Question

Consider a MOS capacitor, in which the thickness of the oxide layer is d=2nm and dielectric constant of the oxide made from SiO2 is eox = 3.9. The body of the MOS capacitor is made from a p-type substrate.The gate metal is chosen in such a way that the flat band voltage of the device turns out to be VFB-0.5 V. The doping density in the p-body region is given by Na = 1017 cm³. The intrinsic carrier density in Si at room temperature is given by n; = 1.45 × 1010 cm³. KT at room temperature is 0.026 eV. 1) When the applied gate voltage is V, = -1.3 V, find regime of operation in which the MOS CAP is currently operating (accumulation,depletion or inversion).а. b. the type of carriers (p-type or n-type) at the metal-oxide interface, c. carrier density of the carriers at the metal-oxide interface. 2) When the applied gate voltage is V, = 1.3 V, (it given that the threshold voltage is V; = 0.376,but you can also confirm this by doing the calculations using the formula for Vt ) find a. regime of operation in which the MOS CAP is currently operating (accumulation,depletion or inversion). b. the type of carriers (p-type or n-type) at the metal-oxide interface, c. carrier density of the carriers at the metal-oxide interface. 3) Mark the two points identifying the above two voltage points in the following chart

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