and photonic devices often have a need for heteroepitaxial films. Dislocations are crystallographic defects, or
irregularities, within a crystal structure.
Dislocations in heteroepitaxial films can be caused by strain in lattice
mismatch. A method for reducing or all together terminating the effects of
these dislocations can improve the quality and function of heteroepitaxial
films and their uses.
University of New Mexico researchers have developed a novel
method by which one can terminate dislocations in crystalline films
heteroepitaxially grown on lattice-mismatched substrates and prevent these
dislocations from propagating into subsequently grown films. Threading dislocations in heteroepitaxial
films often propagate to the film surface.
The film etch rate in a chemical etchant is typically more pronounced
where the dislocations terminate than surrounding areas, thus leaving etch
pits. These etch pits can be filled with
a dielectric material to block the dislocations from propagating further. After the etch pits are filled, one can
manipulate the surface chemistry to continue to grow the same film or a
different heteroepitaxial film selectively on top of the exposed film surface
over the dielectric surface. This
selective growth eliminates random nucleation on the dielectric surface and
prevents polycrystallinity in the subsequently grown films.
STC has filed intellectual property on this exciting new technology and is currently exploring commercialization options. If you are interested in information about this or other technologies, please contact Arlene Mirabal at email@example.com or 505-272-7886.