Semiconductor device and manufacturing methods thereof

Abstract

A method for manufacturing a semiconductor device is provided. The method comprises providing a first structure. The first structure comprises a first substrate, a second substrate, and a multi-layer structure. The second substrate is disposed on the first substrate. The second substrate comprises semiconductor material. The multi-layer structure is in contact with the second substrate. The second substrate is disposed between the first substrate and the multi-layer structure. The multi-layer structure comprises a first spacer layer and a sacrificial layer between the first spacer layer and the second substrate. The method comprises forming a first opening extending through the multi-layer structure to expose the second substrate. The method comprises forming a semiconductor pillar in the first opening. The method comprises forming a first source / drain region over the semiconductor pillar and the first spacer layer. The method comprises removing at least a portion of the sacrificial layer to expose at least a portion of the semiconductor pillar. The method comprises forming a gate structure surrounding the semiconductor pillar. The gate structure comprises a gate dielectric and a gate electrode. The method comprises removing the first substrate. The method comprises removing a portion of the second substrate to form or expose a second source / drain region.