SEMICONDUCTOR DEVICE HAVING A SHALLOW TRENCH ISOLATION STRUCTURE AND A METHOD FOR FABRICATING THE SAME

摘要

A semiconductor device having a shallow trench isolation structure, where the upper part of the trench is broader than the lower part of it, comprises an insulating layer on the sidewalls of the upper part of the trench, another insulating layer buried in the trench for isolating semiconductor devices and low-concentration doped regions near the upper part of the trench and high-concentration doped regions near the lower part of the trench. Therefore, the leakage current is prevented due to the sufficient amount of the ions in the high-concentration doped regions near the lower part of the trench and the narrow width effect is minimized owing to the insulating layer on the sidewalls of the upper part of the trench.