A First-Principles Study of Monolayer B ₄ Cl ₄ : Structural Stability, Anisotropic Electronic Properties, and Ballistic Transport Projections in Sub-5 nm MOSFETs

As traditional semiconductor technologies approach their physical limits, exploring novel two-dimensional materials has become imperative. This study systematically investigates the crystal configuration, structural stability, and electronic properties of chlorinated graphene-like boronene (B4Cl4), as well as its potential in metal-oxide-semiconductor field-effect transistor (MOSFET) applications, via first-principles calculations. Incorporating chlorine enhances B4Cl4’s structural stability and induces anisotropic electronic properties. N-type and p-type B4Cl4-based MOSFET prototypes with different channel lengths are designed to assess the quantum transport limits. Results show that n-type MOSFETs with gate lengths of 5.0 and 4.0 nm meet the International Technology Roadmap for Semiconductors (ITRS) high-performance requirements. Specifically, the 5.0 nm device exhibiting x-directional transport has a subthreshold swing near the theoretical limit of conventional MOSFETs, while the 5.0 nm device exhibiting y-directional transport shows an on-state current 170.63% higher than those of ITRS benchmarks. Optimizing the underlap region extends the compliant gate lengths to 3.0 nm, yielding five devices in which the intrinsic delay and power-delay product are 1 order of magnitude below ITRS standards. This underscores the theoretical potential of B4Cl4 as a channel material in next-generation advanced nanoelectronic devices.