Arsenic implantation to oxide filled trench isolation structure

We have studied crystal defects of devices with oxide filled trench isolation introduced by high dose (∼1015 cm−2) arsenic implantation at 40–80 keV and the dependence of their growth on oxidation conditions. Cross-sectional views of the devices are observed by transmission electron microscopy. Solid phase epitaxial regrowth becomes very slow at the edge of the silicon island. Oxidation of the silicon substrate is influenced by the stress generated in the oxide filled trench structure. Defect density after oxidation (1) is higher for pyrogenic H2+O2 oxidation than for dry oxidation, (2) is lower at the edge than in the central region of the silicon island, and (3) decreases significantly for a low energy arsenic implantation (40 keV).