Abstract:
An alignment system, method and lithographic apparatus are provided for determining the position of an alignment mark, the alignment system comprising a first system configured to produce two overlapping images of the alignment mark that are rotated by around 180 degrees with respect to one another, and a second system configured to determine the position of the alignment mark from a spatial distribution of an intensity of the two overlapping images.
Abstract:
Die Erfindung betrifft ein Verfahren zum Justieren eines Spiegels einer mikrolithographischen Projektionsbelichtungsanlage. Gemäß einem Aspekt der Erfindung weist ein erfindungsgemäßes Verfahren folgende Schritte auf: Aufnehmen eines ersten Teil-Interferogramms zwischen einer an einem ersten Spiegelsegment (101) reflektierten Welle und einer an einer Referenzfläche (110, 310, 510) reflektierten Referenzwelle, Aufnehmen eines zweiten Teil- Interferogramms zwischen einer an einem zweiten Spiegelsegment (102) reflektierten Welle und einer an der Referenzfläche (110, 310, 510) reflektierten Referenzwelle, Ermitteln eines Phasenversatzes zwischen dem ersten Teil-Interferogramm und dem zweiten Teil-Interferogramm, und Justieren des ersten Spiegelsegments (101) und des zweiten Spiegelsegments (102) zueinander auf Basis des ermittelten Phasenversatzes derart, dass der Abstand der betreffenden Spiegelsegmente (101, 102) in Richtung der jeweiligen Oberflächennormalen von einer fiktiven, vorgegebenen Sollfläche in jedem Punkt auf den Spiegelsegmenten kleiner ist als λ/10, wobei λ die Arbeitswellenlänge bezeichnet.
Abstract:
A lithographic apparatus (LA) applies a pattern repeatedly to target portions (fields, C) across a substrate (W). Prior to applying the pattern an alignment sensor (AS) measures positions of marks in the plane of the substrate and a level sensor (LS) measures height deviations in a direction normal to the plane of the substrate. The apparatus applies the pattern to the substrate while (a) positioning the applied pattern using the positions measured by the alignment sensor and (b) focusing the pattern using the height deviations measured by the level sensor. The apparatus is further arranged (c) to calculate and apply corrections in the positioning of the applied pattern, based on derivatives of the measured height deviations. The corrections may be calculated on intrafield and/or interfield basis. The corrections may be based on changes between the observed height deviations and height deviations measured previously on the same substrate.
Abstract:
The invention relates to a method for determining a reference point of an orientation marking on a substrate of a photolithographic mask in an automated manner, comprising the following steps: (a) performing a first line scan within a start region of the substrate in a first direction on a surface of the substrate, wherein the orientation marking is arranged within the start region, in order to find a first element of the orientation marking; (b) performing a second line scan within the start region in at least one second direction on the surface of the substrate, which at least one second direction intersects with the first direction, in order to find a second element of the orientation marking; (c) estimating the reference point of the orientation marking from the found first element and the found second element of the orientation marking; and (d) imaging a target region around the estimated reference point of the orientation marking in order to determine the reference of the orientation marking, wherein the imaging is performed with a higher resolution than the performance of the line scans in steps (a) and (b).
Abstract:
There is provided a lithographic apparatus having a reference body (202) and a positioning system (200). The positioning system includes a main body (204), a reaction body (206), an actuator (208) and a controller (210). The main body is moveable relative to the reference body along a path in a first direction (+z) and a second direction (-z). The first direction is opposite to the second direction. The reaction body is moveable relative to the main body along a further path in the first direction and the second direction. The reaction body is moveably connected to the reference body so as to be moveable relative to the reference body in the first direction and the second direction. The controller is arranged to provide a first signal and a second signal to the actuator. The actuator is arranged between the main body and the reaction body.
Abstract:
An apparatus for measuring positions of marks on a substrate, includes an illumination arrangement for supplying radiation with a predetermined illumination profile across a pupil of the apparatus, an objective lens for forming a spot of radiation on a mark using radiation supplied by said illumination arrangement, a radiation processing element for processing radiation that is diffracted by the mark, a first detection arrangement for detecting variations in an intensity of radiation output by the radiation processing element and for calculating therefrom a position of the mark, an optical arrangement, a second detection arrangement, wherein the optical arrangement serves to direct diffracted radiation to the second detection arrangement, and wherein the second detection arrangement is configured to detect size and/or position variations in the radiation and to calculate therefrom a defocus and/or local tilt of the mark.
Abstract:
An apparatus for measuring positions of marks on a substrate, includes an illumination arrangement for supplying radiation with a predetermined illumination profile across a pupil of the apparatus, an objective lens for forming a spot of radiation on a mark using radiation supplied by said illumination arrangement, a radiation processing element for processing radiation that is diffracted by the mark, a first detection arrangement for detecting variations in an intensity of radiation output by the radiation processing element and for calculating therefrom a position of the mark, an optical arrangement, a second detection arrangement, wherein the optical arrangement serves to direct diffracted radiation to the second detection arrangement, and wherein the second detection arrangement is configured to detect size and/or position variations in the radiation and to calculate therefrom a defocus and/or local tilt of the mark.
Abstract:
Verfahren zum Einstellen eines Beleuchtungssettings in einer Beleuchtungsoptik (4) mit mindestens einer steuerbaren Korrektureinrichtung (23, 27), welche eine Vielzahl von verstellbaren Korrektur-Elementen zur Beeinflussung der Transmission aufweist, wobei das Beleuchtungssetting zur Anpassung eines vorgegebenen Abbildungs-Parameters im Bereich eines Bildfelds (8) variiert wird.
Abstract:
A method of operating a projection exposure tool (10) for microlithography is provided. The projection exposure tool (10) has a projection objective (26) for imaging object structures on a mask (20) into an image plane (28) using electromagnetic radiation (13, 13a, 13b), during which imaging the electromagnetic radiation (13b) causes a change in optical properties of the projection objective (26). The method comprises the steps of: providing the layout of the object structures on the mask (20) to be imaged and classifying the object structures according to their type of structure, calculating the change in the optical properties of the projection objective (26) effected during the imaging process on the basis of the classification of the object structures, and using the projection exposure tool (10) for imaging the object structures into the image plane (28), wherein the imaging behavior of the projection exposure tool (10) is adjusted on the basis of the calculated change of the optical properties in order to at least partly compensate for the change of the optical properties of the projection objective (26) caused by the electromagnetic radiation (13, 13a, 13b) during the imaging process.