Lateral field effect transistor and its fabrication comprising a spacer layer above and below the channel layer

Abstract

A lateral field effect transistor for high switching frequencies having a source region layer () and a drain region layer () laterally spaced and of highly doped first conductivity type, a first-conductivity-type channel layer () of lower doping concentration extending laterally and interconnecting the source region layer () and the drain region layer (). The transistor has a gate electrode () arranged to control the properties of the channel layer (), and a second-conductivity-type base layer () arranged under the channel layer () at least partially overlapping the gate electrode () and at a lateral distance to the drain region layer (), the highly doped second-conductivity-type base layer () being shorted to the source region layer (). The transistor also has at least one of the following: a) a spacer layer () having semiconductor material adjacent to the channel layer () and located between the channel layer () and gate electrode (), at least in the vicinity of the gate electrode (), and/or b) a spacer layer () having semiconductor material adjacent to the channel layer () and located between the channel layer () and the second-conductivity-type base layer ().