Accession Number : ADP006688

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

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Hren, Phillip D. ; Rou, S. H. ; Al-Shareef, H. N. ; Ameen, M. S.

Report Date : 05 APR 1991

Pagination or Media Count : 15

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.

Descriptors :   *LEAD TITANATES, *RANDOM ACCESS COMPUTER STORAGE, ACCESS, AUGERS, BOTTOM, CONDUCTIVITY, DEPOSITION, DEPTH, DIFFUSION, ELECTRICAL CONDUCTIVITY, ELECTRODES, FILMS, ION BEAMS, IONS, LAYERS, MAGNETRONS, MICROANALYSIS, NUMBERS, OXIDES, PHASE, PLATINUM, STABILITY, SUBSTRATES, SURFACES, TEMPERATURE, TITANIUM, X RAYS, ZIRCONATES.

Subject Categories : Industrial Chemistry and Chemical Processing
      Ceramics, Refractories and Glass
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE