摘要:
A reliable, modular, production quality narrow-band KrF excimer laser capable of producing 10 mJ laser pulses at 1000 Hz with a bandwidth of about 0.6 pm or less. The present invention is especially suited to long-term round-the-clock operation in the lithographic production of integrated circuits. Improvements over prior art lasers include a single upstream preionizer tube and acoustic baffles. A preferred embodiment includes reduced fluorine concentration, an anode support bar shaped to reduce aerodynamic reaction forces on blower bearings, a modified pulse power system providing faster pulse rise time, an output coupler with substantially increased reflectivity, a line narrowing module with CaF prism beam expanders, a more accurate wavemeter, a laser computer controller programmed with new and improved pulse energy control algorithm.
摘要:
A method and apparatus that may comprise an EUV light producing mechanism utilizing an EUV plasma source material comprising a material that will form an etching compound, which plasma source material produces EUV light in a band around a selected center wavelength comprising: an EUV plasma generation chamber; an EUV light collector contained within the chamber having a reflective surface containing at least one layer comprising a material that does not form an etching compound and/or forms a compound layer that does not significantly reduce the reflectivity of the reflective surface in the band; an etchant source gas contained within the chamber comprising an etchant source material with which the plasma source material forms an etching compound, which etching compound has a vapor pressure that will allow etching of the etching compound from the reflective surface. The etchant source material may comprises a halogen or halogen compound. The etchant source material may be selected based upon the etching being stimulated in the presence of photons of EUV light and/or DUV light and/or any excited energetic photons with sufficient energy to stimulate the etching of the plasma source material. The apparatus may further comprise an etching stimulation plasma generator providing an etching stimulation plasma in the working vicinity of the reflective surface; and the etchant source material may be selected based upon the etching being stimulated by an etching stimulation plasma. There may also be an ion accelerator accelerating ions toward the reflective surface. The ions may comprise etchant source material. The apparatus and method may comprise a part of an EUV production subsystem with an optical element to be etched of plasma source material.
摘要:
A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.
摘要:
An apparatus and method which may comprise a pulsed gas discharge laser which may comprise a seed laser portion; an amplifier portion receiving the seed laser output and amplifying the optical intensity of each seed pulse; a pulse stretcher which may comprise: a first beam splitter operatively connected with the first delay path and a second pulse stretcher operatively connected with the second delay path; a first optical delay path tower containing the first beam splitter; a second optical delay path tower containing the second beam splitter; one of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors located in the first tower and in the second tower; the other of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors only in one of the first tower and the second tower.
摘要:
The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) F2 injection controls with novel learning algorithm.
摘要:
The present invention provides gas discharge laser systems capable of reliable long-term operation in a production line capacity at repetition rates in the range of 6,000 to 10,0000 pulses power second. Preferred embodiments are configured as KrF, ArF and F2 lasers used for light sources for integrated circuit lithography. Improvements include a modified high voltage power supply capable for charging an initial capacitor of a magnetic compression pulse power system to precise target voltages 6,000 to 10,0000 times per second and a feedback control for monitoring pulse energy and determining the target voltages on a pulse-by-pulse basis. Several techniques are disclosed for removing discharge created debris from the discharge region between the laser electrodes during the intervals between discharges. In one embodiment the width of the discharge region is reduced from about 3 mm to about 1 mm so that a gas circulation system designed for 4,000 Hz operation could be utilized for 10,000 Hz operation. In other embodiments the gas flow between the electrodes is increased sufficiently to permit 10,000 Hz operation with a discharge region width of 3 mm. To provide these substantial increased gas flow rates, Applicants have disclosed preferred embodiments utilize tangential forms of the prior art but with improved and more powerful motors and novel bearing designs. New bearing designs include both ceramic bearings and magnetic bearings. In other embodiments, some or all of the gas circulation power is provided with a blower located outside the laser chamber. The outside blower can be located in the laser cabinet or in separate location.
摘要:
The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75×106 Watts/cm2 and with peak intensity or greater 3.5×106 Watts/cm2 for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities. Techniques and components are disclosed for minimizing the potential for optical damage and for reducing the pulse energy density to less than 100×10−6 J/cm3. Important improvements described in this specification have been grouped into the following subject matter categories: (1) Solution to CaF2 surface damage discovered by Applicants, (2) description of a high power ArF MOPA laser system, (3) description of beam delivery units, (4) polarization considerations (5) a high speed water-cooled auto shutter energy detector module and (6) other improvements.
摘要翻译:本发明提供了用于产生高重复率高功率输出光束的模块化高重复率紫外线气体放电激光器系统的长寿命光学器件。 本发明包括由申请人发现的位于原型激光系统的输出光束的高脉冲强度部分中的CaF 2光学器件的表面损伤问题的解决方案。 实施例包括用于束传送数十亿个输出激光脉冲的光束指向控制的封闭和清除的光束路径。 本文所述的光学部件和模块能够控制波长小于200nm的紫外激光输出脉冲,平均输出脉冲强度大于1.75×6 /瓦/ cm 2,并且与 与在这些脉冲强度中仅仅几分钟之后失效的现有技术部件和模块相比,数十亿个脉冲的峰值强度或更大的3.5×10 6 / cm 2 / SUP。 公开了用于最小化光学损伤的可能性和将脉冲能量密度降低到小于100×10 -6 / cm 3的技术和部件。 本说明书中描述的重要改进已分为以下主题类别:(1)由申请人发现的CaF 2 2表面损伤的解决方案,(2)高功率ArF MOPA激光系统的描述( 3)光束传输单元的描述,(4)偏振考虑(5)高速水冷自动快门能量检测器模块和(6)其他改进。
摘要:
A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the uses of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.
摘要:
The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Feedback timing control techniques are provided for controlling the relative timing of the discharges in the two chambers with an accuracy in the range of about 2 to 5 billionths of a second even in burst mode operation. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality.
摘要:
A narrow band laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed output beam which is used to injection seed the second laser subsystem where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply is provided which is specially configured to precisely time the discharges in the two laser subsystem so that the discharges are properly synchronized. Preferred embodiments include a pulse power system with a pulse transformer unit having two sets of transformer cores. A single upstream pulse compression circuit provides high voltage pulses in parallel to the primary windings of all of the cores in both sets. Separate secondary conductors (one passing through one set of cores and the other passing through the other set of cores) provide very high voltage pulses respectively to separate downstream circuits supplying discharge pulses to the electrodes in each of two separate laser chambers. Preferred embodiments include KrF, ArF and F2 systems. In these preferred embodiments, line narrowing may be accomplished within the resonant cavity of the seed laser or the output of the seed laser could be line narrowed using a pre-gain filter.