Low-temperature processing of a ferroelectric strontium bismuth tantalate layer, and fabrication of ferroelectric components using the layer

US6815224B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Harald Bachhofer · Hersbruck, DE
• Thomas Haneder · Hersbruck, DE
• Oswald Spindler · Vaterstetten, DE
• Rainer Waser · Aachen, DE

Key dates

• Filing date: Feb 24, 2003
• Grant date: Nov 9, 2004
• Expiry date: Feb 24, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/684
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

In a method for producing ferroelectric strontium bismuth tantalate having the composition SrxBiyTa2O9 (SBT) or SrxBiy(Ta, Nb)2O9 (SBTN), the element strontium, which is normally present in an amount y=2, is provided in excess in a range from 2.1≦y≦3.0. This makes it possible to carry out the heat treatment step for converting the deposited material into the ferroelectric phase at a temperature T1, which is lower than 700° C. In addition, the strontium content x can be reduced from a nominal value of 1 to 0.7.