it stops producing any light beam until the optical source 140 is commanded otherwise (for example, if instructed to enter production mode (895) or enter another idle mode (892).
• the idle plan 115 has a limited number of firing patterns ([FPi], where i is finite), and after all the firing patterns are exhausted, the optical source 140 automatically stops firing and waits for a next instruction to enter production mode (891) or for receipt of a new idle plan 115 to be loaded and executed (893).
• idle modes and idle plans 115 are discussed next. Any of the idle modes and idle plans 115 can be operated at any time, and are not mutually exclusive from each other. Thus, it may be that a first set of idle plans are created in a particular manner by the instruction unit 110 for the optical source 140 while a second set of idle plans are created in a different manner by the instruction unit for the same optical source 140. The first set of idle plans and the second set of idle plans can be used at different times, and selected for use based on the circumstances surrounding operation of the optical source 140 or the state of the output device 165.
• the idle plan 115 includes an enable/disable flag that instructs the optical source 140 to operate in either a true idle mode, in which the optical source 140 does not produce any pulses of a light beam, as shown in Fig. 2B, or a warm idle mode, in which the optical source 140 produces the idle light beam 162, as shown in Fig. 2C.
• the flag is set to “enable,” this is an instruction to the optical source 140 to operate in the warm idle mode upon receipt of the idle plan 115.
• the enable/disable flag can be included in the command 105 provided to the idle unit 120; so that the idle unit 120 instructs the optical source 140 to enter the true idle mode if the disable flag is provided, without having to provide an entire idle plan 115 to the optical source 140.
• the command 105 can also be used to instruct the idle unit 120 to halt or exit operation of the optical source 140 in the warm idle mode. In other implementations, even if the optical source 140 has received an idle plan 115 to follow and is operating in warm idle mode, it may be prudent or necessary for the optical source 140 to actually not produce the idle light beam 162 at all even though the optical source 140 is commanded to operating in idle mode.
• an operator of the output device 165 could value saving pulses of the light beam 162 above all else, and is willing to accept some performance degradation after exiting idle mode and entering production mode. Or there may be a need for an easy and quick override to the idle plan 115 that instructs the optical source 140 to operate in a warm idle mode.
• the command 105 is an external manual command such as provided by a user or by the output device 165.
• the command 105 can be sent at any time. In other implementations, the command 105 is sent upon the occurrence of an automatic event.
• the command 105 can be sent to the idle unit 120 to instruct the optical source 140 to enter true idle mode if the metrology unit 451 senses an error that requires the stoppage of the production light beam 160 (or the idle light beam 162). In this example, the metrology unit 451 communicates the command 105 to the idle unit 120.
• the idle plan 115 is created and provided in a manual configuration.
• the sequence 316 shown in Fig. 3, including the firing patterns 317i in the idle plan 115 for operating in warm idle mode can be listed in a file, other media, or can be hard coded within software running on the instruction unit 110 (and provided to the idle unit 120 as the idle plan 115). In this way, the sequence 316 is pre-programmed.
• the optical source 140 executes the sequence 316 contained in the idle plan 115.
• the idle plan 115 can be stored in the idle unit 120, which can be local to the optical source 140, or some tightly coupled hardware, such as, for example, a general purpose computer communicating with the optical source 140.
• Such general purpose computer can receive data from the optical source 140, send commands to the optical source 140, store data, and send data to other users, such as operators of the output device 165, customers, or field service personnel.
• the general purpose computer can execute programs (with the data it receives from the optical source 140), make decisions, and decide which control commands to send to the optical source 140 or what data to send to users.
• Such general purpose computer can be used to implement the idle unit 120.
• the idle plan 115 is created and provided to the optical source 140 in a dynamic configuration.
• the instruction unit 110 determines the idle plan 115, including the sequence 316 of firing patterns 317i and provides the idle plan 115 to the idle unit 120, which provides it to the optical source 140.
• the optical source 140 accepts the idle plan 115 and operates in the warm idle mode.
• the transmission of the idle plan 115 from the idle unit 120 to the optical source 140 can occur by uploading a new file to a controller within the optical source 140, and the controller in the optical source 140 reads and executes the file.
• the idle unit 120 directly controls the optical source 140, such as when implemented within the general purpose computer discussed above.
