Nanoscale Structure of Si/SiO₂/Organics Interfaces

Abstract

X-ray reflectivity measurements of increasingly more complex interfaces involving silicon (001) substrates reveal the existence of a thin low-density layer intruding between the single-crystalline silicon and the amorphous native SiO2 terminating it. The importance of accounting for this layer in modeling silicon/liquid interfaces and silicon-supported monolayers is demonstrated by comparing fits of the measured reflectivity curves by models including and excluding this layer. The inclusion of this layer, with 6-8 missing electrons per silicon unit cell area, consistent with one missing oxygen atom whose bonds remain hydrogen passivated, is found to be particularly important for an accurate and high-resolution determination of the surface normal density profile from reflectivities spanning extended momentum transfer ranges, now measurable at modern third-generation synchrotron sources.

Order and Melting in Self-Assembled Alkanol Monolayers on Amorphous SiO2

“…21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 …”

“…R(q z ) calculated from this model through the Master Formula 36,38 is then least-squares fitted to the measured R(q z ) to yield the model-defining parameter values. The present substrate model is motivated by our recent study 21 , showing the presence of a thin, low-density, Si/SiO 2 interface layer, and the need to account for this layer to achieve physically meaningful parameter values. The dashed purple line in Fig.…”

Morphology and stress at silicon-glass interface in anodic bonding

“…The existence of anodic bonding oxide layer has been confirmed by the experimental observations [14,17]. However, most of the reports focus on the growth of silicon oxide in thermal oxidation processes or native oxidation processes [18][19][20], and the morphologies and structural details of formed silica in anodic bonding have been rarely clarified so far. The morphology of the formed silica determines the stress at the bonding interface, and investigation of this morphology is crucial for evaluating the stress at the bonding interface.…”

The Hydrophobic Gap at High Hydrostatic Pressures

“…TheXRR curves were normalized by the Fresnel reflectivity of an ideally flat silicon/water interface and shifted vertically for better visibility.E lectron density profiles were determined by afitting procedure to the experimental data. Fitting our curves with ar ecently introduced new model for the Si/SiO 2 interface [30] led to the same results for the gap region (not shown). Fitting our curves with ar ecently introduced new model for the Si/SiO 2 interface [30] led to the same results for the gap region (not shown).…”