Bottom Electrodes for Integrated Pb(Zr,Ti)03 Films,

Abstract

Lower electrodes for Pb(Zr,Ti)03 (PZT) used in ferroelectric random access memories must have good electrical conductivity and must interact as little as possible with the PZT film We have evaluated a number of bottom electrodes for use with PZT films deposited by ion beam sputter deposition These electrodes include Pt, PI/Ti, RuO2, ReO3, and CoSi2/Si3N4, all on SiO2/Si; and TiN and Pt on MgO. Films were studied by XTEM, Auger depth profiling, X-ray microanalysis, and XRD. Important issues for platinum include: (a) microstructure (porous for magnetron sputtered Pt); (b) rapid lead diffusion through porous Pt; (c) adhesion (improved by raising deposition temperature or by adding a titanium layer); and (d) hillock formation (related to compressive stress in platinum). RuO2 has good conductivity and has no apparent interfacial layer with PZT. Each of the remaining substrates has drawbacks: CoSi2 forms a surface oxide; ReO3 has poor phase stability; TiN oxidizes and loses conductivity.

Document Details

Document Type
Technical Report
Publication Date
Apr 05, 1991
Accession Number
ADP006688

Entities

People

  • H. N. Al-shareef
  • M. S. Ameen
  • Phillip D. Hren
  • S. H. Rou

Organizations

  • North Carolina State University

Tags

DTIC Thesaurus Topics

  • Adhesion
  • Colorado
  • Conductivity
  • Diffusion
  • Electrical Conductivity
  • Electrodes
  • Ion Beams
  • Ions
  • Magnetrons
  • Microanalysis
  • Microstructure
  • Physical Properties
  • Platinum
  • Substrates
  • Titanium
  • X Rays

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Thin Film Deposition Science.