Stacked Mask
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsBurn Jeng Lin, Hsin-Chang Lee, Sheng-Chi Chin
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Abstract
The present disclosure describes a mask. The mask includes a low thermal expansion material (LTEM) substrate, at least two absorber layers, and a spacer layer separating the two absorber layers. The first absorber layer is deposited over the LTEM substrate. The mask further includes a topcoat layer over the absorber layer. A thickness of the spacer layer is approximately equal to a height of a topography feature on a wafer substrate multiplied by the square of a demagnification of an objective lens. The absorber layers include staged patterns.
Claims20
A mask comprising:
- a low thermal expansion material (LTEM) substrate;
- at least two absorber layers, wherein a first absorber layer is deposited over the LTEM substrate;
- and
- a spacer layer separating the two absorber layers.
A stacked mask comprising:
- a low thermal expansion material (LTEM) substrate;
- at least two absorber layers including a first absorber layer and a second absorber layer, wherein the first absorber layer is deposited over the LTEM substrate;
- and
- a spacer layer separating the two absorber layers, wherein a thickness of the spacer layer is approximately equal to a height of a topography feature on a wafer substrate multiplied by a square of a demagnification of an objective lens.
A method of fabricating a mask, the method comprising:
- receiving a low thermal expansion material (LTEM) substrate;
- depositing a first absorber layer over the LTEM substrate;
- depositing a first spacer layer over the first absorber layer;
- depositing a second absorber layer over the first spacer layer;
- and
- forming staged absorber layer patterns of the mask.
Dependencies are inferred from the claim text.