Today, the main challenge in Si crystal growth development is
the transition from 200 to 300 mm diameter. While the complexity of the
growth process increases with larger charge size and crystal diameter, the
perfection of the growth process must significantly improve to avoid any
disturbances that result in structure loss during growth and, hence, cause massive
material losses. With regard to the future bulk quality, radical changes may be
required as the design rule approaches the size of the prevailing grown-in
defect type. Therefore, grown-in defect free wafers will be required, which can
be produced either directly by pulling, by wafer annealing or by epitaxy. As
substrates for annealed and epitaxial wafers, nitrogen doped and fast pulled
crystals provide sufficient internal gettering capability in low thermal budget
device processes. Moreover, grown-in defects in nitrogen doped crystals are so
small that they are easily covered during epitaxy or annealed during high
temperature treatment.
Source:
Journal of Crystal Growth
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