METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE HAVING RECESS CHANNEL

摘要

PURPOSE: A method for manufacturing a semiconductor device with a recess channel is provided to improve a refresh property by including a bottom protrusion of a fin structure and a bulb recess trench. CONSTITUTION: An upper trench is formed by etching the exposed part of a semiconductor substrate. A silicon nitride layer is formed on the sidewall of the upper trench as an etching barrier layer to block a sidewall and expose the bottom of the upper trench. A bulb recess trench including the upper trench and the lower trench is formed. A bottom protrusion(165) of a fin structure including an upper surface(155) and a side surface is formed by etching a device isolation layer to have a lower surface than the bottom of the lower trench. A gate stack is overlapped with the bulb recess trench and the bottom protrusion.