DRAM having a guard ring and process of fabricating the same

摘要

A DRAM having a guard ring comprises a semiconductor substrate having a memory array area and a guard ring area; a first trench disposed on said memory array area; a second trench disposed on said guard ring area; a first doped strap disposed on the upper surface of said semiconductor substrate around said first trench; a second doped strap disposed on the upper surface of said semiconductor substrate around said second trench. Furthermore, the DRAM comprises a first doped plate disposed on said semiconductor substrate around the bottom of said first trench, and is separated from said first doped strap by a predetermined distance; and a second doped plate disposed on said semiconductor substrate around the bottom of said second trench, and is connected to said second doped strap.