R. Fernández

FinFET and MOSFET preliminary comparison of gate oxide reliability

In this work, the influence of gate oxide reliability on N channel FinFET and MOSFET characteristics has been preliminary compared. For similar oxide damage, the results show that the oxide wear out has larger effects on the functionality of the FinFET than on the MOSFET.

Effect of oxide breakdown on RS latches

In this work, the influence of the oxide breakdown on RS latches performance has been analysed. The NAND and NOR RS latch topologies have been compared in terms of noise margin and switching times for different broken down transistors. Moreover, the influence of the additional current path due to BD and of the variation of the MOSFET parameters on the circuit functionality have been separately evaluated. The results show that RS latches do not lose functionality after BD. However, reductions on noise margin and variations on switching times are observed, which depend on the damaged transistor. The performance degradation of the circuit is mainly due to the additional post-BD gate current whereas the variation of the BD MOSFET parameters has only a small influence.

Influence of oxide breakdown position and device aspect ratio on MOSFET's output characteristics

In this work, the influence of oxide breakdown (BD) location on the MOSFET output characteristics has been studied taking into account the devices aspect ratio. The results show that the BD location plays an important role on the device output characteristics for any device geometry. The characteristics have been included on a circuit simulator in order to consider the BD influence on a three stage inverter. The simulation shows that the BD position can play an important role on circuit performance.

Effects of dielectric degradation and breakdown in MOSFETs characteristics. Impact on digital and analog circuits.

To clarify the impact of the gate oxide degradation and breakdown (BD) on CMOS circuits functionality it is necessary to develop models for broken down devices that can be included in circuit simulators. Transistors with different geometries have been experimentally stressed to provoke oxide degradation and BD. The transistors characteristic curves after degradation have been fitted with SPICE BSIM4 model. The extracted model parameters have been included in a circuit simulator to study the effect of the oxide degradation and BD on analog (current mirror) and digital (RS latches) circuits. The separate influence on the current mirror performance of the BD gate current and the variation of transistor BSIM parameters has also been analyzed.

MOSFET behaviour after oxide breakdown

In this work, the influence of oxide breakdown (BD) on the MOSFET output characteristics has been studied taking into account the BD location along the channel. The results show that the BD location plays an important role on the device output characteristics. In order to quantify the variation of the MOSFET behaviour after BD the BD MOSFET model parameters for these devices have been extracted.

Ring oscillator behavior after oxide breakdown

The influence of the oxide hard breakdown (HBD) path location along the channel in nMOSFETS on the performance and power consumption of a five stages ring oscillator has been evaluated. A simple MOSFET transistor model which takes into account the oxide BD has been used to do the analysis. The results show that in some cases, after oxide BD, the ring oscillator still operates but the circuit could fail due to higher consumption.