METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to prevent the reliability of an insulation layer from being reduced by a phenomenon that a gate insulation layer becomes thin in an interface between an active region and an isolation region by depositing a nitride layer and by performing an annealing process on an oxynitride layer. CONSTITUTION: The first oxide layer and a nitride layer are formed on a semiconductor substrate(10) having the first region and the second region. A high voltage device is formed in the first region, and a low voltage device is formed in the second region. The second region is opened, and a photoresist layer pattern for shielding the first region is formed. An etch process using the photoresist layer pattern as an etch mask is performed to selectively remove the nitride layer and the first oxide layer on the second region. The photoresist layer pattern is stripped. An oxynitride layer(20) and the second oxide layer are formed on the second region so that the first gate insulation layer composed of the first oxide layer and the nitride layer is formed in the first region and the second gate insulation layer composed of the oxynitride layer and the second oxide layer is formed in the second region.