Effect of Spacer and Extension variation on of GSDM-GAAFET for improved Electrical and Subthreshold parameters

In this article, spacer and extension variation is studied on Gate stacked dual material (GSDM) GAAFET. The impact of spacer and extension on drain current characteristics is studied. The spacer length is varied from $2.5 \mathbf{n m}$ to $12.5 \mathbf{n m}$ whereas extension length is varied from 1 nm to 5 nm. Significant improvement is observed in terms of ON and OFF current. The ON current is almost doubled from spacer length $\mathbf{1 2. 5 ~} \mathbf{~ n m}$ to 2. 5 nm. The OFF current is increased by decreasing spacer length. Higher ON resistance is observed with minimum spacer length due to increased series resistance, but improved overall device stability. A spacer length of 6. 5 nm is chosen to have optimum ON and OFF current. Variation of extension also analyzed in terms of performance parameters. An extension length of $1 \mathbf{~ n m}$ is chosen to have optimum OFF current.