FLASH MEMORY CELL

PROBLEM TO BE SOLVED: To provide a flash memory cell reducing steps in a production process and improving electric characteristics and integration degree of elements. SOLUTION: The flash memory cell is formed by the steps of: forming source regions on a SOI substrate; forming a pair of a first and second channel regions, which are p-type impurity regions, at both sides holding each of the source regions on the SOI substrate; forming a pair of a first and second drain regions, which are n-type impurity regions, at an outside of each of the first and second channel regions; forming element isolation films at the first and second drain regions by a thermal oxidation process; forming ONO films on the first and second channel regions, and the source region; and forming word lines in an etching process using a word line mask after forming a conductive material layer. The ONO film is formed by laminating: a tunnel oxide film, which is a lower oxide film, formed so that both ends thereof are contacted with the first and second channel regions; a nitride film formed on the tunnel oxide film and functioning as a floating gate; and a dielectric film, which is an upper oxide film, on the nitride film, in this order. COPYRIGHT: (C)2008,JPO&INPIT