Related Questions10 Items
Q1.MCQ
The intrinsic carrier concentration of a semiconductor is $2.5 \times 10^{16}\ /\text{m}^3$ at $300\ \text{K}$.
If the electron and hole mobilities are $0.15\ \text{m}^2/\text{Vs}$ and $0.05\ \text{m}^2/\text{Vs}$, respectively, then the intrinsic resistivity of the semiconductor (in $\text{k}\Omega\!\cdot\!\text{m}$) at $300\ \text{K}$ is .
(Charge of an electron $e = 1.6 \times 10^{-19}\ \text{C}$)
Q2.MCQ
The electron mobility $\mun$ in a non-degenerate germanium semiconductor at $300 \text{ K}$ is $0.38 \text{ m}^2/\text{Vs}$.
The electron diffusivity $Dn$ at $300 \text{ K}$ (in $\text{cm}^2/\text{s}$, rounded off to the nearest integer) is \\\\\\.
(Consider the Boltzmann constant $kB = 1.38 \times 10^{-23} \text{ J/K}$ and the charge of an electron $e = 1.6 \times 10^{-19} \text{ C}$.)
Q3.M-MCQ
Which of the following can be used as an n-type dopant for silicon?
Select the correct option(s).
Q4.NUMERICAL
Consider a MOS capacitor made with p-type silicon. It has an oxide thickness of $100 \text{ nm}$, a fixed positive oxide charge of $10^{-8} \text{ C/cm}^2$ at the oxide-silicon interface, and a metal work function of $4.6 \text{ eV}$. Assume that the relative permittivity of the oxide is $4$ and the absolute permittivity of free space is $8.85 \times 10^{-14} \text{ F/cm}$. If the flatband voltage is $0 \text{ V}$, the work function of the p-type silicon (in $eV$, rounded off to two decimal places) is .
Q5.NUMERICAL
A non-degenerate n-type semiconductor has $5\%$ neutral dopant atoms. Its Fermi level is located at $0.25\text{ eV}$ below the conduction band ($EC$) and the donor energy level ($ED$) has a degeneracy of $2$. Assuming the thermal voltage to be $20\text{ mV}$, the difference between $EC$ and $ED$ (in $\text{eV}$, rounded off to two decimal places) is .
Q6.NUMERICAL
An NMOS transistor operating in the linear region has $I{DS}$ of $5 \mu\text{A}$ at $V{DS}$ of $0.1 \text{ V}$. Keeping $V{GS}$ constant, the $V{DS}$ is increased to $1.5 \text{ V}$.
Given that $\mun C{ox} \frac{W}{L} = 50 \mu\text{A/V}^2$, the transconductance at the new operating point (in $\mu\text{A/V}$, rounded off to two decimal places) is .
Q7.NUMERICAL
The photocurrent of a PN junction diode solar cell is $1\text{ mA}$. The voltage corresponding to its maximum power point is $0.3\text{ V}$. If the thermal voltage is $30\text{ mV}$, the reverse saturation current of the diode (in $\text{nA}$, rounded off to two decimal places) is .
Q8.MCQ
For non-degenerately doped n-type silicon, which one of the following plots represents the temperature ($T$) dependence of free electron concentration ($n$)?
Q9.M-MCQ
The free electron concentration profile $n(x)$ in a doped semiconductor at equilibrium is shown in the figure, where the points A, B, and C mark three different positions. Which of the following statements is/are true?
image needed to be inserted here
Q10.M-MCQ
Which of the following statements is/are true for a BJT with respect to its DC current gain $\beta$?
Electronics EngineeringElectronic DevicesNumerical Answer (NAT)2 Marks
Q4.
Consider a MOS capacitor made with p-type silicon. It has an oxide thickness of 100 nm, a fixed positive oxide charge of 10−8 C/cm2 at the oxide-silicon interface, and a metal work function of 4.6 eV. Assume that the relative permittivity of the oxide is 4 and the absolute permittivity of free space is 8.85×10−14 F/cm. If the flatband voltage is 0 V, the work function of the p-type silicon (in eV, rounded off to two decimal places) is _______.
A
4.32