| abstract |
Compounds are synthesized with bicyclic amidinate ligands attached to one or more metal atoms. These compounds are useful for the synthesis of materials containing metals. Examples include pure metals, metal alloys, metal oxides, metal nitrides, metal phosphides, metal sulfides, metal selenides, metal tellurides, metal borides, metal carbides, metal silicides and metal germanides. Techniques for materials synthesis include vapor deposition (chemical vapor deposition and atomic layer deposition), liquid solution methods (sol-gel and precipitation) and solid-state pyrolysis. Copper metal films are formed on heated substrates by the reaction of copper(I) bicyclic amidinate vapor and hydrogen gas, whereas reaction with water vapor produces copper oxide. Silver and gold films were deposited on surfaces by reaction of their respective bicyclic amidinate vapors with hydrogen gas. Reaction of cobalt(II) bis(bicyclic amidinate) vapor, ammonia gas and hydrogen gas deposits cobalt metal films on heated substrates, while reaction with ammonia produces cobalt nitride and reaction with water vapor produces cobalt oxide. Ruthenium metal films are deposited by reaction of ruthenium(II) bis(bicyclic amidinate) or ruthenium(III) tris(bicyclic amidinate) at a heated surface either with or without a co-reactant such as hydrogen gas or ammonia or oxygen. Suitable applications include electrical interconnects in microelectronics and magnetoresistant layers in magnetic information storage devices. Hafnium oxide films are deposited by reaction of hafnium(IV) tetrakis(bicyclic amidinate) with oxygen sources such as water, hydrogen peroxide or ozone. The HfO2 films have high dielectric constant and low leakage current, suitable for applications as an insulator in microelectronics. The films have very uniform thickness and complete step coverage in narrow holes. |