A method and an apparatus for improving the uniformity of exposure of a first periodic pattern in a photomask by a collimated beam of monochromatic light in a photolithographic system that prints a second periodic pattern into a photosensitive layer on a substrate that is in proximity to the photomask, include providing a plate that is composed of a material transparent to the beam and that has opposing surfaces that are parallel and separated by a thickness. The plate is arranged in the photolithographic system such that the beam illuminates the plate at an initial angle of incidence and the beam transmitted by the plate illuminates the photomask. The plate is rotated by at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.
G03F 7/00 - Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printed surfacesMaterials therefor, e.g. comprising photoresistsApparatus specially adapted therefor
A method for improving the uniformity of exposure of a first periodic pattern in a photomask by a collimated beam of monochromatic light in a photolithographic system that prints a second periodic pattern into a photosensitive layer on a substrate that is in proximity to the photomask, which method comprises providing a plate that is composed of a material transparent to the beam and that has opposing surfaces that are parallel and separated by a thickness, arranging said plate in the photolithographic system such that the beam illuminates the plate at an initial angle of incidence and the beam transmitted by the plate illuminates the photomask, and rotating said plate by at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.
A method for forming a surface-relief grating with a desired spatial variation of duty cycle in a layer of photoresist includes: providing a first mask bearing a high-resolution grating of linear features, arranging the first mask at a first distance from a substrate, providing a second mask bearing a variable-transmission grating of opaque and transparent linear features that has a designed spatial variation of duty cycle, arranging the second mask at a distance before the first mask such that the linear features of the variable-transmission grating are orthogonal to the linear features of the high-resolution grating, illuminating the second mask while varying the first distance according to displacement Talbot lithography and also displacing the second mask at an angle to its linear features such that there is substantially no component of modulation with the period of the variable-transmission grating in the energy density distribution that exposes the photoresist.
G03F 7/00 - Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printed surfacesMaterials therefor, e.g. comprising photoresistsApparatus specially adapted therefor
G03F 1/70 - Adapting basic layout or design of masks to lithographic process requirements, e.g. second iteration correction of mask patterns for imaging
4.
Methods and systems for printing large periodic patterns by overlapping exposure fields
A method for printing a periodic pattern of linear features into a photosensitive layer which includes providing a mask bearing a pattern of linear features, arranging the substrate parallel to the mask, generating an elongated beam for illuminating the mask with a range of angles of incidence in a plane parallel to the linear features and with a uniform power per incremental distance along the length of the beam except at its ends where the power per incremental distance falls to zero according to first and second profiles over a fall-off distance, and scanning the beam in first and second sub-exposures to print first and second parts of the desired pattern such that the first and second parts overlap by the fall-off distance. The first and second profiles are selected so that their summation across the fall-off distance produces a uniform power per incremental distance.
A method for forming a surface-relief grating with a desired spatial variation of duty cycle in a layer of photoresist, which method comprises providing a first mask (31) bearing a high-resolution grating of linear features (32), arranging said first mask at a first distance from a substrate (33), providing a second mask (28) bearing a variable-transmission grating of opaque and transparent linear features (27) that has a designed spatial variation of duty cycle, arranging said second mask at a distance before the first mask such that the linear features of the variable-transmission grating are orthogonal to the linear features of the high-resolution grating, illuminating the second mask while varying the first distance according to displacement Talbot lithography and also displacing the second mask at an angle to its linear features such that there is substantially no component of modulation with the period of the variable-transmission grating in the energy density distribution that exposes the photoresist.
A method for printing a periodic pattern of linear features into a photosensitive layer which includes providing a mask bearing a pattern of linear features, arranging the substrate parallel to the mask, generating an elongated beam for illuminating the mask with a range of angles of incidence in a plane parallel to the linear features and with a uniform power per incremental distance along the length of the beam except at its ends where the power per incremental distance falls to zero according to first and second profiles over a fall-off distance, scanning said beam in first and second sub-exposures to print first and second parts of the desired pattern such that the first and second parts overlap by the fall-off distance, wherein the first and second profiles are selected so that their summation across the fall-off distance produces a uniform power per incremental distance.
