Intel Corporation

Pei-yang Yan

Guojing Zhang

Hsing-Chien Ma

Ted Liang

Mark Thiec-Hien Tran

Scott R Chegwidden

Fu-Chang Lo

Joseph C Langston

Shoudeng Liang

A photomask and method for fabricating a photomask are generally described. In one example, a photomask includes a substrate, a multilayer (ML) stack having a peripheral region that is rendered substantially opaque for a desired wavelength of radiation by localized heating, and a first and second film applied to the ML stack, the thickness of the first and second films selected to provide desired phase shift and attenuation.

Phase shift mask structure and fabrication process

A reflective mask may include an anti-reflective (AR) coating on an absorber layer to improve inspection contrast in an inspection system using deep ultraviolet (DUV) light. A silicon nitride (SiN) AR coating may be used on a chromium (Cr) or tantalum nitride (TaN) absorber layer.

Mask with minimum reflectivity over absorber layer

Methods to correct a non-flatness of a mask substrate are described. At least a pair of correction layers are formed on the substrate over a non-flat region of a front surface of a substrate. A thickness of the at least the pair of the correction layers is determined by a peak-to-valley distance of the non-flat region of the substrate. A portion of the correction layers over the non-flat region is heated locally. Heating changes the thickness of the portion of the correction layers and removes the non-flat region from a top surface of the correction layers without physically removing any materials. At least the pair of the correction layers is formed on a back surface of the substrate to compensate for a stress induced by the correction layers on the front surface of the substrate.

Method to correct EUVL mask substrate non-flatness

Some embodiments of the present invention include protecting a photomask from particle defects by heating the photomask to initiate a thermophoretic force.

Method and apparatus for clean photomask handling

A composite extreme ultraviolet light (EUV) mask absorber structure and method are disclosed to address the structural and processing requirements of EUV lithography. A first mask absorber layer anisotropically etched with minimal etch bias at a relatively fast etch rate, is combined with a highly-selective second mask absorber layer, to produce a mask absorber with desirable hybrid performance properties.

Dual-layer EUV mask absorber with trenches having opposing sidewalls that are straight and parallel

An extreme ultraviolet lithography (EUVL) mask blank may include a multilayer (ML) capping structure on the ML reflective coatings on the substrate. The ML capping structure may include alternating layers of a capping material, e.g., ruthenium, and a material with a lower EUV absorption coefficient, e.g., silicon. The top layer of the ML structure may be a layer of the capping material. Capping interfaces between the layers may provide constructive interference of reflected light.

Interference multilayer capping design for multilayer reflective mask blanks

Reflective mask with high inspection contrast

An attenuated phase-shifting photomask (APSM) provides adjustment of attenuation from mask to mask. The APSM includes a multilayer substrate, a buffer thin film coupled to the substrate, and a top layer thin film on top of the buffer thin film. The thin films are etched with a circuit pattern to form a photomask, and are chosen to have certain thicknesses which would provide adjustment of attenuation within a specified attenuation operating range and appropriate phase shift without changing said buffer thin film and said top layer thin film.

Photomasking

A mask having a first region and a second region; the first region having a multilayer mirror over a substrate, the multilayer mirror having alternating layers of a first material and a second material, the first material having a high index of refraction, the second material having a low index of refraction; and the second region having a compound of the first material and the second material over the substrate.

Thermally-generated mask pattern

An extreme ultraviolet lithography mask may be formed of a multilayered stack covered by a spacer layer, such as silicon or boron carbide, in turn covered by a thin layer to prevent inter-diffusion, and finally covered by a capping layer of ruthenium. By optimizing the spacer layer thickness based on the capping layer, the optical properties may be improved.

Multilayer reflective extreme ultraviolet lithography mask blanks

An extreme ultraviolet lithography mask may be heated locally to change its reflectivity and to adjust for proximity and other optical disturbances. The localized heating may result in the formation of silicide at the molybdenum silicon interface in the multilayer stack that makes up the extreme ultraviolet lithography mask.

Proximity correcting lithography mask blanks

Double-metal EUV mask absorber

The present invention discloses an EUV mask having an improved absorber layer with a certain thickness that is formed from a metal and a nonmetal in which the ratio of the metal to the nonmetal changes through the thickness of the improved absorber layer and a method of forming such an EUV mask.

Absorber layer for EUV

An extreme ultraviolet light (EUV) mask structure and method are disclosed to address the structural and processing requirements of EUV lithography. A mask absorber layer anisotropically etched with minimal etch bias at a relatively fast etch rate, is combined with a thin ruthenium layer, to produce a mask obviating the need for a conventional buffer or cap layer.

High performance EUV mask

A method of making a photolithographic mask includes forming a metal-silicon layer on a substrate, and processing at least a portion of the metal-silicon layer. The metal-silicon layer has a first thickness and the portions of the metal-silicon layer are processed to a second thickness that is less than the first thickness. The method also includes forming a reflector layer on the metal-silicon layer to produce a mask blank and then forming the mask from the mask blank. The mask blank includes the substrate, metal-silicon layer, and reflector layer.

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Saratoga, CA, United States of America

Pei-yang Yan