International Business Machines Corporation
Replacement bottom spacer for vertical transport field effect transistors

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.