Sidewall epitaxy encapsulation for nanosheet i/o device

Abstract

A method includes forming a first nanosheet fin extending vertically from a first region of a substrate corresponding to a logic device and forming a second nanosheet fin extending vertically from a second region of the substrate corresponding to an input/output device. The first nanosheet fin includes first semiconductor channel layers vertically stacked over the first region. The second nanosheet fin includes an alternating sequence of semiconductor sacrificial layers and second semiconductor channel layers vertically stacked over the second region. An encapsulation layer is epitaxially grown along sidewalls of the alternating sequence of semiconductor sacrificial layers and second semiconductor channel layers, and an oxide layer is formed in contact with a top surface of an uppermost second semiconductor channel layer of the alternating sequence of semiconductor sacrificial layers and second semiconductor channel layers and in contact with opposite sidewalls of the encapsulation layer.