Cymer, Inc.

Asml Netherlands B.v.

Wayne J Dunstan

Robert N Jacques

Matthew Graham

Steven Chang

Paul Frihauf

Herve A Besaucele

Daniel Jason Riggs

Fedor Trintchouk

Charles E Kinney

Andrew Liu

Jeroen Van Der Burgt

Kevin M O'Brien

Toshihiko Ishihara

Alexander Anthony Schafgans

Rajasekhar Rao

James H Crouch

Spencer Rich

Aravind Ratnam

Rajasekhar M Rao

Fedor B Trintchouk

A method and apparatus for control of a dose of extreme ultraviolet (EUV) radiation generated by a laser produced plasma (LPP) EUV light source that combines pulse control mode and pulse modulation. The EUV energy created by each pulse is measured and total EUV energy created by the fired pulses determined, a desired energy for the next pulse is determined based upon whether the total EUV energy is greater or less than a desired average EUV energy times the number of pulses. If the desired pulse energy for the next droplet is within the range of one or more pulse modulation actuators, the pulse is modulated; otherwise, the pulse is fired to miss the droplet. This provides greater control of the accumulated dose as well as uniformity of the EUV energy over time, greater ability to compensate for pulses that generate EUV energy that is higher or lower than nominal expected values, and ability to provide an average EUV energy per pulse that is less than the nominal minimum EUV energy per pulse of the system.

EUV LPP source with improved dose control by combining pulse modulation and pulse control mode

Energy output from a laser-produced plasma (LPP) extreme ultraviolet light (EUV) system varies based on how well the laser beam is focused on droplets of target material to generate plasma at a primary focal spot. Maintaining droplets at the primary focal spot during burst firing is difficult because generated plasma from preceding droplets push succeeding droplets out of the primary focal spot. Current droplet-to-droplet feedback control to re-align droplets to the primary focal spot is relatively slow. The system and method described herein adaptively pre-compensate for droplet push-out by directing droplets to a target position that is offset from the primary focal spot such that when a droplet is lased, the droplet is pushed by the laser beam into the primary focal spot to generate plasma. Over time, the EUV system learns to maintain real-time alignment of droplet position so plasma is generated consistently within the primary focal spot.

System and method to adaptively pre-compensate for target material push-out to optimize extreme ultraviolet light production

Described herein are embodiments of a method to control energy dose output from a laser-produced plasma extreme ultraviolet light system by adjusting timing of fired laser beam pulses. During stroboscopic firing, pulses are timed to lase droplets until a dose target of EUV has been achieved. Once accumulated EUV reaches the dose target, pulses are timed so as to not lase droplets during the remainder of the packet, and thereby prevent additional EUV light generation during those portions of the packet. In a continuous burst mode, pulses are timed to irradiate droplets until accumulated burst error meets or exceeds a threshold burst error. If accumulated burst error meets or exceeds the threshold burst error, a next pulse is timed to not irradiate a next droplet. Thus, the embodiments described herein manipulate pulse timing to obtain a constant desired dose target that can more precisely match downstream dosing requirements.

Method of timing laser beam pulses to regulate extreme ultraviolet light dosing

Energy output from a laser-produced plasma (LPP) extreme ultraviolet light (EUV) system varies based on how well the laser beam can maintain focus on a target material to generate the plasma that gives off light. The system and method described herein optimize EUV light generation by using a closed-loop gradient process to track and fine-tune in real-time the positioning of optical elements that determine how the laser beam is focused on the target material. When real-time alignment of the drive laser on droplet position is achieved, EUV generation is optimized.

System and method to optimize extreme ultraviolet light generation

According to aspects of an embodiment of the disclosed subject matter, a line narrowed high average power high pulse repetition laser micro-photolithography light source bandwidth control method and apparatus are disclosed which may comprise a bandwidth metrology module measuring the bandwidth of a laser output light pulse beam pulse produced by the light source and providing a bandwidth measurement; a bandwidth error signal generator receiving the bandwidth measurement and a bandwidth setpoint and providing a bandwidth error signal; an active bandwidth controller providing a fine bandwidth correction actuator signal and a coarse bandwidth correction actuator signal responsive to the bandwidth error. The fine bandwidth correction actuator and the coarse bandwidth correction actuator each may induce a respective modification of the light source behavior that reduces bandwidth error. The coarse and fine bandwidth correction actuators each may comprise a plurality of bandwidth correction actuators.

