Abstract: In a reflective lithographic projection apparatus, shifts in the image of a pattern of a mask in the scanning direction caused by variations in the position of the pattern surface of the mask along the optical axis are corrected by shifting of the relative position of the mask and/or the substrate in the scanning direction. Correction of the image rotation error may also be accomplished by rotation of the relative positions of the mask and/or the substrate about the optical axis. Variations in the position of the pattern surface of the mask along the optical axis may be determined by interferometers upon installation of the mask to the lithographic projection apparatus. The variations may be mapped and stored to provide control of the lithographic projection apparatus.

Abstract: A lithographic device includes a machine frame which supports a substrate holder, a focusing system and a mask holder in a vertical direction. The substrate holder is displaceable parallel to a horizontal X-direction and a horizontal Y-direction perpendicular to the X-direction by a first positioning device, and the mask holder is displaceable parallel to the X-direction by a second positioning device. The substrate holder and the mask holder are displaced synchronously parallel to the X-direction during exposure of a semiconductor substrate. The second positioning device is capable of positioning the mask holder also parallel to the Y-direction and of rotating it about a vertical axis of rotation. Therefore, a displacement of the mask holder has a parallelism to the X-direction which is determined by a positioning accuracy of the second positioning device and which is not adversely affected by a deviation from parallelism and straightness of a guide of the second positioning device.

Abstract: A positioning device has two transport arms for alternately transferring plate-shaped objects from a storage position into an operational position. The transport arms are each displaceable by means of a separate manipulator, so that a quick exchange of the objects is possible. The manipulators each comprise two parallel Y-guides which are fastened to a frame, and an X-guide which is displaceable along the two Y-guides, while the transport arms are each displaceable along one of the X-guides. The positioning device is used in an optical lithographic device for alternately placing masks on a mask support. A machine frame of the optical lithographic device to which the mask support is fastened is coupled to the frame of the positioning device by spring members. To render an accurate positioning of the masks on the mask support possible, the optical lithographic device is provided with an optical sensor system which is coupled to an electronic control unit for controlling the positioning device.