Methods of forming semiconductor devices having field oxides in trenches and devices formed thereby

摘要

Semiconductor devices and methods of forming devices that have field oxides in trenches are disclosed. According to the methods, a semiconductor substrate is prepared. An upper trench is formed at a predetermined region of the semiconductor substrate and a bottom trench is formed at a bottom surface of the upper trench. A field oxide is formed to fill the bottom trench and the upper trench. At this time, the upper trench has a wider width than the bottom trench.