Abstract: A photographing lens assembly includes, in order from an object side to an image side: a first, a second, a third, a fourth, a fifth and a sixth lens elements. The first lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof, wherein the object-side surface has at least one convex critical point in an off-axis region thereof. The third lens element has an image-side surface being convex in a paraxial region thereof. The fourth lens element has positive refractive power. The fifth lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof, and an image-side surface being convex in a paraxial region thereof. The sixth lens element has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface has at least one convex critical point in an off-axis region thereof.

Abstract: A method for performing a lithography process is provided. The method includes forming a photoresist layer over a substrate, providing a plurality of target droplets to a source vessel, and providing a plurality of first laser pulses according to a control signal provided by a controller to irradiate the target droplets in the source vessel to generate plasma as an EUV radiation. The plasma is generated when the control signal indicates a temperature of the source vessel is within a temperature threshold value. The method further includes directing the EUV radiation from the source vessel to the photoresist layer to form a patterned photoresist layer and developing and etching the patterned photoresist layer to form a circuit layout.

Abstract: A method includes dispensing a droplet into a vacuum chamber; firing a pre-pulse laser to the droplet; sensing a first image of a return beam of the pre-pulse laser from the droplet; after firing the pre-pulse laser, firing a main-pulse laser to the droplet, wherein when the main-pulse laser hits the droplet, the droplet is vaporized into a plasma that emits extreme ultraviolet radiation; after sensing the first image and firing the main-pulse laser, sensing a second image of a return beam of the main-pulse laser from the droplet; and adjusting a plasma position in the vacuum chamber according to at least the second image.

Abstract: A light source for EUV radiation is provided. The light source includes a target droplet generator, a laser generator, and a controller. The target droplet generator is configured to provide target droplets to a source vessel. The laser generator is configured to provide a plurality of first laser pulses according to a control signal to irradiate the target droplets in the source vessel to generate plasma as the EUV radiation. The controller is configured to provide the control signal according to the temperature of the source vessel and droplet positions of the target droplets. When the temperature of the source vessel exceeds a temperature threshold value and a standard deviation of the droplet positions of the target droplets exceeds a first standard deviation threshold value, the controller is configured to provide the control signal to the laser generator, so as to stop providing the first laser pulses.

Abstract: A system for controlling plasma position in extreme ultraviolet lithography light sources may include a vacuum chamber, a droplet generator to dispense a stream of droplets into the vacuum chamber, wherein the droplets are formed from a metal material, a laser light source to fire a plurality of laser pulses, including at least a first pulse and a second pulse, into the vacuum chamber, a sensor to detect an observed plasma position within the chamber, wherein the observed plasma position comprises a position at which the plurality of laser pulses vaporizes a droplet of the stream of droplets to produce a plasma that emits extreme ultraviolet radiation, and a first feedback loop connecting the sensor to the laser light source, wherein the first feedback loop adjusts a time delay between the first and second pulses to minimize a difference between the observed plasma position and a target plasma position.

Abstract: Extreme ultraviolet (EUV) lithography systems are provided. A EUV scanner is configured to perform a lithography exposure process in response to EUV radiation. A light source is configured to provide the EUV radiation to the EUV scanner. A measuring device is configured to measure concentration of debris caused by unstable target droplets in the chamber. A controller is configured to adjust a first gas flow rate and a second gas flow rate in response to the measured concentration of the debris and a control signal from the EUV scanner. A exhaust device is configured to extract the debris out of the chamber according to the first gas flow rate. A gas supply device is configured to provide a gas into the chamber according to the second gas flow rate. The control signal indicates the lithography exposure process is completed.

Abstract: A light source for EUV radiation is provided. The light source includes a target droplet generator, a laser generator, and a controller. The target droplet generator is configured to provide target droplets to a source vessel. The laser generator is configured to provide a plurality of first laser pulses according to a control signal to irradiate the target droplets in the source vessel to generate plasma as the EUV radiation. The controller is configured to provide the control signal according to the temperature of the source vessel and droplet positions of the target droplets. When the temperature of the source vessel exceeds a temperature threshold value and a standard deviation of the droplet positions of the target droplets exceeds a first standard deviation threshold value, the controller is configured to provide the control signal to the laser generator, so as to stop providing the first laser pulses.

Abstract: In accordance with some embodiments, a method of controlling an extreme ultraviolet (EUV) radiation in lithography system is provided. The method includes generating a plurality of target droplets. The method also includes generating a pre-pulse and a main pulse from an excitation laser module to generate EUV light and reflecting the EUV light by a collector mirror. The method further includes measuring a separation between a pre-pulse and a main pulse. Moreover, the method includes determining whether the separation between the pre-pulse and the main pulse in the y-axis is changed, if not adjusting a configurable parameter of the excitation laser module to set the variation in the energy of the EUV light within an acceptable range.

Abstract: An extreme ultraviolet (EUV) light source and a method for patterning a resist layer on a substrate using the EUV light source are disclosed. For example, the EUV light source includes a droplet generator, a droplet catcher, a laser source, a plurality of vanes, and a bucket. The droplet generator is to generate tin droplets. The droplet catcher is opposite to the droplet generator to catch the tin droplets. The laser source is to generate a laser beam striking the tin droplets to form a plasma. The plurality of vanes are arranged around an axis to collect tin debris created from the plasma. The bucket is connected to the vanes and includes a cover, a vane bucket, and a heater. The cover has an opening. The vane bucket is surrounded by the cover. The heater is on a sidewall of the cover and spaced apart from the droplet catcher.

