First Demonstration of Novel Vertical Gate-All-Around Field-Effect-Transistors Featured by Self-Aligned and Replaced High-κ Metal Gates

A novel n-type nanowire/nanosheet (NW/NS) vertical sandwich gate-all-around field-effect-transistor (nVSAFET) with self-aligned and replaced high-κ metal gates (HKMGs) is presented for the first time, aiming at a 3 nm technology node and beyond. The nVSAFETs were fabricated by an integration flow of Si/SiGe epitaxy, quasi-atomic layer etching (qALE) of SiGe selective to Si, formation of SiGe/Si core/shell NS/NW structure, building of nitride dummy gate, and replacement of the dummy gate. This fabrication method is complementary metal oxide semiconductor (CMOS)-compatible, simple, and reproducible, and NWs with a diameter of 17 nm and NSs with a thickness of 20 nm were obtained. Excellent control of short-channel-effects was presented. The device performance was also investigated and discussed. The proposed integration scheme has great potential for applications in chip manufacturing, especially with vertical channel devices.