Title :
Impact of time dependent dielectric breakdown and stress induced leakage current on the reliability of (Ba,Sr)TiO/sub 3/ thin film capacitors for Gbit-scale DRAMs
Author :
Yamamichi, S. ; Yamaichi, A. ; Park, D. ; Hu, C.
Author_Institution :
Fundamental Res. Labs., NEC Corp., Kawasaki, Japan
Abstract :
Time dependent dielectric breakdown (TDDB) and stress-induced leakage current (SILC) are investigated for the reliability of (Ba/sub 0.5/Sr/sub 0.5/)TiO/sub 3/ (BST) thin films. TDDB characteristics show a lifetime longer than 10 years at +1 V for BST films with an SiO/sub 2/ equivalent thickness (t/sub eq/) of 0.70 nm. The breakdown is strongly affected by leakage current properties, and does not depend on the dielectric constant. SILC is studied at +1V in time domain after stress charge injection into BST films. 10 year operation for Gbit-scale DRAMs can be guaranteed in spite of the charge loss caused by SILC.
Keywords :
DRAM chips; barium compounds; electric breakdown; leakage currents; reliability; strontium compounds; thin film capacitors; (Ba,Sr)TiO/sub 3/ thin film capacitor; (Ba/sub 0.5/Sr/sub 0.5/)TiO/sub 3/; 0.70 nm; 1 V; 10 year; DRAM; SiO/sub 2/ equivalent thickness; charge injection; dielectric constant; lifetime; reliability; stress induced leakage current; time dependent dielectric breakdown; Binary search trees; Breakdown voltage; Capacitors; Dielectric breakdown; Dielectric thin films; Electric breakdown; Leakage current; Random access memory; Sputtering; Stress;
Conference_Titel :
Electron Devices Meeting, 1997. IEDM '97. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-4100-7
DOI :
10.1109/IEDM.1997.650377
