Atomic-scale thermocapillary flow in focused ion beam milling
Focused ion beams provide a means of nanometer-scale manufacturing and material processing, which is used for applications such as forming nanometer-scale pores in thin films for DNA sequencing. We investigate such a configuration with Ga{sup +} bombardment of a Si thin-film target using molecular dynamics simulation. For a range of ion intensities in a realistic configuration, a recirculating melt region develops, which is seen to flow with a symmetrical pattern, counter to how it would flow were it driven by the ion momentum flux. Such flow is potentially important for the shape and composition of the formed structures. Relevant stress scales and estimated physical properties of silicon under these extreme conditions support the importance thermocapillary effects. A flow model with Marangoni forcing, based upon the temperature gradient and geometry from the atomistic simulation, indeed reproduces the flow and thus could be used to anticipate such flows and their influence in applications.
- OSTI ID:
- 22403228
- Journal Information:
- Physics of Fluids (1994), Vol. 27, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-6631
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
CAPILLARY FLOW
COMPUTERIZED SIMULATION
DNA SEQUENCING
FLOW MODELS
GALLIUM IONS
GEOMETRY
ION BEAMS
MILLING
MOLECULAR DYNAMICS METHOD
PHYSICAL PROPERTIES
PROCESSING
SILICON
STRESSES
TEMPERATURE GRADIENTS
THIN FILMS