Metal semiconductor field effect transistors having improved intermodulation distortion using different pinch-off voltages

摘要

A comb-shape MESFET assembly has a plurality of unit FETs including first, second and third groups of unit FETs. The pinch-off voltages of the unit FETs are different from group to group by a step difference. The different pinch-off voltages provide a tailored change in the third-order intermodulation distortion in the output of the MESFET assembly. The step differences in the pinch-off voltage is generated by different thicknesses or impurity concentrations of a semiconductor active layer, different gate length of the unit FETs or different types of stress in the gate insulator films.