Calibration system for an extreme ultraviolet light source

An alignment method comprising:

• directing a first amplified light beam toward a target space such that an interaction between the first amplified light beam and a moving target in the target space forms a modified target;
• directing a second amplified light beam toward the target space such that an interaction between the second amplified light beam and the modified target in the target space generates plasma;
• adjusting a position of the first amplified light beam relative to the target to cause the first amplified light beam to overlap the target;
• and
• after adjusting the position of the first amplified light beam relative to the target to cause the first amplified light beam to overlap the target, adjusting the position of the second amplified light beam relative to the first amplified light beam to cause the second amplified light beam to overlap the modified target.

An alignment apparatus comprising:

• a light source configured to direct a first amplified light beam toward a target space within a chamber such that an interaction between the first amplified light beam and a moving target in the target space forms a modified target;
• a target metrology apparatus configured to detect the interaction between the first amplified beam and the target;
• and
• a control system in communication with the light source and the target metrology apparatus, the control system configured to:
• analyze the detected interaction output from the target metrology apparatus;
• and
• instruct the light source to adjust a position of the first amplified light beam relative to the target to cause the first amplified light beam to overlap the target, the adjustment being based on the analysis of the detected interaction.

An alignment method comprising:

• directing a first amplified light beam toward a target space within a chamber such that an interaction between the first amplified light beam and a moving target in the target space forms a modified target;
• detecting the interaction between the first amplified beam and the target;
• analyzing the detected interaction;
• and
• adjusting a position of the first amplified light beam relative to the target to cause the first amplified light beam to overlap the target, the adjustment being based on the analysis of the detected interaction.