METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE WITH BULB TYPE RECESS GATE

摘要

A method for manufacturing a semiconductor device having a bulb type recess gate is provided to increase a width of a bulb pattern without causing a profile error such as a bowing effect of a neck pattern. A hard mask pattern(21) for recess is formed on a semiconductor substrate(20). A neck pattern of a bulb type recess(22) is formed by performing an anisotropic etch process for the semiconductor substrate. A spacer(23) is formed on a sidewall of the neck pattern. An initial bulb pattern of the bulb type recess is formed by performing an isotropic etch process for the semiconductor substrate corresponding to a lower part of the neck pattern. A surface of the semiconductor substrate of the initial bulb pattern is changed to a thermal oxidation layer(24) by performing a thermal oxidation process. A final bulb pattern having a width wider than the width of the initial bulb pattern is formed by removing the thermal oxidation layer.