Xtreme Technologies Gmbh

Kai Gaebel

Guido Hergenhan

Christian Ziener

Diethard Kloepfel

Uwe Stamm

Juergen Kleinschmidt

Guido Schriever

Thomas Brauner

Istvan Balogh

The invention is directed to an arrangement for generating extreme ultraviolet radiation from a plasma generated by an energy beam with high conversion efficiency, particularly for application in radiation sources for EUV lithography. It is the object of the invention to find a novel possibility for generating EUV radiation by means of a plasma induced by an energy beam that permits a more efficient conversion of the energy radiation into EUV radiation in the wavelength region of 13.5 nm and ensures a long lifetime of the optical components and the injection device. According to the invention, this object is met by using a mixture of particles with a carrier gas and the target feed device has a gas liquefaction chamber, wherein the target material is supplied to the injection unit as a mixture of solid particles in liquefied carrier gas, and a droplet generator is provided for generating a defined droplet size and series of droplets, wherein means which are controllable in a frequency-dependent manner and which are triggered by the pulse frequency of the energy beam are connected to the injection unit for the series of droplets.

Arrangement for generating extreme ultraviolet radiation from a plasma generated by an energy beam with high conversion efficiency and minimum contamination

It is the object of a device and method for generating extreme ultraviolet (EUV) radiation to overcome the obstacles formerly posed by the use of efficient metal emitters so that the conversion efficiency can be optimized and, as a result, the radiation output can be increased without shortening the useful life of the collector optics and electrode system. An injection nozzle of an injection device is directed to a discharge area located in a discharge chamber. The injection nozzle supplies a series of individual volumes of a source materials for the electric discharge serving to generate radiation at a repetition rate that corresponds to the frequency of the gas discharge. Further, provision is made for successively vaporizing the individual volumes in the discharge area.

Device and method for generating extreme ultraviolet (EUV) radiation

The invention is directed to an arrangement for providing target material for the generation of short-wavelength electromagnetic radiation, in particular EUV radiation. It is the object of the invention to find a novel possibility for providing target material for the generation of short-wavelength radiation based on an energy beam induced plasma which makes it possible to supply a reproducible successive flow of mass-limited targets in the interaction chamber in such a way that only the amount of target material needed for efficient generation of radiation achieves plasma generation. This object is met, according to the invention, in that the target generator opens into a selection chamber which precedes the interaction chamber and which has, along the target path, an outlet opening into the interaction chamber and in which a target selector is arranged. The target selector has elements for eliminating individual targets needed for the regular target sequence of the target generator, so that only the individual targets needed for efficient plasma generation and radiation generation corresponding to the pulse frequency of the energy beam are admitted to the interaction point.

Arrangement for providing target material for the generation of short-wavelength electromagnetic radiation

The invention is directed to an arrangement for providing a reproducible target flow for the energy beam-induced generation of short-wavelength radiation. It is the object of the invention to find a novel possibility for providing a reproducibly supplied target flow for the generation of a plasma that emits short-wavelength radiation which ensures a high directional stability of the target flow over a large number of individual plasma generation process for any target materials under given process conditions. According to the invention, this object is met in that a nozzle protection device is provided in the interaction chamber between the target nozzle and the interaction point for the generation of the plasma, and the nozzle protection device contains a gas pressure chamber which has an aperture along the target path for unobstructed passage of the target flow and which is filled with a buffer gas that is maintained at a pressure of some 10 mbar.

Arrangement for providing a reproducible target flow for the energy beam-induced generation of short-wavelength electromagnetic radiation

The invention is directed to a collector mirror for short-wavelength radiation based on a plasma. It is the object of the invention to find a novel possibility for managing the temperature of a collector mirror for focusing short-wavelength radiation generated from a plasma which allows an efficient thermal connection to be produced between the optically active mirror surface and a thermostat system without the disadvantages relating to space requirements or high-precision manufacture of the collector mirror. This object is met, according to the invention, in that the collector mirror has a solid, rotationally symmetric substrate which comprises a material with high thermal conductivity of more than 50 W/mK and in which channels for cooling and temperature management are incorporated in the substrate so that a heat transport medium can flow through directly and for rapidly stabilizing the temperature of the optically active mirror surface. Heat of transient temperature spikes which occur in pulsed operation for plasma generation at the mirror surface and which temporarily exceed the temperature average by a multiple is quickly dissipated.

Collector mirror for plasma-based, short-wavelength radiation sources

The invention is directed to an apparatus for generating soft x-radiation, particularly EUV radiation, by laser-induced plasma. The object of the invention, to find a novel possibility for generating EUV radiation by means of a laser-induced plasma by which a temporally stable radiation emission in the desired wavelength region is ensured when interacting with the target without active regulation of the laser beam, is met according to the invention in that at least one laser is directed to the target, wherein the laser has at least one defined plane with a highly stable spatial distribution of the power density of the laser, and this defined plane is imaged on the target by an optical imaging system so as to be reduced so that the optical image of the defined plane is active for the plasma generation instead of the laser focus. The invention is applied in exposure machines for semiconductor lithography for spatially stable generation of radiation.

