Exploring Size Dependent Brittle-to-Ductile Transition in Single Crystal Silicon Using High Temperature MEMS

Research project


Exploring the effect of electron beam irradiation the deformation behavior of thin films One of the fundamental questions that the NSF proposal aims to answer is whether the plastic deformation in Si that was observed in previous in situ TEM studies is intrinsic or an artifact caused by electron beam damage. But before this question can be answered it is essential to understand the effect of beam irradiation on materials that are well characterized. Towards this end, this task will be concerned with quantifying the change in the mechanical behavior (stress-strain response) of thin films of different thicknesses when they are exposed to the electron beam during deformation. These experiments will primarily involve Al films since their stress-strain behavior has been well characterized previously. To perform these in situ TEM experiments the PI (Jagannathan Rajagopalan) will be travelling to the University of Vienna for a period of approximately two weeks. These experiments are expected to provide insight into how various parameters such as film thickness, beam voltage/current and time/intensity of beam exposure affect the deformation response of nanoscale thin films. Fabrication and testing of nanoscale Si thin films This task will be concerned with the fabrication and mechanical testing of nanoscale Si films to understand how the size scale affects the brittle to ductile transition in Si. Si thin films with various thicknesses will be fabricated and their stress-strain response will be characterized using MEMS based tensile testing stages. These experiments will be performed at room temperature only. The PI will be involved in the design and fabrication of the MEMS testing stage as well as performing experiments to determine the mechanical behavior of the Si films. The MEMS stages will be fabricated using the cleanroom facilities at ASU and the experiments will be performed at the PIs lab.
Effective start/end date9/1/126/30/15


microelectromechanical systems
single crystals
thin films
electron beams
transmission electron microscopy
plastic deformation
film thickness
electric potential
room temperature