Plasma-based EUV light source
Various mechanisms are provided relating to plasma-based light source that may be used for lithography as well as other applications. For example, a device is disclosed for producing extreme ultraviolet (EUV) light based on a sheared plasma flow. The device can produce a plasma pinch that can last several orders of magnitude longer than what is typically sustained in a Z-pinch, thus enabling the device to provide more power output than what has been hitherto predicted in theory or attained in practice. Such power output may be used in a lithography system for manufacturing integrated circuits, enabling the use of EUV wavelengths on the order of about 13.5 nm. Lastly, the process of manufacturing such a plasma pinch is discussed, where the process includes providing a sheared flow of plasma in order to stabilize it for long periods of time.
1. A method for producing extreme ultraviolet (EUV) light, comprising:
accelerating a plasma to produce a sheared plasma flow;
forming a plasma pinch from the accelerated plasma; and
sustaining the plasma pinch for a period of time so as to allow the plasma to emit EUV light during at least a portion of said period of time.
2. The method according to claim 1 , further comprising applying a voltage to the plasma before it is accelerated.
3. The method according to claim 2 , wherein the applied voltage is greater than a minimum voltage to achieve a plasma formation.
4. The method according to claim 3 , wherein said minimum voltage is about 500 volts.
5. The method according to claim 1 , wherein said period of time is longer than a time required for said plasma to transit the length of said pinch.
6. The method according to claim 1 , wherein said period of time is longer than a stability time for a static state of said plasma.
7. The method according to claim 6 , wherein said stability time is about 10 nanoseconds.
8. The method according to claim 1 , wherein said plasma pinch is formed at a rate of about 1 to 10 kilohertz.
9. The method according to claim 1 , further comprising controlling the wavelength of said emitted light by a selection of said plasma.
10. An apparatus for producing extreme ultraviolet (EUV) light, comprising:
a first electrode and a second electrode, such that a pinch can be formed between the first electrode the second electrode;
an injection port configured to inject gas or plasma into a region formed between the first electrode and the second electrode, said region being configured to house a sheared flow of said gas or said plasma;
an access port configured to provide light emanating from said gas or plasma that forms said pinch.
11. The apparatus according to claim 10 , further comprising a device for applying a voltage greater than a minimum voltage required to achieve a plasma or gas formation.
12. The apparatus according to claim 10 , wherein said minimum voltage is at least 500 volts.
13. The apparatus according to claim 10 , wherein a device is configured to apply a voltage to the gas or plasma before it is accelerated.
14. The apparatus according to claim 10 , wherein said pinch is formed between said first electrode and said second electrode at a rate of about 1 to 10 kilohertz.
15. The apparatus according to claim 10 , wherein said pinch is formed between said first electrode and said second electrode for a period of time that is longer than a time required for the gas or plasma to transit the length of said pinch.
16. The apparatus according to claim 10 , wherein said pinch is formed between said first electrode and said second electrode for at least 10 nanoseconds.
17. The apparatus according to claim 10 , wherein said apparatus is a light source configurable within a lithography apparatus.
18. A lithography system for producing light, comprising:
a plasma source for emitting light, wherein the plasma source generates the light using sheared flow stabilized plasma;
a mask, wherein the plasma source is directed at the mask; and
a focusing apparatus for controlling the light emanating from the plasma source and passing through at least one aperture of the mask.
19. The system according to claim 18 , wherein the plasma source is configured to emit said light at a rate of about 1 to 10 kilohertz.
20. The system according to claim 18 , wherein the plasma source is configured to emit said light for a desired wavelength.