METHOD FOR FORMING ISOLATION AREA OF SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE THEREBY

摘要

A method for forming an isolation region of a semiconductor device and the semiconductor device thereby are provided to restrain the generation of defects such as voids or moats without the degradation of the isolation region. A mask pattern is formed on a semiconductor substrate(200). First and second trenches(231,232) are formed on the resultant structure by etching selectively the substrate using the mask pattern as an etch mask. The first and the second trench are filled with a nitride layer. A nitride pattern(240') is formed by etching selectively the nitride layer. A third trench(233) is formed between the first and the second trenche by etching the substrate using the nitride pattern as an etch mask. An oxidation is performed on the resultant structure to fill a predetermined portion between the first and the second trenches with oxide. Then, the nitride pattern is removed therefrom.