| 摘要 |
PURPOSE:To decrease distortion in output signal to a large extent, by changing the impurity concentration of a channel along the direction of the width of a gate. CONSTITUTION:The impurity concentration in a channel beneath a first gate electrode 11 has the concentration inclination in the direction of A-A'. The impurity concentration of a channel beneath a second gate electrode 12 has the concentration inclination in the direction of B-B'. For example, the impurity concentrations are formed in three stages, i.e., 1X10<16>cm<-3> (curve 33), 5X10<15>cm<-3> (curve 32) and 1X10<15>cm<-3> (curve 31) in the directions of A-A' and B-B'. The impurity concentration characteristic curves 33, 32 and 31 are obtained as shown in the Figure. The total characteristic curve in this embodiment is shown by 34. Thus mutual conductance becomes constant. The insulating gate type field effect transistor, whose gate bias range is broad, can be obtained. |
