Carl Zeiss Smt Gmbh

Carl Zeiss Ag

Carl Zeiss Sms Ltd.

Holger Seitz

Ulrich Matejka

Thomas Frank

Mario Laengle

Thomas Thaler

Ute Buttgereit

Thomas Trautzsch

Dirk Doering

Heiko Feldmann

Thomas Zeuner

Markus Deguenther

Christoph Husemann

Thomas Scheruebl

Norbert Kerwien

Norbert Rosenkranz

Axel Zibold

Rigo Richter

Asad Rasool

Thomas Rademacher

Mame Kouna Top-Diallo

Robert Birkner

Dominik Grau

The invention relates to an inspection device for masks for semiconductor lithography, comprising an imaging device for imaging a mask, and an image recording device, wherein one or more correction bodies which exhibit a dispersive behavior for at least one subrange of the illumination radiation used for the imaging are arranged in the light path between the mask and the image recording device. The invention furthermore relates to a method for taking account of longitudinal chromatic aberrations in inspection devices for masks, comprising the following steps: recording a specific number of images having differently defocused positions, and selecting a subset of the images and simulating a longitudinal chromatic aberration of a projection exposure apparatus.

Inspection device for masks for semiconductor lithography and method

The invention relates to a method and an apparatus for characterizing a microlithographic mask. In a method according to the invention, structures of a mask intended for use in a lithography process in a microlithographic projection exposure apparatus are illuminated by an illumination optical unit, wherein the mask is imaged onto a detector unit which has a plurality of pixels by an imaging optical unit. Here, a plurality of individual imaging processes are carried out with a pixel resolution specified by the detector unit, wherein these individual imaging processes differ from one another in respect of the position of at least one polarization-optical element situated in the imaging optical unit, wherein image data recorded by the detector unit are evaluated in an evaluation unit, wherein polarization-dependent effects on account of a polarization dependence of the interference of electromagnetic radiation that takes place in the wafer plane during the operation of the microlithographic projection exposure apparatus are emulated, wherein a conversion of the image data obtained in the individual imaging processes is implemented, in each case on the basis of at least one calibration image obtained by imaging a structure-free region of the mask onto the detector unit, wherein the calibration image respectively used is chosen differently depending on the position of the at least one polarization-optical element.

Method and apparatus for characterizing a microlithographic mask

The invention relates to a method and an appliance for predicting the imaging result obtained with a mask when a lithography process is carried out, wherein the mask comprises mask structures to be imaged and the mask is destined to be illuminated in a lithography process in a projection exposure apparatus with a predetermined illumination setting for exposing a wafer comprising a photoresist. In accordance with one aspect of the invention, a method according to the invention comprises the following steps: measuring at least one intensity distribution obtained for the mask in the case of an illumination with illumination light in accordance with the illumination setting in a mask inspection apparatus using a sensor arrangement, ascertaining an electric field resulting from the interaction of the illumination light with the mask structures, both in respect of amplitude and in respect of phase, by way of this intensity measurement, and estimating an intensity distribution obtained in the photoresist when the lithography process is carried out on the basis of a mathematical simulation (forward calculation), in which the electric field ascertained is propagated in a layer system comprising at least the photoresist.

Method and appliance for predicting the imaging result obtained with a mask when a lithography process is carried out

The invention relates to a method and a device for characterizing a mask for microlithography. In a method according to the invention, structures of a mask intended for use in a lithography process in a microlithographic projection exposure apparatus are illuminated by an illumination optical unit, wherein the mask is imaged onto a detector unit by an imaging optical unit, wherein image data recorded by the detector unit are evaluated in an evaluation unit. In this case, for emulating an illumination setting predefined for the lithography process in the microlithographic projection exposure apparatus, the imaging of the mask onto the detector unit is carried out in a plurality of individual imagings which differ from one another with regard to the illumination setting set in the illumination optical unit or the polarization-influencing effect set in the imaging optical unit.

Method and device for characterizing a mask for microlithography

An illumination optical unit serves for illuminating objects to be examined by a metrology system. The illumination optical unit has an optical pupil shaping assembly for generating a defined distribution of illumination angles of illumination light over an object field in which an object to be examined can be arranged. An optical field shaping assembly for generating a defined intensity distribution of the illumination light over the object field is disposed downstream of the pupil shaping assembly in the beam path of the illumination light. The field shaping assembly has at least one optical field shaping element arranged in the region of a pupil plane of the illumination optical unit. This results in an illumination optical unit which ensures an illumination which can be set in a defined manner with regard to an intensity distribution and an illumination angle distribution over the entire object field.

