| 摘要 |
PURPOSE:To obtain the highly integrated IC wherein a threshold voltage value can be precisely controlled, by providing a reverse conductive layer under an active layer and attaching an electrode in an FET having as FF for driving a memory cell. CONSTITUTION:On the surface of a semiinsulating GaAs substrate 8, N<+> source and drain 9 and 10 and an N type active layer 3 are provided. A P layer 11 is embedded under the N layer 3 by ion implantation and annealing, and a back gate electrode 12 for controlling said layer 11 is provided. When a load voltage is gradually applied to the electrode 12 with a source electrode 6 as a reference, the threshold voltage value is continuously and gradually moved from the negative value (depression type) to the positive value (enhancement type). In this constitution, the FET, which is a constituent element of the FF applied memory cell, can be formed without additional major engineering requirements on the conventional processes, and the threshold voltage value can be precisely controlled. |
