Process to make high-K transistor dielectrics

A method of reducing impurities in a high-k dielectric layer, comprising the steps of:

• providing a substrate;
• forming a high-k dielectric layer having impurities therein;
• the high-k dielectric layer being formed by a process that introduces the impurities into the high-k dielectric layer;
• annealing the high-k dielectric layer to reduce the impurities within the high-k dielectric layer, wherein annealing the high-k dielectric layer is performed in an ambient selected from the group consisting of H2, H2/N2, O2/N2, He, and Ar to avoid additional oxidation of the high-k dielectric layer;
• and
• forming a gate layer upon the annealed high-k dielectric layer.