Scalability study of In0.7Ga0.3As HEMTs for 22nm node and beyond logic applications

Compound semiconductor high electron mobility transistors (HEMTs) have recently gained a lot of interest for future high-speed, low-power logic applications due to their high mobility and high effective carrier velocity [1]. Conventional In0.7Ga0.3As HEMTs with 50 to 150nm gate-length (LG) have been experimentally demonstrated [2] with excellent device performance. In this paper, (i) we use two-dimensional numerical drift-diffusion simulations [3] to model the conventional In0.7Ga0.3As HEMTs with different LG from 15 to 200nm and investigate its scalability for future logic applications. (ii) An accurate estimation of effective mobility (μeff) and effective carrier velocity (injection) is presented, highlighting the relevance of ballistic mobility in these short-channel HEMTs. (iii) Due to degradation in performance of the conventional scaled In0.7Ga0.3As HEMT at LG=15nm, three novel HEMT device architectures are studied and the design for the ultimate scaled transistor is proposed.