Composite sacrificial gate with etch selective layer
AssigneeGlobalfoundries Inc.
InventorsQun Gao, Naved Siddiqui, Ankur Arya, John R Sporre
Life of this patent
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Abstract
The manufacture of a FinFET device includes the formation of a composite sacrificial gate. The composite sacrificial gate includes a sacrificial gate layer such as a layer of amorphous silicon, and an etch selective layer such as a layer of silicon germanium. The etch selective layer, which underlies the sacrificial gate layer, enables the formation of a gate cut opening having a controlled critical dimension that extends through the composite sacrificial gate.
Claims14
A method of forming a structure, comprising:
- forming a composite sacrificial gate over a plurality of semiconductor fins, wherein forming the composite sacrificial gate comprises forming an etch selective layer over the fins and forming a sacrificial gate layer over the etch selective layer;
- forming a gate cut opening that extends through the composite sacrificial gate, wherein the gate cut opening is laterally spaced away from each of a pair of the fins, and forming the gate cut opening includes etching the etch-selective layer to form an undercut region that extends laterally beneath the sacrificial gate layer;
- and
- forming an isolation layer within the gate cut opening.
A method of forming a structure, comprising:
- forming an etch selective layer over a plurality of semiconductor fins and extending between the fins;
- forming a sacrificial gate layer over the etch selective layer;
- forming a gate cut opening that extends through the sacrificial gate layer and the etch selective layer, wherein the gate cut opening is laterally spaced away from the fins, and forming the gate cut opening includes etching the etch selective layer to form an undercut region that extends laterally beneath the sacrificial gate layer;
- and
- forming an isolation layer within the gate cut opening.
A method of forming a structure, comprising:
- forming an extended gate oxide over a plurality of semiconductor fins;
- forming a composite sacrificial gate over a plurality of semiconductor fins after forming the extended gate oxide, wherein forming the composite sacrificial gate comprises forming an etch selective layer over the fins and forming a sacrificial gate layer over the etch selective layer;
- forming a gate cut opening by etching the etch selective layer to form an undercut region that extends laterally beneath the sacrificial gate layer and through the composite sacrificial gate, wherein the gate cut opening is laterally spaced away from each of a pair of the fins;
- and
- forming an isolation layer within the gate cut opening.
Dependencies are inferred from the claim text.