A method for printing a desired periodic pattern into a photosensitive layer on a substrate includes providing a mask bearing a periodic pattern whose period is a multiple of that of the desired pattern. The substrate is disposed in proximity to the mask, at least one beam is provided for illuminating the mask pattern to generate a transmitted light-field described by a Talbot distance. The layer is exposed to time-integrated intensity distributions in a number of sub-exposures by illuminating the mask pattern with the at least one beam while changing the separation between substrate and mask by at least a certain fraction of, but less than, the Talbot distance. The illumination or the substrate is configured relative to the mask for the different sub-exposures so that the layer is exposed to the same time-integrated intensity distributions that are mutually laterally offset by a certain distance and in a certain direction.
A method forms a pattern of metallic nanofeatures that generates by plasmonic resonance a desired image having a distribution of colors. The method includes providing a substrate having a layer of photosensitive material, exposing the layer to a high-resolution periodic pattern of dose distribution, and determining a low-resolution pattern of dose distribution such that the sum of the low-resolution pattern and the high-resolution periodic pattern of dose distribution is suitable for forming the pattern of metallic nanofeatures. The lateral dimensions of the metallic nano-features have a spatial variation across the pattern that corresponds to the distribution of colors in the desired image. The layer of photosensitive material is exposed to the low-resolution pattern of dose distribution. The layer of photosensitive material is developed to produce a pattern of nanostructures in the developed photosensitive material. The pattern of nanostructures is processed so that the pattern of metallic nanofeatures is formed.
G03F 7/00 - Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printed surfacesMaterials therefor, e.g. comprising photoresistsApparatus specially adapted therefor
9.
METHODS AND SYSTEMS FOR PRINTING ARRAYS OF FEATURES
A method for printing a desired periodic pattern into a photosensitive layer on a substrate, which includes providing a mask bearing a periodic pattern whose period is a multiple of that of the desired pattern, disposing the substrate in proximity to the mask, providing at least one beam for illuminating said mask pattern to generate a transmitted light-field described by a Talbot distance, exposing the layer to time-integrated intensity distributions in a number of sub-exposures by illuminating the mask pattern with the at least one beam while changing the separation between substrate and mask by at least a certain fraction of, and less than, the Talbot distance, configuring the illumination or the substrate relative to the mask for the different sub-exposures so that the layer is exposed to the same time-integrated intensity distributions that are mutually laterally offset by a certain distance and in a certain direction.
A method for forming a pattern of metallic nanofeatures that generates by plasmonic resonance a desired image having a distribution of colours, which method includes providing a substrate having a layer of photosensitive material, exposing the layer to a high-resolution periodic pattern of dose distribution, determining at least one low-resolution pattern of dose distribution such that the sum of the at least one low-resolution pattern of dose distribution and the high-resolution periodic pattern of dose distribution is suitable for forming the pattern of metallic nanofeatures, wherein the lateral dimensions of said metallic nanofeatures have a spatial variation across the pattern that corresponds to the distribution of colours in the desired image, exposing the layer of photosensitive material to said at least one low-resolution pattern of dose distribution, developing the layer of photosensitive material to produce a pattern of nanostructures in the developed photosensitive material, processing the pattern of nanostructures so that the pattern of metallic nanofeatures is formed with said spatial variation of lateral dimension across the pattern that corresponds to the distribution of colours in the desired image.
G03F 7/00 - Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printed surfacesMaterials therefor, e.g. comprising photoresistsApparatus specially adapted therefor
i/N) times the Talbot distance. The mask pattern is exposed to the same energy density of illumination for each sub-exposure, wherein the period is selected in relation to the wavelength so that only the zeroth and first diffraction orders are transmitted by the mask.
A method for manufacturing a bi-layer wire-grid polarizer, which method includes forming a periodic pattern of alternating and parallel pre-formed lines and grooves on a surface of a substrate, depositing polarizing material onto the pattern to form a top wire of polarizing material having a first width on the top of each pre-formed line and a bottom wire of polarizing material having a second width on the bottom of each groove, each top wire and each of its neighbouring bottom wires having a lateral separation between them, and enlarging the lateral separation between each top wire and each of its neighbouring bottom wires by at least one of increasing the period of the periodic pattern and reducing the first and second widths of the respective top and bottom wires, whereby certain desired transmission and/or polarization properties of the bi-layer wire-grid polarizer are obtained.
