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
$\text{I}_{\text {on}}/\text {I}_{\text {off}}$
ratio of
${6.28}\times {10}^{{9}}$
were achieved. The device performance and it’s optimization were also investigated with the reduction of the external resistance and numerical simulations.