| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory device having an element isolation structure which can improve its electrical isolating property, and also to provide a method for manufacturing the device. SOLUTION: The semiconductor integrated circuit device of an element isolation structure has a semiconductor substrate 1. The substrate has a groove 8b in a region to be later formed as an element isolation region on a diffusion layer 11. The groove is buried with an insulating film 12. In the manufacturing method, a groove is self-alignedly made in the semiconductor substrate with use of a first insulating film formed on a diffusion layer of the semiconductor substrate and a second insulating film 10 formed on an uppermost layer of a gate electrode 9 as masks, and a third insulating film is buried in the groove to thereby forming an element isolation structure. |
