Double gate oxide layer method of manufacture

摘要

A method of manufacturing a double gate oxide layer. A substrate has trenches that divide the substrate into a memory circuit region and a logic circuit region. A dielectric layer is formed on the substrate to fill the trenches. The dielectric layer of the logic region is removed, thereby exposing the substrate. An ion implantation step is performed on the substrate of the logic circuit region using a reverse tone mask. A conformal barrier layer is formed over the substrate. A spin-on layer is formed over the barrier layer. A chemical mechanical polishing step is performed to remove the in-on layer, the barrier layer, and dielectric layer outside the trenches, thereby exposing the substrate. A thermal oxidation step is performed to form a double gate oxide layer that is thicker in the logic circuit region than it is in the memory circuit region.