Preparation of composite high-K/standard-K dielectrics for semiconductor devices

A method of fabricating a semiconductor device having a composite dielectric layer, comprising:

• providing a semiconductor substrate;
• depositing on the semiconductor substrate alternating sub-layers comprising a first dielectric material and a second dielectric material to form a layered dielectric structure having at least two sub-layers of at least one of the first dielectric material and the second dielectric material,
• wherein one of the first dielectric material and the second dielectric material is a high-K dielectric material and an other of the first dielectric material and the second dielectric material is a standard-K dielectric material comprising aluminum oxide and at least one of silicon dioxide, silicon oxynitride, silicon nitride, and silicon-rich silicon nitride;
• and
• annealing the layered dielectric structure at an elevated temperature to form a composite dielectric layer comprising a reaction product of the first dielectric material and the second dielectric material.

A method of fabricating a semiconductor device having a composite dielectric layer, comprising:

• providing a semiconductor substrate;
• depositing on the semiconductor substrate alternating sub-layers comprising a first dielectric material and a second dielectric material to form a layered dielectric structure having at least two sub-layers of at least one of the first dielectric material and the second dielectric material,
• wherein one of the first dielectric material and the second dielectric material is a high-K dielectric material and an other of the first dielectric material and the second dielectric material is a standard-K dielectric material comprising aluminum oxide;
• and
• annealing the layered dielectric structure at an elevated temperature to form a composite dielectric layer comprising a reaction product of the first dielectric material and the second dielectric material, wherein the reaction product comprises a high-K derived metal atom, an aluminum atom and an oxygen atom.