Abstract: The invention provides a process of utilizing CF4 plasma pretreatment to improve high-k dielectric materials. The process is performed by the standard complimentary metal-oxide-semiconductor field enhanced transistor (CMOSFET) in accordance with the high-k dielectric materials, in which CF4 plasma generated by plasma enhanced chemical vapor deposition (PECVD) is used to perform pretreatment on the silicon substrate, and a large amount of fluorine will be incorporated on the surface of silicon substrate. Then, a gate dielectric layer is deposited on the surface of silicon substrate, and a thermal annealing in an oxygen ambience is performed. At this time, the silicon substrate incorporating with fluorine will not respond to the high-k dielectric materials to form silicate; therefore, the property of silicon substrate can be improved. The advantages of high-k dielectric materials formed by the process include low leakage current, high breakdown voltage, and good reliability.