Perspective on Low-dimensional Channel Materials for Extremely Scaled CMOS

Low-dimensional materials (LDMs) such as two-dimensional transition metal dichalcogenides (2D TMDs) and carbon nanotubes (CNTs) have the potential to be the channel material in extremely scaled CMOS transistors. Based on current hardware data, the design space for contacted-gate pitch (CGP) scaled transistors is explored for these materials. The ON current, sources of leakage which limit OFF current, and CGP scaling potential are analyzed by separately considering effects from shrinking the gate length, contact length, and extension length. Doping of LDM is the main challenge to reduce contact and extension resistance for scaled transistors. Experimental control of p-type doping of 2D is reported as an example of doping impact.