• the idle unit 120 can control some aspects of the optical source 140 (such as, for example, actuator settings) and the onboard controller in the optical source 140 can control other aspects (such as the pulse rate and burst pattern).
• the transmission of the idle plan 115 from the idle unit 120 to the optical source 140 can occur by being transmitted directly to software operated by the controller within the optical source 140, by way of a stream of one or more commands, data, extant configuration items such as configurables, parameters, and/or machine constants.
• the instruction unit 110 can create the sequence 316 of firing patterns 317i using a dynamic adaptive configuration.
• the instruction unit 110 can use data collected by the optical source 140 or the metrology unit 451 during a prior or current operation of the optical source 140 to create the idle plan 115.
• the instruction unit 110 can perform a process to optimize performance of the optical source 140 over some parameter space, and then the instruction unit 110 can continually or periodically update the process.
• the instruction unit 110 uses data that is sensed and stored from the optical source 140 as it operates to produce the production light beam 160 for the output device 165.
• the instruction unit 110 can use the data obtained from the optical source 640 in production mode while the lithography exposure apparatus 665 processes several wafers 676.
• the instruction unit 110 can determine how sensitive the optical source 640 is to each length of firing pauses broken into ranges; for example, pauses can range from inter-burst intervals, which can take 50-100 milliseconds (ms), to wafer line changes, which can take 100-200 ms, to wafer exchanges, which can take 15-60 seconds, to lot exchanges, which can take at least 300 seconds, to longer pauses.
• the instruction unit 110 can determine which pause ranges the optical source 140 is most sensitive to, and then the instruction unit can set up the firing pattern 317i to instruct the optical source 140 to produce pulses of the idle light beam 162 in accordance with those pause ranges.
• the instruction unit 110 can adjust the idle plan 115 to ensure that the optical source 140 operates in a way that ensures that a gas controller responds in a manner to maintain an acceptable state of the gas mixture (such as the gas mixture 642).
• the idle plan 115 can be adjusted to ensure a particular component of the gas mixture 642 is maintained above a certain concentration within the gas mixture 642.
• the instruction unit 110 can send the command 105 to the idle unit 120 to enter warm idle mode at a pre-set time, and without waiting to be instructed.
• the instruction unit 110 can obtain data collected from the optical source 140 (for example, via the metrology unit 451) during operation in prior warm idle modes to determine how sensitive the optical source 140 is to particular properties or changes in properties, such as pauses in the firing of the optical source 140 (which produces pauses between the pulses of the idle light beam 162), repetition rates at which the pulses of the idle light beam 162 are produced, energy targets of the pulses of the idle light beam 162, and duty cycles.
• the instruction unit 110 and/or the idle unit 120 can even send a test idle plan 915t to the optical source 140 to operate the optical source 140 according to set of test firing patterns 917T and produce a test light beam 962t.
• the instruction unit 110 can make adjustments to the idle plan 115 (including the sequence 316 and firing patterns 317i) in such a way as to produce pulses at the most sensitive conditions (or properties), thus allowing the optical source 140 to train its other adaptive or learning algorithms under these most sensitive conditions.
• One way to accomplish this is for the idle unit 120 to adjust the firing patterns 917T in one direction and then the instruction unit 110 can determine whether sensitivity increases by such adjustment (for example, by analyzing one or more outputs from the metrology unit 451). If the instruction unit 110 determines that the sensitivity increases, then the idle unit 120 can continue adjusting the firing patterns 917T until the instruction unit 110 determines that the sensitivity ceases to increase (or decreases or reaches a boundary).
• the idle unit 120 can adjust in a different (for example, orthogonal or opposite) direction.
• the instruction unit 110 obtains data from the metrology unit 451 over much longer periods of time, for example, for millions or tens of millions of pulses of the production light beam 160. The instruction unit 110 can determine whether higher duty cycles are needed based on such data.
• the data provided to the instruction unit 110 can indicate a reduction in efficiency in producing the pulses of the idle light beam 162, and the reduction in efficiency is not sufficiently compensated by a gas injection (such as a fluorine gas injection) into one or more chambers that house the gain medium 442 because such gas injections are governed by an open loop control method under the current idle plan 115.
• a gas injection such as a fluorine gas injection
• An increase in the duty cycle of the idle light beam 162 can cause the fluorine control method to transition to closed loop control, thereby increasing the concentration of fluorine gas injections and improving efficiency.