Active spectral control of DUV laser light source

According to aspects of an embodiment of the disclosed subject matter, a line narrowed high average power high pulse repetition laser micro-photolithography light source bandwidth control method and apparatus are disclosed which may comprise a bandwidth metrology module measuring the bandwidth of a laser output flight pulse beam pulse produced by the light source and providing a bandwidth measurement; a bandwidth error signal generator receiving the bandwidth measurement and a bandwidth setpoint and providing a bandwidth error signal; an active bandwidth controller providing a fine bandwidth correction actuator signal and a coarse bandwidth correction actuator signal responsive to the bandwidth error. The fine bandwidth correction actuator and the coarse bandwidth correction actuator each may induce a respective modification of the light source behavior that reduces bandwidth error. The coarse and fine bandwidth correction actuators each may comprise a plurality of bandwidth correction actuators.

Active spectral control of DUV light source

A method and apparatus are disclosed which may comprise predicting the gas lifetime for a gas discharge laser light source for a photolithography process, the light source comprising a halogen containing lasing gas may comprise: utilizing at least one of a plurality of laser operating input and/or output parameters; utilizing a set of at least one parameter of utilization in the photolithography process to determine a gas use model in relation to the respective input or output parameter; predicting the end of gas life based upon the model and a measurement of the respective input or output parameter. The parameter may comprise a pulse utilization pattern. The method and apparatus may comprise performing gas management for a gas discharge laser light source for a photolithography process, the light source comprising a halogen containing lasing gas comprising: utilizing periodic and frequent partial gas refills comprising an inject comprising a mixture of halogen gas and bulk gas in generally the same ration as the premix ratio provided to the laser in a full gas refill, and in an amount less than two percent of the total gas pressure prior to the injection.

Laser gas injection system

A method and apparatus is disclosed which may comprise: a gas discharge laser system energy controller which may comprise: a laser system energy controller providing a first laser operating parameter control signal based on an error signal related to a value of the output energy of the laser system compared to a target value for output energy and an energy controller model of the value of the first laser operating parameter necessary to change the value of the laser system output energy to the target value; a first laser system operating parameter control signal modifier providing a modification to the first laser system operating parameter control signal based upon a controller signal modification model of the impact of a second laser system operating parameter on the value of the first laser system operating parameter necessary to change the value of the output energy to the target value.

Ultraviolet laser light source pulse energy control system

A multi-chambered excimer or molecular halogen gas discharge laser system comprising at least one oscillator chamber and at least one amplifier chamber producing oscillator output laser light pulses that are amplified in the at least one power chamber, having a fluorine injection control system and a method of using same is disclosed, which may comprise: a halogen gas consumption estimator: estimating the amount of halogen gas that has been consumed in one of the at least one oscillator chamber based upon at least a first operating parameter of one of the least one oscillator chamber and the at least one amplifier chamber, and the difference between a second operating parameter of the at least one oscillator chamber and the at least one amplifier chamber, and estimating the amount of halogen gas that has been consumed in the other of the at least one oscillator chamber and the at least one amplifier chamber based upon at least a third operating parameter of the other of the at least one oscillator chamber and the at least one amplifier chamber, and producing an output representative of an estimated halogen gas consumption in the at least one oscillator chamber and of the halogen gas consumption in the at least one amplifier chamber, and a halogen gas injection controller determining the amount of halogen gas injection for the at least one oscillator chamber and the at least one amplifier chamber based upon the estimated fluorine consumption outputs from the fluorine consumption estimator and a cost function comprising a plurality of weighted injection decision determinations.

Growing community of inventors

San Diego, CA, United States of America

Wayne J Dunstan