Sub-5-nm monolayer KMgX (X=P, As, Sb)-based homogeneous CMOS devices for high-performance applications

For CMOS electronics, the channel materials, which can offer symmetrical performance for n- and p-type devices, along with the ability to scale transistors down to the ultra-scale limit, are quite crucial in the next era beyond silicon. Monolayer KMgX (X=P, As, Sb) not only possesses atomically thin structure, but also exhibits high mobilities for both electrons and holes, being advantageous for symmetrical performance and shrinking devices’ size. Based on first-principles calculations, the device performance limit of sub-5-nm monolayer KMgX (X=P, As, Sb) metal-oxide semiconductor field-effect transistors (MOSFETs) with a double-gated setup are investigated. The results show that, for all the three KMgX configurations (X=P, As, Sb), both n- and p-type MOSFETs can meet the ITRS 2013 requirements for 2028 horizon in high-performance applications, even as Lg reduces to 3 nm. The ON-state currents of those systems exceed the performance of most previously reported monolayer MOSFETs. Especially, the 5-nm-Lg n-type KMgSb and KMgAs MOSFETs exhibit ultra-high ON-state currents of 3463 and 3248 A/ m, respectively. Furthermore, the ratios of subthreshold swing, ON-state current, fringe capacitance, delay time, and power-delay product between n- and p-type devices demonstrate a high degree of symmetry. Our results suggest that the use of monolayer KMgX (X=P, As, Sb) MOSFETs would be highly advantageous for the development of sub-5-nm homogeneous CMOS electronics.