SiO2 dielectric breakdown mechanism studied by the post-breakdown resistance statistics

The dielectric breakdown mechanism of ultra-thin SiO2 is discussed on the basis of the experimental results of the post-breakdown resistance (Rbd) distribution. We have noticed that the Rbd of SiO2 in MOS devices is strongly related to the SiO2 breakdown characteristics such as the polarity dependence, the oxide field dependence or the oxidation process dependence of Qbd. In this paper, we discuss the dielectric breakdown mechanism of SiO2 from the viewpoint of the statistical correlation between the Rbd distribution, the Qbd distribution and the discharging energy at the SiO2 breakdown, by changing the stress polarity, the stress field, the oxide thickness and the oxidation process. In the case of hard breakdown, it has been clarified that the Rbd distribution for substrate electron injection is clearly different from that for gate electron injection. We have also found that, irrespective of the stress current density, the gate oxide thickness, the stressing polarity and the oxidation process, Rbd can be uniquely correlated to the discharging energy at dielectric breakdown, in the case of hard breakdown. Furthermore, it has been clarified that the Rbd does not depend on the energy dissipation at soft breakdown.

[1]  Akihiko Ishitani,et al.  SiO2 / Si Interface Structures and Reliability Characteristics , 1995 .

[2]  Akira Toriumi,et al.  A Percolation Approach to Dielectric Breakdown Statistics , 1997 .

[3]  Dielectric breakdown mechanism of thin-SiO/sub 2/ studied by the post-breakdown resistance statistics , 1999 .

[4]  Guido Groeseneken,et al.  A consistent model for the thickness dependence of intrinsic breakdown in ultra-thin oxides , 1995, Proceedings of International Electron Devices Meeting.

[5]  Hidetsugu Uchida,et al.  Cross-sectional Transmission Electron Microscope Studies on Intrinsic Breakdown Spots of Thin Gate Oxides , 1997 .

[6]  Shinichi Takagi,et al.  Correlation between two dielectric breakdown mechanisms in ultra‐thin gate oxides , 1996 .

[7]  George A. Brown,et al.  Nonuniqueness of time-dependent-dielectric-breakdown distributions , 1997 .

[8]  M. Wada,et al.  Stress induced leakage current limiting to scale down EEPROM tunnel oxide thickness , 1988, Technical Digest., International Electron Devices Meeting.

[9]  P. P. Apte,et al.  Constant Current Stress Breakdown in Ultrathin SiO2 Films , 1993 .

[10]  D. Wristers,et al.  Polarity dependence of dielectric breakdown in scaled SiO/sub 2/ , 1994, Proceedings of 1994 IEEE International Electron Devices Meeting.

[11]  K. Taniguchi,et al.  A detailed study of soft- and pre-soft-breakdowns in small geometry MOS structures , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).