Search results
Results from the WOW.Com Content Network
Negative-bias temperature instability (NBTI) is a key reliability issue in MOSFETs, a type of transistor aging.NBTI manifests as an increase in the threshold voltage and consequent decrease in drain current and transconductance of a MOSFET.
A nanowire MOSFET's current–voltage characteristic (left, using logarithmic y-axis) and a simulation of the electron density (right) forming a conductive inversion channel which connects at the ~0.45 V threshold voltage. Extremely little current flows below this voltage.
Therefore, a plot of drain current versus gate voltage with drain, source, and bulk voltages fixed will exhibit approximately log-linear behaviour in this MOSFET operating regime. Its slope is the subthreshold slope. The subthreshold slope is also the reciprocal value of the subthreshold swing S s-th which is usually given as: [1]
Where is the thermal conductivity, is the density of the medium, is the specific heat, =, the thermal diffusivity and is the rate of heat generation per unit volume. Heat diffuses from the source following the above equation and solution in an homogeneous medium follows a Gaussian distribution.
[1] [10] Since 2005, the clock frequency has stagnated at 4 GHz, and the power consumption per CPU at 100 W TDP. The breakdown of Dennard scaling and resulting inability to increase clock frequencies significantly has caused most CPU manufacturers to focus on multicore processors as an alternative way to improve performance.
[1] The amount of subthreshold conduction in a transistor is set by its threshold voltage , which is the minimum gate voltage required to switch the device between on and off states. However, as the drain current in a MOS device varies exponentially with gate voltage, the conduction does not immediately become zero when the threshold voltage is ...
In MOSFETs, hot electrons have sufficient energy to tunnel through the thin gate oxide to show up as gate current, or as substrate leakage current.In a MOSFET, when a gate is positive, and the switch is on, the device is designed with the intent that electrons will flow laterally through the conductive channel, from the source to the drain.
This can lead to thermal runaway and the destruction of the MOSFET even when it is operating within its Vds, Id and Pd ratings. [ 5 ] [ 6 ] Some (usually expensive) MOSFETs are specified for operation in the linear region and include DC SOA diagrams, e.g. IXYS IXTK8N150L.