| 摘要 |
<p>A method for manufacturing a flash memory device is provided to prevent etch residues of a first polysilicon layer as a floating gate by forming both sidewalls of an isolation layer to have vertical profile. A substrate(30) having a first polysilicon layer(32) as a floating gate is prepared. By etching the first polysilicon layer using O2 gas, a first trench is formed to have sidewalls of vertical profile. A second trench is formed by etching the exposed substrate. An isolation layer is then formed in the first and the second trenches. A second polysilicon layer, a dielectric film and a control gate are sequentially formed on the resultant structure.</p> |
