Gate-all-around field effect transistor having stacked U shaped channels configured to improve the effective width of the transistor

摘要

A method of fabricating a semiconductor device is described. The method includes forming a stack of sacrificial layers on a substrate. A U-shaped trench is formed in the stack of the sacrificial layers. A first U-shaped channel layer is deposited in the U-shaped trench. A first U-shaped sacrificial layer is conformally formed covering the U-shaped channel layer. A second U-shaped channel layer is conformally deposited covering the first U-shaped sacrificial layer. A gate is formed around the first and the second U-shaped channel layers.