| 摘要 |
<p>A method for manufacturing a NAND flash memory device is provided to prevent a top portion of a first polysilicon layer from being damaged by delaying an exposing time of the top portion in a PE nitride etching process. Some portions of a tunnel oxide layer(102), a first polysilicon layer(104), and a semiconductor substrate(100) are etched to form trenches. The trenches are buried with an insulating layer to form isolation layers(106). A portion of top surfaces of the isolation layers is removed to control an effective field height of the isolation layers while partially exposing sides of the first polysilicon layer. A buffer oxide layer is formed on the entire surface of the substrate, and then a PE(Plasma Enhanced) nitride layer is formed on the entire surface. The substrate is etched to form the buffer oxide layer and spacers on the sides of the first polysilicon layer, and then the isolation layer is recessed to a portion under the tunnel oxide layer. After the spacers and the buffer oxide layer are removed, a dielectric layer(114) and a second polysilicon layer(116) are formed on the entire surface.</p> |
