摘要:
A high power gas discharge laser for and method of producing laser output light pulses of high energy density is disclosed which may comprise a laser output light pulse beam optical track having a plurality of modular components arranged in order from a laser light source to a laser system output port and defining a laser output light pulse beam path having a single centerline axis; a first optical module and a second optical module in series in the optical track; a flexible interface element intermediate the first and the second optical module and rigidly attached to each of the first and second optical modules; and an optical element having a fixed position in the output laser pulse beam path comprising a rigid attachment to the first optical module, and extending within the flexible interface element. The optical element may comprise a beam expander, which may comprise a lensed beam expander. The optical element may comprise at least a part of a telescoping lens set forming an optical beam expander and the at least a part of a telescoping lens set comprises the entire telescoping lens set forming the optical beam expander or the at least a part of a telescoping lens set may comprise a first part of the beam expander cooperating with at least a second part located in a subsequent optical module in the laser output pulse beam optical track along the same optical centerline axis. A plurality of aligning mechanisms may align the optical element to a first and a second axis of the laser output pulse beam, the first and second axes being generally orthogonal to each other and orthogonal to the optical centerline axis, and also along the optical centerline axis. The beam expander may incorporate as one optic the output coupler optic and may have a moveable lens to enable a range of magnifications.
摘要:
A method and apparatus are disclosed for controlling the output of a two chamber gas discharge laser comprising an oscillator gas discharge laser and an amplifier gas discharge laser that may comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; tracking a multidimensional operating point in the multidimensional variable state space according to the variation of the selected variables in either or both of the oscillator or the amplifier to determine the position of the multidimensional operating point in the multidimensional state space; determining from the position of the multidimensional operating point in the multidimensional operating space a region from a plurality of defined regions in the multidimensional operating space in which the multidimensional operating point is located and identifying the region; based upon the identity of the identified region, and parameters of that region relative to the condition of an actuator in each of the oscillator and the amplifier, determining a necessary modification to the actuator for each of the oscillator and the amplifier to attempt to move the multidimensional operating point from the parameters indicated by the position of the multidimensional operating point being in the particular region to a preselected region in the coordinate system. The method and apparatus may also comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; changing the gas mixture in one or both of the oscillator and amplifier by injection of at least one constituent gas in the gas mixture at least part of which injection for the respective oscillator and amplifier is based upon a calculated estimate of consumption of the at least one constituent gas in the gas mixture in the respective oscillator and amplifier from a prior change in the gas mixture; allowing the oscillator and amplifier to operate for a selected period of time with the changed gas mixture; determining the position of an operating point in the multidimensional variable state space and based upon the location of the operating point in the multidimensional state space determining a respective boost factor to modify the calculated estimate of consumption for the current change of the gas mixture in the respective oscillator and amplifier. A third dimension may be added relating to a spectral characteristic of the output of the oscillator or the amplifier, which may be bandwidth of the output of the amplifier, and including modifying that output with a beam correction device.
摘要:
An excimer laser system with an automatic fluorine control system to permit precise control of the fluorine concentration within an F2 “sweet spot” in a gas discharge laser chamber. This is done with a computer control system which monitors laser parameters, determines &Dgr;E/&Dgr;V, the change of pulse energy with voltage, and automatically and precisely controls the fluorine concentration based on &Dgr;E/&Dgr;V without the need to actually measure the fluorine concentration. The present invention is especially useful in lithography environments in which photo resist having a wide range of sensitivity are used. The present invention permits operation of the laser at substantially maximum efficiency over a wide range of pulse energy outputs.
摘要:
A low cost, high reliability system for correcting aberrations in optical signals is disclosed. A foreoptic assembly, such as a telescope, receives an incoming optical signal and directs it to an active optical element, such as a fast steering mirror. The incoming optical signal is diffracted by a diffractive optical element to shape the image that is formed at a wavefront sensor, such as a quad-cell. The wavefront sensor measures a tip-tilt aberration of the incoming optical signal and the active optical element is adjusted to correct the measured aberration. An outgoing optical signal can be transmitted along substantially the same optical path as the incoming optical signal, but in the opposite direction. Thus, the aberration measured from the incoming optical signal can be automatically accounted for in the outgoing optical signal.
摘要:
The present invention relates to a fluorine gas discharge laser system and control of replenishment of fluorine gas as the gas discharge laser operates and consumes fluorine.
摘要:
The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.
摘要:
A lithograph quality optimization process for controlling laser beam parameters when changing operating modes. The laser is programmed to automatically conduct an optimization procedure preferably in less than one minute to adjust laser operating parameters such as blower speed, total gas pressure and F2 partial pressure in order to optimize beam quality parameters.
摘要:
A method and apparatus are disclosed for controlling the output of a two chamber gas discharge laser comprising an oscillator gas discharge laser and an amplifier gas discharge laser that may comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; tracking a multidimensional operating point in the multidimensional variable state space according to the variation of the selected variables in either or both of the oscillator or the amplifier to determine the position of the multidimensional operating point in the multidimensional state space; determining from the position of the multidimensional operating point in the multidimensional operating space a region from a plurality of defined regions in the multidimensional operating space in which the multidimensional operating point is located and identifying the region.
摘要:
The present invention relates to a fluorine gas discharge laser system and control of replenishment of fluorine gas as the gas discharge laser operates and consumes fluorine.
摘要:
A method and apparatus are disclosed for controlling the output of a two chamber gas discharge laser comprising an oscillator gas discharge laser and an amplifier gas discharge laser that may comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; tracking a multidimensional operating point in the multidimensional variable state space according to the variation of the selected variables in either or both of the oscillator or the amplifier to determine the position of the multidimensional operating point in the multidimensional state space; determining from the position of the multidimensional operating point in the multidimensional operating space a region from a plurality of defined regions in the multidimensional operating space in which the multidimensional operating point is located and identifying the region; based upon the identity of the identified region, and parameters of that region relative to the condition of an actuator in each of the oscillator and the amplifier, determining a necessary modification to the actuator for each of the oscillator and the amplifier to attempt to move the multidimensional operating point from the parameters indicated by the position of the multidimensional operating point being in the particular region to a preselected region in the coordinate system. The method and apparatus may also comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; changing the gas mixture in one or both of the oscillator and amplifier by injection of at least one constituent gas in the gas mixture at least part of which injection for the respective oscillator and amplifier is based upon a calculated estimate of consumption of the at least one constituent gas in the gas mixture in the respective oscillator and amplifier from a prior change in the gas mixture; allowing the oscillator and amplifier to operate for a selected period of time with the changed gas mixture; determining the position of an operating point in the multidimensional variable state space and based upon the location of the operating point in the multidimensional state space determining a respective boost factor to modify the calculated estimate of consumption for the current change of the gas mixture in the respective oscillator and amplifier. A third dimension may be added relating to a spectral characteristic of the output of the oscillator or the amplifier, which may be bandwidth of the output of the amplifier, and including modifying that output with a beam correction device.