ALD dielectric films with leakage-reducing impurity layers

Abstract

A thin sub-layer (<15 Å) of an impurity is formed under, over, or inside a thicker layer (˜30-100 Å) of a high-k (k>12) host material. The sub-layer may be formed by atomic layer deposition (ALD). The layer and sub-layer are annealed to form a composite dielectric layer. The host material crystallizes, but the crystalline lattice and grain boundaries are disrupted near the impurity sub-layer, impeding the migration of electrons. The impurity may be a material with a lower dielectric constant than the high-k material, added in such a small relative amount that the composite dielectric is still high-k. Metal-insulator-metal capacitors may be fabricated by forming the composite dielectric layer between two electrodes.

Dependencies are inferred from the claim text.