METHOD FOR IMPROVED PLASMA NITRIDATION OF ULTRA THIN GATE DIELECTRIC

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a gate dielectric for an integrated circuit device. SOLUTION: An initial oxynitride layer having an initial physical thickness is formed on a substrate. Then a plasma nitride forming treatment is applied for the initial oxynitride layer, and the final oxynitride layer having the final physical thickness is formed. In a first embodiment, the final physical thickness is less than 20Åexceeding the initial physical thickness by less than 5Å. Eventually, the nitrogen concentration in the final oxynitride layer is 2.0×10<15> atoms/cm<2> or more. In a first embodiment, the initial oxynitride layer is formed on the substrate by ion implantation of nitrogen atoms. After implantation of nitrogen atoms, the substrate is heated. In an alternative embodiment, the initial oxynitride layer is formed on the substrate by a rapid heat oxynitride deposition.