Extreme Ultraviolet Lithography Process and Mask
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChih-Tsung Shih, Shinn-Sheng Yu, Jeng-Horng Chen, Anthony Yen
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Abstract
The present disclosure is directed towards an extreme ultraviolet (EUV) mask. The EUV mask includes a low thermal expansion material (LTEM) substrate. The EUV mask has a first region and a second region. The EUV mask also includes a structure disposed in the first region. The structure has a multiple facets with an angle to each other. The EUV mask also includes a conformal reflective multilayer (ML) disposed over the structure in the first region and over the LTEM substrate in the second region. The conformal reflective ML has a similar surface profile as the structure in the first region and a flat surface profile in the second region.
Claims20
An extreme ultraviolet (EUV) mask, comprising:
- a low thermal expansion material (LTEM) substrate having a first region and a second region;
- a structure disposed in the first region, wherein the structure has a structure profile with multiple facets at an angle to each other;
- and
- a conformal reflective multilayer (ML) disposed over the structure in the first region and over the LTEM substrate in the second region, wherein the conformal reflective ML has a surface with two profiles, a first profile in the first region similar to the structure profile, and a second, substantially flat profile in the second region.
An extreme ultraviolet lithography (EUVL) process, comprising:
- receiving an extreme ultraviolet (EUV) mask, the EUV mask includes:
- a low thermal expansion material (LTEM) substrate having a first region and a second region;
- a structure disposed in the first region, wherein the structure has multiple facets with an angle to each other;
- and
- a conformal reflective multilayer (ML) disposed over the LTEM structure in the first region and over the LTEM substrate in the second region, wherein the conformal reflective ML has a similar surface profile as the structure in the first region and a substantially flat surface profile in the second region.
- assigning the first region to a field (a region without polygons) and a second region to a polygon;
- exposing the EUV mask by a illumination;
- collecting and directing a reflected light from the second region of the EUV mask by a projection optics box (POB) to expose a target.
A method of fabricating a mask, the method comprising:
- receiving a low thermal expansion material (LTEM) substrate;
- depositing a structure-built-layer (SBL) over the LTEM substrate;
- patterning the SBL to define a first region and a second region;
- etching the SBL to form a structure with multiple facets in the first region and removing the SBL from the second region;
- and
- depositing a conformal reflective multilayer (ML) over the structure in the first region and over the LTEM substrate in the second region.
Dependencies are inferred from the claim text.