Patent Number: 6,297,527

Title: Multilayer electrode for ferroelectric and high dielectric constantcapacitors

Abstract: A ferroelectric or high dielectric constant capacitor having a multilayerlower electrode comprising at least two layers--a platinum layer and aplatinum-rhodium layer--for use in a random access memory (RAM) cell. Theplatinum layer of the lower electrode adjoins the capacitor dielectric,which is a ferroelectric or high dielectric constant dielectric such asBST, PZT, SBT or tantalum pentoxide. The platinum-rhodium layer serves asan oxidation barrier and may also act as an adhesion layer for preventingseparation of the lower electrode from the substrate, thereby improvingcapacitor performance. The multilayer electrode may have titanium and/ortitanium nitride layers under the platinum-rhodium layer for certainapplications. The capacitor has an upper electrode which may be aconventional electrode or which may have a multilayer structure similar tothat of the lower electrode. Processes for manufacturing the multilayerlower electrode and the capacitor are also disclosed.

Inventors: Agarwal; Vishnu K. (Boise, ID), Derderian; Garo J. (Boise, ID), Gealy; F. Daniel (Kuna, ID)


International Classification:

Expiration Date: 10/02/2013