Abstract: A photomask includes a substrate, a reflective multilayer, a capping layer, and an absorption layer. The reflective multilayer IS over the substrate. The capping layer is over the reflective multilayer. The absorption layer is over the capping layer. The absorption layer has a test pattern having a first and second trenches and a reference pattern having a third and fourth trenches. The test pattern and the reference pattern have substantially the same dimension in a top view. The second trench is shallower than the first trench, the third trench, and the fourth trench. The first to fourth trenches extend in a same direction in the top view. A first distance between the first and second trenches is substantially the same as a second distance between the third and fourth trenches. Each of the first to fourth trenches has a depth smaller than a thickness of the absorption layer.

Abstract: Photosensitive polymers and their use in photoresists for photolithographic processes are disclosed. The polymers are copolymers, with at least one monomer that includes pendant polycyclic aromatic groups and a second monomer that includes an acidic leaving group (ALG). The polymers have high resistance to etching and high development contrast.

Abstract: In a method of manufacturing a photo mask, an etching mask layer having circuit patterns is formed over a target layer of the photo mask to be etched. The photo mask includes a backside conductive layer. The target layer is etched by plasma etching, while preventing active species of plasma from attacking the backside conductive layer.

Abstract: A method of fabricating a mask is provided. The method includes providing a hard mask layer disposed on top of absorber, a capping layer, and a multilayer that are disposed on a substrate. The method includes forming a middle layer over the hard mask layer, forming a photo resist layer over the middle layer, patterning the photo resist layer, etching the middle layer through the patterned photo resist layer, etching the hard mask layer through the patterned middle layer, and etching the absorber through the patterned hard mask layer. In some embodiments, etching the hard mask layer through the patterned middle layer includes a dry-etching process that has a first removal rate of the hard mask layer and a second removal rate of the middle layer, and a ratio of the first removal rate of the hard mask layer to the second removal rate of the middle layer is greater than 5.

Abstract: A pellicle assembly includes a pellicle membrane and a conformal coating on an outer surface of the pellicle membrane. The pellicle membrane can be formed with multiple layers and has a combination of high transmittance, low deflection, and small pore size. The conformal coating is intended to protect the pellicle membrane from damage that can occur due to heat and hydrogen plasma created during EUV exposure.

Abstract: An extreme ultraviolet (EUV) mask, includes a substrate, a reflective multilayer stack on the substrate, and a single layer or multi-layer capping feature on the reflective multilayer stack. The capping feature includes a capping layer or capping layers including a material having an amorphous structure. Other described embodiments include capping layer(s) that contain element(s) having a first solid carbon solubility less than about 3. In multilayer capping feature embodiments, element(s) of the respective capping layers have different solid carbon solubility properties.

Abstract: A mask for use in a semiconductor lithography process includes a substrate, a mask pattern disposed on the substrate, and a light absorbing border surrounding the mask pattern. The light absorbing border is inset from at least two edges of the substrate to define a peripheral region outside of the light absorbing border. In some designs, a first peripheral region extends from an outer perimeter of the light absorbing border to a first edge of the substrate, and a second peripheral region that extends from the outer perimeter of the light absorbing border to a second edge of the substrate, where the first edge of the substrate and the second edge of the substrate are on opposite sides of the mask pattern.

Abstract: An extreme ultraviolet mask including a substrate, a reflective multilayer stack on the substrate and a multi-layer patterned absorber layer on the reflective multilayer stack is provided. Disclosed embodiments include an absorber layer that includes an alloy comprising ruthenium (Ru), chromium (Cr), platinum (Pt), gold (Au), iridium (Ir), titanium (Ti), niobium (Nb), rhodium (Rh), molybdenum (Mo), tungsten (W) or palladium (Pd), and at least one alloying element. The at least one alloying element includes ruthenium (Ru), chromium (Cr), tantalum (Ta), platinum (Pt), gold (Au), iridium (Ir), titanium (Ti), niobium (Nb), rhodium (Rh), molybdenum (Mo), hafnium (Hf), boron (B), nitrogen (N), silicon (Si), zirconium (Zr) or vanadium (V). Other embodiments include a multi-layer patterned absorber structure with layers that include an alloy and an alloying element, where at least two of the layers of the multi-layer structure have different compositions.

Abstract: A method for lithographically patterning a photoresist is provided. The method includes receiving a wafer with the photoresist and exposing the photoresist using an extreme ultraviolet (EUV) radiation reflected by an EUV mask. The EUV mask includes a substrate, a reflective multilayer stack on the substrate, a capping layer on the reflective multilayer stack, a patterned absorber layer on the capping layer. The patterned absorber layer includes a matrix metal and an interstitial element occupying interstitial sites of the matrix metal, and a size ratio of the interstitial element to the matrix metal is from about 0.41 to about 0.59.

Abstract: Methods for removing a catalyst particle from a nanotube film used in a photolithographic patterning process are disclosed. The catalyst particle is identified based on its size in the nanotube film. This identification can be done using an inspection device such as a confocal microscope, which permits comparison of images taken in two or more separate focal planes to determine the size of particles. The catalyst particle is then exposed to a first absorption wavelength using a laser, which is selectively absorbed by the catalyst particle and which heats the catalyst particle to remove the catalyst particle from the nanotube film. Optionally, the catalyst particle-free nanotube film can be further exposed to a second absorption wavelength which is selectively absorbed by the film and promotes repair of the film. The resulting nanotube film can be used in a pellicle membrane.

