MOSFET I-Vg Curve: Which Curve is Impossible?

[zhangz64]

Homework Statement

Below graph shows the I - Vg curve for different MOSFET, which curve is impossible for MOSFET?

Relevant Equations

I - Vg

Homework Statement: Below graph shows the I - Vg curve for different MOSFET, which curve is impossible for MOSFET?
Homework Equations: I - Vg

I am inclined to select 1), as it is not likely to have a sharp transition from subthreshold to Quadritica region. However, graph 5 also looks strange, since it somehow shows current in at subthreshold region. I am therefore confused about whether it should be 1) or 5).

 

[rude man]

I would agree. Could be either.

 

[Tom.G]

I agree curve #1 represent infinite gain, making it clearly impossible.

Curve #5 reminds one of reverse breakdown (due to Electron tunneling) of the gate oxide.
See near the bottom of the page of:
http://www.tibercad.org/sample_application/article/multiscale_simulation_mosfets_based_high_k_oxides
Cheers,
Tom

 

[rude man]

Curve #5 reminds one of reverse breakdown (due to Electron tunneling) of the gate oxide.

You can't tunnel with zero Vgs!