Abstract: Systems, apparatuses, and methods are provided for steering aligning a laser beam and a fuel target. An example method can include generating, at a first rate, first sensing data indicative of a first overlap between a fuel target and a laser beam. The example method can further include generating, at a second rate, second sensing data indicative of a second overlap between the fuel target and the laser beam. The method can further include generating, at a third rate, and based on the first sensing data and the second sensing data, a steering control signal configured to steer the laser beam or the fuel target. In some aspects, the second rate can be different from the first rate, and the third rate can be about equal to the first rate. In other aspects, the first rate and the second rate can be about equal to the third rate.

Abstract: A metrology system includes a light beam metrology apparatus configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects; a target metrology apparatus configured to measure one or more properties of a modified target after a target has interacted with the amplified light beam, and to determine a moment when the modified target achieves a reference calibration state; and a control apparatus configured to: receive the reference calibration state and the moment at which the reference calibration state is achieved from the target metrology apparatus; determine a light beam calibration state of the amplified light beam based on the received reference calibration state and the moment at which the reference calibration state is achieved; and provide the light beam calibration state to the light beam metrology apparatus.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: In a laser produced plasma (LPP) extreme ultraviolet (EUV) system, a plasma created from droplets irradiated by a laser pulse can become destabilized. The instability of the plasma can reduce the amount of EUV energy generated over time. While other systems seek to stabilize the plasma by varying a pulse width of the laser pulses, the systems and methods described herein stabilize the plasma by varying an intensity of the laser pulses. The intensity of the laser pulses is varied based on a comparison of the amount of EUV energy generated from current pulse to an expected amount of EUV energy. The intensity of the laser pulses can be varied on a pulse-by-pulse basis by an EUV controller that instructs a pulse actuator.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: In a laser produced plasma (LPP) extreme ultraviolet (EUV) system, a droplet is irradiated by a laser pulse to produce a plasma in a chamber. This generates forces that cause the plasma to destabilize and subsequent droplets to have their flight trajectory and speed altered as they approach the plasma. This destabilization is detectable from oscillations in the amount of EUV energy generated. To reduce the oscillations by stabilizing the plasma and travel of the droplets, a proportional-integral (PI) controller algorithm is used to modify an energy of subsequent laser pulses based on the EUV energy generated in the chamber. By modifying the energy of subsequent laser pulses, the plasma stabilizes, which reduces effects on droplet flight and stabilizes the amount of EUV energy generated, allowing the plasma chamber to operate for longer intervals and to lower the amount of reserve power maintained by a laser source.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: A method and apparatus for control of a dose of extreme ultraviolet (EUV) radiation generated by a laser produced plasma (LPP) EUV light source that combines pulse control mode and pulse modulation. The EUV energy created by each pulse is measured and total EUV energy created by the fired pulses determined, a desired energy for the next pulse is determined based upon whether the total EUV energy is greater or less than a desired average EUV energy times the number of pulses. If the desired pulse energy for the next droplet is within the range of one or more pulse modulation actuators, the pulse is modulated; otherwise, the pulse is fired to miss the droplet. This provides greater control of the accumulated dose as well as uniformity of the EUV energy over time, greater ability to compensate for pulses that generate EUV energy that is higher or lower than nominal expected values, and ability to provide an average EUV energy per pulse that is less than the nominal minimum EUV energy per pulse of the system.

Abstract: A method includes providing a target material that includes a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; controlling a radiant exposure delivered to the target material from the first beam of radiation to within a predetermined range of radiant exposures; and stabilizing a power of the EUV light emitted from the plasma by controlling the radiant exposure delivered to the target material from the first beam of radiation to within the predetermined range of radiant exposures.

Abstract: A method includes providing a target material that includes a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; controlling a radiant exposure delivered to the target material from the first beam of radiation to within a predetermined range of radiant exposures; and stabilizing a power of the EUV light emitted from the plasma by controlling the radiant exposure delivered to the target material from the first beam of radiation to within the predetermined range of radiant exposures.

Abstract: In a laser produced plasma (LPP) extreme ultraviolet (EUV) system, a droplet is irradiated by a laser pulse to produce a plasma in a chamber. This generates forces that cause the plasma to destabilize and subsequent droplets to have their flight trajectory and speed altered as they approach the plasma. This destabilization is detectable from oscillations in the amount of EUV energy generated. To reduce the oscillations by stabilizing the plasma and travel of the droplets, a proportional-integral (PI) controller algorithm is used to modify an energy of subsequent laser pulses based on the EUV energy generated in the chamber. By modifying the energy of subsequent laser pulses, the plasma stabilizes, which reduces effects on droplet flight and stabilizes the amount of EUV energy generated, allowing the plasma chamber to operate for longer intervals and to lower the amount of reserve power maintained by a laser source.

Abstract: A method includes providing a target material that comprises a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; measuring one or more characteristics associated with one or more of the target material and the modified target relative to the first beam of radiation; and controlling an amount of radiant exposure delivered to the target material from the first beam of radiation based on the one or more measured characteristics to within a predetermined range of energies.

Abstract: In a laser produced plasma (LPP) extreme ultraviolet (EUV) system, a plasma created from droplets irradiated by a laser pulse can become destabilized. The instability of the plasma can reduce the amount of EUV energy generated over time. While other systems seek to stabilize the plasma by varying a pulse width of the laser pulses, the systems and methods described herein stabilize the plasma by varying an intensity of the laser pulses. The intensity of the laser pulses is varied based on a comparison of the amount of EUV energy generated from current pulse to an expected amount of EUV energy. The intensity of the laser pulses can be varied on a pulse-by-pulse basis by an EUV controller that instructs a pulse actuator.

Abstract: In LPP EUV systems, sinusoidal oscillations or instabilities can occur in the generated EUV energy. This is avoided by detecting when the LPP EUV system is approaching such instability and adjusting the LPP EUV system by moving the laser beam of the LPP EUV system. Detection is done by determining when the generated EUV energy is at or above a primary threshold. Adjusting the LPP EUV system by moving the laser beam is done for a fixed period of time, until a subsequently generated EUV energy is below the primary threshold, until a subsequently generated EUV energy is below the primary threshold for a fixed period of time, or until a subsequently generated EUV energy is at or below a secondary threshold below the primary threshold.

Abstract: Methods and systems for improved timing of a source laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) generation system are disclosed. Due to forces within the plasma chamber, a velocity of a droplet can slow as it approaches the irradiation site. Because the droplet is slowed, a source laser fires prematurely relative to the slowed droplet, resulting in only a leading portion of the droplet being irradiated. The resulting amount of EUV energy generated from the droplet is proportional to the slowed velocity of the droplet. To compensate, the firing of the source laser is delayed for a next droplet based on the generated EUV energy. Because the firing of the source laser is delayed for the next droplet, the next droplet is more likely to be in position to be more completely irradiated, resulting in more EUV energy being generated from the next droplet.

Abstract: A method and apparatus for controlling the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed. In one embodiment, a seed laser generates both pre-pulses and main pulses which are amplified and irradiate a target material. The widths of the main pulses are adjusted, for example by the use of an EOM or other optical switch, without adjusting the widths of the pre-pulses, to keep the EUV output energy at a desired level. Only if the main pulse widths are longer or shorter than a desired range is the duty cycle of the laser amplifier adjusted, to keep the main pulse widths in the desired range. Adjusting the main pulse widths in this way before adjusting the pump RF duty cycle allows for less adjustment of the duty cycle, thus causing less adjustment to the pre-pulses.