Illumination optical unit for a metrology system and metrology system comprising such an illumination optical unit

A method is provided for determining an OPC model comprising: recording an aerial image by use of a mask inspection microscope, wherein the aerial image comprises at least one segment of a mask; simulating a plurality of aerial images which comprise at least the segment, proceeding from a mask design and from predefined parameters of an optical model which is part of the OPC model, wherein the parameters differ for each of the simulated aerial images of the plurality of aerial images; determining differences between the measured aerial image and the simulated aerial images; determining those parameters for which the differences between simulated aerial image and measured aerial image are the least. In addition, a mask inspection microscope for carrying out the method is provided.

Method and device for determining an OPC model

A method is provided for emulating the imaging of a scanner mask pattern to expose wafers via a mask inspection microscope, in which the mask was corrected by introducing scattering centers. The method includes determining a correlation between the first values of at least one characteristic of aerial images of the mask pattern as produced by a mask inspection microscope and the second values of the at least one characteristic of aerial images of the mask pattern as produced by a scanner, recording a first aerial image of the mask pattern with the mask inspection microscope, determining the first values of the at least one characteristic from the first aerial image, and determining the second values of the at least one characteristic of the first aerial image, using the correlation. A mask inspection microscope is also provided for emulating the imaging of a mask pattern of a scanner to expose wafers, in which the mask was corrected by introducing scattering centers.

Emulation of reproduction of masks corrected by local density variations

A microscope includes an illumination unit for illuminating a mask at a predetermined non-axial illumination angle, an imaging unit for imaging an aerial image of the mask within a predetermined defocus region, and an imaging field stop, in which as a result of the lateral displacement of the aerial image depending on the position within the defocus region and on the non-axial illumination angle, the opening of the imaging field stop is dimensioned such that the aerial image is either completely encompassed or circumferentially cut within the defocus region. A method for characterizing a mask having a structure includes illuminating the mask at at least one illumination angle using monochromatic illumination radiation such that a diffraction image of the structure is created, recording the diffraction image, establishing the intensities of the maxima of the adjacent orders of diffraction, and establishing an intensity ratio of the intensities.

Microscope and method for characterizing structures on an object

A mask inspection microscope is provided for characterizing a mask having a feature. The mask inspection microscope is configured to generate an aerial image of at least one segment of the feature of the mask, acquire a spatially resolved intensity distribution of the aerial image, and determine a total intensity from the intensities of at least one region of the aerial image.

Method for characterizing a feature on a mask and device for carrying out the method

During mask inspection it is necessary to identify defects which also occur during wafer exposure. Therefore, the aerial images generated in the resist and on the detector have to be as far as possible identical. In order to achieve an equivalent image generation, during mask inspection the illumination and, on the object side, the numerical aperture are adapted to the scanner used. The invention relates to a mask inspection microscope for variably setting the illumination. It serves for generating an image of the structure () of a reticle () arranged in an object plane in a field plane of the mask inspection microscope. It comprises a light source () that emits projection light, at least one illumination beam path (), and a diaphragm for generating a resultant intensity distribution of the projection light in a pupil plane () of the illumination beam path () that is optically conjugate with respect to the object plane. According to the invention, the diaphragm is embodied in such a way that the resultant intensity distribution of the projection light has at least one further intensity value between a minimum and a maximum intensity value.

Mask inspection microscope with variable illumination setting

The invention relates to a method and an apparatus for measuring masks for photolithography. In this case, structures to be measured on the mask on a movable mask carrier are illuminated and imaged as an aerial image onto a detector, the illumination being set in a manner corresponding to the illumination in a photolithography scanner during a wafer exposure. A selection of positions at which the structures to be measured are situated on the mask is predetermined, and the positions on the mask in the selection are successively brought to the focus of an imaging optical system, where they are illuminated and in each case imaged as a magnified aerial image onto a detector, and the aerial images are subsequently stored. The structure properties of the structures are then analyzed by means of predetermined evaluation algorithms. The accuracy of the setting of the positions and of the determination of structure properties is increased in this case.

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Jena, Germany

Holger Seitz