| 摘要 |
PURPOSE:To remove residue on the formation of a second polysilicon layer by forming a field insulating film and a first gate oxide film, forming a thin silicon nitride film on approximately the whole surface and depositing a first polysilicon layer on the silicon nitride film. CONSTITUTION:A field insulating film 2 consisting of silicon oxide and a first gate oxide film are shaped on a P type silicon semiconductor substrate, and a thin silicon nitride film 6 is formed on approximately the whole surface through the thermal nitriding of the oxide film. A first polysilicon layer as a floating gate is deposited on the film 6, and removed through etching. The surface of the first polysilicon layer is oxidized to shape second gate oxide films 4, 4D. Excess second gate oxide film 4D and the first polysilicon layer FG3D are removed by using wet etching, etc. A floating gate FG3 and a control gate CG3 are formed, an N type impurity is introduced to source-drain regions, and an inter-layer insulating film 8, a data line Dm and a final passivation 9 are shaped, thus completing an element. |
