Editing Transistor (section)

===Field-effect transistors===
{{Main|Field-effect transistor}}
The basic principle of the [[field-effect transistor]] (FET) was first proposed by physicist [[Julius Edgar Lilienfeld]] when he filed a [[patent]] for a device similar to [[MESFET]] in 1926, and for an insulated-gate field-effect transistor in 1928.<ref name="auto" /><ref>Lilienfeld, Julius Edgar, "Device for controlling electric current" {{US patent|1900018}} March 7, 1933 (filed in US March 28, 1928).</ref> The FET concept was later also theorized by engineer [[Oskar Heil]] in the 1930s and by [[William Shockley]] in the 1940s.

In 1945, [[JFET]] was patented by [[Heinrich Welker]].<ref>{{cite book |title=The Physics of Semiconductors|author=Grundmann, Marius|isbn=978-3-642-13884-3 |publisher=Springer-Verlag|year=2010}}</ref> Following Shockley's theoretical treatment on JFET in 1952, a working practical JFET was made in 1953 by [[George C. Dacey]] and [[Ian Munro Ross|Ian M. Ross]].<ref>{{cite book | chapter-url=https://link.springer.com/chapter/10.1007%2F978-1-4684-7263-9_11#page-1 | doi=10.1007/978-1-4684-7263-9_11 | chapter=Junction Field-Effect Devices | title=Semiconductor Devices for Power Conditioning | date=1982 | last1=Nishizawa | first1=Jun-Ichi | pages=241–272 | isbn=978-1-4684-7265-3 }}</ref>

In 1948, Bardeen and Brattain patented the progenitor of MOSFET at Bell Labs, an insulated-gate FET (IGFET) with an inversion layer. Bardeen's patent, and the concept of an inversion layer, forms the basis of CMOS and DRAM technology today.<ref>{{cite book | author=Howard R. Duff | title=AIP Conference Proceedings | chapter=John Bardeen and transistor physics | date=2001 | volume=550 | pages=3–32 | doi=10.1063/1.1354371 | doi-access=free }}</ref>

In the early years of the [[semiconductor industry]], companies focused on the [[junction transistor]], a relatively bulky device that was difficult to [[mass-production|mass-produce]], limiting it to several specialized applications. [[Field-effect transistor]]s (FETs) were theorized as potential alternatives, but researchers could not get them to work properly, largely due to the [[surface state]] barrier that prevented the external [[electric field]] from penetrating the material.<ref name="Moskowitz">{{cite book |last1=Moskowitz |first1=Sanford L. |url=https://books.google.com/books?id=2STRDAAAQBAJ&pg=PA168 |title=Advanced Materials Innovation: Managing Global Technology in the 21st century |date=2016 |publisher=[[John Wiley & Sons]] |isbn=9780470508923 |page=168}}</ref>