Vertical C-Shaped-Channel Nanosheet FETs Featured With Precise Control of Both Channel-Thickness and Gate-Length

A novel vertical C-shaped-channel nanosheet field-effect-transistor (VCNFET) featured with precise control of channel-thickness and gate-length, and a unique integration flow of Dual Side Process (DSP) are proposed in this work. The VCNFETs were fabricated by high quality Si/SiGe epitaxy, atomic layer etching with nanometer-scale process control and self-aligned high-k metal gate (HKMG). The integration flow is compatible with mainstream CMOS technology. Thanks to the precise control of channel thickness and doping profiles, perfect SS of 61 mV/dec, small DIBL of 8 mV/V, and remarkably large I-on/I-off ratio of 6.28 x 10(9) were achieved. The device performance and it's optimization were also investigated with the reduction of the external resistance and numerical simulations.

Automated summary

In this work, a novel vertical C-shaped-channel nanosheet field-effect-transistor (VCNFET) with precise control of channel thickness and gate length, and a unique integration flow of Dual Side Process (DSP) is proposed. The VCNFETs are fabricated using high quality Si/SiGe epitaxy, atomic layer etching, and self-aligned high-k metal gate (HKMG). The integration flow is compatible with mainstream CMOS technology. The device exhibits excellent performance with perfect subthreshold slope (SS), small drain-induced barrier lowering (DIBL), and remarkably large on/off ratio.