I've written an addendum to the 18-page 45-year power MOSFET history article for the x-Chapters.
And would appreciate your comments. Here it is:
As we leave this lengthy section, discussing various intricacies in the history of power MOSFETs, we have to admit not mentioning a few important MOSFET topics:
(1.) RF power MOSFETs. These are specialized beasts that work to high power levels (750 watts) and to high frequencies (tens of GHz). This is a very active fast-growing area.
(2.) Lateral power MOSFETs. These avoid using V-grooves and other high-channel-density schemes. They feature a negative tempco bias property, see sections 3.6.4 and 3x.18, are required meat for high-power linear audio power amplifiers. ProFusion sells parts made by Exicon. Hitachi abandoned the market, and now users pray these parts won't disappear.
(3.) Depletion-mode MOSFETs. Unlike enhancement-mode MOSFETs, which are normally off and require a positive bias to turn on, these are normally on, and require a reverse-bias to turn off. See the discussion in section 3.6.2 and Table 3.6 of the main book, and also section 9.3.14 for applications. In this volume see sections 3x.6, 4x.23, 9x.3 and 9x.12. Very nice depletion- mode parts are available, and seem to have a stable marketplace, however we aren't seeing new parts being introduced. There are only n-channel types available.
(4.) Pioneered by companies like Agilent (spun off to Avago, and purchased by Broadcom), super-fast high-frequency small-signal MOSFETs flourished. With technologies like pHEMT (pseudomorphic high-electron-mobility transistor) and E-pHEMT (enhancement-mode pHEMT), we got inexpensive discrete parts like Avago's ATF-38143, a 10GHz 4-volt 200mA FET in a convenient 4-lead SC-70 package. But these handy parts have disappeared, as semiconductor manufacturers created IC-based solutions more attractive to the telecom customer base.** Now we are left with parts like the SAV-551+, made by Mini-Circuits (thank you!) and not even appearing on Octopart This part substitutes for Avago's ATF-55143, and features 2 ohms Ron and 0.4pF Cout, numbers we were getting used to in the good-old-days.
** footnote: Of the parts on John Larkin's 2017 small pHEMT list (with pinouts and SMT labels), only CEL's CE3514 is still available, and Mouser has a pile of SKY65050 parts left in stock.