Roles of sidewall oxidation in the devices with shallow trench isolation

The effects of sidewall sacrificial and sidewall oxidations on the characte ristics of devices with shallow trench isolation (STI) have been investigat ed. We found that sidewall sacrificial and sidewall oxidations significantl y affected junction leakage and gate oxide integrity (GOI). The sidewall sa crificial oxidation was shown to reduce oxidation-induced stresses and make the trench top corner more rounded. This reduced stress and more rounded t op corner led to much improved junction leakage and GOI. These results clea rly show that the sidewall sacrificial oxidation is worth using, although i t adds complexity to the STI process.