Abstract: An apparatus for detecting a pre-aligning element at a wafer and a method for pre-aligning a wafer are disclosed. In an embodiment, the apparatus includes a sensor arrangement configured to illuminate subsequent edge portions of the wafer edge and to output a first and a second sensor signal, wherein the first sensor signal is based on the transmitted fractions of the illumination and the second sensor signal is based on the reflected fractions of the illumination; and an evaluation unit configured to evaluate the first sensor signal and to determine a first position information indicating a coarse position of the pre-aligning element, and, after having determined the first position information, to determine a second position information based on the second sensor signal and the first position information, wherein the second position information indicates a fine position of the pre-aligning element.

Abstract: An apparatus for detecting a pre-aligning element at a wafer and a method for pre-aligning a wafer are disclosed. In an embodiment, the apparatus includes a sensor arrangement configured to illuminate subsequent edge portions of the wafer edge and to output a first and a second sensor signal, wherein the first sensor signal is based on the transmitted fractions of the illumination and the second sensor signal is based on the reflected fractions of the illumination; and an evaluation unit configured to evaluate the first sensor signal and to determine a first position information indicating a coarse position of the pre-aligning element, and, after having determined the first position information, to determine a second position information based on the second sensor signal and the first position information, wherein the second position information indicates a fine position of the pre-aligning element.

Abstract: An apparatus detects a pre-aligning element at a wafer. The wafer has the pre-aligning element at a wafer edge. The apparatus includes a sensor arrangement and an evaluation unit. The sensor arrangement is configured to illuminate subsequent edge portions of the wafer edge, to receive transmitted fractions and reflected fractions of the illumination from the illuminated edge portions with an illumination sensor, and to output a first and a second sensor signal. The first sensor signal is based on the transmitted fractions of the illumination and the second sensor signal is based on the reflected fractions of the illumination. The evaluation unit is configured to evaluate the first sensor signal and to determine a first position information with respect to a coarse position of the pre-aligning element if the first sensor signal indicates that the transmitted fractions of the illumination has reached a predetermined threshold value.

Abstract: Structures of a backside of a wafer can be aligned to structures of a frontside of the wafer for a lithographic treatment of the backside. The wafer is transparent for electromagnetic radiation of a specific wavelength. The wafer is placed on a wafer stage such that the frontside is facing the wafer stage and the backside is facing alignment optics. The backside is illuminated with electromagnetic radiation of the specific wavelength in a dark-field configuration, such that the electromagnetic radiation propagates through the wafer towards three-dimensional structures of a three-dimensional alignment target located at the frontside or inside the wafer and is scattered at the three-dimensional structures. The scattered electromagnetic radiation is captured with the alignment optics, and the backside is aligned to the frontside of the wafer based on the scattered electromagnetic radiation.

Abstract: An apparatus detects a pre-aligning element at a wafer. The wafer has the pre-aligning element at a wafer edge. The apparatus includes a sensor arrangement and an evaluation unit. The sensor arrangement is configured to illuminate subsequent edge portions of the wafer edge, to receive transmitted fractions and reflected fractions of the illumination from the illuminated edge portions with an illumination sensor, and to output a first and a second sensor signal. The first sensor signal is based on the transmitted fractions of the illumination and the second sensor signal is based on the reflected fractions of the illumination. The evaluation unit is configured to evaluate the first sensor signal and to determine a first position information with respect to a coarse position of the pre-aligning element if the first sensor signal indicates that the transmitted fractions of the illumination has reached a predetermined threshold value.

Abstract: Structures of a backside of a wafer can be aligned to structures of a frontside of the wafer for a lithographic treatment of the backside. The wafer is transparent for electromagnetic radiation of a specific wavelength. The wafer is placed on a wafer stage such that the frontside is facing the wafer stage and the backside is facing alignment optics. The backside is illuminated with electromagnetic radiation of the specific wavelength in a dark-field configuration, such that the electromagnetic radiation propagates through the wafer towards three-dimensional structures of a three-dimensional alignment target located at the frontside or inside the wafer and is scattered at the three-dimensional structures. The scattered electromagnetic radiation is captured with the alignment optics, and the backside is aligned to the frontside of the wafer based on the scattered electromagnetic radiation.

Abstract: A system and method for prealigning a substrate. One embodiment provides a rotor configured to rotate a carrier around a rotation axis in response to a rotation signal. The carrier includes a main surface substantially perpendicular to the rotation axis. The substrate is disposable on the carrier. The substrate includes a main surface and a mark such that an orientation of the substrate with respect to the rotation axis is detectable. An electromagnetic radiation source is configured to illuminate the main surface of the substrate with electromagnetic radiation. An optical/electrical converter is responsive to the electromagnetic radiation reflected back from the main surface, detecting the mark of the substrate and providing a sensing signal. A controller is configured to receive the sensing signal and providing the rotation signal.

Abstract: A system and method for prealigning a substrate. One embodiment provides a rotor configured to rotate a carrier around a rotation axis in response to a rotation signal. The carrier includes a main surface substantially perpendicular to the rotation axis. The substrate is disposable on the carrier. The substrate includes a main surface and a mark such that an orientation of the substrate with respect to the rotation axis is detectable. An electromagnetic radiation source is configured to illuminate the main surface of the substrate with electromagnetic radiation. An optical/electrical converter is responsive to the electromagnetic radiation reflected back from the main surface, detecting the mark of the substrate and providing a sensing signal. A controller is configured to receive the sensing signal and providing the rotation signal.