BeTe/Si heterostructures for MIS and quantum device applications

The fabrication of silicon-based quantum devices and advanced buried-gate MIS transistors and circuits may require the development of an epitaxial insulating material that is lattice matched to silicon and also bonds with it to minimize interface states. We report the results of a search for new materials based on earlier partial successes with ZnS/Si. This work has identified beryllium chalcogenides as candidates with high stacking-fault energies for defect suppression. Initial growth and characterization experiments on BeTe/Si, a lattice mismatched system, bear out the theoretical predictions, and result in high-quality insulating films with >1 MV cm-1 breakdown fields. These experiments strongly suggest that lattice-matched BeSe0.45Te0.55 will be an even more suitable material.