| abstract |
In particular, very thin aluminum oxide and lanthanide layers formed by an atomic layer deposition (ALD) type process serve as an interfacial layer between two or more materials. This interface layer can prevent oxidation of the substrate and can prevent diffusion of molecules between these materials. In the illustrated embodiment, a high dielectric constant dielectric material is sandwiched between two layers of aluminum oxide or lanthanide oxide when forming a transistor gate dielectric or memory cell dielectric. Aluminum oxide is less than one complete monolayer and can act as a nucleation layer. One or more single layers can also act as a diffusion barrier, protecting the substrate from oxidation and the high dielectric constant dielectric from impurity diffusion. The nanolaminate is formed by a number of alternating interface layers and high dielectric layers, and the intermediate interface layer can divide the crystal structure of the high dielectric constant material and reduce the level of leakage. |