# US 9,049,774 B2 · EUVL light source system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,049,774 B2 - Document ID: US9049774B2 - Status: Granted - Kind: B2 - Application number: 14/333,268 - Filed: 2014-07-16 - Published: 2015-02-05 - Granted: 2015-06-02 - Earliest claimed: 2013-07-24 - Assignees: Semiconductor Manufacturing International (Shanghai) Corporation - Applicants: Semiconductor Manufacturing International (Shanghai) Corporation - Inventors: Emily Yixie Shu - Web page: https://patentgrep.com/patent/US9049774B2 ## CPC - H05G 2/009: {Auxiliary arrangements not involved in the plasma generation} - H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321) ## Abstract EUVL light source systems and methods are provided. A laser or a high-voltage-discharge device is used to excite EUV light source material to generate EUV light along with droplets flying out of the EUV light source material. A collector is positioned to guide the EUV light into a desired direction. A cooling assembly is configured to wrap around the collector along the EUV light in the desired direction. At least a first portion of the plurality of molten droplets reaches and condenses on a surface of the cooling assembly. ## Claims ### Claim 1 An EUVL light source system, comprising: a laser configured to provide laser pulses and to excite an EUV light source material to emit EUV light, wherein a plurality of molten droplets is generated to fly out of the EUV light source material; a collector comprising a plurality of reflective mirrors each movable, configured to at least partially surround the EUV light source material and positioned to guide the EUV light into a desired direction; a cooling assembly configured to wrap around the collector along the EUV light in the desired direction, wherein at least a first portion of the plurality of molten droplets reaches and condenses on a surface of the cooling assembly; and a mirror control system synchronized to operate with the laser and configured to control the plurality of reflective mirrors in a reflective state for reflecting the EUV light and in a non-reflective state for allowing at least a second portion of the plurality of molten droplets to pass through adjacent reflective mirrors for preventing contamination from the molten droplets. ### Claim 2 (depends on 1) The system according to claim 1, wherein the cooling assembly comprises an electro-thermal cooling condenser or a cooling material configured therein, the cooling material comprising a water coolant, liquid nitrogen, or liquid helium. ### Claim 3 (depends on 1) The system according to claim 1, wherein the laser provides the laser pulses with a period allowing the second portion of the molten droplets at slower flying speeds than the first portion to pass through adjacent reflective mirrors. ### Claim 4 (depends on 1) The system according to claim 1, wherein: the plurality of reflective mirrors are controlled to move into the non-reflective state at a delay time T1 after the starting time of each laser pulse; and the delay time T1 is configured to open the reflective mirrors to pass the fastest among the second portion molten droplets. ### Claim 5 (depends on 1) The system according to claim 1, wherein: a time length for the plurality of reflective mirrors being controlled in the non-reflective state is greater than the time length for all of the second portion of the molten droplets at various speeds to pass through adjacent reflective mirrors. ### Claim 6 (depends on 1) The system according to claim 1, wherein each of the plurality of reflective mirrors comprises a reflective surface comprising: a material comprising molybdenum, molybdenum alloy, silicon, ruthenium, a ruthenium alloy, or a combination thereof; or a multi-layer structure comprising one or more of a silicon molybdenum film, a molybdenum alloy, ruthenium, and a ruthenium alloy film, formed on a substrate. ### Claim 7 (depends on 1) The system according to claim 1, further comprising: an outer droplet stopper provided on an outer periphery of the collector to receive molten droplets passing through the collector. ### Claim 8 An EUVL light source system, comprising: a high-voltage-discharge device configured to provide a high-voltage discharge pulse to excite an EUV light source material to emit EUV light, wherein a plurality of molten droplets is generated to fly out of the EUV light source material; a collector comprising a plurality of reflective mirrors each movable, configured to at least partially surround the EUV light source material and positioned to guide the EUV light into a desired direction; a cooling assembly configured to wrap around the collector along the EUV light in the desired direction, wherein at least a first portion of the plurality of molten droplets reaches and condenses on a surface of the cooling assembly; and a mirror control system synchronized to operate with the high-voltage-discharge device and configured to control the plurality of reflective mirrors in a reflective state for reflecting the EUV light and in a non-reflective state for allowing at least a second portion of the plurality of molten droplets to pass through adjacent reflective mirrors for preventing contamination from the molten droplets, wherein the plurality of reflective mirrors in the non-reflective state is configured substantially parallel to a flying direction of the second portion of the molten droplets. ### Claim 9 (depends on 8) The system according to claim 8, wherein the cooling assembly comprises an electro-thermal cooling condenser or a cooling material configured therein, the cooling material comprising a water coolant, liquid nitrogen, or liquid helium. ### Claim 10 (depends on 8) The system according to claim 8, wherein the high-voltage-discharge device provides the high-voltage discharge pulse with a period allowing the second portion of the molten droplets at slower flying speeds than the first portion to pass through adjacent reflective mirrors. ### Claim 11 (depends on 8) The system according to claim 8, wherein: the plurality of reflective mirrors are controlled to move into the non-reflective state at a delay time T1 after the starting time of each laser pulse; and the delay time T1 is configured to open the reflective mirrors to pass the fastest among the second portion molten droplets. ### Claim 12 (depends on 8) The system according to claim 8, wherein: a time length for the plurality of reflective mirrors being controlled in the non-reflective state is greater than the time length for all of the second portion of the molten droplets at various speeds to pass through adjacent reflective mirrors. ### Claim 13 (depends on 8) The system according to claim 8, further comprising: an outer droplet stopper provided on an outer periphery of the collector to receive molten droplets passing through the collector. ### Claim 14 A method for configuring an EUVL light source system, comprising: providing a laser or a high-voltage-discharge device to excite an EUV light source material to emit EUV light, wherein a plurality of molten droplets is also generated to fly out of the EUV light source material; positioning a collector to guide the EUV light generated from the EUV light source material into a desired direction, the collector comprising a plurality of reflective mirrors each movable, configured to at least partially surround the EUV light source material; configuring a cooling assembly to wrap around the collector along the EUV light in the desired direction, wherein at least a first portion of the plurality of molten droplets reaches and condenses on a surface of the cooling assembly; and configuring a mirror control system synchronized to operate with the laser or the high-voltage-discharge device to control the plurality of reflective mirrors in a reflective state for reflecting the EUV light and in a non-reflective state for allowing at least a second portion of the plurality of molten droplets to pass through adjacent reflective mirrors for preventing contamination from the molten droplets, wherein the plurality of reflective mirrors in the non-reflective state is controlled substantially parallel to a flying direction of the second portion of the molten droplets. ### Claim 15 (depends on 14) The method according to claim 14, further comprising: configuring the plurality of reflective mirrors to move into the non-reflective state at a delay time T1 after the starting time of each laser pulse, wherein the delay time T1 is configured to open the reflective mirrors to pass the fastest among the second portion molten droplets. ### Claim 16 (depends on 14) The method according to claim 14, further comprising: configuring the plurality of reflective mirrors being in the non-reflective state for a time length greater than a time length for all of the second portion of the molten droplets at different flying speeds to pass through adjacent reflective mirrors. ### Claim 17 (depends on 15) The method according to claim 15, further comprising: providing the laser or the high-voltage-discharge device capable of providing laser pulses or high-voltage-discharge pulses with a period allowing the second portion of the molten droplets at slower flying speeds than the first portion to pass through adjacent reflective mirrors.