Why do the low frequency and high frequency cv curves

Question

Consider the low frequency C_lf/C_ox versus CG curve in figure 1. It is for a MOS capacitor with a p-type substrate (N_A = N_A1), a metal gate and V_FB = 0. Draw the C_if/C_Cox versus V_G curve for the device if the metal gate is replaced with a p-type poly-Si gate doped to N_A = N_A1. Explain your answer.

Figure 1. lf CV characteristics of a MOS capacitor

The subthreshold ID-VG curves of a MOSFET are shown in Figure 2 before and after stressing the device. Determine the interface trap density change ΔD_it (in cm^-2eV^-1) induced by the stress. T = 300K, ε_ox = 3.9, t_ox = 10 nm.

Figure 2. Transfer characteristics of a MOSFET before and after stress

You may find the following useful: ?D_it = C_ox/2.3kT.(1/(slope before)-1/(slope after))

Why do the low frequency and high frequency CV curves differ in inversion?

Using the transfer characteristics shown in Figure 3 (VD = 2V; W/L = 10:1). Calculate the following:

The threshold voltage

The field effect mobility

Figure 3. Transfer characteristics of a TFT

Answer 1

You have to consider for sort out the solution of question Consider the low frequency Clf/Cox versus CG curve in figure 1. It is for a MOS capacitor by a p-type substrate (NA = NA1), a metal gate and VFB = 0. Draw the Cif/CCox versus VG curve for the device if the metal gate is swapped through a p-type poly-Si gate doped to NA = NA1. Describe your answer. The sub threshold ID-VG curves of a MOSFET are exposed in Figure 2 before and after stressing the device. Find out the interface trap density change ?Dit (in cm-2eV-1) induced by the stress. T = 300K, eox = 3.9, tox = 10 nm. You may discover the subsequent useful? Dit = Cox/2.3kT.(1/(slope before)-1/(slope after)) Why do the low frequency and high frequency CV curves differ in inversion? Using the transfer traits shown in Figure 3 (VD = 2V; W/L = 10:1). Compute the subsequent