List of top Electronic Devices Questions on MOSFET

Which statement(s) is/are true?
A. The drain current in an enhancement-type MOSFET is inversely proportional to the relative permittivity of the gate oxide. 
B. The threshold voltage in an MOS capacitor does not depend on the gate oxide thickness. 
C. The drain current in an enhancement-type MOSFET is directly proportional to the relative permittivity of the gate oxide. 
D. The threshold voltage in an MOS capacitor depends on the gate oxide thickness.
Choose the correct answer from the options given below.

Consider an ideal long channel nMOSFET (enhancement-mode) with gate length 10 $\mu$m and width 100 $\mu$m. The product of electron mobility ($\mu_n$) and oxide capacitance per unit area ($C_{OX}$) is $\mu_n C_{OX} = 1\ \text{mA/V}^2$. The threshold voltage of the transistor is 1 V. For a gate-to-source voltage $V_{GS} = [2 - \sin(2t)]$ V and drain-to-source voltage $V_{DS} = 1$ V (substrate connected to source), the maximum value of the drain-to-source current is ________________.

For an n-channel silicon MOSFET with 10 nm gate oxide thickness, the substrate sensitivity \( \left( \frac{\partial V_T}{\partial |V_{BS}|} \right) \) is found to be 50 mV/V at a substrate voltage \[ |V_{BS}| = 2 \, \text{V}, \text{ where } V_T \text{ is the threshold voltage of the MOSFET. Assume that } |V_{BS}| \gg 2 \Phi_B, \text{ where } q \Phi_B \text{ is the separation between the Fermi energy level } E_F \text{ and the intrinsic level } E_i \text{ in the bulk. Parameters given are:} \] \[ \text{Electron charge } (q) = 1.6 \times 10^{-19} \, \text{C}, \quad \text{Vacuum permittivity } (\varepsilon_0) = 8.85 \times 10^{-12} \, \text{F/m}, \] \[ \text{Relative permittivity of silicon } (\varepsilon_{si}) = 12, \quad \text{Relative permittivity of oxide } (\varepsilon_{ox}) = 4. \] \text{The doping concentration of the substrate is:}