Layer alignment in FinFET fabrication
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsMing-Feng Shieh, Kuei-Liang Lu
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Abstract
Methods for aligning layers more accurately for FinFETs fabrication. An embodiment method includes forming a first pattern in a workpiece using a first photomask, forming a second pattern in the workpiece using a second photomask, the second photomask aligned to the first pattern, and aligning a third pattern to the first and the second patterns by aligning a first feature of the third pattern to a first feature of the first pattern in a first direction, and aligning a second feature of the third pattern to a first feature of the second pattern in a second direction orthogonal to the first direction.
Claims20
A method, comprising:
- forming a first feature in a workpiece with a first patterning process;
- after forming the first feature, forming a second feature in the workpiece with a second patterning process;
- aligning a third photomask in a first direction and a second direction, the aligning in the first direction being performed by aligning one or more features of the third photomask to the first feature formed with the first patterning process and no features formed by the second patterning process, and the aligning in the second direction being performed by aligning one or more features of the third photomask to the second feature formed with the second patterning process and no features formed by the first patterning process, the second direction is different than the first direction;
- and
- forming a third pattern using the third photomask;
- wherein a second pattern is formed using a second photomask, wherein the second photomask is aligned to a first pattern formed using a first photomask, and wherein the first pattern comprises a sidewall of a fin.
A method, comprising:
- forming a first feature in a workpiece with a first patterning process;
- after forming the first feature, forming a second feature in the workpiece with a second patterning process;
- aligning a third photomask in a first direction and a second direction, the aligning in the first direction being performed by aligning one or more features of the third photomask to the first feature formed with the first patterning process and no features formed by the second patterning process, and the aligning in the second direction being performed by aligning one or more features of the third photomask to the second feature formed with the second patterning process and no features formed by the first patterning process, the second direction is different than the first direction;
- and
- forming a third pattern using the third photomask;
- wherein the second pattern is formed using a second photomask, wherein the second photomask is aligned to the first pattern, and wherein the second pattern comprises an end of a fin.
Dependencies are inferred from the claim text.