Asymmetric tilt boundaries and generalized heteroepitaxy

Abstract

In conventional heteroepitaxy, lattice mismatch is accommodated through biaxial strain and interfacial misfit dislocations. In studies of the heterophase boundaries appearing in semicoherent \ensuremath{\alpha}-${\mathrm{Si}}_{3}$${\mathrm{N}}_{4}$ precipitates grown in situ in a silicon matrix, we have found that part of the lattice mismatch can be accommodated by formation of low-energy asymmetric tilt boundaries, which accommodate the lattice mismatch without producing a long-range stress field. This result suggests that growth of misfit-dislocation--free lattice-mismatched tilted structures should be possible.