Optimization of Ballistic Carbon Nanotube Field-Effect Transistor Using Response Surface Methodology for Enhanced Current Ratio Performance

Carbon nanotube field-effect transistors (CNTFETs) are promising candidates for future nanoscale devices owing to their exceptional properties. The objective of this study is to optimize the performance of a ballistic CNTFET by identifying the optimal configuration of the principal geometrical and material parameters to maximize the current ratio (Ion/Ioff). In a joint study of ballistic transport modeling using the FETToy tool and a Central Composite Design (CCD), the diameter of carbon nanotube (d), oxide thickness (tox), and dielectric material (k) were varied. The results show that the dielectric material has a significant influence on the current ratio (Ion/Ioff). Furthermore, the optimum combination of 3 nm carbon nanotube diameter, 1 nm oxide thickness, and ZrO2(25) dielectric material offers a significant gain in the Ion/Ioff performance. The analysis of variance (ANOVA) underscores these findings, highlighting the dielectric material in diameter and oxide thickness. Specifically, the ANOVA highlighted interaction effects between the CNT diameter and the dielectric material. This multi-parametric approach provides a more rigorous modeling framework for these transistors, unlike previous studies that optimized parameters independently. In addition, it provides a better understanding of the interactions between key parameters (CNT diameter, oxide thickness, and dielectric material) governing performance.