NEW PRECURSORS FOR ATOMIC LAYER DEPOSITION OF METALS

Harvard University, Cambridge MA

Investigators

Abstract

Intellectual Merit Atomic layer deposition (ALD) is a method for constructing thin layers of materials atom by atom, providing exquisitely detailed control over the nano-structure and composition of the layers. In ALD, two reactant vapors are supplied alternately to a surface on which they react to form thin layers. Films with highly uniform thickness and composition and sharp interfaces can be deposited over large areas and even within very narrow holes. However, ALD processes are known for only a few metals. We propose to discover and develop ALD precursors and processes for depositing many metals, including chromium, manganese, tantalum, iron, ruthenium, cobalt, nickel, copper and silver, for which no ALD processes are known. These new precursors will also be tested for ALD of metal compounds of interest in semiconductor microelectronics, such as lanthanum oxide, praseodymium oxide, titanium nitride and tantalum nitride. Broader Impact ALD of metals may form the basis for future devices for both the processing and the storage of information. ALD of copper, cobalt and tantalum films may become a key to further miniaturization of copper wires on semiconductor chips. Metal nitrides are needed as conformal diffusion barriers and as conformal contacts in capacitors containing metal oxides with high dielectric constants. Future magnetic data storage may be integrated with the silicon semiconductor chips that process this data. The proposed research should help to supply the scientific base for the realization of these hopes, as well as providing relevant training for undergraduates, graduate students and post-doctoral fellows.