Meirav Saraf

Light-induced self-synchronizing flow patterns

In this paper, we present the observation of light-induced self- synchronizing flow patterns in a light-fluid system. A light beam induces local flow patterns in a fluid, which oscillate periodically or chaotically in time. The oscillations within different regions of the fluid interact with each other through heat- and surface-tension-induced fluid waves, and they become synchronized. We demonstrate optical control over the state of synchronization and over the temporal correlation between different parts of the flow field. Finally, we provide a model to elucidate these results and we suggest further ideas on light controlling flow and vice versa.

Complex Nonlinear Opto-Fluidity

We demonstrate symbiotic dynamics of light and nano-particles suspended in liquid. Light-force varies the local particle density, modifies the fluid properties (surface-tension, viscosity), inducing motion/rotation in the fluid, causing synergetic nonlinear-dynamics of light and fluid.

Chemical bonding and interdiffusion in scaled down SiO2∕Si3N4∕SiO2 stacks with top oxide formed by thermal ed copyoxidation

The influence of thermal oxidation on the composition of silicon nitride films in SiO2∕Si3N4∕SiO2 stacks for advanced nonvolatile memories is reported. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry analyses lead to the conclusion that wet thermal (pyrogenic) oxidation of silicon nitride enhances the incorporation of oxygen into the silicon nitride layer and creates a silicon oxynitride layer. In the oxynitride layer formed by wet oxidation, O is mostly bonded to N, whereas in the native oxynitride at the silicon nitride surface, O is preferentially bonded to Si. Dry oxidation (1200°C) results in an even higher amount of oxygen incorporation into the silicon nitride layer as compared with the pyrogenic process. After both pyrogenic and dry oxidation, hydrogen concentration decreases in the bulk of the silicon nitride layer. Following wet oxidation, hydrogen was found to accumulate at the surface layers of the grown oxynitride film. Oxygen penetration into the nitride l...

Nitrogen diffusion and accumulation at the Si∕SiO2 interface in SiO2∕Si3N4∕SiO2 structures for nonvolatile semiconductor memories

Time-of-flight secondary ion mass spectrometry (SIMS) depth profiling was used to study nitrogen distribution in SiO2∕Si3N4∕SiO2 (ONO) structures employed in advanced semiconductor memories. We have investigated different factors that affect nitrogen accumulation at the Si∕SiO2 interface of the ONO structure. To isolate the impact of ion beam enhanced nitrogen diffusion towards the Si∕SiO2 interface in SIMS measurements, the top silicon oxide and silicon nitride layers were chemically etched before the SIMS procedure. Thermal diffusion effects were investigated by comparing specimens with different thermal budgets and different thickness of layers in the ONO stack. Our results unambiguously suggest that nitrogen can be accumulated at the Si∕SiO2 interface during ONO fabrication.

Low thermal budget SiO2∕Si3N4∕SiO2 stacks for advanced SONOS memories

SiO2∕Si3N4∕SiO2 (ONO) stacks are used as trapping media in industrial semiconductor memories. This memory device uses deep traps in the silicon oxynitride interlayer between the silicon nitride layer and the top oxide. In this research, low-thermal budget (low temperature) ONO layers were designed suitable for integration into advanced scaled down semiconductor technologies. The alternative growing procedure included oxidation of silicon nitride surface in oxygen plasma. Low temperature oxidation of the silicon nitride layer in oxygen plasma allows incorporation of oxygen into the silicon nitride layer, thus forming a silicon oxynitride layer. The chemical composition of the silicon oxynitride interlayer was similar to the oxynitride of thermally grown ONO. The plasma procedure did not cause any surface roughening. The memory devices with the low-temperature-oxygen-plasma ONO stack showed similar performance to memories with standard high temperature ONO. ONO structures were characterized chemically and s...

Memory functions for comparative nonlinear dynamics: A new class of dynamic systems unifying chaotic Optofluidics and Electronics

We unite chaotic Optofluidics and chaotic Electronics in a single class of topologically-equivalent dynamic systems. This is made possible with a new comparative approach for dynamic systems research, based on the memories of the systems.

Optical control of surface-tension effects in complex nanofluids

We study coupling between light and nano-particle suspensions, through surface-tension effects in capillaries. Increasing light intensity far-away from the interface causes huge changes in the fluid level, manifesting optical control over mechanical properties of fluids.

Complex Dynamic Optofluidics: Symbiotic Nonlinear Controls, Self-pulsation, and Chaos

We experimentally demonstrate dynamic nonlinear optofluidic controls: symbiotic action between light and fluid introduces a new class of high-level, entirely optofluidic devices, revealing a self-pulsating light-fluid oscillator and chaotic dynamics with universal traits.