Ferroelectric thin film composites made by metalorganic decomposition

US6071555A · kind A · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Somnath Sengupta · Ellicott City, US
• Steven Stowell · Columbia, US
• Louise Sengupta · Ellicott City, US
• Pooran Chandra Joshi · Vancouver, US
• Sasangan Ramanathan · San Ramon, US
• Seshu B. Desu · Amherst, US

Key dates

• Filing date: Nov 5, 1998
• Grant date: Jun 6, 2000
• Expiry date: Nov 5, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02282
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Thin films of ferroelectric composite material comprising barium strontium titanate (BSTO) combined with magnesium oxide additive are produced by metalorganic decomposition. The barium strontium titanate magnesium oxide ferroelectric composite comprises Ba.sub.1-x Sr.sub.x TiO.sub.3 /MgO, wherein x is greater than 0.0 but less than or equal to 0.75 and preferably is 0.4, and wherein the weight ratio of BSTO to magnesium oxide may range from 99 to 40 weight percent BSTO to 1 to 60 weight percent magnesium oxide. These films have desirable electronic properties and may have application to both active microwave and dynamic random access memory devices, including low dielectric constant, low loss factor, high tunability, and high resistivity. The films produced are uniformly thick and impurity free, with thicknesses of only 0.4 microns.