What is Threshold voltage?

Threshold voltage in the explanations

• Reverse-biasing the source-to-body junction widens the depletion region under the gate and increases its charge, so a larger gate voltage is needed to compensate—the threshold voltage rises (the body effect).

  In an n-channel MOSFET, what happens to the threshold volta…

• An enhancement-mode pMOS therefore has a negative threshold voltage (e.g., −0.4 V).

  What is the sign of the threshold voltage (relative to the …

• Lowering threshold voltage increases overdrive (VGS − Vth) and on-current at the same supply, but subthreshold behavior makes off-state leakage grow exponentially—about tenfold per 60–80 mV.

  What is the general effect of lowering a MOSFET's threshold…

Questions that mention Threshold voltage (37)

1. What is the condition for an enhancement-mode n-channel MOSFET to turn on (conduct)? (VGS: gate-source voltage, Vth: threshold voltage)
2. When a long-channel MOSFET operates in the saturation region, the drain current ID is roughly proportional to what? (VGS: gate-source voltage, Vth: threshold voltage)
3. In an n-channel MOSFET, what happens to the threshold voltage when a negative voltage is applied to the substrate (body) relative to the source (body bias)?
4. What is the sign of the threshold voltage (relative to the source) of an enhancement-mode p-channel MOSFET?
5. What is the general effect of lowering a MOSFET's threshold voltage?
6. How does the absolute value of a MOSFET's threshold voltage generally change as temperature rises?
7. How does the threshold voltage change when the impurity concentration of the channel region (p-type substrate) of an nMOSFET is increased?
8. If the gate insulator of an nMOSFET is made thicker with all else unchanged, how does the magnitude of the threshold voltage generally change?
9. Which is the common condition for "strong inversion" used to define the threshold voltage of a MOSFET? (φF: Fermi potential)
10. In QLC (4 bits per cell) NAND flash, how many threshold voltage states must one cell distinguish?
11. In flash memory erase, what happens to a cell's threshold voltage when electrons are removed from the floating gate or similar layer?
12. In NAND flash, which programming method applies repeated program pulses with gradually increasing voltage, checking the threshold voltage after each one?
13. In high-k/metal gate transistors, which is one of the main ways to adjust the threshold voltage?
14. In very small transistors, what is the phenomenon called in which the threshold voltage varies because of statistical variation in the number and positions of dopant atoms in the channel?
15. What is the inspection called that measures TEG parameters such as threshold voltage and sheet resistance on wafers that have completed front-end processing, to confirm the process met specifications?

Related terms

Mobility Work function Interface states Inversion layer Fermi level Floating gate Flat-band voltage NBTI (negative bias temperature instability) Yield Saturation region