A method for printing a periodic pattern of features into a photosensitive layer, which includes providing a mask bearing a periodic pattern, providing a substrate bearing the photosensitive layer, arranging the substrate substantially parallel to the mask, forming a beam of collimated monochromatic light for illuminating said mask pattern so that the light-field transmitted by the mask forms Talbot image planes separated by a Talbot distance, and performing N sub- exposures of the mask with said beam and changing the separation between sub-exposures so that the relative separation during the ith sub-exposure with respect to that during the first sub-exposure is given by (mi + ni/N) times the Talbot distance, and exposing the mask pattern to the same energy density of illumination for each sub-exposure, wherein the period is selected in relation to the wavelength so that only the zeroth and first diffraction orders are transmitted by the mask.
An apparatus and a method for printing a desired pattern into a photosensitive layer. A mask bears a pattern of linear mask features parallel to a first direction. The layer is arranged parallel to and separated from the mask. Substantially monochromatic light is generated and the mask pattern is illuminated with the light over a range of angles of incidence in a plane parallel to the first direction, at substantially a single angle in an orthogonal plane of incidence and so that the light of each angle of incidence transmitted by the mask forms a light-field component at the layer. The integration of the components prints the desired pattern. The range of angles is selected so that the integration of the components is substantially equivalent to an average of the range of transversal intensity distributions formed between Talbot image planes by light at one of the angles of incidence.
A method for printing a periodic pattern having a first symmetry and a first period into a photosensitive layer. The method includes providing a mask bearing a pattern of at least two overlapping sub-patterns which have a second symmetry and a second period, the features of each sub-pattern being formed in a transmissive material, providing a substrate bearing the layer, arranging the mask with a separation from the substrate, providing light having a central wavelength for illuminating the mask to generate a light-field in which light of the central wavelength forms a range of intensity distributions between Talbot planes, illuminating said mask pattern with said light while maintaining the separation or changing it by a distance whereby the photosensitive layer is exposed to an average of the range of intensity distributions, wherein the light transmitted by each sub-pattern is shifted in phase relative to that transmitted by another sub-pattern.
A method and an apparatus print a pattern of periodic features into a photosensitive layer. The methods includes the steps of: providing a substrate bearing the layer, providing a mask, arranging the substrate such that the mask has a tilt angle with respect to the substrate in a first plane orthogonal thereto, and providing collimated light for illuminating the mask pattern so as to generate a transmitted light-field composed of a range of transversal intensity distributions between Talbot planes separated by a Talbot distance so that the transmitted light-field has an intensity envelope in the first plane. The mask is illuminated with the light while displacing the substrate relative to the mask in a direction parallel to the first plane and to the substrate. The tilt angle and the intensity envelope are arranged so that the layer is exposed to an average of the range of transversal intensity distributions.
A method for printing a desired periodic pattern includes providing a mask bearing a pattern of features having a period, providing a substrate bearing a photosensitive layer, arranging the substrate with a separation from the mask, generating collimated light with a wavelength and an intensity, at least the former of which may be temporally varied to deliver a spectral distribution of energy density, illuminating the mask pattern with the light while varying at least its wavelength so as to deliver a spectral distribution of energy density, such that the light-field transmitted by the mask is instantaneously composed of a range of transversal intensity distributions between Talbot planes. The layer is exposed to a time-integrated intensity distribution that prints the desired pattern. The separation, spectral distribution and period are arranged so that the time-integrated intensity distribution corresponds to an average of the range of transversal intensity distributions.
A method for printing a desired periodic or quasi-periodic pattern of dot features into a photosensitive layer disposed on a substrate including the steps of designing a mask pattern having a periodic or quasi-periodic array of unit cells each having a ring feature, forming a mask with said mask pattern, arranging the mask substantially parallel to the photosensitive layer, arranging the distance of the photosensitive layer from the mask and illuminating the mask according to one of the methods of achromatic Talbot lithography and displacement Talbot lithography, whereby the illumination transmitted by the mask exposes the photosensitive layer to an integrated intensity distribution that prints the desired pattern.