Abstract: A method includes forming a reflective multilayer over a substrate; depositing a first capping layer over the reflective multilayer, wherein the first capping layer is made of a ruthenium-containing material or a chromium-containing material; performing a treatment to the first capping layer to introduce nitrogen or fluorine into the first capping layer; forming an absorption layer over the first capping layer; and patterning the absorption layer.

Abstract: A pellicle assembly includes a pellicle membrane with a nanotube layer formed from nanotubes having a minimum length of 1,000 ?m. The pellicle membrane can be formed with multiple layers and has a combination of high transmittance, low deflection, and small pore size. A conformal coating may applied to an outer surface of the pellicle membrane. The conformal coating is intended to protect the pellicle membrane from damage that can occur due to heat and hydrogen plasma created during EUV exposure.

Abstract: A method includes forming a test pattern and a reference pattern in an absorption layer of a photomask structure. The test pattern has a first trench and a second trench, the reference pattern has a third trench and a fourth trench, the test pattern and the reference pattern have substantially the same dimension in a top view, and the second trench is deeper than the first trench, the third trench, and the fourth trench. The method further includes emitting a light beam to the test pattern to obtain a first interference pattern reflected from the test pattern, emitting the light beam to the reference pattern to obtain a second interference pattern reflected from the reference pattern; and comparing the first interference pattern with the second interference pattern to obtain a measured complex refractive index of the absorption layer.

Abstract: A mask characterization method comprises measuring an interference signal of a reflection or transmission mask for use in lithography; and determining a quality metric for the reflection or transmission mask based on the interference signal. A mask characterization apparatus comprises a light source arranged to illuminate a reflective or transmissive mask with light whereby mask-reflected or mask-transmitted light is generated; an optical grating arranged to convert the mask-reflected or mask-transmitted light into an interference pattern; and an optical detector array arranged to generate an interference signal by measuring the interference pattern.

Abstract: Photosensitive polymers and their use in photoresists for photolithographic processes are disclosed. The polymers are copolymers, with at least one monomer that includes pendant polycyclic aromatic groups and a second monomer that includes an acidic leaving group (ALG). The polymers have high resistance to etching and high development contrast.

Abstract: A method for lithographically patterning a photoresist is provided. The method includes receiving a wafer with the photoresist and exposing the photoresist using an extreme ultraviolet (EUV) radiation reflected by an EUV mask. The EUV mask includes a substrate, a reflective multilayer stack on the substrate, a capping layer on the reflective multilayer stack, a patterned absorber layer on the capping layer. The patterned absorber layer includes a matrix metal and an interstitial element occupying interstitial sites of the matrix metal, and a size ratio of the interstitial element to the matrix metal is from about 0.41 to about 0.59.

Abstract: Methods for removing a catalyst particle from a nanotube film used in a photolithographic patterning process are disclosed. The catalyst particle is identified based on its size in the nanotube film. This identification can be done using an inspection device such as a confocal microscope, which permits comparison of images taken in two or more separate focal planes to determine the size of particles. The catalyst particle is then exposed to a first absorption wavelength using a laser, which is selectively absorbed by the catalyst particle and which heats the catalyst particle to remove the catalyst particle from the nanotube film. Optionally, the catalyst particle-free nanotube film can be further exposed to a second absorption wavelength which is selectively absorbed by the film and promotes repair of the film. The resulting nanotube film can be used in a pellicle membrane.

Abstract: An extreme ultraviolet mask including a substrate, a reflective multilayer stack on the substrate and a multi-layer patterned absorber layer on the reflective multilayer stack is provided. Disclosed embodiments include an absorber layer that includes an alloy comprising ruthenium (Ru), chromium (Cr), platinum (Pt), gold (Au), iridium (Ir), titanium (Ti), niobium (Nb), rhodium (Rh), molybdenum (Mo), tungsten (W) or palladium (Pd), and at least one alloying element. The at least one alloying element includes ruthenium (Ru), chromium (Cr), tantalum (Ta), platinum (Pt), gold (Au), iridium (Ir), titanium (Ti), niobium (Nb), rhodium (Rh), molybdenum (Mo), hafnium (Hf), boron (B), nitrogen (N), silicon (Si), zirconium (Zr) or vanadium (V). Other embodiments include a multi-layer patterned absorber structure with layers that include an alloy and an alloying element, where at least two of the layers of the multi-layer structure have different compositions.

Abstract: A pellicle assembly includes a pellicle membrane with a nanotube layer formed from nanotubes having a minimum length of 1,000 ?m. The pellicle membrane can be formed with multiple layers and has a combination of high transmittance, low deflection, and small pore size. A conformal coating may applied to an outer surface of the pellicle membrane. The conformal coating is intended to protect the pellicle membrane from damage that can occur due to heat and hydrogen plasma created during EUV exposure.

Abstract: A mask container for storing a mask for photolithography, includes a cover and a base having a plurality of tapered corners. The tapered corners taper outward and downward from a top major surface of the base. The cover having the tapered corners extends downward that covers the tapered corners of the base when the cover is attached to the base. The tapered corners of the cover are tapered at about the same angle as the tapered corners of the base so that a surface of the tapered corners of the cover is substantially parallel to a corresponding surface of the tapered corner of the base when the cover is attached to the base. A recess is located in the tapered corners of the cover. A biasing member and a ball-shaped member are located in the tapered corners of the base to mate with the recess when the cover is attached to the base.