| 摘要 |
PROBLEM TO BE SOLVED: To decrease the oxidation stress generated during one manufacturing of a device, by setting the magnitude of the protruding top surface located higher than the main surface of a silicon substrate at the sufficient magnitude for preventing the expansion of a divot formed later under the surface of the substrate. SOLUTION: A DRAM cell has a trench capacitor and an (n)-channel transistor 310. In order to separate the DRAM cell for another DRAM cell or a device, a protruding shallow trench isolation(STI) is provided. The top surface of the protruding STI is located higher than the surface of a silicon substrate. The protruding distance of the top surface higher than the surface of the substrate is effectively sufficient to decrease the formation of the divot under the silicon surface. Thus, corner reduction is suppressed. By protruding the STI surface higher than the substrate surface, the formation of the divot is avoided, and a nitride liner contributing the divot formation can be made unnecessary. |
