Patent ID: 7468302

Claim:
A method of forming a trench type isolation film of a semiconductor device, the method comprising: sequentially forming a pad oxide film and a nitride film for a hard mask on a semiconductor substrate in which a cell region and a peri region are defined; patterning the nitride film in the cell region using an etch process employing a cell array mask, thereby forming a patterned nitride film; coating a photoresist on the entire structure including the patterned nitride film of the cell region; patterning the photoresist in the peri region using a peri ISO mask, thereby forming a patterned photoresist; sequentially etching the nitride film, the pad oxide film, and the semiconductor substrate of the peri region using the patterned photoresist covering the entire cell region as an etch mask, thereby forming first trenches in the peri region; stripping the photoresist; etching the semiconductor substrate of the cell region and the peri region using the patterned nitride film as an etch mask, thereby forming second trenches in the cell region, the second trenches having a vertical profile within the semiconductor substrate, and third trenches, which are consecutive to the first trenches, in the peri region, the third trenches having a vertical profile and a sloped bottom within the semiconductor substrate; and forming an isolation film within the second and third trenches.