SEMICONDUCTOR DEVICE AND METHOD FOR FORMING THE SAME

摘要

A method for forming a semiconductor device is provided. The semiconductor device includes a PMOS device and the steps of forming the PMOS device comprise: forming a gate stack structure which includes a gate dielectric layer (120), a gate and sidewalls (144), wherein the gate dielectric layer (120) is formed on a semiconductor substrate (100), the gate is formed on the gate dielectric layer (120), and the sidewalls (144) are around the gate and the gate dielectric layer (120) or around the gate and covering the gate dielectric layer (120); removing the sidewalls(144) to form a cavity(182); filling the cavity(182) with an auxiliary layer(184) which has a first compressive stress. A semiconductor device formed with the method is also provided. It helps to improve the performance of the device.