Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: Output beam parameters of a gas discharge laser are stabilized by maintaining a molecular fluorine component at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is subject to depletion within the discharge chamber. Gas injections including molecular fluorine can increase the partial pressure of molecular fluorine by a selected amount. The injections can be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure. The amount per injection and/or the interval between injections can be varied, based on factors such as driving voltage and a calculated amount of molecular fluorine in the discharge chamber. The driving voltage can be in one of multiple driving voltage ranges that are adjusted based on system aging. Within each range, gas injections and gas replacements can be performed based on, for example, total applied electrical energy or time/pulse count.

Abstract: A pulse-stretcher has an optical delay loop including a beamsplitter. The beamsplitter divides an input pulse into a temporal sequence of pulse replicas, a first of which is transmitted by the beamsplitter and the remainder of which are reflected by the beamsplitter along the path of the transmitted replica. The sequence of replicas form an initially stretched pulse having a longer duration and lower peak power than the input pulse. A prism cooperative with the delay loop reflects the initially stretched pulse back into the delay loop along a path laterally displaced from the replica path. The beamsplitter divides the initially stretched pulse into a temporal sequence of pulse replicas propagating along a common path to form a finally stretched pulse, having a longer duration and a lower peak power than the initially stretched pulse. The finally stretched pulse has a sequence of power peaks.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: An excimer master-oscillator-power amplifier (MOPA) system includes two laser discharge units (LDUs). Optical modules are associated the LDUs for forming the master oscillator and the power amplifier. The discharge units are each assembled onto a chassis via a vibration-damping suspension. The optical modules are assembled on a frame that is separately attached to the chassis. Providing the separate frame for optical modules, mechanically isolated from the LDUs because of the vibration isolating suspension, minimizes transmission of vibrations from the LDUs to the optics modules.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.

Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.

Abstract: A method for operating an excimer or molecular fluorine laser system at a stabilized wavelength includes generating a laser beam and directing a beam portion through a wavelength measurement system, calibrating the wavelength measurement system to an absolute reference, determining the wavelength of the laser beam including figuring in a drift compensation value of the wavelength, and tuning the wavelength to a target wavelength when the determined wavelength differs from the target wavelength.

Abstract: Fast wavelength stabilization can be obtained for a gas discharge laser, such as an excimer or molecular fluorine laser, using a fast wavelength correction unit. A fast wavelength correction unit can include a fast, precise motor driver unit, such as a linear or rotary voice coil motor, a piezo-ceramic motor, or a piezo motor driver unit. These motors can be used to rotate a tuning element, for example, in order to provide for precise and fast wavelength stabilization. The wavelength correction unit can be fully contained within an optical module, without the need for seals, bellows, or feedthroughs as in existing drive systems. Various arrangements and embodiments are described which can be appropriate for differing applications and/or systems.

Abstract: An on-board diagnostic tool can be used to monitor the spectral purity of a lithography laser, such as an excimer or molecular fluorine laser, instead of simply measuring the FWHM bandwidth of the laser. One such on-board tool utilizes a Fabry-Perot Interferometer etalon with a high-finesse and a small free spectral range, which provides the precision necessary to determine spectral purity, while providing the small footprint and light weight necessary to use the tool on-board. A high signal-to-noise detector can be used to improve the accuracy of the measurements.

Abstract: A wavelength chirp compensation method for an excimer or molecular fluorine laser system operating in burst mode, includes pre-programming into a computer of the laser system resonator tuning optic adjustments for making the adjustments during pauses between bursts to compensate wavelength chirp at beginnings of succeeding bursts.

Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.

Abstract: A wavelength chirp compensation method for an excimer or molecular fluorine laser system operating in burst mode, includes pre-programming into a computer of the laser system resonator tuning optic adjustments for making the adjustments during pauses between bursts to compensate wavelength chirp at beginnings of succeeding bursts.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.

Abstract: An apparatus and method are provided for bandwidth narrowing of an excimer laser to &Dgr;&lgr;≈6 pm or less with high spectral purity and minimized output power loss. Output stability with respect to pulse energy, beam pointing, beam size and beam output location is also provided. The excimer laser includes an active laser medium for generating a spectral beam at an original wavelength, means for selecting and narrowing the broadband output spectrum of the excimer laser, a resonator having at least one highly reflecting surface, and an output coupler. Means for adapting a divergence of the resonating band within the resonator is further included in the apparatus of the invention. The divergence adapting causes the spectral purity to improve by between 20% and 50% and the output power to reduce by less than 10%. A method according to the invention includes selecting and aligning the divergence adapting means.