Evaluation for Anomalous Stress-Induced Leakage Current of Gate $ \hbox{SiO}_{2}$ Films Using Array Test Pattern

Using the array test pattern, gate current through the tunnel oxide on the order of 10-16 A can be measured for about 1 000 000 transistors within 4 min. Because this test pattern can be fabricated by simple processes and its peripheral circuits are simple structures, the tunnel dielectric formation method and condition can be changed drastically. It was found that anomalous stress-induced leakage current (SILC) appears or disappears by applying electrical stress, and it is annealed out during a relatively high temperature measurement at 60 °C. Random telegraph signal in SILC can be observed in some transistors. These are very similar phenomena observed in Flash memory cells. We consider that, using this test pattern for the development of tunnel oxide, we can clarify the origin of anomalous SILC and promote the downscaling of tunnel oxide thickness.

[1]  Shinichi Takagi,et al.  Experimental evidence of inelastic tunneling in stress-induced leakage current , 1999 .

[2]  Kenji Taniguchi,et al.  Electrical stress-induced variable range hopping conduction in ultrathin silicon dioxides , 1997 .

[3]  Katsuhiko Kubota,et al.  Detailed observation of small leak current in flash memories with thin tunnel oxides , 1998, ICMTS 1998. Proceedings of 1998 International Conference on Microelectronic Test Structures (Cat. No.98CH36157).

[4]  S. Takagi,et al.  A new I-V model for stress-induced leakage current including inelastic tunneling , 1999 .

[5]  Salvatore Lombardo,et al.  Soft breakdown of gate oxides in metal–SiO2–Si capacitors under stress with hot electrons , 1999 .

[6]  M. Heyns,et al.  Soft breakdown of ultra-thin gate oxide layers , 1996 .

[7]  Tadahiro Ohmi,et al.  Very Low Bit Error Rate in Flash Memory using Tunnel Dielectrics formed by Kr/O2/NO Plasma Oxynitridation , 2006 .

[8]  A. Shigetomi,et al.  Excess currents induced by hot hole injection and FN electron injection in thin SiO/sub 2/ films , 2001 .

[9]  H. Kameyama,et al.  A new data retention mechanism after endurance stress on flash memory , 2000, 2000 IEEE International Reliability Physics Symposium Proceedings. 38th Annual (Cat. No.00CH37059).

[10]  D. J. Dumin,et al.  Correlation of stress-induced leakage current in thin oxides with trap generation inside the oxides , 1993 .

[11]  R. S. Scott,et al.  The Transient Nature of Excess Low‐Level Leakage Currents in Thin Oxides , 1995 .

[12]  Excess currents induced by hot-hole injection and F-N stress in thin SiO/sub 2/ films [flash memories] , 1996, Proceedings of International Reliability Physics Symposium.

[13]  C. Glenn Shirley.  High Field Phenomena in Thermal SiO2 , 1985 .

[14]  B. Riccò,et al.  High-field-induced degradation in ultra-thin SiO/sub 2/ films , 1988 .

[15]  A. Brand,et al.  Novel read disturb failure mechanism induced by FLASH cycling , 1993, 31st Annual Proceedings Reliability Physics 1993.

[16]  T. Nakamura,et al.  Impact of nitridation engineering on microscopic SILC characteristics of sub-10-nm tunnel dielectrics , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).

[17]  Akira Toriumi,et al.  A Two-Step Tunneling Model for the Stress Induced Leakage Current in Thin Silicon Dioxide Films , 1993 .

[18]  Tsu-Jae King,et al.  Variable stress-induced leakage current and analysis of anomalous charge loss for flash memory application , 2003, 2003 IEEE International Reliability Physics Symposium Proceedings, 2003. 41st Annual..

[19]  Alessandro Paccagnella,et al.  Soft breakdown current noise in ultra-thin gate oxides , 2002 .

[20]  H. Hazama,et al.  Non-uniform current flow through thin oxide after Fowler-Nordheim current stress , 1996, Proceedings of International Reliability Physics Symposium.

[21]  Robert W. Brodersen,et al.  Quantum yield of electron impact ionization in silicon , 1985 .

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

[23]  J. Maserjian,et al.  Observation of positively charged state generation near the Si/SiO2 interface during Fowler–Nordheim tunneling , 1982 .

[24]  C. Hu,et al.  Stress-induced current in thin silicon dioxide films , 1992, 1992 International Technical Digest on Electron Devices Meeting.

[25]  T. Lewis,et al.  Flash EPROM disturb mechanisms , 1994, Proceedings of 1994 IEEE International Reliability Physics Symposium.

[26]  Guido Groeseneken,et al.  On the properties of the gate and substrate current after soft breakdown in ultrathin oxide layers , 1998 .

[27]  George A. Brown,et al.  Polarity dependence of thin oxide wearout , 1989 .

[28]  Jordi Suñé,et al.  Switching events in the soft breakdown I–t characteristic of ultra-thin SiO2 layers , 1999 .

[29]  Andrea L. Lacaita,et al.  A statistical model for SILC in flash memories , 2002 .

[30]  Yung-Huei Lee,et al.  RTS Noise Characterization in Flash Cells , 2008, IEEE Electron Device Letters.

[31]  Dominique Vuillaume,et al.  Study of defects induced by high-electric-field stress into a thin gate oxide (11 nm) of metal-oxide-semiconductor capacitors , 1993 .

[32]  Kenji Taniguchi,et al.  A new soft breakdown model for thin thermal SiO/sub 2/ films under constant current stress , 1999 .

[33]  Bruno Ricco,et al.  Modeling and simulation of stress-induced leakage current in ultrathin SiO/sub 2/ films , 1998 .