METHOD FOR FABRICATING A SEMICONDUCTOR DEVICE

摘要

A method for manufacturing a semiconductor device is provided to improve a yield of the semiconductor device by reducing a block etch ratio of a gate region in a post-process. A first gate oxide layer(103) is formed on a silicon substrate(101) including a high voltage region and a low voltage region. An etch process is performed to remove the first gate oxide layer except for the low voltage region. A second gate oxide layer(104) thicker than the first oxide layer is formed on the front surface of the silicon substrate. A selective etch process is performed to remove the second gate oxide layer except for the high voltage region. A cleaning process is performed to remove foreign materials from the first and second gate oxide layers. A megasonic cleaning process is performed to remove water marks from the first and second gate oxide layers.