Time-Dependent Dielectric Breakdown of 4H-SiC MOS Capacitors and DMOSFETs

Time-dependent dielectric breakdown measurements were performed at 200 degC on 4H-SiC MOS capacitors and vertical DMOSFETs with 50-nm-thick nitrided oxides in order to better understand the physical mechanisms of failure and to predict the component reliability. Oxide breakdown locations are shown to have no correlation to defects in the SiC epitaxial layer. Characterization of the electric-field acceleration of failures indicates that failure modes differ at low and high electric fields. Specifically, extrapolations from measurements at electric fields greater than 8.5 MV/cm predict anomalously high reliability at normal operating fields. Thus, we have shown that SiC MOS reliability characterization must ensure that electric field stresses be performed at low electric fields in order to accurately predict failure times.

[1]  J. Suehle.  Ultrathin gate oxide reliability: physical models, statistics, and characterization , 2002 .

[2]  Kenji Fukuda,et al.  Correlation between reliability of thermal oxides and dislocations in n-type 4H-SiC epitaxial wafers , 2006 .

[3]  P. Chaparala,et al.  A new physics-based model for time dependent dielectric breakdown , 1996, Proceedings of the 7th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis.

[4]  A. Agarwal,et al.  Temperature dependence of Fowler-Nordheim current in 6H- and 4H-SiC MOS capacitors , 1997, IEEE Electron Device Letters.

[5]  N. Goldsman,et al.  Time-Dependent Bias Stress-Induced Instability of SiC MOS Devices , 2006 .

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

[7]  Guido Groeseneken,et al.  New insights in the relation between electron trap generation and the statistical properties of oxide breakdown , 1998 .

[8]  A. Hefner,et al.  Reliability of SiC MOS devices , 2004 .

[9]  M. Imaizumi,et al.  Successful enhancement of lifetime for SiO/sub 2/ on 4H-SiC by N/sub 2/O anneal , 2004, IEEE Electron Device Letters.

[10]  Prasad Chaparala,et al.  Field and temperature acceleration of time-dependent dielectric breakdown in intrinsic thin SiO/sub 2/ , 1994, Proceedings of 1994 IEEE International Reliability Physics Symposium.

[11]  A. Agarwal,et al.  Reliability of High Voltage 4H-SiC MOSFET Devices , 2006 .

[12]  J. Cooper,et al.  Time-dependent-dielectric-breakdown measurements of thermal oxides on n-type 6H-SiC , 1999 .

[13]  James W. Kretchmer,et al.  Silicon carbide MOSFET technology , 1996 .

[14]  J. W. Palmour,et al.  Insulator investigation on SiC for improved reliability , 1999 .

[15]  P. Friedrichs,et al.  Reliability of metal–oxide–semiconductor capacitors on nitrogen implanted 4H-silicon carbide , 1998 .

[16]  Martin Pölzl,et al.  Ultra-thick gate oxides: charge generation and its impact on reliability , 2001, Microelectron. Reliab..

[17]  J. Suehle,et al.  Ultra-Fast Characterization of Transient Gate Oxide Trapping in SiC Mosfets , 2007, 2007 IEEE International Reliability Physics Symposium Proceedings. 45th Annual.

[18]  Temperature-dependent tunneling through thermally grown SiO2 on n-type 4H– and 6H–SiC , 2000 .

[19]  K. Fukuda,et al.  Effects of n-type 4H-SiC epitaxial wafer quality on reliability of thermal oxides , 2004 .

[20]  D. Arnold,et al.  Impact ionization, trap creation, degradation, and breakdown in silicon dioxide films on silicon , 1993 .

[21]  J. Nasadoski,et al.  DC and Transient Performance of 4H-SiC Double-Implant MOSFETs , 2008, IEEE Transactions on Electron Devices.