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AssigneeAmerican Research Corporation of Virginia
InventorsUsha Varshney, Angus I. Kingon
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A method for developing large area highly oriented polycrystalline ferroelectric thin films using spin-on sol-gel deposition and laser crystallization techniques that allow for precise control of temperature distribution. The present invention improves quality, reliability, performance and cost effective production of ferroelectric non-volatile random access memory (FNVRAM) on thermally sensitive silicon and gallium arsenide semiconductor substrates compatible with very large scale integrated circuit technologies. The method is time effective, as crystallization is performed in three seconds as compared to thirteen hours in a conventional furnace for 1 cm.times.1 cm wafer. In addition, crystallization of the film is further achieved without exposing the underneath device structure to detrimental high temperature annealing conditions. The present invention results in minimization of thermal budget, interdiffusion of substrates/electrodes/films and phase segregation, and increased compatibility of PZT ferroelectric thin films with thermally sensitive semiconductor substrates.
A method for crystallizing a ferroelectric thin film on a substrate comprising the steps of creating a film precursor solution, depositing the film precursor solution as a thin film on the substrate, thus creating a thin film-coated substrate, heat treating the film and pyrolyzing residual organic species in the film, placing the film-coated substrate in a laser crystallization chamber, evacuating the chamber providing an inert environment in the chamber, providing a laser beam, directing the laser beam into the chamber, directing the laser beam onto the film on the substrate, relatively moving the laser beam and the film-coated substrate, and laser crystallizing the film on the substrate in a laser crystallization chamber.
Dependencies are inferred from the claim text.