FLASH MEMORY DEVICE AND METHOD FOR FABRICATING THE SAME

摘要

A flash memory device and its manufacturing method are provided to secure high coupling ratio and to improve reliability of the flash memory device by laminating an oxide layer and a ZAZ(ZrO2/Al2O3/ZrO2) layer to form a gate dielectric between a floating gate and a control gate. A tunnel dielectric and a conductive layer for a floating gate are formed on a semiconductor substrate(10). The conductive layer for the floating gate has a thickness of 500 to 2000 Å. A first oxide layer(13) and a ZAZ(ZrO2/Al2O3/ZrO2) layer(14) are formed on the conductive layer for the floating gate. Thermal treatment is performed on the resultant structure. A second oxide layer(15) is formed on the ZAZ layer to form a gate dielectric that is comprised of the ZAZ layer and the second oxide layer. A conductive layer for a control gate is formed on the gate dielectric.