Patent ID: 7393750

Claim:
A method comprising: forming a trench having a prescribed depth in a semiconductor substrate to establish a protruding active region; forming an isolation layer in the trench; removing a first prescribed portion of the isolation layer from the trench through etching, leaving a first horizontal portion of the isolation layer and side portions of the isolation layer adjacent to and contacting sides of the active region and having a side wall shape; removing a second prescribed portion of the isolation layer from the first horizontal portion and side portions to form a curved surface sloping from the first horizontal portion to the sides of the active region, such that the active region protrudes from the semiconductor substrate and has an isolation layer formed at sides thereof; sequentially forming a first and a second insulating layer on the semiconductor substrate, before defining the active region and the isolation region; forming a first and a second insulating layer pattern by selectively removing the first and the second insulating layer to expose the isolation region of the semiconductor substrate; and forming the trench having the prescribed depth by selectively removing the semiconductor substrate by using the first and the second insulating layer pattern as a mask; and removing the first and the second insulating layer pattern and removing a prescribed thickness of the isolation layer from the horizontal portion to form the protruding active region of the semiconductor substrate.