Pattern generator for avoiding stitching errors

Claim 1

An apparatus for creating a pattern on a workpiece, such as a photomask, a semiconductor wafer, an electronic interconnect device, a printed circuit board, a display panel, a microoptical device or a printing plate, whereby a pattern with less visible edges is created, comprising a source for emitting electromagnetic radiation with energy content in the wavelength range from EUV to IR, a spatial light modulator having multitude of modulating elements, illuminated by said radiation, a projection system creating an image of the modulator on the workpiece, an electronic data delivery system accepting a digital description of the pattern to be written, extracting a sequence of partial patterns from the digital pattern description, converting said partial patterns to modulator signals, and feeding said signals to the modulator, a precision mechanical system moving said workpiece relative to said projection system, an electronic control system coordinating the movement of the workpiece, the feeding of the signals to the modulator and the emitted radiation, so that a large pattern is stitched together from the partial images created by the sequence of partial patterns, where at least two adjacent images being stitched together are overlapping at the common boundary, each of said overlapping images having essentially the same pattern and a reduced exposure dose in the overlapping area.

Claim 2

An apparatus for creating a pattern on a workpiece, such as a photomask, a semiconductor wafer, an electronic interconnect device, a printed circuit board, a display panel, a microoptical device or a printing plate, whereby a pattern with less visible edges is created, comprising a source for emitting electromagnetic radiation with energy content in the wavelength range from EUV to IR, a spatial light modulator having multitude of modulating elements, illuminated by said radiation, a projection system creating an image of the modulator on the workpiece, an electronic data delivery system accepting a digital description of the pattern to be written, extracting a sequence of partial patterns from the digital pattern description, converting said partial patterns to modulator signals, and feeding said signals to the modulator, a precision mechanical system moving said workpiece relative to said projection system, an electronic control system coordinating the movement of the workpiece, the feeding of the signals to the modulator and the emitted radiation, so that a large pattern is stitched together from the partial images created by the sequence of partial patterns, where at least two adjacent images being stitched together are overlapping at the common boundary, each of said overlapping images having essentially the same pattern and a reduced exposure dose in the overlapping area.