Field oxidation by implanted oxygen (FIMOX)

摘要

A method of forming a field oxide isolation region is described, in which a masking layer is formed over a silicon substrate. The masking layer is patterned to form an opening for the field oxide isolation region, whereby the remainder of the masking layer forms an implant mask. A conductivity-imparting dopant is implanted through the opening into the silicon substrate. Oxygen is implanted through the opening into the silicon substrate in multiple implantation steps. The implant mask is removed. The field oxide isolation region is formed in and on the silicon substrate, by annealing in a non-oxygen ambient. Alternately, the field oxide isolation region is formed by annealing in oxygen, simultaneously forming a gate oxide in the region between the field oxide isolation regions.