MOSFET 1962 Classify Release Second Transistor Family
# Classify and Release: A Second, Fundamentally Different Transistor Family Enters Production
## 1. Why This Device Doesn't Need to Win the Comparison It Just Lost
This closing step classifies the finished devices by electrical grade, exactly as every series since 1957 has closed, and releases them to production — but it closes this series against a genuinely different kind of claim than any earlier closing article in this project has made, because Step 9 already showed this device loses its most direct head-to-head comparison against a contemporary bipolar transistor on switching speed. Every earlier series in this project closed by demonstrating an improvement over what came before it — a faster device, a more reliable device, a cheaper device, measured on the same axis the prior device was already measured on. This series cannot make that claim honestly, and does not need to, because Step 9 also showed this device's steady gate current is effectively zero, which changes what quantity actually matters once many of these devices are meant to coexist on a single piece of silicon: not how fast any one gate switches, but how many gates a fixed power budget can hold in their intended state simultaneously.
where $N_{\text{gates}}$ is the number of gates a fixed power budget $P_{\text{budget}}$ can sustain, $I_G$ the per-gate steady current Step 9 showed is effectively zero for this device family, $V_{DD}$ the supply voltage, and $\tau_{\max}$ an acceptable switching-speed floor the application must still meet — this is 1961's own closing figure of merit with its constraint and its optimized quantity exchanged: that series held a breakdown-voltage floor fixed and maximized speed; this series holds a speed floor merely adequate and maximizes how many gates a shared power budget can support, because $I_G$ in the denominator approaching zero is precisely what this device family offers that a current-controlled device cannot.
## 2. Real Diagram: The Line Forks, for the First Time in This Project's History
Every earlier closing article in this project drew a single line of succession, one structure replacing the structure before it. This closing article draws something this project has never needed to draw before: a fork, because this series' device does not replace the bipolar transistor this project has refined since 1947 — it begins a second, parallel line that now runs alongside it.
## 3. The First Closing Article That Doesn't End a Lineage, It Starts a Second One
Every earlier closing article in this project's history, from 1957's own Step 18 through 1961's own Step 10, named a structure that became the new default this project's later series would assume — the planar oxide-covered junction after 1959, the epitaxial collector after 1961, each one replacing what a later series could otherwise have needed to re-justify. This closing article cannot make that same claim, because this device does not replace the bipolar transistor's own role in this project's lineage; it exists beside it, chosen when the quantity that matters most is how many gates a fixed power budget can hold rather than how quickly any single gate can switch. The 1961 series' own closing figure of merit resolved a single device's internal conflict into a constraint and a quantity to optimize; this closing figure of merit resolves something larger — which of two entire device families an application should choose, with the honest answer being that the choice now depends on the application, not on which device is simply better.
Step 10 does not conclude that this device replaces anything this project has built before; it concludes that, as of 1962, this project's own lineage is no longer a single line, and the right question for a future engineer is no longer which transistor is faster, but which transistor fits the circuit being built around it.