Summary: Developed experimental and mathematical techniques for extracting mobility and threshold voltage (VT) degradation after gate oxide breakdown. The degradation is significant, is dominated by the VT shift, and is worse in short channel devices. As a consequence, the widely accepted practice of using multiple device fingers to make circuits more robust to breakdown is not generally correct.

IEEE Transactions on Electron Devices, 61 66 (2014)

KEY PUBLICATIONS

Summary: Identified nearest-neighbor hopping conduction as the transport mechanism for the leakage instability in amorphous silicon antifuse devices and constructed a reliability projection technique from this finding.

Proceedings of the IRPS, 42 (1995)

Summary: Invented an equivalent circuit that correctly models MOSFET behavior after gate oxide breakdown, enabling accurate simulation of post breakdown circuit functionality.

IEEE Transactions on Electron Devices, 58 1170 (2011)

Summary: A minimum of two traps is required to cause breakdown in SiON films. At least one must be an interface state and at least one must be a bulk state. The rate limiting step for breakdown transitions from bulk to interface state generation below the 3V threshold for vibrational excitation (VE) of Si-H bonds. This response indicates that VE is operative and validates the optimistic power law TDDB model, which is needed for continued aggressive scaling and is valid only when VE is the trap generation mechanism.

IEDM Technical Digest, 743 (2006)

Summary: We show for the 1st time that trap generation and breakdown in SiON are triggered by the release of two hydrogen species (H+ and H0) from the anode during stress.

IEDM Technical Digest, 403 (2005)

Summary: The widely established practice of directly extrapolating time-to-breakdown from stress to operation overestimates the lifetime if the device is stressed in the F-N Tunneling regime.

IEEE Electron Device Letters, 30 1185 (2009)

Summary: Plasma nitridation significantly extends the reliability scaling limit of SiO2. Trap generation rates are minimized and reliability is optimized when the nitrogen profile is uniform. (This work enabled TI to be the first company to implement these films into production).

IEDM Technical Digest, 545 (2000)

Summary: Invented the Low-Voltage-Stress-Induced-leakage-Current (LV-SILC) technique, which separates the effects of bulk and interface traps on post stress leakage currents. Surface states at both top and bottom interfaces participate in transport and LV-SILC resolves the location. This technique is now widely used throughout the industry.

Journal of Applied Physics, 104 053718-1 (2008)

​Proceedings of the IRPS, 400 (1999)

Summary: Conclusively proved the IBM theory that oxide breakdown is is voltage rather than field driven. This work was instrumental in in ending the long running controversy in the industry on breakdown models (BEST PAPER AWARD).

Proceedings of the IRPS, 7 (2000)

Summary: Uniform substrate hot electron injection can be used to assess dielectric reliability in the low current weak inversion state when devices are used as voltage dividers. Core devices can be safely operated at higher voltages, thus avoiding the costs of extra mask levels.

​Proceedings of the IRPS, 385 (2010)