Introduction
I've Got You Covered is your NE406 pocket guide to how transistors evolved from flat to finned to all-around designs.
Think of it as a teeny-tiny light switch or water faucet for electricity.
A transistor’s gate acts like a switch handle: voltage high opens a conductive channel from source to drain (1), voltage low shuts it off (0). Billions of these rapid switches shape every digital operation.
The perfect switch allows max current ON and almost none OFF. As devices shrink, keeping leakage low becomes the challenge.
Key Takeaways
A flat little switch that launched the computer age.
“Planar” means all regions sit on a flat surface. The gate presses the channel from above; shrinking to tens of nanometers weakens that control, letting leakage sneak under.
The design was easy to manufacture and powered Moore’s Law for decades—until short-channel effects raised off currents.
Flat silicon with a gate on top. At normal size the gate blocks current; at ultra-short length a faint glow leaks underneath.
Making transistors tiny caused a pesky leak problem.
As channels shortened, the gate couldn’t pinch the channel fully. Leakage rose, wasting power like a dripping faucet.
Engineers needed more gate surface on the channel—wrap-around control—to tame leakage and keep scaling.
h⁺Idea: hug the channel from more sidesA fin-shaped channel that the gate hugs from three sides.
The channel stands vertically like a fin. A U-shaped gate wraps three faces, boosting electrostatic control and cutting leakage.
Multiple fins under one gate add drive strength—like extra lanes for current.
Toggle the gate to hide/show current arrows and glow. Move the slider to add fins symmetrically (center first, then pairs).
Key Takeaways
Wrapping the channel on all sides for maximum control.
Nanowire or nanosheet channels are completely encircled by the gate—top, bottom, all around. Leakage reduced.
To increase the current without taking up more space, stack the sheets vertically. Also, adjust the sheet width to get the best performance for the power you need.
Key Takeaways
Pick a device, toggle its gate, and imagine how leakage changes.
Compare
placeholder
Toggle the gate and imagine leakage shrinking from Planar → FinFET → GAA. The gate “hug” tightens, letting almost no current sneak through in the OFF state.
Who wins the gate control game?
Transistor Cards
A planar MOSFET lives on a flat silicon surface; the gate presses from one side only, which eventually leaks at tiny lengths.
The channel stands up like a fin so the gate can wrap around three sides. Better electrostatics, far less leakage.
Nanowire or nanosheet channels fully wrapped by the gate for 360° control. Minimal leakage, stackable sheets.
Quiz
Which transistor has the strongest gate control over the channel?
Pick an option, then tap Check to see if you're right.