US Patent 11387319 Nanosheet transistor device with bottom isolation

A method of forming a nanosheet transistor device is provided. The method includes forming a segment stack of alternating intermediate sacrificial segments and nanosheet segments on a bottom sacrificial segment, wherein the segment stack is on a mesa and a nanosheet template in on the segment stack. The method further includes removing the bottom sacrificial layer to form a conduit, and forming a fill layer in the conduit and encapsulating at least a portion of the segment stack.