Event

Heterogeneous Integration of Extremely High Mobility and Low-power Transistors and Ge Photonics on Si

Shrinking feature sizes of transistor has enabled increase in transistor densities and this rising number of transistors increases the power consumption in ICs. Low-power consumption would imply lower heat dissipation, prolonged battery life and reduced cooling requirements, which all add up to significant reductions in cost and energy savings. Going forward and beyond the 10 nm technology node, transistor scaling will require high mobility channel materials, low bandgap III-V and Ge semiconductors, novel device architectures (tunnel transistors, 3D FinFETs) and their heterogeneous integration with highly dense Si CMOS for lowering power consumption. These nanoscale Ge/InGaAs transistors operating at ultra-low voltage (~300 mV) are attractive for implantable medical devices due to their extremely low power consumption. Also, heterogeneous integration of such high mobility materials with Si is one of the most promising ways to harvest the potential of III-Vs for optical chip-to-chip communication on a Si platform and eliminate the need for developing large area and expensive III-V wafers. However, there are many fundamental challenges that arise in attempting to use device quality Ge/In_xGa_1-xAs materials on Si. The first and foremost, there is a challenge in understanding the band alignment of Ge/In_xGa_1-xAs. Second, there is a challenge to demonstrate lower defect density III-V materials on Si for electronic and optical devices. Third, the amount of strain incorporated into Ge that would not relax during the device fabrication. Fourth, there is a challenge to measure the optical bandgap and the effective mass as a function of strain in Ge due to quantization effect. In this talk, I will present the recent development on the III-V, Ge and mixed As-Sb based materials and device structures on Si from our group that has the capacity for ultra-low power logic, photonics, and multifunctional device applications.

About the Speaker

Dr. Mantu Hudait is an Associate Professor in the Bradley Department of Electrical and Computer Engineering, Virginia Tech. Prior joining at Virginia Tech, he was a Senior Engineer in the Intel Corporation's Advanced Transistor and Nanotechnology Group. His research at Virginia Tech focuses on next generation materials and devices, tunable Ge laser and multijunction solar cells. He work was press released in 2007 and 2009 and received two Divisional Recognition Awards from Intel, 49 US Patents issued, and over 150 technical publications. Dr. Hudait’s teaching focuses on integrating research and industry experience into the curriculum. He is a Senior Member of the IEEE and AVS member.