LITHOGRAPHIC METHOD FOR MASKLESS PATTERN TRANSFER ONTO A PHOTOSENSITIVE SUBSTRATE

摘要

The invention proposes a Subpixel Scroll method, which optically shifts the position of the mirror elements to the projection axis by one subpixel size each,with an additional 45° mirror between DMD and projection optics. In a preferred embodiment, the 45° mirror is shifted by 1/4 mirror element width by means of a controllable actuator. The size of this change of position and the time are synchronized in such a way by the position indicator signals of the scan sled that the mirror element (as with the standard scrolling method) seems to stand relative to the substrate surface element. Differently than with the standard scrolling method, this resetting is however not bound to the DMD - switching speed of kHz. The invention reduces the blur at the edge transition by the higher resolution and facilitates a higher scan velocity, whereby the scan velocity depends on the dynamics of the actuator, the effective UV - power of the UV - source and the sensitivity of the photosensitive polymer. A further advantageous function of the invention is the possibility of transferring a pattern with higher resolution than given by the mirror element size. For an increase of the resolution in X (scan direction) and Y (perpendicular to the scan direction) two mirror actuators are necessary, which work in X and Y.