Structural features of ∑ = 3 and 9, [110] GaAs tilt grain boundaries

The planar density of coincidence sites appears to be high along the observed boundary planes for the ∑ = 3 and 9, [110] GaAs tilt grain boundaries. The polarity in each grain on either side of the tilt grain boundaries has been confirmed by direct or indirect methods. The result indicates that a lower number of anti-site type bonds occur along the boundaries compared to when the polarity of one grain is reversed. Based on high-resolution transmission electron microscopy (HRTEM) analysis of several different symmetric and asymmetric ∑ = 3 and 9, [110] tilt grain boundaries in GaAs, models for the atomic structures of these boundaries have been made for the first time; particular atomic arrangements form the structural units of these boundaries.