METHOD FOR MANUFACTURING NONVOLATILE SEMICONDUCTOR MEMORY WITH NARROW VARIATION IN THRESHOLD VOLTAGES OF MEMORY CELLS

摘要

PURPOSE: To provide a manufacturing method of a non-volatile semiconductor memory capable of solving various problems such as gate disturb by suppressing fluctuation of threshold voltage. CONSTITUTION: Each material of a floating gate 3, a first insulation film 7 and a control gate 8 is formed on a tunnel oxidation film 2 in a laminated state. The control gate 8, the first insulation film 7 and the floating gate 3 are processed in the form of stripes. Then, isotropic etching is performed, and a part 2d corresponding directly under the side wall of the floating gate 3 of the tunnel oxidation film 2 is removed. A second insulation film 10 is piled to cover the control gate 8, the first insulation film 7, the floating gate 3 and the side wall of the tunnel oxidation film 2 by the second insulation film 10.