• the duty cycle of the idle light beam 162 is reduced once the efficiency has recovered to an acceptable level, to reduce the total number of pulses fired during idle mode, and thus save on wear of the optical source 140 and overall cost.
• Such dynamic adaptive operation is possible because the instruction unit 110 (that generates idle plans 115) is imbued with the knowledge of how other parts of the optical source 140 work (such as gas control and operation efficiency), and the instruction unit 110 is able to decide based on this knowledge and measurements of performance of the optical source 140, how to adjust the idle plan 115 to achieve desired results.
• the instruction unit 110 can use previous data relating to how the optical source 140 fires, that is, produces pulses of the light beam (which can be the production light beam 160 or the idle light beam 162), to determine the severity of a cold start for this optical source 140.
• a cold start is a transition from an idle mode (that is not producing the idle light beam 162) to production mode.
• a cold start that is “severe” requires more transition time.
• the instruction unit 110 can create a more aggressive idle plan 115.
• a more aggressive idle plan 115 can include producing pulses at a higher duty cycle to prevent modules within the optical source 140 from becoming too “cold.” A module is too cold if it requires too much time to transition from the idle mode to the production mode.
• the instruction unit 110 can create a less aggressive idle plan 115 having lower duty cycles or longer pauses or even no pulse production (Fig. 2B) if the cold start of the optical source 140 is less severe.
• the apparatus 100 can be configured to start a warm idle mode whenever it detects an opportunity is available.
• the instruction unit 110 can determine that the optical source 140 has been in true idle mode for a significant time, and is getting too cold, and is approaching a state at which a cold start would require a significant amount of time.
• the instruction unit 110 can send the command 105 to the idle unit 120 to automatically enter the warm idle mode (using the idle plan 115) to keep the optical source 140 warm enough to efficiently restart.
• An apparatus for controlling an idle mode of an optical source that, during production mode, produces a production light beam for use by an output device comprising: an instruction unit configured to create an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode in which the production light beam is not being produced for use by the output device, wherein each property in the set can be assigned any value within a continuous range of values; and an idle unit in communication with the instruction unit and configured to communicate with the optical source, the idle unit configured to: receive, from the instruction unit, the idle plan; store the idle plan; and provide the idle plan to the optical source upon receiving a command related to the idle mode.
• each firing pattern includes one or more of: a rate at which the idle light beam produces pulses; an energy of the pulses of the idle light beam; a total number of bursts of the pulses of the idle light beam; a number of pulses within each burst; an interval between bursts; and pauses that extend the interval between bursts.
• the set of coded properties comprises one or more of: a voltage, a discharge timing target between two or more chambers; one or more properties or settings within the optical source; and one or more signals provided to actuators within the optical source.
• the idle unit is configured to receive the command related to the idle mode from one or more of: the output device and an entity other than the output device.
• the instruction unit is configured to create the idle plan based on an analysis of a prior state of the optical source.
• the instruction unit is configured to create the idle plan based on an analysis that seeks to optimize or improve a performance of one or more of the optical source and the output device.
• the changes in the values of one or more of the coded properties include one or more of: changes to the pauses that extend an interval between bursts of pulses of the idle light beam; changes to the rate at which the idle light beam produces pulses; changes to the energy of the pulses of the idle light beam; changes to the total number of bursts of the pulses of the idle light beam; and changes to the number of pulses within each burst.
• determining the sensitivity of the optical source to the changes in the values of one or more of the coded properties includes analyzing data collected from a metrology unit during operation of the optical source in a prior idle mode, in a prior production mode, or in both a prior idle mode and a prior production mode.
• An apparatus comprising: an optical source configured to be in one of a plurality of modes of operation including: a production mode in which a production light beam is produced for use by an output device; and an idle mode in which the production light beam is not produced for use by the output device; a production unit configured to communicate with the optical source and to operate the optical source during the production mode; and an idle unit configured to communicate with the optical source and to: receive, at any moment in time including during any operating mode of the optical source, an idle plan that includes a set of coded properties that together define operation of the optical source in the idle mode; and upon receiving a command, provide the idle plan to the optical source to thereby operate the optical source during the idle mode.
