Question

The threshold voltage of an n-channel MOSFET can be increased by:

• A. Increasing the channel dopant concentration.
• B. Reducing the channel length
• C. Reducing the gate oxide thickness.
• D. Reducing the channel dopant concentration

Answer 1

The correct option is D Reducing the channel dopant concentration

Threshold voltage is the minimum amount of $V_{GS}$ at which channel is enhenced between drain and source. so that current $I_0$ formes when $V_{DS}$ (drain to source) voltage$n_a$ is applied.

if channel dopent concentration increases, minority carriers (np) decreases. we must apply more voltage to get same charge ( $Ie$ required charge). so, the threshold voltage of n- channel MOSFET can be increased.