Chemical Fluid Deposition Method for the Formation of Metal and Metal Alloy Films on Patterned and Unpatterned Substrates
A novel process by which high-purity metals or metal oxides are deposited from supercritical carbon dioxide solution by the chemical reduction or oxidation of soluble organometallic compounds. The process is demonstrated by deposition of ultra-high purity copper, platinum, ruthenium, palladium, gold, and their alloys as well as hafnium oxide, titania and other materials onto substrates including silicon wafers. The same method could be used to deposit a wide variety of metal and semiconductor thin films.
Principal application is the deposition of high purity metal or metal oxide films suitable for microelectronic devices. The invention overcomes two significant deficiencies of the current state of the art, chemical vapor deposition. The invention can also be used for the metallization of porous inorganic solids for use as supported catalysts where conventional approaches such as metal ion exchange are ineffective. Water purification and hydrocarbon processing could be two target markets.
The principle benefits of this invention are four-fold. First, in combination with US 5,789,027, it enables the conformal deposition of pure films in very high aspect ratio features. Conformal deposition is possible because of high precursor concentrations that yield surface reaction rate-limited depositions. Second, because transport occurs in supercritical solution, precursor volatility constraints are eliminated. Third, alloys of defined composition can be deposited in a single step using this technique. Finally, deposition temperatures are lower than traditional CVD processes.
Office of Commercial Ventures and Intellectual Property