Explore a MOSFET cross-section where gate voltage opens a channel through the oxide and switches the source-to-drain current on and off.
At the base of every computer, billions of this tiny part are packed in. The transistor — a switch that switches electricity with electricity. Look at the cross-section. The source and drain at each end, the channel between them, the gate riding on top. Between the gate and the channel is a thin insulating film (oxide), so the gate does not touch the channel. Without touching, how does it control the current?
Rotate the cross-section and confirm the positions of source / drain / gate / oxide / channel.
