Patent ID: 10008586

Abstract:
A patterned stack of a first silicon-germanium alloy nanowire, a second silicon-germanium alloy nanowire, and a silicon-containing nanowire is formed on a substrate. After formation of a first dielectric isolation layer around the patterned stack, a disposable gate structure can be formed. End portions of the second silicon-germanium alloy nanowire are removed to form first cavities underlying end portions of the silicon-containing nanowire. Dielectric nanowires are formed in cavities concurrently with formation of a gate spacer. After recessing the first dielectric isolation layer, a second cavity is formed by removing the first silicon-germanium alloy nanowire. The second cavity is filled with a second dielectric isolation layer, and raised active regions can be formed by a selective epitaxy process. After formation of a planarization dielectric layer, the disposable gate structure and the remaining portion of the second silicon-germanium alloy nanowire with a replacement gate structure.