A simulation study of core–shell gate-all-around nanosheet MOSFET for sub-5 nm technology node

Abstract N/P type gate-all-around nanosheet field-effect transistors (NSFETs) with Si/Si 1− x Ge x and Si 1− x Ge x /Si ( x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) core–shell channels are proposed to systematically investigate the improvement in the static characteristics. The incomplete conduction caused by the quantum well introduced by core/shell structures was regulated by the mole fraction of Si 1− x Ge x to smooth the channel energy band profile. The device performances under different channel architectures, mole fraction in Si 1− x Ge x and thickness of shell ( T shell ) are investigated by analyzing the differences between surface scattering, energy bands and quantum wells to find the dominant underlying physical mechanisms of the static characteristics. Compared to conventional NSFETs, the I on / I off improvement in the best N/P-type FETs (N/PFETs) is 36.72%/14.41% for the Si 1− x Ge x -core devices and 47.01%/20.74% for Si-core devices, respectively. The results demonstrate that the proposed core–shell device is a potential candidate for advanced technology nodes.