Photomask having a plurality of shielding layers
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChih-Chiang Tu, Chun-Lang Chen
Life of this patent
Estimating the term…
Abstract
In some embodiments, a patterned photomask has a plurality of shielding layers. In some embodiments, a photomask for mask patterning is described. The photomask includes a phase shift layer overlying a transparent layer. The photomask also includes a first shielding layer overlying the phase shift layer. The first shielding layer has a first thickness and a first optical density. The photomask further includes a second shielding layer overlying the first shielding layer. The second shielding layer has a second thickness and a second optical density. The second thickness is less that than the first thickness and the second optical density is less than the first optical density.
Claims20
A photomask for mask patterning, comprising:
- a phase shift layer overlying a transparent layer;
- a first shielding layer overlying the phase shift layer, wherein the first shielding layer has a first thickness and a first optical density;
- and
- a second shielding layer overlying the first shielding layer, wherein the second shielding layer has a second thickness and a second optical density, and wherein the second thickness is less than the first thickness and the second optical density is less than the first optical density.
A photomask for mask patterning, comprising:
- a phase shift layer comprised of molybdenum silicide (MoSi) overlying a transparent layer comprised of quartz;
- a first shielding layer overlying the phase shift layer, wherein the first shielding layer is comprised of tantalum borate (B5O15Ta3) having a first thickness of 20 nanometers (nm) to 28 nm;
- and
- a second shielding layer overlying the first shielding layer, wherein the second shielding layer is comprised of chromium nitride (CrN) having a second thickness of 3 nm to 7 nm.
A method for mask patterning, the method for mask patterning comprising:
- forming a phase shift layer comprised of molybdenum silicide (MoSi) overlying a transparent layer comprised of quartz;
- forming a first shielding layer overlying the phase shift layer, wherein the first shielding layer has a first thickness and a first optical density;
- forming a second shielding layer overlying the first shielding layer, wherein the second shielding layer has a second thickness and a second optical density, and wherein the second thickness is less that than the first thickness and the second optical density is less than the first optical density;
- and
- forming a photoresist layer overlying the second shielding layer.
Dependencies are inferred from the claim text.