Provided is a reflective mask capable of reducing out-of-band light when transferring a prescribed pattern onto a wafer by exposure using EUV light in a process of manufacturing a semiconductor device. The mask blank substrate is provided with a base film on a substrate, the base film is formed with a material having a refractive index smaller than the substrate over a wavelength range of not less than 190 nm and not more than 280 nm, and reflectance of the base film arranged on the surface of the substrate is smaller than the reflectance of the substrate over a wavelength range of not less than 190 nm to not more than 280 nm.

Provided is a reflective mask capable of reducing out-of-band light when transferring a prescribed pattern onto a wafer by exposure using EUV light in a process of manufacturing a semiconductor device. The mask blank substrate is provided with a base film on a substrate, the base film is formed with a material having a refractive index smaller than the substrate over a wavelength range of not less than 190 nm and not more than 280 nm, and reflectance of the base film arranged on the surface of the substrate is smaller than the reflectance of the substrate over a wavelength range of not less than 190 nm to not more than 280 nm.

A photomask includes a substrate, a multilayer stack disposed over the substrate and configured to reflect a radiation, a capping layer over the multilayer stack, and an anti-reflective layer over the capping layer. The anti-reflective layer comprises a first pattern, wherein the first pattern exposes the capping layer and is configured as a printable feature. The photomask also includes an absorber spaced apart from the printable feature from a top-view perspective.

A method of testing a photomask assembly includes placing the photomask assembly into a chamber, wherein the photomask assembly includes a pellicle attached to a first side of a photomask. The method further includes exposing the photomask assembly to a radiation source having a wavelength ranging from about 160 nm to 180 nm in the chamber to accelerate haze development, wherein the exposing of the photomask assembly includes illuminating an entirety of an area of the photomask covered by the pellicle throughout an entire illumination time and illuminating a frame adhesive attaching the pellicle to the photomask. The method further includes detecting haze of the photomask following exposing the photomask assembly to the radiation source. The method further includes predicting performance of the photomask assembly during a manufacturing process based on the detected haze of the photomask following exposing the photomask assembly to the radiation source.

A method of testing a photomask assembly includes placing the photomask assembly into a chamber, wherein the photomask assembly includes a pellicle attached to a first side of a photomask. The method further includes exposing the photomask assembly to a radiation source having a wavelength ranging from about 160 nm to 180 nm in the chamber to accelerate haze development, wherein the exposing of the photomask assembly includes illuminating an entirety of an area of the photomask covered by the pellicle throughout an entire illumination time and illuminating a frame adhesive attaching the pellicle to the photomask. The method further includes detecting haze of the photomask following exposing the photomask assembly to the radiation source. The method further includes predicting performance of the photomask assembly during a manufacturing process based on the detected haze of the photomask following exposing the photomask assembly to the radiation source.

In an embodiment, a photomask includes: a substrate over a first conductive layer, the substrate formed of a low thermal expansion material (LTEM); a second conductive layer over the first conductive layer; a reflective film stack over the substrate; a capping layer over the reflective film stack; an absorption layer over the capping layer; and an antireflection (ARC) layer over the absorption layer, where the ARC layer and the absorption layer have a plurality of openings in a first region exposing the capping layer, where the ARC layer, the absorption layer, the capping layer, and the reflective film stack have a trench in a second region exposing the second conductive layer.

In an embodiment, a photomask includes: a substrate over a first conductive layer, the substrate formed of a low thermal expansion material (LTEM); a second conductive layer over the first conductive layer; a reflective film stack over the substrate; a capping layer over the reflective film stack; an absorption layer over the capping layer; and an antireflection (ARC) layer over the absorption layer, where the ARC layer and the absorption layer have a plurality of openings in a first region exposing the capping layer, where the ARC layer, the absorption layer, the capping layer, and the reflective film stack have a trench in a second region exposing the second conductive layer.

A metrology system for measuring wave-front aberration of an extreme ultraviolet (EUV) mask inspection system is disclosed. The test mask includes a substrate formed from a material having substantially no reflectivity for EUV illumination, and one or more patterns formed on the substrate, the one or more patterns having a reflective portion configured to reflect EUV illumination, positioned in a common plane with an absorption portion having substantially no reflectivity for EUV illumination, on or above the substrate.

A metrology system for measuring wave-front aberration of an extreme ultraviolet (EUV) mask inspection system is disclosed. The test mask includes a substrate formed from a material having substantially no reflectivity for EUV illumination, and one or more patterns formed on the substrate, the one or more patterns having a reflective portion configured to reflect EUV illumination, positioned in a common plane with an absorption portion having substantially no reflectivity for EUV illumination, on or above the substrate.

Embodiments described herein relate to apparatus and methods for removing one or more films from a photomask to create a black border and one or more pellicle anchor areas thereon. A photomask substrate is exposed by removing the one or more films in the black border and pellicle anchor areas. The black border prevents a pattern on the photomask from overlapping a pattern on a substrate being processed. To create the black border and pellicle anchor areas, a laser beam is projected through a lens and focused on a surface of the films. The films are ablated by the laser beam without damaging the photomask substrate.