Question

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1. Consider the following MOSFET characteristics. What type of device is it? A. N-channel depletion-mode MOSFET B. N-channel enhancement-mode MOSFET. C. P-channel depletion-mode MOSFET. D. P-channel enhancement-mode MOSFET. Ip(mA) 1.5 1.0 0.5 V 00 V 0 0 2.0 4.0 6.0 Consider an n-channel MOSFET. Assuming no interface charge due to defects and/or traps, how would the the following parameters change when the oxide thickness is reduced? The flat band voltage VFB A. Increase B. Increase; c. Unchange: D. Unchange The threshold voltage VTN Increase Decrease. Increase Decrease Consider an n-channel MOSFET. Which of the following will increase the drain current ip under the same W/L, Ves and Vos? (0 Replacing the silicon dioxide (SiO2) with a dielectric material of a smaller permittivity e. (ll) Increase the substrate doping level. (l) Using a gate material with a larger work function. B. (1) and (ll). C. (l) and (ll), D. (1) and (II).

Answer 1

For Depletion mode, Gate Voltages must be Negative This is Clear indication of N - channel enhancement MOSFET because of positive Gate voltage So, option (B) if there is No trapping of charges, then of Lutz band remain unchanged, oxide thickness alpha V_th As oxide thickness then V_th downarrow So, option 'D' So, option D As the substrate doping Level increases, then more Gate voltage require to create channel, so I_D hand to raise So, eliminate option B and C it will be A or D rightarrow Larger work function provide Higher threshold for So, I_D does not raise so options 'D' therefore option (A) required Answer