Forum › Category: Layout › How does temperature affect transistor characteristics?
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AvatarDigitalWorld asked 6 months ago
Transistor characteristics are significantly effected by temperature changes. For instance, as temperature rises, carrier mobility decreases, which affects the overall performance of the transistor.
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AvatarCircuitDesigner answered 6 months ago

I've noticed that the characteristics of transistors change with temperature. As the temperature increases, the carrier mobility tends to decrease. temperature, and a fitting parameter.

One important aspect to note is that the threshold voltage of a transistor decreases almost linearly with temperature. This means that as the temperature goes up, the threshold voltage goes down.

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AvatarTechGuru answered 5 months ago

Temperature has a mixed impact on different parameters. For example, subthreshold leakage increases exponentially with temperature, while gate leakage remains almost unaffected.

At high gate-source voltages (Vgs), the current in the transistor tends to decrease with temperature. On the other hand, at low Vgs, the current increases with temperature, which means the OFF current is higher at elevated temperatures.

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Avatarsemiconductor answered 1 month ago
I think temperature impacts lower and higher technology nodes differently because of the way transistors behave. In lower nodes, like 7nm or 5nm, I’ve noticed that temperature variations can lead to significant changes in mobility and threshold voltage. The decrease in carrier mobility reduces the current drive, which slows down circuits. At the same time, the threshold voltage drop can sometimes partially compensate for this. You can see how these two factors fight each other, and the balance depends on the specific design. In my experience, the impact of temperature is less straightforward in advanced nodes because the supply voltage is lower, and mechanisms like Zero Temperature Coefficient (ZTC) voltages come into play.