SMT Optimization of PMOSFET Based on Multi-Deposition and In-Situ N2 Plasma Treatment

The implementation of stress memory technique (SMT) can indeed improve the performance of NMOSFET. However, it results in the degradation of PMOSFET which is attributed to the hydrogen diffusion and loss of boron in the PMOS. Therefore, we gave a new SMT process, in which strained SiN film deposition was performed by several rounds together with in-situ N2 plasma treatment during former rounds, thereby reducing the amount of hydrogen diffused and the loss of boron, to enhance the PMOS performance.