Method of making dynamic random access memory cell having a SDHT structure

摘要

A SDHT structured DRAM Cell with a P type silicon substrate and a P well region with a first trench formed into the P well region and a CVD oxide film layer formed on the wall of the first trench is disclosed. A second trench is formed in the bottom of the first trench. A capacitive oxide film layer is formed on the CVD oxide film layer of the first trench and on the second trench with a conducting material filling the trenches to form an inside charge storage electrode. A N MOSFET is formed on the P well region near the first trench with the N MOSFET having a soure N+ region and a drain N+ region, each including a LDD region.