| 摘要 |
<p>A method for forming an isolation layer of a flash memory device is provided to improve the interference margin and to minimize the deformation of EFH(Effective Field oxide Height) by automatically forming a spacer at sidewalls of a conductive layer. A substrate(10) including a tunnel oxide layer(11), a conductive layer and a pad nitride layer is prepared. A trench is formed by etching the pad nitride layer, the conductive layer, the tunnel oxide layer and the substrate. A sidewall protecting layer(19) is formed at both sidewalls of the conductive layer. By forming an SOD(Spin On Dielectric) layer(20A) in the spacer and planarizing, a field oxide layer(20B) is formed in the trench. By removing the pad nitride layer, the spacer is protruded on the conductive layer. The effective height of the field oxide layer is controlled by etching the SOD layer using dry-etching to expose the spacer. Further, the SOD layer is PSZ layer.</p> |
