Title :
Electrical and reliability characteristics of lead-zirconate-titanate (PZT) ferroelectric thin films for DRAM applications
Author :
Carrano, J. ; Sudhama, C. ; Lee, J. ; Tasch, A. ; Miller, W.
Author_Institution :
Microelectron. Res. Center, Texas Univ., Austin, TX, USA
Abstract :
The electrical and reliability characteristics of lead-zirconate-titanate (PZT) ferroelectric capacitors are presented. Thin Pb(Zr/sub 0.5/Ti/sub 0.5/)O/sub 3/ films of 350 nm were prepared using a solution-gelatin technique. Hysteresis loop and pulse measurement methods indicate that PZT films exhibit a large charge storage density of 7.3 mu C/cm/sup 2/ and an equivalent dielectric constant of approximately 577. In addition, good endurance behavior (no fatigue or aging wearout after >10/sup 13/ cycles under accelerated unipolar stressing), reasonable transient characteristics (with estimated write time of approximately 0.1 ns and refresh time of approximately 2.5 s), and high effective breakdown field suggest that the PZT ferroelectric material has good potential for applications in advanced DRAMs (dynamic RAMs).<>
Keywords :
DRAM chips; VLSI; ferroelectric materials; ferroelectric storage; ferroelectric thin films; lead compounds; life testing; materials testing; permittivity; reliability; 0.1 ns; 2.5 s; 350 nm; DRAM applications; PZT films; PbZrO3TiO3; ULSI; VLSI; accelerated unipolar stressing; breakdown field; charge storage density; dielectric constant; dynamic RAMs; electric characteristics; endurance behavior; ferroelectric capacitors; ferroelectric thin films; permittivity; pulse measurement methods; refresh time; reliability characteristics; solution-gelatin technique; transient characteristics; write time; Accelerated aging; Capacitors; Dielectric constant; Dielectric thin films; Fatigue; Ferroelectric films; Ferroelectric materials; Hysteresis; Life estimation; Pulse measurements;
Conference_Titel :
Electron Devices Meeting, 1989. IEDM '89. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-0817-4
DOI :
10.1109/IEDM.1989.74273
