2D Material-Based FETs for Next Generation Integrated Circuits

In the last few years, a significant interest has been shown in 2D field effect transistor (2D-FETs) as an appropriate candidate for advanced electronics devices. This study of a two-dimensional FET (2D-FET) works with a channel made of MoS₂, MoSe₂, and MoTe₂ and different dielectric materials. Materials such as molybdenum disulfide (MoS₂), molybdenum diselenide (MoSe₂), and molybdenum ditelluride (MoTe₂) belong to the transition metal dichalcogenide (TMD) family and are known for their fascinating electronic properties. Transition metal dichalcogenides like MoS₂ have emerged as promising candidates, boasting satisfactory bandgaps, thermal stability, high carrier mobility, and compatibility with silicon CMOS processes. Their ability to reduce scattering events, electrical insulating qualities, and suitability for 2D semiconductor channels make them excellent choices for low-power setups. The ideal dielectric, however, must also consider the particular needs of the device, including its operating environment, targeted performance indicators, and 2D semiconductor channel material. These materials have showcased immense potential in device applications, offering superior electrostatics and resilience against short-channel effects compared to traditional silicon channels. From the classic Metal-Oxide-Semiconductor FET (MOSFET) to the evolution of dual-gate FETs, tri-gate devices, and the current pinnacle, Gate-All-Around Field-Effect Transistors (GAA FETs), each technological era has presented unique opportunities and challenges. These materials have different band gaps, carrier mobilities, and intrinsic properties that make them ideal candidates for 2D transistor channels. The I_ON/I_OFF graph is a critical metric for evaluating the performance of Field-Effect Transistors (FETs), providing insights into the on-state (I_ON) and off-state (I_OFF) current characteristics. In scenarios involving a HfO₂ spacer, MoS₂ consistently demonstrates superior performance compared to alternative 2D materials such as MoTe₂ and MoSe₂. The I_ON/I_OFF graph for MoS₂ FETs typically exhibits a more favorable ratio, emphasizing a higher on-state current coupled with a lower off-state current. This advantageous combination is attributed to MoS₂‘s unique electronic properties, including its favorable band structure and superior carrier mobility. The HfO₂ spacer enhances the gate control over the channel, contributing to efficient modulation of the FET’s conductivity. In contrast, MoTe₂ and MoSe₂ may exhibit comparatively higher off-state currents or reduced on-state currents due to factors like lower carrier mobility or less effective gating. The I_ON/I_OFF graph underscores MoS₂‘s prowess as a promising material for FET applications with HfO₂ spacers, highlighting its potential for high-performance electronic devices. In this study, we investigate the influence of different dielectric materials on the performance of 2D FETs with MoS₂, MoSe₂, and MoTe₂ as channel materials, with a strong focus on high-speed operation. Our study analyzes performance metrics like on-current (I_ON), off-current (I_OFF), and I_ON/I_OFF ratio which will be more when compared with Si-based FETs. Notably, the choice of dielectric significantly influences these metrics, with high-k dielectrics and HfO₂ often surpassing SiO₂.