5:00 PM - EP09.03.04
Multiscale Modeling Framework for 2D-Material MOS Transistors
Madhuchhanda Brahma1,Santanu Mahapatra1
Indian Institute of Science, Bangalore1
Atomically thin 2D materials have ushered in a new era in the field of materials science and has been translated to notable advancements in the design of sensors, optoelectronic devices, flexible electronics . These atomically thin materials are predicted to replace conventional bulk materials, Si and Ge, for transistor channels and extend the complementary metal oxide semiconductor technology road-map beyond the ultimate scaling limit . Constant efforts are being made to synthesize devices based on some of the recently discovered van der Waal's materials such as graphene, hexagonal boron nitride, MoS2, phosphorene [3,4,5]. Density functional theory (DFT) calculations have suggested a large number of 2D materials and their derivatives for device applications . In order to narrow down the material and design selection space for time- and cost-heavy experimental device fabrication, atomic level DFT calculations need to be coupled with device-level physics models. Thus, starting from first principles DFT calculations, we propose a multiscale computational framework to extract important electronic parameters, such as effective mass, band gap, real and complex band dispersion, and phonon spectrum, which are then used to construct the material Hamiltonian. A self-consistent solution of the Schrodinger and the Poisson's equations through the non-equilibrium Green’s function approach  is then obtained to describe the complex, spatially heterogeneous intrinsic carrier transport and resulting device performance in both ballistic and dissipative regimes. Modeling studies on three devices: (i) monolayer germanane metal oxide semiconductor field effect transistors (MOSFETs), (ii) monolayer GeSe based tunneling field effect transistor (TFET), and (iii) phosphorene based MOSFET and TFET, will be presented and their design and performance limits will be evaluated to guide future material selection and device fabrication.
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