Abstract: An illuminator includes a first facet mirror receiving and reflecting an exposure radiation, an adjustable shielding element disposed on the first facet mirror, the adjustable shielding element adjusting intensity uniformity of the exposure radiation reflected by the first facet mirror, and a second facet mirror receiving and reflecting the exposure radiation reflected by the first facet mirror.

Abstract: A light source for EUV is provided. The light source includes a target droplet generator, a laser generator, and a controller. The target droplet generator is configured to provide target droplets to a source vessel. The laser generator is configured to provide first laser pulses according to a control signal to irradiate the target droplets in the source vessel. The controller is configured to provide the control signal according to at least two of process parameters including temperature of the source vessel, droplet positions of the target droplets, and beam sizes and focal points of the first laser pulses. When the average value or the standard deviation of the temperature of the source vessel and the droplet positions of the target droplets exceed the predetermined range, the controller is configured to provide the control signal to the laser generator to stop providing the first laser pulses.

Abstract: In accordance with some embodiments, a method of controlling an extreme ultraviolet (EUV) radiation in lithography system is provided. The method includes generating a plurality of target droplets. The method also includes generating a pre-pulse and a main pulse from an excitation laser module to generate EUV light and reflecting the EUV light by a collector mirror. The method further includes measuring a separation between a pre-pulse and a main pulse. Moreover, the method includes determining whether the separation between the pre-pulse and the main pulse in the y-axis is changed, if not adjusting a configurable parameter of the excitation laser module to set the variation in the energy of the EUV light within an acceptable range.

Abstract: An extreme ultraviolet (EUV) light source and a method for patterning a resist layer on a substrate using the EUV light source are disclosed. For example, the EUV light source includes a volume to collect liquid tin debris remaining after a plasma generation process, a cover coupled to the volume, wherein the cover comprises at least one opening to allow the liquid tin debris to fall through the at least one opening of the cover and into the volume, and a heater coupled to the cover, wherein the heater is to melt solid tin that forms from cooling of the liquid tin debris on a surface around the at least one opening of the cover.

Abstract: A system for controlling plasma position in extreme ultraviolet lithography light sources may include a vacuum chamber, a droplet generator to dispense a stream of droplets into the vacuum chamber, wherein the droplets are formed from a metal material, a laser light source to fire a plurality of laser pulses, including at least a first pulse and a second pulse, into the vacuum chamber, a sensor to detect an observed plasma position within the chamber, wherein the observed plasma position comprises a position at which the plurality of laser pulses vaporizes a droplet of the stream of droplets to produce a plasma that emits extreme ultraviolet radiation, and a first feedback loop connecting the sensor to the laser light source, wherein the first feedback loop adjusts a time delay between the first and second pulses to minimize a difference between the observed plasma position and a target plasma position.

Abstract: An extreme ultraviolet (EUV) lithography system includes a vane bucket module. The vane bucket module includes a temperature adjusting pack and a collecting tank inserted into the temperature adjusting pack. The temperature adjusting pack has a plurality of inlets. The collecting tank has a cover and the cover includes a plurality of through holes. The inlets of the temperature adjusting pack are aligned with the through holes of the cover. Thicknesses of edges of the cover is different from a thickness of a center of the cover.

Abstract: In accordance with some embodiments, a method of controlling an extreme ultraviolet (EUV) radiation in lithography system is provided. The method includes generating a plurality of target droplets. The method also includes generating a pre-pulse and a main pulse from an excitation laser module to generate EUV light and reflecting the EUV light by a collector mirror. The method further includes measuring a separation between a pre-pulse and a main pulse. Moreover, the method includes determining whether the separation between the pre-pulse and the main pulse in the y-axis is changed, if not adjusting a configurable parameter of the excitation laser module to set the variation in the energy of the EUV light within an acceptable range.

Abstract: An extreme ultraviolet (EUV) light source and a method for patterning a resist layer on a substrate using the EUV light source are disclosed. For example, the EUV light source includes a volume to collect liquid tin debris remaining after a plasma generation process, a cover coupled to the volume, wherein the cover comprises at least one opening to allow the liquid tin debris to fall through the at least one opening of the cover and into the volume, and a heater coupled to the cover, wherein the heater is to melt solid tin that forms from cooling of the liquid tin debris on a surface around the at least one opening of the cover.

Abstract: An extreme ultraviolet (EUV) lithography system includes a vane bucket module. The vane bucket module includes a collecting tank and a temperature adjusting pack. The collecting tank has a cover and the cover includes a plurality of through holes. Thicknesses of edges of the cover is greater than a thickness of a center of the cover. The temperature adjusting pack surrounds the collecting tank. The temperature adjusting pack includes a plurality of inlets aligned with the through holes.

Abstract: Extreme ultraviolet (EUV) lithography systems are provided. A EUV scanner is configured to perform a lithography exposure process in response to EUV radiation. A light source is configured to provide the EUV radiation to the EUV scanner. A measuring device is configured to measure concentration of debris caused by unstable target droplets in the chamber. A controller is configured to adjust a first gas flow rate and a second gas flow rate in response to the measured concentration of the debris and a control signal from the EUV scanner. A exhaust device is configured to extract the debris out of the chamber according to the first gas flow rate. A gas supply device is configured to provide a gas into the chamber according to the second gas flow rate. The control signal indicates the lithography exposure process is completed.

Abstract: A radiation source apparatus is provided. The radiation source apparatus includes a chamber, an exhaust module, a measuring device, a gas supply module and a controller. The exhaust module is configured to extract debris caused by unstable target droplets out of the chamber according to a first gas flow rate. The measuring device is configured to measure concentration of the debris in the chamber. The gas supply module is configured to provide a gas into the chamber according to a second gas flow rate. The controller is configured to adjust the first gas flow rate and the second gas flow according to the measured concentration of the debris.