METHOD FOR FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE

摘要

A method for forming an isolation layer in a semiconductor device is provided to prevent degradation of devices due to seams by forming a groove on a gap-filled trench having a relatively narrow width. A substrate(21) having a first trench(T1) and a second trench(T2) with a relatively wide width is prepared. A first gap-fill insulating layer(22) is filled in the first trench having a relatively narrow width. A groove(23) is formed on the upper of the first trench by selectively removing the first gap-fill insulating layer. Then, a second gap-fill insulating layer(24) is deposited on the resultant structure including the groove of the first trench so as to entirely fill the second trench. The second gap-fill insulating layer is polished by CMP.