PMOS device and preparation method thereof

The invention provides a PMOS device and a preparation method thereof, the PMOS device comprises a gate structure located on a substrate, a source electrode and a drain electrode, the source electrode and the drain electrode are located in the substrate on the two sides of the gate structure, the gate structure sequentially comprises an interface oxide layer, a gate oxide insulating layer, a work function layer and a silicon material layer from bottom to top, the gate oxide insulating layer is doped with metal ions, and the work function layer is doped with silicon materials. The interface dipole is formed on the interface oxide layer and the gate oxide insulating layer, and the work function can be effectively adjusted through the polarity and the size of the interface dipole, so that the lower threshold voltage is obtained. 本发明提供一种PMOS器件及其制备方法，PMOS器件包括位于衬底上的栅极结构，位于所述栅极结构两侧衬底中的源极和漏极，所述栅极结构由下至上依次包括界面氧化物层、栅氧绝缘层、功函数层和硅材料层，所述栅氧绝缘层中掺杂有金属离子，以在所述界面氧化物层和栅氧绝缘层形成界面偶极子，可以通过界面偶极子的极性和大小来有效调节功函数，以获得较低的阈值电压。