Field effect transistor
 The mobility of carriers in the channel region of a field effect transistor can be increased by providing a layered structure wherein electrons are separated from impurities. The channel is made up of external layers of wide bandgap material and internal layers with a narrower bandgap where the bottom of the conduction band of one layer is below the top of the valence band of the adjacent layer. A structure is shown with a layered channel having AlSb external layers and at least one or both of InAs and GaSb internal layers. 
International Business Machines Corporation
H
H01L
inventional
Emilio E. Leo Leroy L. Chin-An
Mendez Esaki Chang Chang