This talk will study the prospects of two different emerging materials system (the atomically thin two-dimensional materials and ferroelectric oxides) in energy efficient electronic devices for future Systems-on-a-Chip (SoC’s) applications.
Novel device concepts based on quantum mechanical tunneling (i.e. inter-band tunneling, hot electron injection) and two-dimensional materials can overcome some of the limitations of conventional CMOS devices for both low power and high frequency. I will demonstrate inter-band tunneling transistors with room temperature negative differential resistance using van der Waals heterostructure for low power applications. Moreover, I will show vertical hot electron transistor (HET) utilizing tunneling injection of hot electrons, which may enable high-frequency operation that currently CMOS cannot provide. The integration of the highly conductive ultra-thin (0.3 nm) monolayer graphene integrated with GaN platform by van der Waals interaction can simultaneously offer both scalability and high performance in ballistic HET.
In the second part of the talk, I will discuss how the use of ferroelectric HfO2 on conventional (Si, GaN, InGaAs) semiconductor as well as two-dimensional materials systems offers a new degree of freedom when designing new devices. I will demonstrate that the integration of ferroelectric HfO2 can enable ultra-low power (MoS2 FET with subthreshold swing <60 mV/decade) as well as high frequency applications. Finally, I will present a proposal for a new analog synaptic device using ferroelectric HfO2 for in-memory computation in future SoC platforms
Thesis Supervisors: Tomas Palacios , Mildred Dresselhaus (posthumous)