Apparatus for the temporally stable generation of EUV radiation by means of a laser-induced plasma

The invention is directed to a method and an arrangement for the plasma-based generation of intensive short-wavelength radiation, particularly EUV radiation. The object of the invention, to find a novel possibility for plasma-based generation of intensive soft x-radiation, particularly EUV radiation, which permits efficient energy conversion in the desired spectral band with high repetition frequency (several kHz) of the plasma excitation, minimized emission of debris and low erosion of the nozzle of the target generator, is met according to the invention in that an additional energy beam is directed on the target flow spatially in advance of its interaction with the high-energy beam, the target flow being acted upon by this additional energy beam with substantially weaker energy pulses compared to the high-energy beam in order to divide the target flow into a first portion and at least one second portion, wherein the target flow is excited at an interaction point within the second portion by the high-energy beam for generating a hot, radiating plasma, and the second portion is decoupled from the first portion and therefore from the target generator in such a way that a hydrodynamic disturbance generated in the second portion by the pulse of the high-energy beam is transmitted into the first portion only negligibly.

Method and arrangement for the plasma-based generation of intensive short-wavelength radiation

In a radiation source for the generation of short-wavelength radiation, it is the object of the invention to effectively increase the protection of the collimator optics by a buffer gas without substantially reducing the radiation transmission. A vacuum chamber which encloses a radiation-emitting plasma and is outfitted with at least one feed line and one outlet line for a buffer gas in order to ensure protection against debris for at least one optical element which directs the radiation to a radiation outlet opening in the vacuum chamber has chamber areas with particle deceleration of varying magnitude by the buffer gas. The particle deceleration is greater at least in a first chamber area in which the optical element is arranged than in any other chamber area.

Radiation source for the generation of short-wavelength radiation

The invention is directed to an arrangement for generating a pulsed laser beam with high average output, in particular for generating a hot plasma which emits extreme ultraviolet (EUV) radiation. It is the object of the invention to find a novel possibility for generating a laser beam with a high repetition rate and average output which allows the repetition frequency and, therefore, the output of the laser system to be increased by connecting together a plurality of individual lasers having limited repetition rate without degradation of the beam quality on the target compared to that of an individual laser. This object is met, according to the invention, in that an oriented mirror surface is associated with each individual laser in such a way that a beam bundle which is emitted by each individual laser so as to be offset with respect to time and which is reflected at the mirror surface is coupled into a common beam path, and laser pulses in the common beam path are directed to a target one after the other in a regular, defined pulse sequence, and, with a continuously dynamic mirror movement for coupling the laser pulses into the common beam path, optical means are provided in the common beam path for compensating the directional change caused by the mirror movement.

Arrangement for the generation of a pulsed laser beam of high average output

The invention is directed to a method and an arrangement for plasma-based generation of soft x-radiation, particularly for the generation of extreme ultraviolet (EUV) radiation. The object of the invention, to find a novel possibility for providing a target for a plasma-based radiation source which permits a reduction in the heating and erosion of the nozzle and therefore permits an improved temperature control at the injection device, is met according to the invention in that a closure device is arranged between the target nozzle and the interaction region which interrupts an opening for temporarily passing the target flow by mechanically moving elements, wherein at least a portion of the target flow that is provided in a reproducible manner is separated in order to interact with the energy beam only during those time intervals in which an optical transmission from the interaction region to the target nozzle is prevented by the closure device.

Method and arrangement for the plasma-based generation of soft x-radiation

A short-wavelength radiation is generated which is stable over time from a plasma generated by energy input into a target jet, in which intensity variations due to altered coupling of excitation radiation into the target jet are minimized. Measuring devices are provided for successive detection over time of deviations of at least one of the directions of the target jet or the energy beam from an intersection point of the two directions that is provided as an interaction point. The measuring devices have output signals which are suitable as regulating variables for the orientation of the directions on the interaction point, and actuating elements are provided for adjusting and tracking at least one of the directions of either the target jet or the energy beam depending on the output signal of the measuring devices in the manner of a control loop.

Arrangement for the stabilization of the radiation emission of a plasma

The invention is directed to an arrangement for generating intensive radiation based on a plasma, particularly short-wavelength radiation from soft x-ray radiation to extreme ultraviolet (EUV) radiation. The object of the invention is to find a novel possibility for generating radiation generated from plasma in which the individual pulse energy coupled into the plasma and, therefore, the usable radiation output are appreciably increased while retaining the advantages of mass-limited targets. According to the invention, this object is met in that the target generator has a multiple-channel nozzle with a plurality of separate orifices, wherein the orifices generate a plurality of target jets, the excitation radiation for generating plasma being directed simultaneously portion by portion to the target jets.

Arrangement for the generation of intensive short-wave radiation based on a plasma

The invention is directed to a radiation source for generating extreme ultraviolet (EUV) radiation, particularly for photolithography exposure processes. The object of the invention is to find a novel possibility for realizing radiation sources for generating extreme ultraviolet (EUV) radiation which permits a uniform basic construction for ensuring beam characteristics that are reproducible over the long term and in which the source is conceived so as to be flexible with respect to specific applications. This object is met according to the invention in that any plasma generation unit is provided for introducing high energy input supplied in a pulsed manner in a vacuum chamber, and the radiation generated from the plasma is monitored by an energy monitor unit which measures the pulse energy of the emitted radiation and by a radiation diagnosis unit which detects the radiation characteristics to obtain result data for influencing the excitation conditions for the plasma and to influence the parameters of the plasma generation in an application-specific manner by means of the main control unit.

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Jena, Germany

Kai Gaebel