DRAM device with embedded flash memory for redundancy and fabrication method thereof

A dynamic random access memory (DRAM) device with an embedded flash memory, comprising:

• a semiconductor substrate having a dynamic random access memory (DRAM) array region and a peripheral region, wherein the peripheral region includes an embedded flash memory forming region and a first transistor forming region;
• a plurality of DRAM memory cells in the DRAM array region;
• a flash memory in the embedded flash memory forming region, wherein the flash memory comprises an oxide-nitride-oxide (ONO) storage structure and a flash memory gate;
• and
• a first transistor in the first transistor forming region, wherein the DRAM memory cells comprise a plurality of buried word lines, a bit line disposed on a contact structure located between the buried word lines, a plurality of storage node contact structures, and a plurality of capacitor structures, wherein the ONO storage structure is made of three stacking layers of silicon oxide, silicon nitride, and silicon oxide.