The C-V characteristic of an ideal MOS capacitor is shown below. (a) Is the semiconductor component of the MOS-C doped N-type or P-type? Indicate how you arrived at your answer. (b) Draw the MOS-C energy band diagram corresponding to (2) on the plot above. Clearly label all important parameters. (c) Draw the block charge diagram corresponding to (1) on the plot above. (d) If the area of the MOS-C is 5⋅10−3 cm2, what is the oxide thickness (x0)?
![Q. 4 The capacitance-voltage (C−V) characteristic of a silicon MOS capacitor is shown in Figure Q4. The capacitor comprises a metal gate with a work function of 5.62 eV. The gate dielectric is made of silicon-dioxide (SiO2) with a relative permittivity of 3.9. (a) Sketch the block charge diagram corresponding to point (1) on the C - V curve. [4 marks] (b) If the capacitor area is 2×10−3 cm2, determine the oxide thickness. [3 marks] (c) Determine the depletion layer width at point (2). [4 marks] (d) Briefly describe two ways to reduce the threshold voltage of the capacitor. [4 marks] (e) If the flatband voltage is 0.7 V, determine the work function of the substrate. [3 marks] (f) Sketch the energy band diagram corresponding to point (2) on the C - V curve. Is the capacitor under accumulation, depletion, or inversion? Briefly explain. [7 marks] Figure Q4: Capacitance-voltage (C−V) characteristic of a silicon MOS capacitor.](https://www.doubtrix.com/uploads/editor/3301654154bUocnyQJRA.png)
