There are a few pages on Static Induction Transistor theory in Power Electronics Handbook by Muhammad H. Rashid.
https://archive.org/details/RASHIDPowerElectronicsHandbook/page/n1/mode/2up chapt 9 book page 127.
https://archive.org/details/RASHIDPowerElectronicsHandbook/page/n1/mode/2up chapt 9 book page 127.