Laser Shock Nanostraining of 2D materials and van der Waals heterostructures

Maithilee Motlag, Ph.D.

Micron Technology

Since the successful exfoliation of graphene, two-dimensional (2D) materials have attracted a lot of scientific interest due to their electronic, chemical, and mechanical properties. Due to their reduced dimensionality, these 2D materials exhibit superior mechanical and optoelectronic
properties when compared to their bulk counterparts. It is possible to leverage the distinct characteristic properties of these 2D materials, which are held together by van der Waals forces, by stacking different 2D layers on top of each other resulting in van der Waals (vdW)
heterostructures. In this talk, I will discuss a scalable laser-shock nanostraining technique which can be used to modulate the optomechanical properties of van der Waals (vdW) heterostructures for practical semiconductor industry applications. The deformation processes and related
mechanical behaviors in laser shocked 2D materials are examined using atomistic simulations. These atomistic simulations can effectively capture the material behavior at the nanoscale level and help us not only understand the mechanical properties of these materials but also aid in the design of novel metamaterials. We can obtain moiré heterostructures by introducing a twist angle between these 2D layers, which can result in vdW materials with different properties, thereby adding an additional degree of freedom in the process-property design approach. We were able to successfully create a tunable strain profile in 2D materials and vdW heterostructures to modulate the local properties such as friction, and bandgap by controlling the level of laser shock, twist angle between the 2D layers and by applying appropriate laser shock pressure. I will discuss the pathways of strain modulation using a combination of laser shocking process, Moiré engineering, and strain engineering in 2D materials consisting of graphene, BN, and MoS2 and to develop the process – property relationships in vdW materials. This understanding provides us with opportunities for deterministic design of 2D materials with controllable properties for semiconductor and nanoelectronics applications. Towards the end of the talk, I will discuss some future perspectives in context to material modeling for semiconductor applications.

Speaker Bio: Dr. Maithilee Motlag is a Test Chip Vehicle Integration Lead at Micron Technology Inc. and serves as the technical point of contact for the NAND test chip vehicle development and NAND product enablement. Previously, she was an Advanced Material Modeling Engineer Postdoc at Micron Technology Inc., where she implemented Multiphysics modeling methods to facilitate Technology Pathfinding of next generation memory semiconductor manufacturing processes. Her Ph.D. research provides a systematic understanding of the effect of laser shock process on Van der Waals materials and demonstrated the modulation of mechanical and optoelectronic properties.
She has authored 11 publications in journals such as Nature Communications, Advanced Materials, Advanced Sciences and was also the recipient of Bilsland Dissertation Scholarship. During her time at Purdue, she served as a President for Industrial Engineering Graduate Student Organization and President for Industrial Engineering Graduate Women’s Group. She received the Purdue Outstanding Service Award and McDonnell Doughlas Scholarship for her active involvement and service in STEM outreach. Dr. Motlag has a Ph.D. in IE (2021) and a MS in ME (2013) from Purdue University, U.S.A and a B.E. in ME from Cummins College of Engineering for Women, India (2012)