G03F 1/00 - Originals for photomechanical production of textured or patterned surfaces, e.g. masks, photo-masks or reticlesMask blanks or pellicles thereforContainers specially adapted thereforPreparation thereof
A method for printing a periodic pattern (19) of features into a photosensitive layer (21), which method includes providing a mask (18) bearing a mask pattern, providing a substrate (20) bearing the layer, arranging the substrate parallel to the mask, providing a number of lasers (1) having a plurality of peak wavelengths, forming from said light a beam for illuminating the mask with a spectral distribution of exposure dose and a degree of collimation, illuminating the mask with said beam such that the light of each wavelength transmitted by the mask pattern forms a range of transversal intensity distributions between Talbot planes and exposes the photosensitive layer to an image component, wherein the separation and spectral distribution are arranged so that the superposition of said components is equivalent to an average of the range of transversal intensity distributions formed by light of one wavelength and the collimation is arranged so that the features are resolved.
A method for printing a desired periodic pattern, which includes providing a mask bearing a pattern of features having a period, providing a substrate bearing a photosensitive layer, arranging the substrate with a separation from the mask, generating collimated light with a wavelength and an intensity, at least the former of which may be temporally varied to deliver a spectral distribution of energy density, illuminating the mask pattern with said light whilst varying at least its wavelength so as to deliver a spectral distribution of energy density, such that the light-field transmitted by the mask is instantaneously composed of a range of transversal intensity distributions between Talbot planes, and whereby the layer is exposed to a time-integrated intensity distribution that prints the desired pattern, wherein the separation, spectral distribution and period are arranged so that the time-integrated intensity distribution corresponds to an average of the range of transversal intensity distributions.
A method and apparatus for printing a pattern of periodic features into a photosensitive layer, including the steps of providing a substrate bearing the layer, providing a mask, arranging the substrate such that it has a tilt angle with respect to the substrate in a first plane orthogonal thereto, providing collimated light for illuminating the mask pattern so as to generate a transmitted light-field composed of a range of transversal intensity distributions between Talbot planes separated by a Talbot distance, and so that said transmitted light-field has an intensity envelope in the first plane, illuminating the mask with said light whilst displacing the substrate relative to the mask in a direction parallel to the first plane and to the substrate, wherein the tilt angle and the intensity envelope are arranged so that the layer is exposed to an average of the range of transversal intensity distributions.
A method for printing a periodic pattern having a first symmetry and a first period into a photosensitive layer that includes providing a mask bearing a pattern of at least two overlapping sub-patterns which have a second symmetry and a second period, the features of each sub-pattern being formed in a transmissive material, providing a substrate bearing the layer, arranging the mask with a separation from the substrate, providing light having a central wavelength for illuminating the mask to generate a light-field in which light of the central wavelength forms a range of intensity distributions between Talbot planes, illuminating said mask pattern with said light whilst maintaining the separation or changing it by a distance whereby the photosensitive layer is exposed to an average of the range of intensity distributions, wherein the light transmitted by each sub-pattern is shifted in phase relative to that transmitted by another sub-pattern.
A method for printing a pattern of features including the steps of providing a substrate having a recording layer disposed thereon, providing a mask bearing a periodic pattern of features, arranging the substrate parallel to the mask and with a separation having an initial value, providing an illumination system for illuminating the mask with an intensity of monochromatic light to generate a transmitted light-field for exposing the recording layer, and illuminating the mask for an exposure time while changing the separation by a distance having a desired value and with a rate of change of separation, wherein at least one of the rate of change of separation and the intensity of light are varied during the change of separation, whereby the mask is illuminated by an energy density per incremental change of separation that varies over said distance.
A method for printing a pattern of features including the steps of providing a substrate having a recording layer disposed thereon, providing a mask bearing a periodic pattern of features, arranging the substrate parallel to the mask and with a separation having an initial value, providing an illumination system for illuminating the mask with an intensity of monochromatic light to generate a transmitted light-field for exposing the recording layer, and illuminating the mask for an exposure time whilst changing the separation by a distance having a desired value and with a rate of change of separation, wherein at least one of the rate of change of separation and the intensity of light are varied during the change of separation, whereby the mask is illuminated by an energy density per incremental change of separation that varies over said distance.
