A new source heterojunction strained channel structure for ballistic gate all around nanowire transistor

A new type of Gate All Around Nanowire Transistor (GAA NWT) which employs source heterojunction and strained channel is proposed and its electrical characteristics are compared with SiGe GAA NWT and with conventional Silicon GAA NWT. The effect of band-offset energy at the source SiGe/strained-Si heterojunction is to enhance carriers’ kinetic energy when injected from the source into the channel. In this analysis, a quantum mechanical transport approach based on non-equilibrium Green’s function method in the frame work of effective mass theory is employed. Simulation routine consists of self consistent solutions of a three dimensional Poisson’s equation, a Schrodinger equation on the radial direction, and also transport equation. We analyze the electrical characteristics of the source heterojunction strained channel GAA NWT. Also, the advantages of this novel structure in terms of current drive capability and conduction band edge are discussed. It is shown that proposed structure provides a higher on current, lower leakage, lower threshold voltage and lower subthreshold slope in comparison with SiGe GAA NWT and conventional Silicon GAA NWT.