Microstructure of location-controlled grains by mu-Czochralski process was characterized with electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). We confirmed that defects in the location-controlled grain are mainly D twin boundary generating from near the rim of the grain filter, while random grain boundaries hardly exist. Dependence of the population was investigated on process parameters. We found that most of the Sigma 3 twin boundaries have {I 1 11 facet plane, which, in same case, are massed with a nano-meter spacing. Sigma 3 twin boundaries having facet planes {112} and {111}/{115} were also found to exist. (c) 2007 Elsevier B.V. All rights reserved.