Replacement bottom spacer for vertical transport field effect transistors
AssigneeInternational Business Machines Corporation
InventorsRuilong Xie, Heng Wu, Jay Strane, Hemanth Jagannathan, Lan Yu, Tao Li
Life of this patent
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Abstract
A method of forming a vertical channel semiconductor structure, comprises forming a source/drain layer in contact with at least one semiconductor fin. A first sacrificial layer is formed over the source/drain layer. A second sacrificial layer is formed over the first sacrificial layer. A trench is formed in the second sacrificial layer to expose a portion of the first sacrificial layer. After forming the second sacrificial layer, the first sacrificial layer is selectively removed to form a cavity under the second sacrificial layer. A spacer layer is then formed within the cavity.
Claims20
A method of forming a vertical channel semiconductor structure, the method comprising:
- forming a source/drain layer in contact with at least one semiconductor fin;
- forming a first sacrificial layer over the source/drain layer;
- forming a second sacrificial layer over the first sacrificial layer;
- forming a trench in the second sacrificial layer to expose a portion of the first sacrificial layer;
- after forming the second sacrificial layer, selectively removing the first sacrificial layer forming a cavity directly under the second sacrificial layer;
- and
- forming a spacer layer within the cavity and directly under the second sacrificial layer.
A method of forming a vertical channel semiconductor structure, the method comprising:
- forming a source/drain layer in contact with at least one semiconductor fin;
- forming a first sacrificial layer over the source/drain layer;
- forming a second sacrificial layer over the first sacrificial layer;
- forming a trench in the second sacrificial layer to expose a portion of the first sacrificial layer;
- after forming the second sacrificial layer, selectively removing the first sacrificial layer forming a cavity directly under the second sacrificial layer;
- and
- forming a spacer layer within the cavity between the bottom surface of the second sacrificial layer and the top surface of the source/drain.
A method of forming a vertical channel semiconductor structure, the method comprising:
- forming a source/drain layer in contact with at least one semiconductor fin;
- forming a first sacrificial layer over the source/drain layer;
- forming a second sacrificial layer over the first sacrificial layer;
- forming a trench in the second sacrificial layer to expose a portion of the first sacrificial layer;
- after forming the second sacrificial layer, selectively removing the first sacrificial layer forming a cavity directly under the second sacrificial layer and above the top surface of the source/drain layer;
- and
- forming a spacer layer within the cavity.
Dependencies are inferred from the claim text.