Carl Zeiss Smt Gmbh

Dirk Hellweg

Renzo Capelli

Markus Koch

Aksel Goehnermeier

Martin Dietzel

Jens Kugler

Bernhard Gellrich

Ulrich Weber

Bernhard Geuppert

Stefan Xalter

Franz Sorg

Armin Schoeppach

Ulrich Loering

Stefan Hembacher

Wolfgang Emer

Guido Limbach

Peter Meyer

Toralf Gruner

Markus Hauf

Johannes Ruoff

Jochen Weber

Ulrich Schoenhoff

Arif Kazi

Jens Timo Neumann

Joerg Zimmermann

Walter Pauls

Dirk Juergens

Payam Tayebati

Tilmann Heil

Alexander Sauerhoefer

Michael Thier

Ole Fluegge

Klaus Gwosch

Stefan Mueller

Ralf Gehrke

Gerhard Focht

Grizelda Kersteen

Jörg Zimmermann

Dirk JÜRGENS

When measuring a reflectivity of an object for measurement light, initially the object and a reflectivity measurement apparatus are provided. The latter includes a measurement light source, an object holder for holding the object and a spatially resolving detector for capturing measurement light reflected by the object. A measurement light beam impinges on a section of the object within a field of view of the measurement apparatus. The reflected measurement light coming from the impinged-upon section of the object is captured. A surface area of the captured section is at most 50 μm×50 μm. The measurement is performed by the detector. Next, at least one reflectivity parameter of the object is determined on the basis of an intensity of the captured measurement light. The result is a measurement method and a metrology system operating therewith, whereby reflectivities in particular of very finely structured objects, such as lithography masks, can be measured with sufficient precision.

Method for measuring a reflectivity of an object for measurement light and metrology system for carrying out the method

A method of heating an optical element in a microlithographic projection exposure apparatus and an optical system includes using a heating arrangement to introduce a heating power into the optical element. The heating power is regulated based on a setpoint value. The setpoint value is varied over time during the operation of the projection exposure apparatus. Varying the setpoint value for the heating power comprises a simulation of the effects of changes in the heating power relative to the actual value thereof based on a model for the thermal behavior of the optical element.

Method for heating an optical element in a microlithographic projection exposure apparatus and optical system

For the qualification of a mask for microlithography, the effect of an aerial image of the mask on the wafer is ascertained by means of a simulation for predicting the wafer structures producible by means of the mask.

Method for the qualification of a mask for microlithography

For the purposes of measuring structures of a microlithographic mask, a method for capturing absolute positions of structures on the mask and a method for determining structure-dependent and/or illumination-dependent contributions to the position of an image of the structures to be imaged, or of the edges defining this structure, are combined with one another. As a result of this, establishing an edge placement error that is relevant to the exposure of a wafer and, hence, a characterization of the mask can be substantially improved.

Microlithographic mask, method for determining edge positions of the images of the structures of such a mask and system for carrying out such a method

For determining a structure-independent contribution of a lithography mask to a fluctuation of the linewidth, recorded 2D intensity distributions () of an unstructured measurement region of a lithography mask are evaluated in a spatially resolved manner.

Method for determining a structure-independent contribution of a lithography mask to a fluctuation of the linewidth

An EUV greyscale filter of an EUV optical unit of a metrology system has a membrane that is at least partly transmissive in regions for EUV light in the wavelength range of between 5 nm and 30 nm. The latter interacts with a whole beam of the EUV light in the operational position of the EUV greyscale filter. This results in a metrology system with extended application possibilities on account of the EUV greyscale filter.

Metrology system having an EUV optical unit

The invention relates to a method for examining a photolithographic mask for the extreme ultraviolet (EUV) wavelength range in a mask metrology apparatus. In this method, at least one structured region of the mask is selected, a scanner photon number in the extreme ultraviolet (EUV) wavelength range for which the mask in the lithographic production run is provided and a metrology photon number in the extreme ultraviolet (EUV) wavelength range with which the measurement is performed are determined. Next, a photon statistics examination mode is established on the basis of the scanner photon number and the metrology photon number and at least one aerial image of the at least one structured region is produced with the mask metrology apparatus.

Method for examining photolithographic masks and mask metrology apparatus for performing the method

For determining a focus position of a lithography mask (e.g., 5), a focus stack of a measurement region free of structures to be imaged is recorded and the speckle patterns of the recorded images are evaluated.

Method for determining a focus position of a lithography mask and metrology system for carrying out such a method

Determining an imaging aberration contribution of an imaging optical unit for measuring lithography masks involves firstly focus-dependently measuring a 3D aerial image of the imaging optical unit as a sequence of 2D intensity distributions in different measurement planes in the region of and parallel to an image plane of an imaging of an object by use of the imaging optical unit. A spectrum of a speckle pattern of the 3D aerial image is then determined by Fourier transformation of the measured 2D intensity distributions having speckle patterns. For a plurality of spectral components in the frequency domain, a focus dependence of a real part RS(z) and an imaginary part IS(z) of said spectral component is then determined. From the determined values of the focus dependence of the real part RS(z) and the imaginary part IS(z), a contribution made to the speckle pattern spectrum by a mask structure, which contribution is to be eliminated, is then separated from an imaging aberration contribution made to the speckle pattern spectrum by the imaging optical unit. The imaging aberration contribution is then represented. This results in a method for determining the imaging aberration contribution of the imaging optical unit having little additional time expenditure in comparison with the measurement time on the respective lithography mask.

Method for determining an imaging aberration contribution of an imaging optical unit for measuring lithography masks

A method for measuring an angularly resolved intensity distribution in a reticle plane () of a projection exposure apparatus (). The apparatus includes an illumination system (), irradiating a reticle () arranged in the reticle plane () and having a first pupil plane (). All planes of the projection exposure apparatus which are conjugate thereto are further pupil planes, and the reticle plane () and all planes which are conjugate thereto are field planes. The method includes: arranging a spatially resolving detection module () in the region of one of the field planes () such that the detection module is at a smaller distance from this field plane than from the closest pupil plane (), radiating electromagnetic radiation () onto an optical module () from the illumination system, and determining an angularly resolved intensity distribution of the radiation from a signal recorded by the detection module.

Method for measuring an angularly resolved intensity distribution and projection exposure apparatus

A method of reducing image placement errors in a microlithographic projection exposure apparatus includes providing a mask, a light sensitive layer and a microlithographic projection exposure apparatus which images features of the mask onto the light sensitive surface using projection light. Subsequently, image placement errors associated with an image of the features formed on the light sensitive surface are determined either by simulation or metrologically. Then an input state of polarization of the projection light is changed to an elliptical output state of polarization which is selected such that the image placement errors are reduced.

Optical system of a microlithographic projection exposure apparatus and method of reducing image placement errors

The disclosure relates to an optical system, such as a projection exposure apparatus for semiconductor lithography, including a manipulable correction arrangement for reducing image aberrations. In some embodiments, the system includes at least one manipulator configured to reduce image aberrations. The manipulator can include at least one optical element which can be manipulated by at least one actuator. The manipulator can be formed in changeable fashion together with an actuator.

Optical system with an exchangeable, manipulable correction arrangement for reducing image aberrations

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Langenau, Germany

Dirk Hellweg