Integrated process for fabrication of graded composite dielectric material layers for semiconductor devices

A method of fabricating a semiconductor device, comprising:

• providing a semiconductor substrate;
• and
• depositing by CVD over the semiconductor substrate a composite dielectric material layer comprising elements of at least one high-K dielectric material and at least one standard-K dielectric material, and having a concentration gradient of the first dielectric material relative to the second dielectric material in a thickness direction of the composite dielectric material layer,
• wherein the high-K dielectric material comprises at least one of hafnium oxide (HfO2), zirconium oxide (ZrO2), tantalum oxide (Ta2O5), barium titanate (BaTiO3), titanium dioxide (TiO2), cerium oxide (CeO2), lanthanum oxide (La2O3), lanthanum aluminum oxide (LaAlO3), lead titanate (PbTiO3), strontium titanate (SrTiO3), lead zirconate (PbZrO3), tungsten oxide (WO3), yttrium oxide (Y2O3), bismuth silicon oxide (Bi4Si2O12), barium strontium titanate (BST) (Ba1−xSrxTiO3), PMN (PbMgxNb1−xO3), PZT (PbZrxTi1−xO3), PZN (PbZnxNb1−xO3) and PST (PbScxTa1−xO3),
• the standard-K dielectric material comprises one or more of silicon dioxide, silicon oxynitride, silicon nitride, silicon-rich silicon nitride and aluminum oxide,
• the step of depositing comprises providing a high-K precursor at a first rate and a standard-K precursor at a second rate and varying at least one of the first rate or the second rate and depositing simultaneously at least a portion of the at least two dielectric materials, and
• the composite dielectric material layer comprises a metal silicate, a metal aluminate or a mixture of a metal silicate and a metal aluminate.