| 摘要 |
PURPOSE:To improve the hybrid modulation characteristics of a dual gate type field effect transistor by linearly forming the dual gate type field effect transistor in wide range by employing an element exhibiting triode characteristics but not exhibiting saturated characteristics in first field effect transistor. CONSTITUTION:p<+>-Type layer 2-4 are selectively formed in a p-type semiconductor substrate 1, an n-type epitaxial layer 5 is superimposed thereon, and B is diffused from the surface to connect it to the layers 2-4. At this time the p-type layer 6 is selectively formed, and distance from the substrate 1 is reduced less than 2mu, a depletion layer extended from the gate layer 6 to the n-type layer 5 at no bias time reaches the substrate, and the channel is depleted. Then, there are formed n<+>-type layer 7-9, a gate insulating film 10, a field insulating film 11, and source and drain electrodes S and D, and gate electrodes G1, G2. The field effect transistor with the insulated gate G2 exhibits the conventional pentode characteristics with very narrow linear portion, and the field effect of the junction gate G1 is completely depleted in the channel in no bias state. Therefore, it exhibits triode characteristics. Accordingly, the linear range of the device is increased to suppress the occurrence of the signal strain. |
