Your question is CMOS Gate Cross-Section. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Explain the cross-sectional view of a CMOS gate and what the structure implies about operation.
Describe the roles of the substrate or well, source, drain, gate oxide, gate electrode, contacts, and isolation structures. Explain how an applied gate voltage creates or removes an inversion channel, how NMOS and PMOS devices operate together in a CMOS gate, and how the physical structure affects switching, leakage, capacitance, and reliability. Relate relevant physical properties to embedded hardware security concerns such as fault injection, probing, and side-channel leakage.