Same shape, better materials
Open the Chip Builder. You should still have your silicon transistor from Lesson 1 (if not, rebuild it — takes 60 seconds with Guided Build). We're going to upgrade three layers and re-run the same tests. Same architecture, different physics.
Swap 1 — Silicon channel → GaN
Delete your Silicon Channel and drop a GaN Channel in its place. GaN's electron mobility is similar to silicon for unstrained devices but it has a 3.4 eV band gap (vs 1.1 eV for Si) — meaning higher breakdown voltage and much less leakage at small geometries.
Swap 2 — SiO₂ → PZT piezo gate
Delete the SiO₂ Gate Oxide. Drop a PZT Piezo Gate in its place. PZT is piezoelectric — it generates its own gate voltage from mechanical stress. We'll exploit that fully in Lesson 3 when we add EM coupling.
Add 3 — Gate-all-around wrapper
Add a GAA Wrapper component around the channel. This wraps the gate field around all four sides of the channel, dramatically improving subthreshold swing and turning the device into a modern-node-equivalent transistor.
Side-by-side speed test
Open the Test Lab and run Switching Speed on your crystal device. Then load the silicon template (Templates menu → 'Silicon Baseline') and run the same test. Compare the maximum switching frequency. The crystal device should win — by how much?
You just learned how to read a comparison result: same architecture, different materials, measurable delta. Next lesson: we wire up the EM antenna and gate this device wirelessly.
- Take the silicon MOSFET from Lesson 1 and swap each layer for a crystal equivalent.
- Silicon channel → GaN crystal channel.
- SiO₂ gate oxide → PZT piezoelectric gate.
- Add a gate-all-around (GAA) wrapper for tighter control.
- Run the same switching speed test on both and compare.