SEMICONDUCTOR DEVICE HAVING SHALLOW TRENCH ISOLATION STRUCTURE AND METHOD OF MANUFACTURING THE SAME

摘要

A semiconductor device having an STI structure and a manufacturing method thereof are provided to effectively suppress an HEIP and an area of an active region while providing stable device isolation characteristics. A semiconductor substrate(100) includes an upper trench(110) and a lower trench(120). The upper trench defines an active region. The lower trench is formed at a lower portion of the upper trench to communicate with the upper trench. A device isolation film(150) is formed in the upper trench and the lower trench of the semiconductor substrate. The device isolation film includes a first insulation film, a second insulation film, and a third insulation film. The first insulation film is formed in the upper trench and covers an inner wall of the upper trench in a spacer form. The second insulation film is buried in the upper trench. The third insulation film covers an inner sidewall of the lower trench.