Recent developments in heterojunction devices in silicon have allowed impressive accomplishments in the commercial realization of, for example, SiGe/Si integrated circuits for ultra-high-speed and wireless telecommunications markets. These developments continue to be supported by contributions from the materials science, device physics and process technology communities. Furthermore, exploratory work in novel materials such as SiGeC and SiC alloys for exotic quantum mechanical devices, optoelectronic devices, and micromachining applications is gathering momentum. Record-high mobilities and novel micromechanical and photonic architectures demonstrate new potential for these materials to follow the path toward commercialization. This volume captures the excitement of this rapid progress by focusing on the materials issues in the evolution toward manufacturing -- materials design and laboratory demonstration through prototyping to production. Practitioners of many forms of epitaxy come together here with specialists in integrated circuit design and processing. In addition, both theoretical and experimental approaches to heterostructure design are reviewed with recent advances in materials characterization and processing.