Damascene process for MOSFET fabrication

摘要

An improved MOSFET transistor is disclosed having a high dielectric constant gate dielectric and a metal gate electrode. With such a procedure, the known problems with polysilicon gate electrodes on very thin gate oxide transistors are greatly improved, resulting in improved gate threshold voltage control and improved transistor electrical properties, without loss of the benefit of self aligned source and drain electrodes available with polysilicon gates. Dual metal gate electrodes are also disclosed and exhibit improved CMOS transistor function compared to polysilicon gates, resulting in better and more controlled transistor properties. Thus the metal Damascene gate process results in faster and more consistent MOS and CMOS transistors and improved IC fabrication.