GRAIN-BOUNDARY STRUCTURE AND SEGREGATION IN DIRECT-BONDED SILICON BICRYSTAL

In order to examine the effect of bonding methods on the properties of bonded interface in silicon, bicrystals with (($) over bar 112)Sigma 3 coincidence boundaries were prepared by direct-bonding and hot-press bonding. Boundary structures and sepregation in the bicrystals were studied by HRTEM and EDS. Main results are as follows. (1) A small amount of oxygen segregation and oxide particles were observed along the boundaries in the hot-press bonded bicrystals, whereas neither segregation nor oxide formation were observed in the directly bonded ones. (2) For the direct-bonded bicrystals, the HRTEM observation revealed two kinds of periodic structures, possibly of periodic dislocation arrays, along the boundary. They were successfully described by the geometric models based on the coincidence and O-lattice theories.