• each firing pattern includes one or more of: a rate at which the idle light beam produces pulses; an energy of the pulses of the idle light beam; a total number of bursts of the pulses of the idle light beam; a number of pulses within each burst; an interval between bursts; and pauses that extend the interval between bursts.
• the set of coded properties comprises one or more of: a voltage, a discharge timing target between two or more chambers; one or more properties or settings within the optical source; and one or more signals provided to actuators within the optical source.
• the idle unit is configured to receive the command related to the idle mode from one or more of: the output device and an entity other than the output device.
• each property in the set of coded properties of the idle plan can be assigned any value within a continuous range of values.
• An apparatus comprising: a plurality of optical sources, at least one optical source being in service relative to an output device, and each in service optical source being configured to be in one of a plurality of modes of operation including: a production mode in which a production light beam is produced for use by the output device; and an idle mode in which the production light beam is not being produced for use by the output device; a production unit configured to communicate with the in service optical source and to operate the in service optical source during the production mode; and an idle unit configured to: receive, at any moment in time, an idle plan that includes a set of coded properties that together define operation of one or more in service optical sources in the idle mode; and upon receiving a command, provide the idle plan to the optical source in service to thereby operate the in service optical source during the idle mode.
• the idle plan includes a set of coded properties that together define operation of a plurality of in service optical sources in the idle mode.
• the idle unit is configured to provide the idle plan to each of the in service optical sources of the plurality to thereby operate the in service optical sources during respective idle modes.
• the in service optical source produces a pulsed idle light beam
• the set of coded properties comprises a sequence of a plurality of firing patterns, each firing pattern defining the pulsed idle light beam.
• a method for controlling a mode of an optical source comprising: enabling operation of the optical source in either a production mode in which the optical source is producing a production light beam for use by an output device or an idle mode in which the production light beam is not being produced for use by the output device; receiving, at any moment in time including while operating the optical source in the production mode or in the idle mode, an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode; and upon receipt of a command related to the idle mode, providing the idle plan to the optical source.
• providing the idle plan to the optical source comprises one or more of: beginning operating the optical source in idle mode based on the provided idle plan after halting operating the optical source in production mode; and continuing operating the optical source in idle mode based on the provided idle plan.
• a method for controlling a mode of an optical source comprising: enabling operation of the optical source in either a production mode in which the optical source is producing a production light beam for use by an output device or in an idle mode in which the production light beam is not being produced for use by the output device; receiving an idle plan that includes a set of coded properties that together define operation of the optical source in an idle mode, wherein each property in the set can be assigned any value within a range and not limited to a set of discrete values; and upon receipt of a command related to the idle mode, providing the idle plan to the optical source.
• providing the idle plan to the optical source comprises one or more of: beginning operating the optical source in idle mode based on the provided idle plan after halting operating the optical source in production mode; and continuing operating the optical source in idle mode based on the provided idle plan.

Landscapes

• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Optics & Photonics (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Lasers (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=76662531

Family Applications (1)

Country Status (4)

Citations (2)

Family Cites Families (14)

• 2021
  • 2021-05-25 WO PCT/US2021/034102 patent/WO2021262374A1/en active Application Filing
  • 2021-05-25 CN CN202180045302.9A patent/CN115735306A/zh active Pending
  • 2021-05-25 JP JP2022570358A patent/JP2023532401A/ja active Pending
  • 2021-06-04 TW TW110120369A patent/TWI794828B/zh active

Patent Citations (2)

Also Published As

Similar Documents

Legal Events