The two types of FET are:
(i) Junction field effect transistor. (JFET)
(ii) Metal oxide semiconductor field effect transistor (MOSFET) or Insulated Gate field Effect transistor (IGFET).
FET can be fabricated with either n-channel or p-channel. For fabricating n-channel FET, first a narrow bar of n-type semiconductor material is taken and then two pn-juntions are diffused on opposite sides of its middle part. These junctions form two pn-junctions and area between these gate is called channel. The two p regions are internally connected and a single lead is brought out which is called gate terminal. Ohmic contacts are made at the two ends of the bar called source terminal s and the other drain terminal D.
