Experimental Work - Atom Probe Tomography At Iowa State University S. Dumpala, S. Broderick, A. Bryden, K. Kaluskar and K. Rajan
Feb 14, 2016
Experimental Work - Atom Probe Tomography
At Iowa State University
S. Dumpala, S. Broderick, A. Bryden, K. Kaluskar and K. Rajan
• Growth behavior of ultrathin silica layers by laser detonation hyperthermal atomic beam source (1-15 eV) of atomic and molecular oxygen
• Study of occurrence of pure Si, SiOx,and SiO2 and growth directions of oxidized (black arrows) and silica layers (red arrows)
Study of Growth of Different Oxidized Layers : APT
U. Khaliov, et al. J. Phys. Chem.C, 115, 2011
ReaxFF Simulations
Atom Probe Tomography(Model System – Oxidation of Aluminum)
• Oxidation of Aluminum at 450 C, 2.5 x 10-3 Torr for 10 min.
• Chemical composition and atomic structure from 3D image of elemental mapping with atomic-scale resolution
Bulk Al2O3 phase Bulk Al phase
Al
O
Study of Interfaces
Possible Link
Diffusion Profiles - APT Mass and Charge distributions – ReaxFF Simulations
U. Khaliov, et al. J. Phys. Chem.C, 115, 2011
Al
O
Effect of Growth Temperature
U. Khaliov, et al. J. Phys. Chem.C, 116, 2012
Environmental Chamber- APT
• Different Temperatures up to 800 C
• Different pressures ranges (low 10 -5 torr)
• Different gas phase chemistries
• Different time scales
• Different sample orientations
Possible Experimental Studies - Oxidation
ReaxFF SimulationsAPT
Mass Spectra - APT
Ion Evaporation Map
Diffusion ProfilesStudy of Interfaces
Use APT to study compound formation, bond strengths (crystal structure changes), evaporation physics/ionic dissociation, and charge states of bonded atoms.
Experimental Studies at Maryland
• 10 coupons each with 36 Si (100) micro tips (6x6 rows) were sent to University of Maryland to obtain the samples of known fluence and energy spectrum to evaluate the change in surface morphology
Typical Silicon Coupon