Silicon Atomic Quantum Dots Enable Beyond-CMOS Electronics

We review our recent efforts in building atom-scale quantum-dot cellular automata circuits on a silicon surface. Our building block consists of silicon dangling bond on a H-Si(001) surface, which has been shown to act as a quantum dot. First the fabrication, experimental imaging, and charging character of the dangling bond are discussed. We then show how precise assemblies of such dots can be created to form artificial molecules. Such complex structures can be used as systems with custom optical properties, circuit elements for quantum-dot cellular automata, and quantum computing. Considerations on macro-to-atom connections are discussed.Comment: 28 pages, 19 figure

Étude de la modification par illumination de la structure du silicium amorphe hydrogéné

Le silicium amorphe hydrogéné -- Processus physiques durant le dépôt -- Cellules photovoltaïques -- L'effet staebler-Wronski -- Résumé des théories sur l'effet SW -- Lumière pulsée -- La spectroscopie photoacoustique -- Théorie Rosencwaig-Gersho -- Spectroscopie à transformée de Fourier -- L'absorption infrarouge du A-Si:H -- Simulation du signal photoacoustique -- Méthode de mesure photoacoustique -- Résultats expérimentaux en photoacoustique -- Déconvolution du spectre PA pour matériau bot-wire -- Déconvolution du spectre PA pour matériau hot-wire -- Déconvolution du spectre PA pour matériau glow-discharge -- Évolution du spectre IR sous illumination, matériau hot-wire -- Évolution du spectre IR sous illumination, matériau glow-discharge -- Comparaison au calcul analytique -- Amélioration possibles des mesures photoacoustiques -- Mesures des énergies d'activation de conductivité du A-S:H -- Nanocalorimétrie

Self-directed growth of contiguous perpendicular molecular lines on H-Si(100) surfaces

Future nanoscale integrated circuits will require the realization of interconnections using molecular-scale nanostructures; a practical fabrication scheme would need to be largely self-assembling and operate on a large number of like structures in parallel. The self-directed growth of organic molecules on hydrogen-terminated silicon(100) [H 12Si(100)] offers a simple method of realizing one-dimensional molecular lines. In this work, we introduce the ability to change the growth direction and form more complex, contiguous shapes. Numerous styrene and trimethylene sulfide L shapes were grown on a H 12Si(100)-3 71 surface in parallel with no intermediate surface lithography steps, and similar shapes were also grown using allyl mercaptan and benzaldehyde on H 12Si(100)-2 71. Registered scanning tunneling microscopy (STM) images and high-resolution electron energy loss spectroscopy (HREELS) were used to investigate the growth process.Peer reviewed: YesNRC publication: Ye

Scanning tunneling microscopy and computational study of the self-directed growth of 1,3-butadiene and 2,3-dimethyl-1,3-butadiene on hydrogen-terminated silicon(1 0 0)-2 7 1

Peer reviewed: YesNRC publication: Ye

Indications of field-directing and self-templating effects on the formation of organic lines on silicon

It has previously been shown that multimolecular organic nanostructures form on H-Si(100)-21 via a radical mediated growth process. In this mechanism, growth begins through the addition of a molecule to a silicon surface dangling bond, followed by the abstraction of a neighboring H atom and generation of a new dangling bond on the neighboring site. Nanostructures formed by this mechanism grow along one edge of a dimer row. Here, we explored the possibility of using lithographically prepared, biased metal contacts on the silicon surface to generate an electric field that orients molecules during the growth process to achieve growth in the perpendicular-to-row direction. The formation of some nanostructures in a direction that was nearly perpendicular to the dimer rows was achieved, whereas such features were not formed in the absence of the field. Analysis of the scanning tunneling microscopy images suggests that the formation of these nanostructures may involve self-templating effects in addition to dangling bond diffusion rather than a straightforward additionabstraction mechanism. These initial results offer some indication that a molecular pattern writer can be achieved. \ua9 2011 American Institute of Physics.Peer reviewed: YesNRC publication: Ye