The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 06, 1997
Filed:
Oct. 03, 1994
Usha Varshney, Radford, VA (US);
Angus I Kingon, Cary, NC (US);
American Research Corporation of Virginia, Radford, VA (US);
Abstract
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.