초록 ▼

A method of operating an immersion lithography system, including steps of immersing at least a portion of a wafer to be exposed in an immersion medium, wherein the immersion medium comprises at least one bubble; directing an ultrasonic wave through at least a portion of the immersion medium to disru

A method of operating an immersion lithography system, including steps of immersing at least a portion of a wafer to be exposed in an immersion medium, wherein the immersion medium comprises at least one bubble; directing an ultrasonic wave through at least a portion of the immersion medium to disrupt and/or dissipate the at least one bubble; and exposing the wafer with an exposure pattern by passing electromagnetic radiation through the immersion medium subsequent to the directing. Also disclosed is a monitoring and control system for an immersion lithography system.

대표청구항 ▼

What is claimed is: 1. A method of operating an immersion lithography system, comprising: immersing a wafer to be exposed in a liquid immersion medium; directing a laser beam through a portion of the immersion medium; determining if a portion of the laser beam beyond a predetermined threshold valu

What is claimed is: 1. A method of operating an immersion lithography system, comprising: immersing a wafer to be exposed in a liquid immersion medium; directing a laser beam through a portion of the immersion medium; determining if a portion of the laser beam beyond a predetermined threshold value becomes scattered, thereby indicating that at least one bubble is present in the immersion medium; directing an ultrasonic wave into at least the portion of the immersion medium to disrupt and/or dissipate the at least one bubble; and exposing the wafer with an exposure pattern by passing electromagnetic radiation through the immersion medium subsequent to the directing. 2. The method of claim 1, wherein at least one of the at least one bubble is disposed in a traversal volume of the immersion medium. 3. The method of claim 1, wherein the immersion medium comprises a refractive index substantially similar to a refractive index of optical elements in the system. 4. The method of claim 1, wherein the ultrasonic wave has a frequency in the range from about 20,000 Hz to about 500 MHz. 5. The method of claim 1, wherein the ultrasonic wave disrupts localized structure of the immersion medium to disrupt and/or dissipate the at least one bubble. 6. The method of claim 1, wherein the at least one bubble comprises a bubble having a diameter in a range from about 20 nm to about 100 μm. 7. The method of claim 1, wherein the at least one bubble comprises a bubble having a diameter sufficient to interfere with the electromagnetic radiation used in the exposing. 8. The method of claim 1, wherein the method results in reduced scattering of the electromagnetic radiation. 9. The method of claim 1, wherein the bubbles comprise air bubbles. 10. The method of claim 1, further comprising exposing the wafer with the exposure pattern if the determining indicates that a scattered portion of the laser beam is less than the predetermined threshold value. 11. The method according to claim 1, wherein the determining is carried out by analyzing information relating to detected scattered light. 12. The method according to claim 11, wherein the information relating to detected scattered light comprises intensity of the scattered light, location of the scattered light and combinations thereof. 13. The method according to claim 1, wherein the determining is carried out by analyzing information relating to a detection of the laser beam. 14. The method according to claim 13, wherein the information relating to the laser beam comprises intensity of the laser beam incident on a detecting assembly, location of the laser beam incident on a detecting assembly, and combinations thereof. 15. The method according to claim 1, wherein the entire traversal volume is monitored for the presence of the at least one bubble. 16. The method according to claim 15, wherein multiple laser beams are used to monitor for the presence of the at least one bubble. 17. The method according to claim 15, wherein at least one laser beam is scanned through the traversal volume to monitor for the presence of the at least one bubble. 18. The method according to claim 1, further comprising controlling the immersion lithography system to direct the ultrasonic wave into at least a portion of the immersion medium if at least one bubble is detected. 19. The method according to claim 18, wherein the immersion lithography system is controlled to wait a predetermined period of time and repeat the directing and determining following the directing an ultrasonic wave. 20. A method of operating an immersion lithography system, comprising: immersing a wafer to be exposed in a liquid immersion medium; directing a laser beam through a volume of the immersion medium through which an exposure pattern is configured to traverse; determining if a portion of the laser beam beyond a predetermined threshold value becomes scattered, thereby indicating that at least one bubble is present in the traversal volume; directing an ultrasonic wave through at least the traversal volume to disrupt and/or dissipate the at least one bubble; and exposing the wafer with an exposure pattern by passing electromagnetic radiation through the traversal volume subsequent to the directing. 21. The method of claim 20, wherein the at least one bubble comprises a bubble having a diameter sufficient to interfere with the electromagnetic radiation used in the exposing. 22. The method of claim 20, wherein the method results in reduced scattering of the electromagnetic radiation.