Grown-in defects in nitrogen doped Czochralski silicon (Cz-Si) crystals were studied. It was found that oxygen precipitates with volume density about 109/cm3 are formed in as grown crystals. Some voids were also found in the crystals which were pulled under high V/G (the ratio of pulling rate to thermal gradient along pull direction in crystals during crystal growth) condition. The morphology of the voids seems to be a set of tetrahedrons, which is different from that of voids in Cz-Si crystals without nitrogen doping. The annealed wafers made from nitrogen doped Cz-Si crystals showed good oxide integrity and has no COPs (Crystal Originated Particles defects) at the surface. In the bulk, on the other hand, much oxygen precipitates were found with the density of about 109/cm3. These oxygen precipitates are considered to be made from the grown-in oxygen precipitates in the nitrogen doped crystals. To investigate the growth behavior of the grown-in defects, a set of isochronal annealing experiments was carried out and it was found that the grown-in oxygen precipitates grow by oxygen diffusion limited process.
|Number of pages
|Solid State Phenomena
|Published - 1999
|Proceedings of the 1999 8th International Autumn Meeting on Gettering and Defect Engineering in Semiconductor Technology (GADEST '99) - Hoor, Swed
Duration: 1999 Sept 25 → 1999 Sept 28