| 摘要 |
<p>A method for fabricating a flash memory device is provided to avoid defects generated in a tunnel oxide layer or a dielectric layer by selecting nano crystals and by making the nano crystal contain electrons. A tunnel oxide layer(12), an oxide layer(14) and a first conductive layer are sequentially formed on a semiconductor substrate(10). The first conductive layer is made of polysilicon. First etchant is infiltrated through grains of the first conductive layer to form a plurality of nano crystal points in the oxide layer. The first conductive layer is removed by using second etchant. While the first conductive is removed, the nano crystal point in the oxide layer is eliminated by using the second etchant to form a plurality of nano crystal formation holes in the oxide layer. The plurality of holes are filled with a non-conductive layer to form a plurality of nano crystals(18N) of an isolated type. A dielectric layer(20) and a second conductive layer(22) are sequentially formed on the oxide layer including the plurality of nano crystals. The second conductive layer, the dielectric layer, the oxide layer including the nano crystal, and the tunnel oxide layer are sequentially patterned. The first and the second etchant include HF.</p> |
