Patent ID: 8904316

Claim:
A method of printing a desired two-dimensional periodic pattern of features having a first lattice symmetry and a first nearest-neighbor distance into a photosensitive layer, the method which comprises: a) providing a phase-shift mask bearing a mask pattern composed of at least two overlapping periodic sub-patterns of features each having a second lattice symmetry and a second nearest-neighbor distance, the features of each sub-pattern being formed in or on at least one transmissive material; b) providing a substrate with the photosensitive layer; c) arranging the mask substantially parallel to and with a separation from the substrate; d) providing substantially collimated light having a central wavelength and a spectral bandwidth for illuminating the mask pattern to generate a transmitted light-field in which light of the central wavelength forms a range of transversal intensity distributions between Talbot planes; e) illuminating the mask pattern with the light while maintaining the separation or changing the separation by a displacement distance to thereby expose the photosensitive layer to substantially an average of the range of transversal intensity distributions and printing the desired pattern; arranging the separation either according to the spectral bandwidth and the second nearest-neighbor distance and maintaining the separation during the illumination, or changing the separation during the illumination by a displacement distance that is related to the central wavelength and the second nearest-neighbor distance; forming the sub-patterns so that the light transmitted by each sub-pattern is shifted in phase relative to the light transmitted by at least one other sub-pattern; selecting the second nearest-neighbor distance in relation to the central wavelength so that first diffraction orders are formed in the transmitted light-field, and wherein the desired two-dimensional periodic pattern is printed using achromatic Talbot lithography (ATL) or displacement Talbot lithography (DTL) in which the mask is illuminated by the light.