Xtreme Technologies Gmbh

Lambda Physik Ag

Xtreme Technologies Gbmh

Guido Schriever

Juergen Kleinschmidt

Imtiaz Ahmad

Uwe Stamm

Max Christian Schuermann

Ulrich Rebhan

Kai Gaebel

Denis Bolshukhin

Alexander Christian Keller

Lutz Dippmann

Sven Goetze

The invention is related to a gas discharge-based radiation source which emits short-wavelength radiation, wherein an emitter is ionized and compressed by pulse-shaped currents between two electrodes arranged in a vacuum chamber and is excited to form an emitting plasma. According to the invention, the plasma is preserved by means of a high-frequency sequence of pulse-shaped currents the pulse repetition period of which is adjusted so as to be shorter than a lifetime of the plasma so that the plasma is kept periodically alternating between a high-energy state of an emitting compressed plasma and a low-energy state of a relaxing plasma. For exciting the relaxing plasma to the compressed plasma, excitation energy is coupled into the relaxing plasma by making use of pulse-shaped currents with repetition frequencies between 50 kHz and 4 MHz and pulse widths equal to the pulse repetition period.

Method and apparatus for the generation of short-wavelength radiation by means of a gas discharge-based high-frequency, high-current discharge

The invention is related to the adjustment of characteristics of a beam bundle of high-energy radiation emitted from a plasma, particularly for applications in semiconductor lithography. For acquiring and adjusting characteristics of a beam bundle of high-energy radiation emitted from a plasma and focused by means of collector optics, an intensity distribution of the radiation is acquired over the cross section of a convergent beam bundle in a measuring plane perpendicular to the optical axis in front of an intermediate focus of the collector optics, and intensity values are recorded in defined sectors for a quantity of reception regions of a measuring device which are aligned with different radii concentric to the optical axis, and measured quantities and control variables are determined from a comparison of the intensity values of different sectors for aligning the collector optics.

Method and arrangement for the adjustment of characteristics of a beam bundle of high-energy radiation emitted from a plasma

The invention is directed to a method and an arrangement for cleaning optical surfaces of reflection optics which are arranged in a plasma-based radiation source or exposure device arranged downstream and contaminated by debris particles emitted by a hot plasma of the radiation source. It is the object of the invention to find a novel possibility for in-situ cleaning of the optical surfaces of reflection optics which are contaminated by debris in plasma-based radiation sources so as to allow an integrated generation of known gas radicals and the isotropic distribution thereof on the contaminated optical surfaces. According to the invention, this object is met in that the gas radicals are generated by dielectrically impeded discharge between two surface electrodes along the entire optical surface. The gas radicals are generated almost exclusively by electron transfer on at least one barrier layer which covers the entire surface of at least one of the surface electrodes, an AC voltage in the Hz to kHz range is applied to the surface electrodes for periodically eliminating the charge polarization at the barrier layer so that a cold plasma is generated continuously and the deposited debris particles are removed as gaseous reaction products by the gas flow guided over the optical surface.

Method and arrangement for cleaning optical surfaces in plasma-based radiation sources

A detector for use with an EUV photon source emitting around 11-15 nm includes at least one multilayer mirror for reflecting the beam along an optical path include a detector element, a filter for reducing the bandwidth of the beam, and the detector element. The detector element preferably comprises a Si pn diodes with doped dead region and zero surface recombination or PtSi-nSi barrier for increasing the long term stability of the detector.

Stable energy detector for extreme ultraviolet radiation detection

The invention is directed to a method and an arrangement for generating extreme ultraviolet (EUV) radiation, i.e., radiation of high-energy photons in the wavelength range from 11 to 14 nm, based on a gas discharge. The object of the invention, to find a novel possibility for generating EUV radiation in which an extended life of the system is achieved with stable generation of a dense, hot plasma column, is met according to the invention in that a preionization discharge is ignited between two parallel disk-shaped flat electrodes prior to the main discharge by a surface discharge along the superficies surface of a cylindrical insulator with a plasma column generated through the gas discharge with pulsed direct voltage, which preionization discharge carries out an ionization of the working gas in the discharge chamber by means of fast charged particles. The preionization discharge is triggered within a first electrode housing and the main discharge takes place between a narrowed output of the first electrode housing and a part of the second electrode housing close to the outlet opening of the discharge chamber. The plasma develops in a part of the second electrode housing covered by a tubular insulator and, as a result of the current-induced magnetic field, contracts to form a dense, hot plasma column, one end of which is located in the vicinity of the outlet opening of the second electrode housing.

