Title :
HSG storage capacitor dielectric reliability of 0.13 μm embedded DRAM CMOS technology
Author :
Bruyère, S. ; Roy, D. ; Jacques, D. ; Boccaccio, C.
Author_Institution :
Central R&D Labs, STMicrolectronics, Crolles, France
fDate :
30 March-4 April 2003
Abstract :
The continued down-scaling of DRAM cell size is required while maintaining a sufficiently high storage capacitance per cell (>25 fF/cell). Before introducing high K dielectrics, optimization of the ON (Oxide-Nitride) stack using hemispherical-grained (HSG) polysilicon for the bottom electrode is analyzed in detail. First of all, it is necessary to identify the failure modes relevant to such cell stacks. Capacitance and current stability under temperature and electrical stress are demonstrated to be not critical for the 0.13 μm CMOS technology under investigation. On the contrary, soft breakdown events limit the cell lifetime. By knowing the critical parameters, we demonstrate that oxidation step suppression enables us to find good candidates considering capacitance, leakage current and reliability.
Keywords :
CMOS memory circuits; DRAM chips; capacitance; dielectric thin films; electric breakdown; integrated circuit reliability; leakage currents; nitridation; oxidation; thin film capacitors; 0.13 μm embedded DRAM CMOS technology; 0.13 micron; DRAM cell size down-scaling; HSG storage capacitor dielectric reliability; SiO2-Si3N4; bottom electrode; capacitance; cell lifetime; current stability; dielectric breakdown; dielectric wear-out; electrical stress; failure modes; hemispherical-grained polysilicon; high K dielectrics; high storage capacitance; leakage current; oxidation step suppression; oxide-nitride stack optimization; soft breakdown events; thermal stress; CMOS technology; Capacitance; Capacitors; Electrodes; High K dielectric materials; High-K gate dielectrics; Maintenance; Random access memory; Stability; Temperature;
Conference_Titel :
Reliability Physics Symposium Proceedings, 2003. 41st Annual. 2003 IEEE International
Print_ISBN :
0-7803-7649-8
DOI :
10.1109/RELPHY.2003.1197761
