Seminar

Chul-Ho Lee^{1, 2}

¹KU-KIST Graduate School of Converging Science & Technology, ²Department of Integrative Energy Engineering, Korea University, Seoul 02841, Republic of Korea

 

Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have emerged as a promising material for implementing beyond-CMOS electronics due to excellent gate coupling and immunity to short channel effects at the ultimate scaling. In addition, owing to a van der Waals (vdW) layered structure, they hold great potential for non-conventional electronics capable of heterogeneous integration and deformation. To achieve high-performance 2D electronic devices, it is highly required to control the electronic states and energy band profiles at various heterointerfaces among the semiconductor channel, the gate dielectric, and metal electrodes. In this talk, I will present two types of proof-of-concept 2D field-effect transistors (FETs) enabled by interface band engineering: 1) modulation-doped FETs (MODFETs) and 2) metal-semiconductor FETs (MESFETs). In a MODFET, we demonstrated remote modulation doping in the type-II band-modulated channel, enabling us to achieve high mobility by suppressing dopant-induced charge impurity scattering [1]. The vdW MESFETs were also demonstrated using the Fermi-level pinning-free metal Schottky gate, whose device characteristics approach the Boltzmann switching limit.

 

[1]  Nature Electron. 4, 664 (2021)