Ideal electrodes for monolayer boron phosphide and their device performance

Pursuing low contact resistance is crucial for ameliorating performances of short-channel Schottky barrier field effect transistors (SBFETs). We have studied the electrical contact properties of semiconducting monolayer (ML) boron phosphide (BP) with metallic MXenes (Zr2NF2, Zr2CF2, Ti2NF2, and Ti2CF2) and metallic TMDs (1T-TaS2, 2H-TaS2, 1T-VS2, and 2H-VS2) using ab initio calculations. The BP/MXene and BP/TMD contacts have clean interfaces without metal-induced gap states and show weak Fermi-level pinning. The n- and p-type (quasi) ohmic contact is obtained with low-work-function metals (Zr2NF2 and Zr2CF2) and high-work-function metals (2H-TaS2, 2H-VS2, and 1T-VS2), respectively. The 9-nm-gate ML BP SBFET with Zr2NF2 (2H-VS2) electrode is an n- (p-) type high-performance (HP) device with the on-state current (Ion), delay time (tau), and power dissipation (PDP) of 1872 (1129) mu A/mu m, 0.29 (0.15) ps, and 0.27 (0.09) fJ/mu m at a supply voltage of Vdd = 0.5 V, surpassing the 12nm-gate International Roadmap for Device and Systems (IRDS) HP targets for the year 2037 at Vdd = 0.6 V and superior to the Ion of several previously studied ML SBFETs with ML metal electrodes at Vdd = 0.5-0.74 V with 9-10 nm gate. Our study suggests that ML BP SBFETs (with ideal electrodes) are promising candidates for HP applications for more Moore electronics.