Components Research Engineer, Intel Corporation
Two-Dimensional Black Phosphorus for High Performance Field Effect Transistors
Two-dimensional (2D) materials have attracted incredible interest from the electronic device community during the past decade. These materials have a layered crystal structure and could provide scalability of the transistor channel down to a single monolayer. Therefore, they could be a potential platform for scaled logic devices. Other applications of 2D materials include sensors, flexible electronics and other innovative device concepts owing to the unique physical properties of 2D materials. Black phosphorus (BP) has recently emerged as a new promising layered semiconductor due to its unique material properties. BP has high electron and hole mobility, tunable band-gap ranging from 0.3 eV (bulk) to 1-2 eV (monolayer) and highly asymmetric effective mass. BP metal-oxide-semiconductor field-effect transistors (MOSFETs) have the potential to outperform other 2D semiconductors mainly due to the lighter effective mass of BP, which leads to higher mobility, and narrower band-gap, which can reduce contact resistance due to the Schottky barrier height lowering. In this work, BP n- and p-type MOSFETs with record performance are demonstrated. A comprehensive experimental and theoretical evaluation of the design and operating parameters that limit the off-state performance and subthreshold slope in BP MOSFETs is performed. Next, the effect of asymmetric crystal orientation on BP MOSFET performance is quantified and the anisotropic mobility in a realistic MOSFET geometry is analyzed. Finally, contact engineering is utilized to achieve record-low contact resistance in BP p-MOSFETs.
Nazila Haratipour received her B.S. degree in Electrical Engineering in 2011 from the University of Tehran, Iran. She received her M.S. in Electrical Engineering with a minor in physics and her Ph.D. in Electrical Engineering under the supervision of Professor Steven J. Koester from the University of Minnesota in 2017. Her research has focused on fabrication, characterization, and analysis of field effect transistors based on novel two-dimensional materials such as graphene, transition metal dichalcogenides and black phosphorus for future generation of electronics. Nazila’s Ph.D. dissertation is centered around two-dimensional black phosphorus for high-performance field effect transistors. She has done comprehensive experimental and theoretical studies to improve black phosphorus transistor performance and the outcome of her Ph.D. research has been 14 papers and abstracts in major conferences and journals. She was awarded the University of Minnesota Doctoral Dissertation Fellowship in 2016-17. Currently she is a Component Research Engineer in Intel Corporation, Hillsboro, OR, USA.