Patent ID: 8896808
Filing Date: 2014-11-25
Classification: G03F

Abstract:
1. A lithographic apparatus, comprising: an array of individually controllable elements configured to modulate a radiation beam; a projection system configured to project the modulated radiation beam onto a target portion of a substrate; a measuring system configured to measure a separation between an image plane of the projection system and the target portion of the substrate; a memory coupled to the control system, the memory being configured to store pre-calculated adjusted patterns; and a control system configured to determine a projected pattern to be formed by the array of individually controllable elements, the determination including selection of a pattern from the pre-calculated adjusted patterns stored in the memory, the selection based on the measured separation between the image plane of the projection system and the target portion of the substrate such that the image plane of the projected pattern is shifted by an amount so as to focus the projected pattern onto the target portion of the substrate in response to the measured separation between the target portion of the substrate and the image plane.