Multi head scanning lithographic laser writer and a method for operating

A scanning lithographic laser writer, comprising:

• a substrate holder having attachment means for holding a substrate with a laser-light sensitive surface in a substrate plane;
• an irradiation arrangement, said irradiation arrangement having a laser source, said irradiation arrangement arranged for providing laser light from said laser source to irradiate said substrate plane, said irradiation arrangement further having a multi head modulator arrangement and m writing head arrangements, where m≥2, said irradiation arrangement arranged for providing said laser light from said laser source, via said multi head modulator arrangement to said m writing head arrangements to irradiate said substrate plane;
• and
• a control unit, said control unit being configured for controlling a relative mechanical displacement between said substrate holder and said m writing head arrangements in at least one scan direction parallel to said substrate plane, said control unit being configured for controlling a sweep of laser light exiting from each of said m writing head arrangements in a sweep direction parallel to said substrate plane and transverse to said at least one scan direction,
• wherein said multi head modulator arrangement is configured to split an input beam originating from said laser source into n beams, where n≥1, for each of said m writing head arrangements by use of an acousto-optical crystal, and wherein said multi head modulator arrangement is further configured to modulate said n beams simultaneously into n modulated beams, and
• wherein said m writing head arrangements are positioned such that the laser light exiting from each of said m writing head arrangements becomes displaced with a predetermined non-zero distance in the sweep direction with respect to each other.