Time Dependent Dielectric Breakdown Characteristics of Low-k Dielectric (SiOC) Over a Wide Range of Test Areas and Electric Fields

Time-dependent dielectric breakdown (TDDB) of low-k dielectrics is reported for fully integrated carbon-doped silica dielectric (SiOC, keff=2.9) at wafer level over a wide range of area and electric-field test conditions at 105degC. In addition, long-term package level TDDB data were taken at 105degC for over 2 years on integrated comb-serpent test structures. The field acceleration parameter (gamma=4.5 plusmn 0.5 cm/MV) was found to be approximately independent of area (over 4 decades of area) and over a wide range of field (1.5-6.0 MV/cm), respectively. TDDB data, taken over long periods, agree well with predictions based on more rapid wafer-level TDDB testing. The low-k TDDB data suggest that, while the time-to-failure is a strong function of area and field, the time-to-failure physics does not vary greatly for fully integrated SiOC films as both the area and field are scaled. Furthermore, the fact that gamma is approximately constant (independent of area and applied E-field) indicates that silica-based low-k dielectric TDDB follows closely a thermochemical E-model for all areas and fields examined.

[1]  S. Holland,et al.  A quantitative physical model for time-dependent breakdown in SiO2 , 1985, 23rd International Reliability Physics Symposium.

[2]  K. Hinode,et al.  Impact of low-k dielectrics and barrier metals on TDDB lifetime of Cu interconnects , 2001, 2001 IEEE International Reliability Physics Symposium Proceedings. 39th Annual (Cat. No.00CH37167).

[3]  Ernest Y. Wu,et al.  On the Weibull shape factor of intrinsic breakdown of dielectric films and its accurate experimental determination. Part I: theory, methodology, experimental techniques , 2002 .

[4]  J. Scarpulla,et al.  A TDDB model of Si/sub 3/N/sub 4/-based capacitors in GaAs MMICs , 1999, 1999 IEEE International Reliability Physics Symposium Proceedings. 37th Annual (Cat. No.99CH36296).

[5]  Pseudo-breakdown events induced by biased-thermal-stressing of intra-level Cu interconnects-reliability and performance impact , 2002, 2002 IEEE International Reliability Physics Symposium. Proceedings. 40th Annual (Cat. No.02CH37320).

[6]  Chih-I Wu,et al.  Correlation of Surface and Film Chemistry with Mechanical Properties in Interconnects , 2003 .

[7]  Suzumura Naohito,et al.  A NEW TDDB DEGRADATION MODEL BASED ON CU ION DRIFT IN CU INTERCONNECT DIELECTRICS , 2007 .

[8]  Wen Wu,et al.  A physical model of time-dependent dielectric breakdown in copper metallization , 2003, 2003 IEEE International Reliability Physics Symposium Proceedings, 2003. 41st Annual..

[9]  J. McPherson,et al.  Acceleration Factors for Thin Gate Oxide Stressing , 1985, 23rd International Reliability Physics Symposium.

[10]  J. McPherson,et al.  UNDERLYING PHYSICS OF THE THERMOCHEMICAL E MODEL IN DESCRIBING LOW-FIELD TIME-DEPENDENT DIELECTRIC BREAKDOWN IN SIO2 THIN FILMS , 1998 .

[11]  W. Mckee,et al.  Leakage and breakdown reliability issues associated with low-k dielectrics in a dual-damascene Cu process , 2000, 2000 IEEE International Reliability Physics Symposium Proceedings. 38th Annual (Cat. No.00CH37059).

[12]  Ennis T. Ogawa,et al.  Leakage, breakdown, and TDDB characteristics of porous low-k silica-based interconnect dielectrics , 2003, 2003 IEEE International Reliability Physics Symposium Proceedings, 2003. 41st Annual..

[13]  J. Gill,et al.  Reliability Characterization of BEOL Vertical Natural Capacitor using Copper and Low-k SiCOH Dielectric for 65nm RF and Mixed-Signal Applications , 2006, 2006 IEEE International Reliability Physics Symposium Proceedings.

[14]  K. Banerjee,et al.  Comparison of E and 1/E TDDB models for SiO/sub 2/ under long-term/low-field test conditions , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).

[15]  J. McPherson,et al.  A Statistical Evaluation of the Field Acceleration Parameter Observed During Time Dependent Dielectric Breakdown Testing of Silica-Based Low-k Interconnect Dielectrics , 2006, 2006 IEEE International Reliability Physics Symposium Proceedings.