A method for printing a desired pattern into a photosensitive layer that includes providing a mask bearing a pattern of linear features that are parallel to a first direction, arranging the layer parallel to and separated from said mask, generating substantially monochromatic light, and illuminating the mask pattern with said light over a range of angles of incidence in a plane parallel to said first direction, at substantially a single angle in an orthogonal plane of incidence and so that the light of each angle of incidence transmitted by the mask forms a light-field component at the layer whereby the integration of said components prints the desired pattern, wherein the range of angles is selected so that the integration of said components is substantially equivalent to an average of the range of transversal intensity distributions formed between Talbot image planes by light at one of the angles of incidence.
A method for printing a desired pattern into a photosensitive layer that includes providing a mask bearing a pattern of linear features that are parallel to a first direction, arranging the layer parallel to and separated from said mask, generating substantially monochromatic light and illuminating the mask pattern with said light over a range of angles substantially in a plane parallel to said first direction, whereby the light of each angle of illumination transmitted by the mask forms a range of transversal intensity distributions between Talbot planes and forms a light-field component at the layer, and the superposition of said components prints the desired pattern, wherein the range of angles is selected in relation to the wavelength, the separation and the period so that the superposition of said components is substantially equivalent to an average of the range of transversal intensity distributions formed by light at one of the angles.
A lithographic method related to Talbot imaging for printing a desired pattern of features that is periodic or quasi-periodic in at least one direction onto a substrate surface, which method includes providing a mask bearing a pattern of mask features, arranging the substrate parallel and in proximity to the mask, providing an illumination source having a central wavelength and a spectral bandwidth, forming from said source an illumination beam with an angular distribution of intensity, arranging the distance of the substrate from the mask and exposing the mask pattern to said beam so that each angular component of illumination exposes the substrate to substantially the entire range of lateral intensity distributions that occur between successive Talbot image planes for the illumination wavelengths, wherein the angular distribution of the beam is designed in conjunction with the pattern of features in the mask and the distance of the substrate from the mask.
A lithographic method related to Talbot imaging for printing a desired pattern of features that is periodic or quasi-periodic in at least one direction onto a substrate surface, which method includes providing a mask bearing a pattern of mask features, arranging the substrate parallel and in proximity to the mask, providing an illumination source having a central wavelength and a spectral bandwidth, forming from said source an illumination beam with an angular distribution of intensity, arranging the distance of the substrate from the mask and exposing the mask pattern to said beam so that each angular component of illumination exposes the substrate to substantially the entire range of lateral intensity distributions that occur between successive Talbot image planes for the illumination wavelengths, wherein the angular distribution of the beam is designed in conjunction with the pattern of features in the mask and the distance of the substrate from the mask.
A method for printing a desired periodic or quasi-periodic pattern of dot features into a photosensitive layer disposed on a substrate including the steps of designing a mask pattern having a periodic or quasi-periodic array of unit cells each having a ring feature, forming a mask with said mask pattern, arranging the mask substantially parallel to the photosensitive layer, arranging the distance of the photosensitive layer from the mask and illuminating the mask according to one of the methods of achromatic Talbot lithography and displacement Talbot lithography, whereby the illumination transmitted by the mask exposes the photosensitive layer to an integrated intensity distribution that prints the desired pattern.
G03F 1/00 - Originals for photomechanical production of textured or patterned surfaces, e.g. masks, photo-masks or reticlesMask blanks or pellicles thereforContainers specially adapted thereforPreparation thereof
30.
System and a method for generating periodic and/or quasi-periodic pattern on a sample
A system for generating periodic or quasi-periodic patterns on a sample by means of an interference lithography technique includes a photon source, a mask and a sample holder. The mask has a grating for generating a predetermined pattern, wherein the mask is positioned at a first distance from the photon source. The sample holder is disposed at a second distance from the mask on a side facing away from the photon source. The second distance is selected to be where an intensity distribution is substantially stationary and distance-invariant, or the second distance is varied to obtain a desired average intensity distribution on the sample surface.
patents
