Transistor and method for forming the same

摘要

A transistor and a method for forming the transistor are provided. The transistor can be formed over a substrate including a first region and second regions on opposite sides of the first region. On the substrate, a first SiGe layer can be formed, followed by forming a first silicon layer on the first SiGe layer and forming a second SiGe layer on the first silicon layer. The second SiGe layer and the first silicon layer within the second regions are removed. The first silicon layer within the first region is removed to form a cavity such that the second SiGe layer is floated. An isolating layer is formed in the cavity. Second silicon layers are formed in the second regions. A gate structure is formed on the second SiGe layer within the first region and the second silicon layers are doped to form a source and a drain.

主权项

1. A method for forming a transistor, comprising:
providing a substrate, wherein the substrate comprises a first region and a plurality of second regions on opposite sides of the first region; forming a first SiGe layer on the substrate; forming a first silicon layer on the first SiGe layer; forming a second SiGe layer on the first silicon layer; forming a hard mask layer on the second SiGe layer, the hard mask layer exposing the second SiGe layer within the plurality of second regions; removing the second SiGe layer and the first silicon layer within the plurality of second regions; removing the first silicon layer between the first SiGe layer and the second SiGe layer within the first region; forming an isolating layer between the first SiGe layer and the second SiGe layer within the first region; removing the hard mask layer; forming a second silicon layer within each of the plurality of second regions, wherein the second silicon layer has a top surface leveling with a top surface of the second SiGe layer; and forming a gate structure on the second SiGe layer within the first region.