Dislocation behavior near the seeding interface in <110>-oriented CZ-Si single crystals

The behavior of dislocations due to thermal shock and lattice misfit in <110>-oriented Czochralski (CZ) Si crystals, in which the {111} slip plane is parallel to the growth direction, was investigated. The B concentration in the seed and grown crystal was varied from undoped to 3x1019 atoms/cm3, and the cross-sections of the grown crystals were examined by X-ray topography. Increasing the B concentration in the seed reduced the density of dislocations due to thermal shock. These were completely suppressed at a B concentration of 1.5x1019 atoms/cm3 in the seed crystal. Furthermore, by matching the B concentration in the grown crystal to that in the seed, dislocations due to lattice misfit could also be effectively suppressed. Consequently, it was revealed that dislocation-free <110>-oriented CZ-Si crystals as well as < 100 >-oriented CZ-Si crystals can be grown without the Dash-necking process.