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Problem 3. Consider MOS system with p type substrate. Given: Explain qualitatively that the total capacitance for the depletion condition is the series combination of oxide capacitance and depletion capacitance for low frequency ac and slowly varying input ramp (DC). (10 points) Explain qualitatively that the total capacitance for the strong inversion condition is the oxide capacitance for low frequency ac and slowly varying input ramp (DC). (10 points)Do we have an inversion layer at the surface for high frequency ac and slowly varying input ramp? Explain. (10 points) How does the total capacitance change for high frequency ac and slowly varying ramp in strong inversion condition? Explain it with the plot of Cg/Cox vs. Gate voltage. (10 points) Why the depletion width does not change in strong inversion condition for high frequency ac and slowly varying input ramp? Explain. (10 points)

Problem 3. Consider MOS system with p type substrate. Given: Explain qualitatively that the total capacitance for the depletion condition is the series combination of oxide capacitance and depletion capacitance for low frequency ac and slowly varying input ramp (DC). (10 points) Explain qualitatively that the total capacitance for the strong inversion condition is the oxide capacitance for low frequency ac and slowly varying input ramp (DC). (10 points)Do we have an inversion layer at the surface for high frequency ac and slowly varying input ramp? Explain. (10 points) How does the total capacitance change for high frequency ac and slowly varying ramp in strong inversion condition? Explain it with the plot of Cg/Cox vs. Gate voltage. (10 points) Why the depletion width does not change in strong inversion condition for high frequency ac and slowly varying input ramp? Explain. (10 points)

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Problem 3. Consider MOS system with p type substrate. Given: Q s = ± 2 ε s i K T N a [ ( e − q ϕ S / k T + q ϕ S K T − 1 ) + n i 2 N a 2 ( e q ϕ S / k T − q ϕ S K T − 1 ) ] 1 / 2
  1. Explain qualitatively that the total capacitance for the depletion condition is the series combination of oxide capacitance and depletion capacitance for low frequency ac and slowly varying input ramp (DC). (10 points)
  2. Explain qualitatively that the total capacitance for the strong inversion condition is the oxide capacitance for low frequency ac and slowly varying input ramp (DC). (10 points)
  3. Do we have an inversion layer at the surface for high frequency ac and slowly varying input ramp? Explain. (10 points)
  4. How does the total capacitance change for high frequency ac and slowly varying ramp in strong inversion condition? Explain it with the plot of C g / C o x vs. Gate voltage. (10 points)
  5. Why the depletion width does not change in strong inversion condition for high frequency ac and slowly varying input ramp? Explain. (10 points)

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