IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Semiconductors Tuesday Sessions
       Session SC-TuA

Invited Paper SC-TuA7
Heteroepitaxy of Highly Mismatched Systems and the Role of Coincidence Lattice

Tuesday, October 30, 2001, 4:00 pm, Room 124

Session: Semiconductor Heterojunctions
Presenter: K.H. Ploog, Paul Drude Institute for Solid State Electronics, Germany
Correspondent: Click to Email
While till mid 1980 a good lattice match of substrate and constituent layers in most semiconductor heterostructures was considered to be mandatory for successful device operation, this constraint has since become more relaxed. Today not only semiconductor materials with considerable lattice mismatch are explored in devices, but also heterostructures combining materials very dissimilar in structure, bonding, and chemical properties play an ever increasing role in the development of novel device concepts. In the heteroepitaxy of such highly mismatched systems, the existence of a "coincidence" lattice at the interface often leads to a unique epitaxial alignment and misfit accommodation in the early stages of epitaxy. This structural coincidence between the adjacent lattices helps to generate a low-energy interface. Using functional selforganized molecular beam epitaxy (MBE), even the epitaxy of metastable phases (like cubic GaN-on-GaAs), of M-plane oriented GaN[GaN(1-100) on g-LiAlO2(100)], and of layers with a symmetry different from the substrate (like hexagonal MnAs on cubic GaAs) can be obtained and the resulting nanostructures at the respective interface can be controlled in a reproducible manner. The M-plane group-III nitride heterostructures are of great importance for highly efficient blue/UV light emitters, and ferromagnetic MnAs on GaAs heterostructures are paving the way to spin-electronics operating at room temperature.