Patent attributes
A gate-all-around (GAA) semiconductor device structure and method for forming the same. The GAA structure includes a nanosheet stack disposed over a patterned portion of a substrate, and an encapsulation structure surrounding the patterned portion of the substrate underlying the nanosheet stack. The method for forming the GAA structure includes forming a liner over and in contact with a nanosheet fin, a sacrificial layer disposed below the nanosheet fin, and a patterned portion of a substrate underlying the nanosheet fin. At least one portion of the liner is etched down to the sacrificial layer. The sacrificial layer is removed thereby forming a cavity between the nanosheet fin and the patterned portion of the substrate. An insulting layer is formed within the cavity, where the patterned portion of the substrate within one or more gate regions is encapsulated by the insulting layer and the liner.