Nanosheet MOSFET with gate fill utilizing replacement spacer

• Main Authors: Zhang, Chen, Yeung, Chun W
• Format: Patent
• Language: English
• Published: 01.09.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; NANOTECHNOLOGY; PERFORMING OPERATIONS; SEMICONDUCTOR DEVICES; SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; TRANSPORTING

A method of forming a semiconductor structure includes forming outer spacers surrounding a dummy gate, the dummy gate being disposed over a channel stack comprising two or more nanosheet channels and sacrificial layers formed above and below each of the two or more nanosheet channels. The method also includes forming an oxide surrounding the outer spacers, the oxide being disposed over source/drain regions surrounding the channel stack. The method further includes removing the dummy gate, removing the outer spacers, and performing a channel release to remove the sacrificial layers in the channel stack following removal of the outer spacers. The method further includes performing conformal deposition of a dielectric layer and a work function metal on exposed portions of the oxide, and filling a gate metal over the channel stack, the gate metal being surrounded by the work function metal.