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: 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: 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: 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: 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 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: 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: An extreme ultraviolet (EUV) mask and method of forming an EUV mask are provided. The method includes forming a mask layer on a semiconductor wafer, generating extreme ultraviolet (EUV) light by a lithography exposure system, forming patterned EUV light by patterning the EUV light by a mask including an absorber having extinction coefficient at an EUV wavelength that exceeds extinction coefficients of TaBN and TaN at the EUV wavelength, and exposing the mask layer by the patterned EUV light.

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: Methods for plasma stability in a plasma treatment tool are disclosed. A laser is positioned within a plasma treatment chamber within a skin depth of the electromagnetic field generated therein. The laser can be synchronized with the electrical triggering signals that generate the electromagnetic field. This scheme provides a stable and efficient method of plasma ignition.

Abstract: A reflective mask includes a substrate, a lower reflective multilayer disposed over the substrate, an intermediate layer disposed over the lower reflective multilayer, an upper reflective multilayer disposed over the intermediate layer, a capping layer disposed over the upper reflective multilayer, and an absorber layer disposed in a trench formed in the upper reflective layers and over the intermediate layer. The intermediate layer includes a metal other than Cr, Ru, Si, Si compound and carbon.

Abstract: Coated nanotubes and bundles of nanotubes are formed into membranes useful in optical assemblies in EUV photolithography systems. These optical assemblies are useful in methods for patterning materials on a semiconductor substrate. Such methods involve generating, in a UV lithography system, UV radiation. The UV radiation is passed through a coating layer of the optical assembly, e.g., a pellicle assembly. The UV radiation that has passed through the coating layer is passed through a matrix of individual nanotubes or matrix of nanotube bundles. UV radiation that passes through the matrix of individual nanotubes or matrix of nanotube bundles is reflected from a mask and received at a semiconductor substrate.

Abstract: A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, and an absorber layer disposed on the capping layer. The absorber layer includes a base material made of one or more of a Cr based material, an Ir based material, a Pt based material, or Co based material, and further contains one or more additional elements selected from the group consisting of Si, B, Ge, Al, As, Sb, Te, Se and Bi.

Abstract: Methods for plasma stability in a plasma treatment tool are disclosed. A laser is positioned within a plasma treatment chamber within a skin depth of the electromagnetic field generated therein. The laser can be synchronized with the electrical triggering signals that generate the electromagnetic field. This scheme provides a stable and efficient method of plasma ignition.

Abstract: A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, and an absorber layer disposed on the capping layer. The absorber layer includes a base material made of one or more of a Cr based material, an Ir based material, a Pt based material, or Co based material, and further contains one or more additional elements selected from the group consisting of Si, B, Ge, Al, As, Sb, Te, Se and Bi.

Abstract: A reflective mask includes a substrate, a lower reflective multilayer disposed over the substrate, an intermediate layer disposed over the lower reflective multilayer, an upper reflective multilayer disposed over the intermediate layer, a capping layer disposed over the upper reflective multilayer, and an absorber layer disposed in a trench formed in the upper reflective layers and over the intermediate layer. The intermediate layer includes a metal other than Cr, Ru, Si, Si compound and carbon.

Abstract: Coated nanotubes and bundles of nanotubes are formed into membranes useful in optical assemblies in EUV photolithography systems. These optical assemblies are useful in methods for patterning materials on a semiconductor substrate. Such methods involve generating, in a UV lithography system, UV radiation. The UV radiation is passed through a coating layer of the optical assembly, e.g., a pellicle assembly. The UV radiation that has passed through the coating layer is passed through a matrix of individual nanotubes or matrix of nanotube bundles. UV radiation that passes through the matrix of individual nanotubes or matrix of nanotube bundles is reflected from a mask and received at a semiconductor substrate.