申論題

MOS capacitor and MOSFET
5.Assumed that there is an Al/ SiO₂/ p -Si metal-oxide-semiconductor (MOS) capacitor. Denote the permittivity of SiO₂ (Si) as and it is given that the thickness of SiO2 is , the p-Si is uniformly doped to N_A, and the MOS capacitor can be regarded as one-dimensional.

(d) Explain the difference between enhancement type and depletion type, for both n-channel MOSFET and p-channel MOSFET, in term of threshold voltage. If the Al / SiO₂ / p - Si MOS structure in (a) is part of an MOSFET, is this MOSFET enhancement type or depletion type? Repeat for the Al / SiO₂ /n- Si MOS structure in (c). (3%, 2%,2%)