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A technique is presented for measuring the density of interface traps versus energy DIT(E) using the Hall effect in metal-oxide-semiconductor samples. Good agreement is obtained between this Hall approach and standard C–V techniques in both SiC and silicon test devices. DIT(E) is found to be much higher in 4H–SiC compared to 6H devices oxidized at the same time. DIT(E) in both SiC poly types increases exponentially with energy approaching the conduction bandedge.

A model to treat Ge segregation with simultaneous growth and exchange during Si/SiGe layer growth by molecular beam epitaxy is described. Within this three layer formalism, the segregating layers were treated in two limiting cases, a solid surface model in which no surface diffusion occurs, and a fluid surface model, in which surface diffusion is very fast. Simultaneous treatment of exchange and growth within the fluid surface model was the only one of the two that allowed the accumulation of Ge in the top two layers to significantly exceed that of the bulk in surface alloys, in agreement with experimental observations.

We formulate and discuss principles for designing computationally useful networks of Coulomb-blockade devices. Our particular focus is on locally interconnected synchronous networks in which the numerical discreteness of a computation is represented directly by the quantization of electron charge, i.e., electrons represent bits. To highlight our emphasis on circuits and architectural issues, and on performing locally interconnected computation rather than traditional logic as has been the interest heretofore (single-electron logic), we refer to our networks as single-electron digital circuits (SEDCs). In addition to being single-electron and locally interconnected, the SEDCs we propose have a regular ‘‘cellular’’ structure with occupancy-independent biasings and with electron-electron interactions carefully controlled. The chief virtue of SEDCs is their scalability, both as devices (because of their Coulomb blockade basis) and as circuits (because of their local interconnectivity), perhaps even to molecular dimensions. We illustrate our approach with a number of new ‘‘device’’ and network designs based on electron-pump-like structures and mostly directed at performing lattice-gas simulation. For this application we effectively create an electron gas within a SEDC which precisely mimics the lattice gas. Finally, we have validated our designs using numerical simulation and expect that at least some of them should be realizable in current technology. However, their promise of enormous levels of integration and performance should be tempered with a clear awareness of the many obstacles associated with fabrication and economics which must be overcome if they are ever to be the foundation for a practical computer technology.