Gold—silicon

This system has been extensively investigated by AES, LEED and photoemission over a range of adsorption temperatures. In general, there seems to be reasonable agreement between the various authors [277— 281] on the structure and composition of the interface. 

The precise stoichiometry and orientation relationships of the silicides need not concern us further here, but it is crucially important to be aware of their presence and their influence on surface analytical investigations. Their formation has been carefully studied by AES combined with depth composition profiling [277, 280] and it was shown to be essential to follow the development of the Si peaks due to silicides at 88.5 and 95 eV. It is not sufficient to monitor only the main Au (69.5 eV) and Si(92eV) peaks to assess accurately the surface composition [278, 279], since this does not take account of compound formation. 

The most detailed information of Au—Si room temperature interactions has been obtained by Braicovich et al. [281] for Si lll 2x 1 cleaved surfaces. They used photoemission with synchrotron radiation covering the photon energy range from 10 to 200 eV and studied Au coverages from d = 0.15 monolayer to d — 160 monolayers. We give a brief summary of their results, which not only indicate the degree of complexity of some 

With increasing coverage up to 15 monolayers, emission from Au becomes less atomic-like and more similar to that from bulk material, but at the same time the energy separation between the Au 4f and Si 2p 

---

Inorganic nanoparticles have also attracted interest in the field of drug delivery [73]. These inorganic nanoparticles include calcium phosphate, gold, silicon oxide, and iron oxide. They can be prepared easily with controllable size and can be readily... 

A prerequisite for all etch-stop techniques discussed so far is an electrical connection to an external power supply. However, if the potential required for passivation in alkaline solutions is below 1 V, it can be generated by an internal galvanic cell, for example by a gold-silicon element [As4, Xil]. An internal galvanic cell can also be realized by a p-n junction illuminated in the etchant, as discussed in the next section. Internal cells eliminate the need for external contacts and make this technique suitable for simple batch fabrication. 

J.W. Klement, R.H. WiUens, P. Duwez, Non-crystalline structure in solidified gold-silicon alloys, Nature 187 (1960) 869-870. 

Abstract We review various methods for the photochemical grafting of organic polymers to various substrates including, organic films, membranes, planar gold, silicon wafers, glass, silica gel, silica nanoparticles, and polydimethylsiloxane micro-channels. An emphasis is placed on photoinitiated synthesis of polymer brushes from planar gold and silicon. 

Fig. 15. Typical time development of a passivation profile measured on a gold-silicon Schottky diode by the C-V method during the hydrogenation process (Seager and Anderson, 1988). Ordinate is the net density of fixed negative charge, i.e., B minus H+. Hydrogenation was at constant ion flux, 298 K, and with the gold film held at 3 V positive with respect to the silicon base. The lines are computer-generated fits to the model described in the text.

Aluminum, copper, diamond, gold, silicon Anisotropic etching, isotropic etching... 

K. Shabtai, S. R. Cohen, H. Cohen, and I. Rubinstein, A Composite Gold-Silicon Oxide Surface for Mesoscopic Patterning, J. Phys. Chem. B 107, 5540-5546 (2003). 

External 26 standards Internal d-spacing standards Primary Silicon a-Quartz Gold Silicon CSRM 640b ... 

Okamoto H, Massalski TB (1990) Au-Si (gold-silicon). In Massalski T, Okamoto H, Subramanian P, Kacprzak L (eds) Binary alloy phase diagrams, vol 1. ASM International, Materials Park, pp 428-431... 

These micelles were isolated as a solid material and could be re-suspended in water. No structural changes occurred within several months. On most solid substrates (gold, silicon, mica, hydrophobic polymers) individual micelles retained... 

---