METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

A method for fabricating a semiconductor device is provided to improve mobility of hole carriers in a channel region of a PMOS transistor by causing compressive strain in the channel region of the PMOS transistor. A substrate(11) is prepared in which an NMOS region and a PMOS region are defined. A pad oxide layer(12) and a pad nitride layer(13) are sequentially deposited on the substrate. The pad nitride layer, the pad oxide layer and the substrate are etched to form a trench. A wall oxide layer(15) is formed on the inner surface of the trench. A liner nitride layer(16) is deposited along the step of the upper surface of the resultant structure. The liner nitride layer deposited in the PMOS region is selectively removed. An isolation layer is formed to bury the trench. The process for forming the isolation layer includes the following steps. An isolating insulation layer is deposited to fill the trench. The isolating insulation layer is planarized.