FLASH MEMORY AND THE MANUFACTURING PROCESS THEREOF

摘要

A flash memory and its manufacturing method are provided to program in a low voltage range by improving the capacitance between a floating gate and a control gate using a convexo-concave portion of the floating gate. A gate oxide layer(2) is formed on a semiconductor substrate(1). A first polysilicon layer is deposited on the gate oxide layer. A floating gate(3) with a convexo-concave portion is formed on the resultant structure by patterning selectively the first polysilicon layer using a slit mask as an etch mask. A dielectric film(4) is formed on the resultant structure. A second polysilicon layer is formed thereon. A control gate(5) is formed on the dielectric film by patterning selectively the second polysilicon layer.