Nanomechanics, Nanomaterials, NanoManufacturing Laboratory (NM3L) is a group led by Dr. Michael Cai Wang at the University of South Florida.
I joined the research group in the late November of 2019, my freshman fall semester. From December 2019 - February 2020, I was mentored by MD Rubayat Tanjil and was assisting him with sample preparation for top-bottom metal nanosheets preparation project. Since February 2020 onwards, after my 'official appointment', I have been mentored by / working with Yunjo Jeong on our electromigration project (find the details below).
2D film-assisted mitigation of electromigration and enhancement of performance in micro- and nano- electronics (Feb 2020 - August 2021)
Developed a 2D material transfer technique using polymers such as PDMS and PC. Applications include deterministic 2D heterostructure preparation, and transfer of desired 2D material flake from Silicon wafer to a desired surface (Micron dimensioned Copper interconnects in this project's case)
Worked on 2D material flake preparation on Silicon wafers using scotch tape exfoliations from bulk crystals. This also included tuning surface chemistry of Silicon wafers for better adhesion, using PVA polymer. Material capability expands to Graphene and HbN 2D flakes
Developed an electrical characterization setup for quasi-static measurements in the lab from scratch, using Keithley bi-channel Source Measuring Unit, wave form generators, Oscilloscope(s), and source meters.
Fabricated HbN transferred Copper interconnect samples for final manuscript and relevant official documentations. Also conducted the Current-Voltage measurements for performance comparison.
Gained experience on Lithography processes and metrological study tools such as AFM, SEM, Profilometry, and Raman Spectroscopy.
MoS2 Moiré pattern based atomically thin resistive memory switches (March 2021 - August 2021)
Worked with stacking clean interfacial twisted 2D materials using standard transfer techniques.
Observed twisted angle using STM images.
Phase change studies on 2D Transition Metal Dichalcogenides (TMDs) under applied stress (January 2021 - August 2021)
Polished Diamond using standard grit friction procedures
Prepared mono-few layer MoS2 flakes using lab-developed gold exfoliation methodology on Silicon substrates
Transferred 2D TMDs onto the polished diamond table from Silicon wafers for further stress application steps and Raman characterization
Neural networks based 2D material flake identification on Silicon wafers (December 2020 - August 2021)
Plans are to utilize the famous image recognition technique called Mask_RCNN, to detect mono-few layer exfoliations on Silicon wafer as they are about perfectly transparent and not easily identifiable if the researcher does not has prior experiences of 2D material "hunting".
Currently learning the basics of neural networks and the mathematical thought process behind image recognition using them
Top-down processing towards Ångstrom-thin two-dimensional (2D) elemental metals (December 2019 - February 2020)
Learnt the top-down fabrication of 2D metals through repetitive rolling reduction
Prepared double digit samples for further characterizations (Thinnest sample created was copper sheets with a thickness of 60 nanometers)