Arrangement for generating extreme ultraviolet (EUV) radiation based on a gas discharge

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.

Radiation source for generating extreme ultraviolet radiation

The invention is directed to a detector arrangement for energy measurement of pulsed x-ray radiation, particularly for monitoring the energy emitted by pulsed EUV radiation sources. The object of the invention, to find a novel possibility for energy measurement of high-energy x-ray radiation or EUV radiation which permits an accurate monitoring of the radiation dose over the entire life of the radiation source without continual calibration of the radiation detectors, is met according to the invention in that a closed vessel is provided which has an inlet opening for the radiation to be detected, is filled with a suitable gas under defined pressure for absorbing the radiation and has a linear extension, at least in the direction of incidence of the radiation, which is adapted to the absorption behavior of the gas so that the radiation to be detected is absorbed before it can reach a wall of the vessel, and at least one pressure sensor is arranged in the vessel for measuring a pressure wave generated due to the local temperature change occurring as a result of temporary intensive radiation absorption.

Detector arrangement for energy measurement of pulsed x-ray radiation

The invention is directed to a radiation source for generating extreme ultraviolet (EUV) radiation based on a hot, dense plasma generated by gas discharge. The object of the invention, to find a novel possibility for the realization of an EUV radiation source which achieves a high average radiation output in the EUV region and sufficiently long life and long-term stability, is met according to the invention in that a first electrode housing and a second electrode housing which are electrically separated from one another so as to be resistant to breakdown form parts of a vacuum chamber for a gas discharge for plasma generation, and the second electrode housing has an electrode collar which is enclosed concentrically by the first electrode housing so that the gas discharge is oriented substantially only parallel to the axis of symmetry of the electrode housings, and the electrode collar is stepped radially relative to the concentric insulator layer in such a way that at least one end region of the electrode collar is at a distance from the concentric insulator layer such that a concentric gap is formed. A substantially longer operating duration is achieved by the optimized electrode geometry in conjunction with material selection and effective heat dissipation.

Radiation source with high average EUV radiation output

The method and system herein pertain to an EUV photon source which includes a plasma chamber filled with a gas mixture, multiple electrodes within the plasma chamber defining a plasma region and a central axis, a power supply circuit connected to the electrodes for delivering a main pulse to the electrodes for energizing the plasma around the central axis to produce an EUV beam. The system can also include a preionizer for ionizing the gas mixture in preparing to form a dense plasma around the central axis upon application of the main pulse from the power supply circuit to the electrodes. A set of baffles may be disposed along the beam path outside of the pinch region to diffuse gaseous and contaminant particulate flow emanating from the pinch region and to absorb or reflect acoustic waves emanating from the pinch region away from the pinch region.

Method and apparatus for generating high output power gas discharge based source of extreme ultraviolet radiation and/or soft x-rays

The invention is directed to a method for generating extreme ultraviolet (EUV) radiation based on a radiation-emitting plasma, particularly for generating EUV radiation with a wavelength around 13 nm. The object of the invention, to find a novel possibility for generating extreme ultraviolet radiation based on a radiation-emitting plasma in which the emission output of the EUV source is increased to the wavelength range above the L-absorption edge of silicon without substantially increasing the technical and monetary expenditure for plasma generation, is met in a method for generating extreme ultraviolet radiation through emission of broadband radiation from a plasma under vacuum conditions in that the plasma is generated using at least one element from V to VII in the p-block of the fifth period of the periodic table of elements. Iodine, tellurium, antimony or materials containing these elements or chemical compounds formed with these elements are preferably used. The invention is advantageously applied in EUV lithography for semiconductor chip fabrication.

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Goettingen, Germany

Guido Schriever